PL01 Liver: Metastases (ePoster) 
Selection of ePoster Presentations from Abstract Submissions
PL01-02 Hepatic Resection for Neuroendocrine Liver Metastases: Contemporary Indications and Outcomes from a Population-Based Cohort
Jordan Cloyd, United States

S. Scoville1, D. Xourafas1, A. Ejaz1, M. Dillhoff1, A. Tsung1, T. Pawlik1, J. Cloyd2
1The Ohio State University, United States, 2Surgery, The Ohio State University, United States

Introduction: Surgical resection is associated with favorable long-term outcomes among patients with neuroendocrine liver metastases (NELM), however, the current indications for and outcomes of liver resection (LR) for NELM from a population-based perspective are not well understood.
Methods: A retrospective review of the 2014-2017 ACS-NSQIP and targeted hepatectomy databases was performed to identify patients who underwent LR for NELM. Perioperative characteristics and 30-day morbidity and mortality were analyzed.
Results: Among 669 patients who underwent LR for NELM, the median age was 60 (IQR 51-67) and 51% were male. The most common number of metastases resected was 1 (45%) but ranged from 1 to 9 while most (68%) had tumors < 5cm. Most patients underwent partial hepatectomy (71%) while fewer underwent a right or left hepatectomy or trisectionectomy. The majority of operations were open (82%) compared to laparoscopic (17%) or robotic (1%). In addition, 30% of patients received intraoperative ablation (IA) while 45% had another concomitant operation including cholecystectomy (28.8%), bowel resection (20.2%), or partial pancreatectomy (3.4%). Overall 30-day morbidity and mortality was 29% and 1.3%, respectively. On multivariate analysis, ASA class ≥ 3 (OR 2.089, 95%CI: 1.197-3.645), open approach (OR 1.867, 95%CI: 1.148-3.036), right hepatectomy (OR 1.618, 95%CI: 1.014-2.582), and prolonged operative time >230 minutes (OR 1.731, 95%CI: 1.168-2.565) were associated with higher 30-day morbidity while IA and concomitant procedures were not.
Conclusions: LR for NELM is performed with relatively low postoperative morbidity and mortality. Concomitant procedures performed at the time of LR did not increase morbidity.
PL01-04 Meta-Analysis of Survival Following Pulmonary Resection for Colorectal Cancer Metastases
Bathiya Ratnayake, New Zealand

B. Ratnayake1, C. Wells1, P. Atherton2, J. Hammond2, S. White2, J. French2, D. Manas2, S. Pandanaboyana2
1Department of Surgery, Auckland City Hospital, New Zealand, 2Department of Hepatobiliary, Pancreatic and Transplant Surgery, Freeman Hospital, United Kingdom

Background: Controversy exists regarding the optimal management of colorectal lung metastases (CRLM). This meta-analysis compared surgical (Surg) vs interventional (Chemotherapy and/or Radiotherapy) and observational non-surgical (NSurg) management of CRLM.
Methods: A systematic review of the major databases including Medline, Embase, SCOPUS, and the Cochrane library was performed.
Results: Ten studies including 2232 patients; 1551 (69%) comprised the Surg cohort, 521 (23%) the interventional NSurg group and 160 (7%), the observational NSurg group. A significantly higher overall survival was observed when Surg was compared to interventional NSurg at one-year (Surg 89%, 359/402 interventional NSurg 70%, 343/625, OR 2.76 (CI 2.10-3.63), P< 0.001), at three-years (Surg 59%, 857/1444 interventional NSurg 26%, 138/521, OR 2.61 (CI 1.65-4.15), P=0.002), at-five years (Surg 47%, 533/1144 interventional NSurg 23%, 45/196, OR 3.24 (CI 1.42-7.39), P=0.009) and at ten-years (Surg 27%, 306/1122 interventional NSurg 1%, 2/168, OR 15.64 (CI 1.87-130.76), P=0.031). In contrast however, Surg was associated with a greater overall survival than observational NSurg at only one-year (Surg 89%, 1009/1132 observational NSurg 67%, 93/138, OR 4.49 (CI 1.16-17.40), P=0.041) and was similar to observational NSurg at all other overall survival time points. Comparable survival was observed among Surg and overall NSurg cohorts at three- and five-year survival in articles published within the last three years.
Conclusions: Recent evidence suggests comparable survival with Surg and NSurg modalities for CRLM, contrasting to early evidence where Surg had an improved survival. Significant selection bias.
PL01-05 Identification of Glisson's Capsule Invasion during Hepatectomy for Colorectal Liver Metastasis by Contrast-Enhanced Ultrasonography Using Perflubutane
Junko Hiroyoshi, Japan

J. Hiroyoshi1, T. Ishizawa1, H. Abe2, A. Ichida1, N. Akamatsu1, J. Kaneko1, J. Arita1, T. Ushiku2, K. Hasegawa1
1Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, University of Tokyo, Japan, 2Department of Pathology, University of Tokyo, Japan

Background: The aim of this study was to evaluate efficacy of contrast-enhanced intraoperative ultrasonography (IOUS) in diagnosis of Glisson invasion in hepatectomy for colorectal liver metastasis (CLM).
Methods: Subject consisted of 50 consecutive patients undergoing hepatectomy for CLM. Intraoperatively, presence or absence of Glisson invasion was estimated by IOUS with Perflubutane, based on the following four key findings on Glisson's capsule adjacent to the tumor:
[Pattern-1] tumor thrombus,
[2] border irregularity,
[3] caliber change, and
[4] peripheral dilatation.
These findings were compared with results of pathological examinations.
Results: Among 187 CLMs resected, Glisson invasion was proved in 24 tumors (13%; 7 tumors with macroscopically-obvious Glisson invasion and 17 tumors with microscopic Glisson invasion). Sensitivity/specificity of contrast-enhanced IOUS for diagnosis of macroscopic Glisson invasion was 43%/98% for the [Pattern-1], 14%/97% for [2], 86%/97% for [3], and 43%/98% for [4]. If presence of one or more key findings by IOUS were determined as a predictor of Glisson invasion, its sensitivity and specificity reached up to 100% and 90%, respectively. In contrast, sensitivity and specificity of preoperative contrast-enhanced MRI for Glisson invasion were respectively 29% and 97%. The proportion of R1 resection was not significantly different between CLM patients with Glisson invasion (82%) and those without Glisson invasion (85%).
Conclusions: Evaluation of Glisson capsule adjacent to CLM by contrast-enhanced IOUS may be effective for estimation of Glisson invasion, which enables surgeons to divide Glisson capsule at the site free from the invasion, leading to avoid unexpected R1/R2 resection.
PL01-06 Gold Nanoparticles Inhibit Colorectal Cancer Liver Metastasis through Inhibiting the TGF-β Pathway
Binhao Zhang, China

B. Zhang, C. Wang
Surgery, Tongji Hospital of Huazhong University of Science and Technology, China

Introduction: The application of gold nanoparticles (AuNPs) to the management of cancer is currently the new breakthrough in cancer research. However, the role of AuNPs on tumor growth and metastasis in colon cancer and the mechanism by which AuNPs regulate tumor growth and liver metastasis in colorectal cancer (CRCLM) are unclear.
Method: We established two TGF-β inducible luciferase colon cancer cell line and orthotopic colon cancer and liver metastasis animal models. We also overexpressed or knockdown Smad4, an important transduction factor of the TGF-β signaling pathway, to explore the molecular mechanism by which AuNPs regulate CRCLM.
Results: AuNPs inhibited TGF-β secretion of colon cancer, and downregulated the downstream reporter genes of TGF-β signaling pathway. AuNPs inhibited cell proliferation, migration and invasion in vitro, and reduced tumor growth and liver metastasis in vivo. ERK, P38 MAPK and AKT was inactivated by AuNPS, leading to down-regulation of VEGF secretion and Vimentin while up-regulation of E-Cadherin. When Smad4 was knockdown, cells were significantly more sensitive to AuNPs treatment. The TGF-β inducible luciferase cell line were established, and used for liver metastasis animal models. Mice were treated with the TGF-β receptor inhibitors, and the results showed that this model could observe the activation of TGF-β signaling pathway as well as tumor progression in vivo.
Conclusions: These results provided evidences that AuNPs inhibit CRCLM through inhibiting the TGF-β pathway. This research provided theoretical evidences for the clinical use of AuNPs for the treatment of colon cancer or CRCLM.
PL01-07 Parenchymal-Sparing Hepatectomies for Colorectal Liver Metastases
Yukihiro Okuda, Japan

Y. Okuda1,2
1Sugita Genpaku Memorial Obama Municipal Hospital, Obama, Japan, 2Gastroenterological Surgery and Oncology, Kitano Hospital, The Tazuke Kofukai Medical Research Institute, Osaka, Japan

Introduction: Parenchymal-sparing hepatectomies (PSH) have been performed widely for the patients of colorectal liver metastases (CLM) to preserve much liver parenchyma and allow for future re-resection. Herein, we divide PSH into 3 types of hepatectomies,
ⅰ) limited anatomical resection,
ⅱ) tumor-vessel detachment resection, and
ⅲ) tumor enucleation locating at the deep part of liver parenchyma from the parenchymal slit.
In this presentation, we show each case, and evaluate the feasibility.
Case1: In this case, the tumor was located at the boundary of S1 and S4. The tumor was 2cm in size, and involving the main trunk of middle hepatic vein (MHV). To preserve lateral section and left hepatic vein, we selected anatomical S1/S4 resection concomitant with MHV resection.
Case2: The second patient had a tumor in S7, which was adjacent to the right hepatic vein (RHV). To preserve the venous return from the posterior section, we performed partial resection by detaching the tumor from the RHV.
Case3: The last patient had multiple CLMs in bilateral lobe. Most tumors were located in the shallow part of liver parenchyma and dissected by partial resections. However, one tumor in S8 was located at the deep part of liver. Hence, we made parenchymal slit and enucleated the tumor.
Results: We archived R0 resection in all cases. Postoperative mortality and morbidity were nil.
Conclusions: PSH can be classified into 3 types. All types of PSH are feasible and can be performed safely.
PL01-08 Nationwide Population-Based Study on Preoperative Imaging for Colorectal Liver Metastases
Arthur K.E. Elfrink, Netherlands

A.K.E. Elfrink1,2, M. Pool3, E. Marra1, M.R. Meijerink4, M. Burgmans5, D.J. Grunhagen6, J.M. Klaase2, N.F.M. Kok7, Dutch Hepato Biliary Audit Group
1Scientific Bureau, DICA, Netherlands, 2Surgery, UMCG, Netherlands, 3Surgery, Amsterdam UMC, AMC, Netherlands, 4Radiology, Amsterdam UMC, VUmc, Netherlands, 5Radiology, LUMC, Netherlands, 6Surgery, Erasmus MC, Netherlands, 7Surgery, Netherlands Cancer Institute, Netherlands

Background: In patients with colorectal liver metastases (CRLM) preoperative may include contrast-enhanced(ce)MRI and 18F-FDG-PET-CT. This study assessed trends and variation between hospitals and oncological networks in the use of preoperative imaging in the Netherlands.
Methods: All patients who underwent liver resection for CRLM in the Netherlands between 2014 and 2018 were retrieved from a nationwide auditing database. Multivariable logistic regression analysis was used to assess use of ceMRI, 18F-FDG-PET-CT and combined ceMRI and 18F-FDG-PET-CT and trends in preoperative imaging and hospital and oncological network variation.
Results: In total 4510 patients were included of whom 1562 underwent ceMRI, 872 underwent 18F-FDG-PET-CT and 1293 underwent combined ceMRI and 18F-FDG-PET-CT. Use of ceMRI increased over time from 9.6% to 26.2% (p< 0.01), use of 18F-FDG-PET-CT decreased (25% to 6.0%, p< 0.01) and use of ceMRI and 18F-FDG-PET-CT (17%) remained stable. Unadjusted variation in use of ceMRI, 18F-FDG-PET-CT and combined ceMRI and 18F-FDG-PET-CT ranged from 5% to 100% between hospitals. After case-mix correction, hospital and oncological network variation was present regarding all imaging.
Discussion: Significant variation exists concerning use of preoperative imaging for CRLM between hospitals and oncological networks in the Netherlands. The use of MRI is increasing whereas use of 18F-FDG-PET-CT is decreasing.
PL01-11 Complete Remission of Lung Metastases in Hepatocellular Carcinoma Treated with Thalidomide
Chih-Yi Chen, Taiwan, Republic of China

C.-Y. Chen, C.-C. Yong
Surgery, Kaohsiung Chang Gung Memorial Hospital, Taiwan, Republic of China

Introduction: Advanced-stage hepatocellular carcinoma (HCC) has poor prognosis mainly because of the underlying liver disease and lack of effective therapeutic options. Pulmonary metastases is the most common site of extra-hepatic spread.
Methods: We report the case of complete response with thalidomide for multiple pulmonary metastases from HCC.
Results: A 63-year old female, who was a carrier of hepatitis C virus, was preoperatively diagnosed with double primary malignancies of the liver and ampulla. Pancreaticoduodenectomy with synchronous liver resection was performed. Pathology revealed a 4cm moderately differentiated HCC classified as stage IIIB (pT3bN0) with LHV tumor thrombus and a 1cm moderately differentiated adenocarcinoma at the papilla of vater classified as stage IA (pT1N0). Four months later, AFP levels elevated markedly and chest radiograph demonstrated multiple variable sized nodules in both lungs. She was started on sorafenib. However, a tenfold increase in AFP levels and progressive disease on chest radiograph were found after 6 weeks. We changed the regimen to thalidomide at a daily dose of 100mg. Within a month, AFP levels declined rapidly and the number and size of the metastatic lung nodules decreased. After two months, chest radiograph showed complete response of the lung metastases. The patient has received thalidomide for the past three years, and no signs of recurrence of lung metastases have been observed.
Conclusions: The role of systemic chemotherapy for metastatic HCC has not yet been clarified. Our findings suggest that treatment with thalidomide may be a promising method for patients with metastatic lung cancer from HCC.
[Changes in alpha-fetoprotein]
PL01-13 Long-Term Outcome and Prognostic Factors of Synchronous Colorectal Liver Metastases
Nozomu Sakai, Japan

N. Sakai, H. Yoshitomi, K. Furukawa, T. Takayashiki, S. Kuboki, S. Takano, D. Suzuki, M. Ohtsuka
Department of General Surgery, Chiba University, Japan

Introduction: The prognosis of patients with multiple colorectal liver metastases (CRLM) has been reported to be poor. An appropriate treatment strategy should be planned based on tumor load and biology of each patients.
Method: One hundred and twenty three patients underwent initial hepatectomy for synchronous CRLM between 2001 and 2018. Long-term outcome and clinicopathological data were analyzed retrospectively.
Results: Five-year OS and MST after initial hepatectomy for synchronous CRLM were 46.8% and 53 months. Three-year DFS were 20.9%. KRAS status was assessed in 101 patients during the study period. KRAS mutation was identified in 37 patients (36.6%). Univariate analysis demonstrated that bilobar distribution, number of tumors, major hepatectomy (>3 segments), early recurrence (< 12 months after hepatectomy) and KRAS mutation were significantly associated with poor prognosis. Multivariate analysis demonstrated that KRAS mutation and early recurrence were independent prognostic factors. Repeat resection rate was significantly low in patients with KRAS mutation compared with that in KRAS wild type.
OS was significantly better in patients with adjuvant chemotherapy for synchronous and multiple CRLM compared with patients without adjuvant chemotherapy.
Simultaneous resection of primary tumors and CRLM was performed in 20 patients. OS after simultaneous resection was comparable to that after two-staged resection.
Conclusions: KRAS mutation is an independent prognostic factor in patients with synchronous CRLM. One of the reasons for poor prognosis might be significantly frequent unresectable recurrences after initial hepatectomy. In terms of perioperative chemotherapy, adjuvant chemotherapy might improve OS of patients with synchronous and multiple CRLM.
PL01-14 Indication for Surgical Resection of Liver Metastases from Pancreatic Cancer
Yusuke Mitsuka, Japan

Y. Mitsuka, S. Yamazaki, T. Higaki, T. Takayama
Digestive Surgery, Nihon University School of Medicine, Japan

Introduction: Resection of liver metastases in pancreatic cancer has been considered as contraindication because of poor outcomes. In contrast, recent progress in adjuvant chemotherapy and resection for recurrent site allowed longer survival in patients with pancreatic cancer. In this study, we examined cases of long-term survival after surgical resection for liver metastasis of pancreatic cancer.
Method: Between 2005 and 2015, data was collected from the patients who underwent curative surgical resection for pancreatic cancer. The solitary metachronous liver recurrence and absence of any other local or distant metastasis were the indication for liver resection.
Results: A total of five patients were included in 72 patients who underwent R0 resection for pancreatic cancer. Two patients were further performed twice liver resection for metachronous liver recurrence. The median disease-free interval (DFI) was 21 (3-44) months. The median of second DFI was 12 (2-39) months. The median follow-up time after primary surgical resection was 72(24-100)months. In particular, the median follow-up time after reoperation for recurrence was 39(10-63) months. Two patients who underwent twice liver resections, they survived more than 7 years from the primary surgery.
Conclusions: The patients with solitary liver metastasis after prolonged DFI (>12 months) may be a good indication for liver resection.
PL01-19 Renin-Angiotensin Inhibition Attenuates Tumour Progression in the Future Liver Remnant and And Modulates Anti-Tumour Immunity
Georgina Riddiough, Australia

G. Riddiough, K. Walsh, T. Fifis, V. Muralidharan, C. Christophi, M. Perini
Department of Surgery, University of Melbourne, Australia

Introduction: Experimental and clinical data demonstrates that liver regeneration after hepatectomy drives tumour progression in the future liver remnant. The aim of this study is to assess the efficacy of renin-angiotensin inhibition (RASi) at reducing CRLM growth within the regenerating liver following partial hepatectomy.
Methods: Male CBA mice underwent induction of colorectal liver metastases (CRLM) in conjunction with 70% partial hepatectomy. Mice were treated with either control or RASi, captopril 250mg/kg. Fresh tissues were processed for flow cytometrical analysis of T cell subsets.
Results: RASi significantly reduced tumour burden within the regenerating liver (p< 0.01). RASi was associated with a significant upregulation of CD8 and double negative T cells (p=0.01 and p< 0.01 respectively). RASi also led to a significant increase in the PD1 expression of CD8 and double negative T cells (p=0.01 and p< 0.01 respectively).
Furthermore, analysis of the CD8+/PD1+ T cell subpopulation revealed the majority co-express CD44 and CD69 (tissue resident T cell markers). 75% of CD8/PD1+ T cells in the liver of captopril treated mice were both CD44+ and CD69+. In liver, captopril treatment was also associated with a significant upregulation of CD69 expression (p< 0.01) compared to control.
Conclusions: RASi are immunomodulatory and re-direct the immune response in favour of immune destruction of tumour cells. RASi significantly increases the proportion of PD1+ CD8 and double negative T cells. We have shown that the vast majority of CD8+/PD1+ T cells are tissue resident and this may explain why these cells appear to maintain their anti-tumour effects.
PL01-21 Indeterminate Liver Lesions - A Virtual Epidemic: A Cohort Study over 8 Years
Li Lian Kuan, United Kingdom

L.L. Kuan1,2, A. Mavilakandy2, T. Oyebola2, N. Bhardwaj2, A. Dennison2, G. Garcea2
1Department of Surgery, The Queen Elizabeth Hospital, Adelaide, Australia, 2Department of Hepatobiliary and Pancreatic Surgery, Leicester General Hospital, Leicester, United Kingdom

Background: Within the last decade, advances and availability in radiologic imaging have led to an increase in the detection of incidental liver lesions (ILL) in the asymptomatic patient population. This poses a diagnostic conundrum. This study was undertaken to review the outcome of liver lesions labelled as “indeterminate” in asymptomatic patients without a biopsy-proven concomitant primary tumour. The secondary aim was to assess the impact on health care resources and cost-effectiveness with regards to the frequency and modality of radiological scans, MDT discussions and clinic reviews.
Methods: The study consisted of a retrospective analysis of prospectively collected data from the University Hospitals of Leicester MDT database. The study period ranged from 2010-2015. All patients were followed-up for 3 years to ensure no late re-occurrences with malignancy.
Result: Ninety two patients with ILL were identified. The median age was 72. The median size of these ILLs was 10mm. Eighty seven patients required supplementary imaging and 42 required a third imaging. Ninety one patients had benign lesions. Only one case was biopsy proven to be malignant.
Conclusion: Small (< 15 mm) hepatic lesions discovered incidentally in patients with no known primary malignancy and risk factors are virtually always benign, with a 1% risk of malignancy. There is a need for a classification system, which stratifies ILLs by malignant potential based on a standardized and evidence-based approach. This is important to prevent unnecessary investigations. A multidisciplinary approach in an experienced HPB centre is recommended until such a classification exists.
PL01-22 Impact of Septic Complications after Liver Resection for Colorectal Metastases
Miroslav Levy, Czech Republic

M. Levy, V. Visokai, L. Lipska, M. Mracek, P. Smejkal, R. Strnad, J. Simsa
Surgical Department, Thomayer Hospital, Charles University Prague, Czech Republic

Introduction: Liver metastases will appear approximately in 40% of patients with colorectal carcinoma, surgery remains the only option for curative radical treatment. Complications occur in about 20% of cases and most are mild . Severe complications that are specific to liver resection include bile leak or fistula, bleeding, liver failure, respiratory complications (fluid collection) and perihepatic abscess.
Aim of our study was to describe postoperative complications and to evaluate their impact on disease free interval.
Materials and methods: There were 311 liver resections in 253 patiens operated for CRLM from 1996 to 2018 at our surgery.
We identified minor complications (Clavien-Dindo classification I, II) in 13 %of patients, moderate complications (Clavien-Dindo III) in 6% of patients ), and severe in 3,5% of patients.
Results: Median follow up was 38 months. Overall five year survival was 41%. Postoperative complications occurs in 22,5% of resections. Postoperative mortality was 2%. Overall five year disease free survival is 30%. Significantly worse disease-free interval was found in patients with severe septic complications. Other, less serious complications also increase the risk of recurrence, but not statistically significantly.
Conclusion: Severe septic complications has an adverse effect on the further course of the disease in terms of relapse. In addition, serious complications increases postoperative mortality, prolong hospitalization, increase the cost of treatment.
Supported by grants: AZV 17-30920A, MH CZ - DRO ("Thomayer hospital - TN, 00064190)
PL01-23 Indication of Neoadjuvant Chemotherapy for Patients with Colorectal Cancer Liver Metastases in our Hospital
Ryo Kamimura, Japan

R. Kamimura, T. Kawai, K. Iguchi, H. Terajima
Gastroenterological Surgery and Oncology, Kitano Hospital Medical Research Institute, Japan

Background: Whether neoadjuvant chemotherapy (NAC) is approriate for the patients with initially resectable colorectal cancer liver metastases (CRLM) remains controversial. The indication of NAC was examined at the surgical meeting in our hospital. The aim of this study is to retrospectively validate our indication of NAC.
Patients and Methods: From 2009 to 2019, 84 patients underwent hepatectomy for CRLM. They were divided into two groups: synchronous CRLM (SM-group n=56) and metachronous CRLM (MM-group n=28) and the indication of NAC was validated. Additionally, long-term outcomes were compared between patients who received NAC (NAC(+)-patients) and those didn't receive NAC (NAC(-)-patients).
Results: NAC was performed in 41 patients (73.3%) in SM-group and 12 patients (42.9%) in MM-group. In SM-group (28 single metastasis (sgl-Met) and 28 multiple metastases (multi-Met) ), the patients with multi-Met significantly received NAC (57.1% in sgl-Met vs. 89.3% in multi-Met, p=0.01). In MM-group (15 sgl-Met and 13 multi-Met), the period from excision of the primary cancer to the development of liver metastasis was tended to be shorter in NAC(+)-patients than NAC(-)-patients (NAC (+) 309 days vs. NAC (-) 656 days, median, p=0.09). In SM-group, there was no significant difference of 5-year OS between NAC(+)-patients and NAC(-)-patients(NAC (+) 63.6% vs. NAC (-) 74.6%, p=0.93). In MM-group, there was no significant difference between NAC(+)-patients and NAC(-)-patients(90.9% vs. 82.1%, p=0.40).
Conclusion: NAC for CRLM tended to be performed to the patients with multiple- synchronous-metastasis and metachronous-metastases developing within 1year after excision of the primary cancer. According to our strategy, long-term outcomes were favorable.
PL01-28 Treatment Strategy for Synchronous Liver Metastases from Colorectal Cancer
Yuji Morine, Japan

Y. Morine, M. Shimada, S. Imura, T. Ikemoto, Y. Arakawa, Y. Saito, S. Yamada
Department of Surgery, Tokushima University, Japan

Background: Our surgical indication for CRLM as follows: i) curative resection and ii) future remnant liver volume over 35%, and positively introduced conversion surgery for unresectable CRLM. Based on our experience, we have established treatment strategy for synchronous CRLM.
Methods: Among 280 CRLM patients, 72 initially curative resection of synchronous CRLM and 51 unresectable, received current chemotherapy such as FOLFOX, FOLFILI IRIS, XEROX and FOLFOXIRI, were included.
1) Initially resectable: Multivariate analysis revealed MDN (Maximum Diameter x Number) index over 20 of metastatic tumor (HR5.171, p=0.0230) and poor differentiation of primary tumor (HR10.982, p=0.0009). Also, postoperative adjuvant chemotherapy consisted of FOLFOX, XELOX and IRIS enhanced the better surgical outcomes.
2) Unresectable for conversion surgery: Among 51 unresectable synchronous CRLM, Conversion surgery introduced in 28 cases (54.9%). Conversion group significantly highly indicated MDN under 70, without remote organ metastasis and induction of FOLFOXIRI regimen compared to non-Conversion group. Also FOLFOXIRI regimen was applied to 18 patients. The Conversion rate in FOLFIXIRI group and other regimen group were 71.4% and 43.3% (p=0.0472), and Overall survival in FOLFOXIRI group has been better than that in other regimen group and 3-years survival rates were 77.4% and 47.0%, respectively (p=0.0008).
Conclusion: In synchronous CRLM with MDN>20/< 70, even if unresectable, FOLFOXIRI plus molecular target drug could introduce the chance for conversion surgery.
PL01-29 Emergency Right Hemihepatectomy and Resection of Retroperitoneal Masses to Control Refractory Hypoglycemia from Metastatic Insulinoma Presenting 14 Years after Resection of Non-functioning Pancreatic Neuroendocrine Tumour
Nagappan Kumar, United Kingdom

N. Kumar1, A. Rees2, A. Kalhan3
1Cardiff Liver Unit, University Hospital of Wales, United Kingdom, 2Department of Endocrinology, University Hospital of Wales, United Kingdom, 3Department of Endocrinology, Royal Glamorgan Hospital, United Kingdom

Introduction: Insulinoma is rare and only 5-15% are malignant. Transformation of nonfunctioning pancreatic neuroendocrine tumour (pNET) into insulinoma has only been reported in 6 cases and all happened early. We present the first case of metastatic insulinoma that presented as an emergency,14 years after previous distal pancreatectomy for non-functioning pNET, and was refractory to medical treatment. A right hemihepatectomy and resection of retroperitoneal masses was curative.
Case report:
Results: A 59 year old woman was found unconscious at home. Paramedics found the blood glucose at 1.1 mmol/L and initiated a dextrose infusion. She regained consciousness. Further investigations showed a insulin of >1000 mu/L, C-peptide of 2953 pmol/L and a negative sulfonylurea screen. A CT scan showed (pic1) multiple masses in segments 5,6,7,8 of liver, the largest being 11.3 cm and large masses in left retroperitoneum. She was treated with 20% dextrose, diazoxide and Octreotide and referred to our unit.
She underwent right hepatic artery embolisation which allowed transient rise in the blood glucose which then fell to 2.4 mmol/L. She developed extensive rash and pyrexia from allergy to diazoxide and hence stopped. It was difficult to maintain blood glucose and hence she underwent an uneventful emergency right hepatectomy and resection of the large retroperitoneal masses. She came off dextose infusion and discharged 10 days later with no medications and normoglycemia.
Conclusion: A first report of successful emergency right hepatectomy and resection of large retroperitoneal masses for metastatic insulinoma leading to normoglycemia.
[CT scan showing one of the large liver metastases and a left retroperitoneal mass.]
PL01-30 Peri-operative Epidural Analgesia Offers No Oncological Benefit Following Open Resection of Colorectal Liver Metastases: Long Term Follow up of Two Randomized Controlled Trials
Michael Hughes, United Kingdom

M. Hughes1, R. Bell2, M. Wojtowicz3, E. Hidalgo2, P. Lodge2, E. Harrison3, S. Wigmore3
1Royal Infirmary of Edinburgh, United Kingdom, 2St James's University Hospital, United Kingdom, 3University of Edinburgh, United Kingdom

Introduction: The use of epidural analgesia (EA) for liver surgery remains controversial. Reports suggest EA offers a positive impact on survival following liver resection for cancer when compared to systemic opiates. No study has compared the oncological benefit of epidural analgesia compared to local anaesthetic wound infiltration (WI). This study aimed to assess the effect of analgesic modality on survival following liver resection for colorectal liver metastases (CRLM).
Method: The survival outcomes of patients who participated in two RCTs were obtained. The included patients had been randomised to receive either EA or WI as perioperative analgesia following open liver resection for CRLM in two UK centres. Baseline data were obtained. Median and five year overall (OS) and disease free survival (DFS) outcomes were compared by Kaplan-Meier survival curves.
Results: 96 (EA=49, WI=47) patients were identified from two RCTs as having undergone resection of CRLM. The median follow up time was 61.1 (IQR 30.5-69) months. No differences between the groups' baseline and oncological characteristics were identified. Median OS for EA was 56.6 months and 71.6 months for WI. Median DFS was 18.8 months for EA and 31.2 months for WI. Five year OS was 50.8% for EA and 61.2% for WI (p=0.57). Five year DFS was 38.6% for EA and 46.1% for WI (p=0.39).
Conclusions: In contrast to previous reports, EA did not offer a survival advantage following liver resection for CRLM when, on this occasion, compared with WI. Both EA and WI could be considered appropriate for oncological liver surgery.
PL01-31 Results of ALPPS Procedure for Colorectal Cancer Liver Metastasis
Mihail Vozdvizhenskiy, Russian Federation

M. Vozdvizhenskiy1,2, A. Orlov1, S. Frolov1
1Samara State Oncology Center, Russian Federation, 2Samara State Medical University, Russian Federation

Objectives: The aim of this study was to assess the effectiveness of ALPPS in the treatment of primary unresectable liver metastasis of colorectal cancer.
Materials and methods: 29 patients with colorectal cancer liver metastasis, which seemed to be unresectable with standard liver resection, were considered for ALPPS. ALPPS was performed in patients with insufficient volume and / or quality of the future remnant. The study included 16 men, and 13 women. The average age of the patients was 64.8 years. 7-9 days after first stage of ALPPS CT-volumetry was performed, then the second stage of the surgical procedure was made.
Results: The preoperative mean volume of the remnant was 468 cm3. The average postoperative volume of the remnant after first stage of ALPPS was 810 cm3. The average difference between the pre- and postoperative volume of the remnant was 342 cm3; the average volume of the remnant is increased by 73%. We haven't observed any cases of liver failure. In 17 patients we had postoperative complications Grade II-IIIa Clavien-Dindo. 2 patients died - thromboembolia of pulmonary artery and multiple organ failure. The median follow-up was 56.6 (4.5-74.0) months, the 1-, 3- and 5-years overall survival rates were 72.4%, 44.8%, and 10.3% respectively.
Conclusion: ALPPS makes it possible to avoid the development of postresectional hepatic failure and to perform the liver resection in patients that earlier seemed to be unresectable, improving survival.
PL01-32 High Mobility Group Box 1 Level Is Associated with Long Term Survival Following Liver Resection for Colorectal Liver Metastases
Michael Hughes, United Kingdom

M. Hughes1, M. Wojtowicz2, B. Stutchfield1, E. Harrison2, S. Wigmore2
1Royal Infirmary of Edinburgh, United Kingdom, 2University of Edinburgh, United Kingdom

Introduction: High mobility group box-1 (HMGB1) is a biomarker associated with cancer survival in a number of malignancies. The impact of HMGB1 production on survival after surgery for colorectal liver metastases (CRLM) has not been investigated. This study aimed to determine if perioperative HMGB1 is associated with survival following liver resection for CRLM.
Method: The survival outcomes of patients enrolled in a previous RCT who had undergone liver resection for CRLM were reviewed. Serum HMGB1 levels were obtained on post-operative day (POD) one by ELISA. Demographic, perioperative and oncological data were recorded. Date of death or censor were obtained. Patients were allocated to groups according to level of HMGB1 recorded on POD 1. Univariate and multivariate analyses were performed.
Results: 51 patients underwent open liver resection for CRLM between December 2012 and June 2014. The median follow up period was 63 (IQR 36.5-69.2) months. Two matched groups of 25 patients with low level of HMGB1 on POD 1 (mean 3±1ng/mL) and 26 with high levels (mean 9.7±5.9ng/mL) were compared. Median overall survival was significantly reduced in the high HMGB1 group (53.7 months) and was not reached in the low HMGB1 group. 5 year survival was 50% versus 76% in the high HMGB1 versus low HMGB1 groups respectively (p=0.03). No independent predictors of survival were identified on multivariate analysis.
Conclusion: High POD1 HMGB1 level is associated with survival following liver resection for colorectal liver metastases. This could provide an early indicator of higher risk of recurrence during the follow up period.
PL01-33 Liver-first versus Classical Strategy for Synchronous Colorectal Liver Metastases: An Updated Meta-analysis
Dimitris Zacharoulis, Greece

D. Zacharoulis1, M. Fergadi1, A. Diamantis1, G. Tzovaras1, D. Symeonidis1, D. Magouliotis1,2
1Department of Surgery, University of Thessaly, Greece, 2Division of Surgery and Interventional Sciences, University College London, United Kingdom

Introduction: The aim of the present study was to compare the clinical outcomes of liver-first (LFS) versus classical (CS) strategy for the management of synchronous colorectal liver metastases (sCRLM).
Methods: A thorough literature search was performed in PubMed, Scopus and Cochrane databases, in accordance with the PRISMA guidelines. The Odds Ratio, Weighted Mean Difference and 95% Confidence Interval were evaluated by means of the Random-Effects model.
Results: Ten articles met the inclusion criteria, incorporating 3,656 patients. Patients in the LFS group reported increased size of sCRLM and a higher rate of major hepatectomies. This study reveals comparable overall survival and disease-free survival at 1, 3 and 5 years postoperatively between the two strategies. Moreover, the mean operative time, length of hospital stay, the incidence of severe complications, the 30-day and 90-day mortality were similar between the two groups. The mean intraoperative blood loss was significantly increased in the LFS group.
Conclusion: These outcomes suggest that both approaches are feasible and safe. Since there are no randomized clinical trials currently available, this meta-analysis represents the best currently available evidence. Nonetheless, the results should be treated with caution given the small number of the included studies. Randomized trials comparing LFS to CS are necessary to further evaluate their outcomes.
PL01-34 The Effectiveness of Transcatheter Arterial Chemoembolization in the Treatment of Unresectable Hepatic Metastases
Dmitry Panchenkov, Russian Federation

E. Zvezdkina1, Y. Stepanova2, D. Astakhov3, D. Lebedev1, V. Kosiy1, Y. Ivanov3, D. Panchenkov4
1Federal Research Clinical Center for Specialized Types of Health Care and Medical Technologies of Federal Medical and Biology Agency, Russian Federation, 2Vishnevsky National Medical Research Center for Surgery, Russian Federation, 3Evdokimov Moscow State University of Medicine and Dentistry, Russian Federation, 4State Scientific Center for Laser Medicine of Federal Medical and Biology Agency, Russian Federation

Introduction: This study investigated the effectiveness of transcatheter arterial chemoembolization using drug-eluting beads (DEB-TACE) in the treatment of unresectable hepatic metastases.
Methods: 40 patients with unresectable hepatic metastases treated with DEB-TACE in an institutional review board approved protocol from 2011 to 2019 were studied retrospectively. The time to progression (TTP) was estimated by CT and MRI according to RECIST 1.1. Primary tumors were: colorectalregion(40%), lung (15%), uterus and cervix (15%), prostate (10%), ovaries (5%), pancreas (5%), liver (5%), breast (5%).
Results: We distinguished 2 groups of patients. Group 1 consisted of 13 patients who underwent DEB-TACE after 21-42 months from the detection of metastases after previous therapy failure. Mortality during the first 12 months after DEB-TACE was 5 %, mortality after 13 months - 42%. TTP was 10-24 months, which required second DEB-TACE in 6 patients with TTP 10-14 months.
Group 2 consisted of 27 patients who underwent DEB-TACE after 1-11 months from the detection of metastases in combination with systemic chemotherapy.
Mortality during the first 12 months after DEB-TACE was 5%, mortality after 13 months - 41%. TTP was 9-24 months, which required second DEB-TACE in 2 patients with TTP over to 10 months.
Conclusion: 1)Mortality and TTP were similar in both groups; 2)the number of repeated DEB-TACE in group 1 was higher than in group 2; 3)DEB-TACE is effective both in the initial and in the later stages of treatment of unresectable hepatic metastases.
PL01-35 Splenic Enlargement Induced by Preoperative Chemotherapy Is an Useful Indicator for Predicting Liver Regeneration after Resection for Colorectal Liver Metastases
Takanori Konishi, Japan

T. Konishi1, H. Yoshidome1, H. Yoshitomi1, K. Furukawa1, T. Takayashiki1, S. Kuboki1, S. Takano1, M. Miyazaki1,2, M. Ohtsuka1
1General Surgery, Hepato-Biliary-Pancreatic Unit, Chiba University, Japan, 2Surgery and Digestive Disease Center, International University of Health and Welfare School of Medicine, Japan

Introduction: Conversion chemotherapy may downsize unresectable colorectal liver metastases (CRLMs), but may cause liver injury and splenic enlargement. The effect of preoperative chemotherapy on liver regeneration after liver resection remains undetermined. The aim of this study was to examine whether splenic enlargement induced by preoperative chemotherapy is an indicator to identify high-risk patients for impaired liver regeneration and liver dysfunction after resection.
Methods: We retrospectively reviewed 118 Japanese patients with CRLMs. Fifty one patients had conversion chemotherapy. The other 67 patients underwent upfront liver resection. We clarified effects of conversion chemotherapy on splenic volume, liver function, and postoperative liver regeneration. Perioperative outcome was also analyzed.
Results: A ratio of the splenic volume before and after chemotherapy (SP index) in the oxaliplatin-based chemotherapy group was significantly greater than other chemotherapy groups after 9 or more chemotherapy cycles. Patients whose SP index was 1.2 or more had significantly higher indocyanine green retention rate at 15 min (ICG-R15) than patients without chemotherapy. Analyses of covariance showed liver regeneration rate after resection was decreased in patients whose SP index was 1.2 or more. The incidence of postoperative liver dysfunction in patients whose SP index was 1.2 or more was significantly greater than patients without chemotherapy. Multivariate analysis showed SP index was a significant predictive factor of impaired liver regeneration.
Conclusion: Splenic enlargement induced by preoperative chemotherapy was a useful evaluation indicator for impaired liver regeneration after resection and a decision-making tool for treatment strategy for unresectable CRLMs.
PL01-37 A Case of Focal Hepatic Sinusoidal Obstruction Mimicking Colorectal Liver Metastases
Makoto Hayasaka, Japan

M. Hayasaka, S. Hata, H. Yamaguchi, M. Teruya, M. Kaminishi
Gastroenterological Surgery, Showa General Hospital, Japan

Introduction: Oxaliplatin is a platinum-based antineoplastic agent, and it is common for the treatment of colorectal cancer. Oxaliplatin-induced hepatic sinusoidal obstruction syndrome (HSOS) has been reported, and it may present as reticular hypointensity on hepatobiliary phase images of gadoxetic acid‑enhanced magnetic resonance images (EOB‑MRI). We experienced that HSOS presented focal lesions, and we could not distinguished between HSOS and metastatic lesion in the liver.
Method: A case report.
Result: A 51-year old female underwent high anterior resection for rectal cancer, and the pathological diagnosis was advanced rectal cancer, pT4aN2aM0 pStageIIIc. The patient received six cycles of oxaliplatin-based chemotherapy with capecitabine as postoperative adjuvant chemotherapy. Eight months after the operation, the contrast enhanced computed tomography revealed two low density lesions in the liver. The hepatobiliary phase of the EOB-MRI demonstrated three lesions in the liver as hypointense tumors relative to the surrounding hepatic parenchyma. These findings of the preoperative images were compatible to metastatic liver tumors from the rectal cancer, and we performed limited resection of the liver. Histopathological findings of three lesions which were recognized preoperatively revealed that sinusoid within lobules dilated and space of Disse bled. It indicated sinusoidal obstruction injury. There was no malignant lesion. The patient recovered completely and discharged from our hospital on 7th postoperative day.
Conclusions: Focal HSOS mimicking metastatic liver tumors is very rare, and it is difficult to discriminate between focal HSOS and liver metastases in the patients who undergo oxaliplatin-based chemotherapy.
PL01-38 A Survey of the International Management of Disappearing Colorectal Liver Metastases
Laleh Melstrom, United States

L. Melstrom1, S. Warner1, P. Wong1, V. Sun2, M. Raoof1, G. Singh1, T. Hugh3,4
1Surgery, City of Hope Medical Center, United States, 2Population Sciences, City of Hope Medical Center, United States, 3Surgery, University of Sydney, Australia, 4Royal North Shore Hospital, Australia

Introduction: Chemotherapy response rates have markedly improved leading to the occurrence of “disappearing” colorectal liver metastases (dCRLM). The aim of this work is to assess the management of dCRLM as determined by a survey of an international body of hepatobiliary surgeons.
Methods: A survey was designed and tested for item relevance and readability, and a content validity index (CVI) was determined based on review by 10 content experts. IRB exemption was obtained and the survey was distributed to the AHPBA, IHPBA and ANZHPBA.
Results: The majority of 226 respondents were < 15 years of training (156,69%), practiced in academics (183,82%) and devoted more than 50% of their practice to hepatobiliary (169,75%). Most had completed fellowship training (Hepatobiliary-74%, Surgical Oncology-39% and Transplant-39%). Surgeons utilize CT (45%) or MRI (47%) for preoperative planning with recent imaging (< 6 weeks) prior to surgery. Nearly all surgeons have experienced dCRLM (99%) and 63%(143) of surgeons have waited a few months to assess for a durable response prior to definitive surgical/ablative therapy. Interestingly, 24% of surgeons surveyed place fiducials for lesions < 1-cm prior to neoadjuvant chemotherapy. Intraoperatively, 97% of surgeons perform ultrasound, and 71% ablation. When a tumor has “disappeared,” 49% elect for observation and 31% resect if the dCRLM is superficial. Of those electing observation, 87% believe there is effective treatment possible with progression on surveillance imaging.
Conclusion: While nearly all surgeons experienced dCRLM, half elect for observation with the belief that there remains an opportunity to re-address these lesions in the future.
PL01-39 Tumor Progression Molecular Pathways after ALPPS and Conventional Two-stage Hepatectomy in Patients with Colorectal Liver Metastases
Ricardo Robles Campos, Spain

R. Robles Campos1, V. López López1, R. Brusadín1, C. Martínez Cáceres2, A. Caballero Illanes3, P. Gómez Valles1, A. López Conesa1, Á. Navarro Barrios1, J. De la Peña Moral3
1Department of Surgery, Virgen de la Arrixaca University Hospital (IMIB-Virgen de la Arrixaca), Spain, 2Department of Translational Investigation Support, IMIB, Spain, 3Department of Pathology, Virgen de la Arrixaca University Hospital (IMIB-Virgen de la Arrixaca), Spain

In multiple and bilobar colorectal liver metastases (CRLM), ALPPS achieves faster liver regeneration than Two-Stage hepatectomy (THS) with a lower drop-out for tumor progression. It is currently unknown if the inflammatory phenomena related to very accelerated regeneration lead to an increase of oncogenesis. The aim was to analyze the gene expression profiles of CRLM tumor progression in patients undergoing both techniques.
Between 2011 and 2019, tumor progression was analyzed in biopsies of the removed liver metastases by T-ALPPS (n=22) and compared with those by TSH between 2000 and 2011 (n=21). Samples were stained with specific antibodies to establish several tumoral progression and inmunity factors.
Between stage 1 and 2 there were no significant differences in any of the tumor progression factors in the T-ALPPS, while in TSH there was a significant increase of Ki 67 (p=0.003) and FOXP3i (p=0.003) and a decrease of T-CD8i (p=0.021). In stage 1 of both techniques, T-ALPPS had a higher Ki 67 (p˂0.001), CD68i (p˂0.001) and FOXP3i (p = 0.007) while TSH had a higher CD 44 (p˂0.001). In stage 2, T-ALPPS had a higher Ki 67 (p˂0.001), CD68i (p˂0.001), T -CD8i (p= 0.035) and FOXP3i (p = 0.001) while TSH had a higher CD 44 (p = 0.001) and (p˂0.001).
The proliferative stimulus induced by the T-ALPPS technique, despite the proliferation of subpopulation intratumoral stem cells that could explain the tumor progression in some cases, does not seem to significantly influence tumor progression in itself, unlike what does occur in TSH.
PL01-40 A Composite Score to Predict Survival in Patients Undergoing Resection because of Colorectal Liver Metastases (CRLM)
Petter Frühling, Sweden

P. Frühling, J. Urdzik, B. Isaksson
Uppsala University, Sweden

Introduction: Several scoring systems exist to predict survival in patients with CRLM. Many of these, however, are cumbersome, and do not take into account the role of inflammation and recent treatment strategies. Thus there is a need for an up-to-date robust prognostic model to predict overall survival in these patients.
Method: Data on patients that underwent liver resection for the first time because of CRLM between 2005 and 2015 at two hepatobiliary centers were included. Univariable and multivariable analyses were performed, and a Cox regression model was developed.
Results: In total 849 patients were included. Predictive factors included age > 70 years, per-operative ablation, extended and two-stage resections, as well as a high Glasgow Prognostic Score (GPS), and a Tumour Burden Score (TBS). No correlation between GPS and TBS was observed (Spearman, r= 0.168). Based on the predictive factors, GPS and TBS a Composite Score was developed, which classified patients into separate cohorts. Survival differences between the cohorts were significant, and outperformed both GPS and TBS. Median overall survival according to the Composite Score was: 1 = 53 months, 2 = 31 months and 3 = 20 months.
Conclusion: The Composite Score offers a good prognostic tool in the assessment of overall survival in patients undergoing resection after CRLM. Notably, the model identifies a group (Composite score 3), which may not benefit from surgery since it performs worse than the median estimated survival in palliative patients with CRLM. The model is currently undergoing external validation.
[Overall Survival]
PL01-41 Long-Term Survival after Liver Resection for Colorectal Liver Metastases: A Retrospective Single-Centre Study with 10-Year Follow-Up
Gael R. Nana, United Kingdom

G.R. Nana1,2, H. Malik3, P. Kron1,4, I. Rajput1, M. Attia1, P.J.A. Lodge1, G.J. Toogood1
1Department of HPB & Transplant, St James's University Hospital, United Kingdom, 2Leeds Institute of Medical Research, University of Leeds, United Kingdom, 3School of Medicine, University of Leeds, United Kingdom, 4Swiss HPB and Transplant Centre, University Hospital of Zurich, Switzerland

Introduction: Hepatic resection is the curative treatment for colorectal liver metastases (CRLM). The reporting of 10-year survival data is important for assessment of cure rates, frequency and outcomes of late recurrences. The aim of this study was to assess ten-year survival of patients undergoing liver resection at a single centre.
Methods: Liver resections for CRLM performed between 1995 and 2008 with follow-up to 2018 were retrospectively reviewed. Demographic, clinicopathological and survival data were analysed. The Fong clinical risk score was dichotomised into low (0-2) and high (3-5) risk and ten-year survival was the primary outcome measure. Kaplan Meier curves and Cox regression were used to analyse factors associated with 10-year survival.
Results: A total of 1120 patients underwent liver resection for CRLM. The median age was 68 (range 23-91) years. Synchronous disease was present in 50%, with 56% of patients having adjuvant chemotherapy after primary colorectal cancer resection. 29.4% had a high Fong score (3-5) with 15.4% of patients having repeat liver resections for recurrent metastases. The median post-operative survival was 2 years. Overall ten-year survival was 12.3%. Fong risk classification had a statistically significant association (p=0.006, 95% CI 0.706 - 0.943) with ten-year survival. 2.6% (n=29) of patients with Fong score 3-5 were alive at 10 years.
Conclusion: In this single center analysis the ten-year survival rate for resection in CRLM was 12.3%. Patients with high Fong clinical risk score have poorer long-term outcomes. Therefore, further trials are required to assess the benefit of additional treatment such as chemotherapy.
PL01-42 Frailty as a Predictor of Postoperative Morbidity and Mortality Following Liver Resection
Pablo Serrano, Canada

P. Serrano1,2, T. Bao1, T. McKechnie2, M. Fabbro3, C. Thieu1, L. Ruo1,2
1Department of Surgery, Juravinski Hospital, Canada, 2McMaster University, Canada, 3Trinity College, Ireland

Background: Frailty, defined as a state of decreased physiologic reserve, characterized by a loss of resiliency in the face of acute stress is a condition frequently encountered by liver surgeons. We sought to evaluate frailty as a predictor of postoperative complications following liver resection using the modified frailty index (mFI).
Methods: This retrospective cohort study follows consecutive adult patients undergoing liver resection between 2011 and 2018 at a single academic institution. An mFI consisting of 11 variables adapted for the NSQIP database from the Canadian Study of Health and Aging Frailty Index was used. Patients were stratified as high mFI (≥0.27) and low mFI (< 0.27).
Results: Among 409 liver resections, 58/409(14%) patients had a high mFI. Low mFI patients were significantly younger (63vs.70 years, p< 0.001) and more likely to meet >4 METS(90%vs.60%, p< 0.001). Median length of hospital stay was significantly longer for the high mFI group (9.5 vs. 5days, p< 0.001). Patients with a high mFI had a significantly higher proportion of postoperative complications (79%vs.46%, p< 0.001). This was true for minor complications, major complications and 90-day postoperative mortality. Longer operating time, per 30-minute increase (OR=1.15, 95%CI[1.03 to 1.27]), higher number of liver segments resected (OR=1.43, 95%CI 1.12 to 1.82), and high mFI, per unit increase (OR=6.74, 95%CI [2.76 t o16.51]) were independent predictors for the development of major complications and 90-day mortality.
Conclusion: The mFI predicts postoperative outcomes following liver resection and can be used as a risk stratification tool for patients being considered for surgery.
PL01-43 Early Results of Liver Resection and Role of Extended Histology (LIREcH) Study
Bobby VM Dasari, United Kingdom

U. Mathuram Thiyagarajan1, R. Brown2, N. Chatzizacharias1, D. Bartlett1, R. Sutcliffe1, K.J. Roberts1, P. Muiesan1, D. Mirza1, B.V. Dasari1
1HPB and Liver Transplantation Unit, Queen Elizabeth Hospital, United Kingdom, 2Department of Cellular Pathology, Queen Elizabeth Hospital, United Kingdom

Introduction: Positive margin of the resected colorectal liver metastases (CRLM) is an independent negative prognostic factor. However, liver resection involves an unaccounted 5-6mm tissue loss due to the use of energy devices or CUSA. The aim of this study is to assess the correlation between the margin status on the specimen side(R1s) and that from the patient side (base of resection)(R1p) and its influence on the outcomes.
Methods: In this prospective study, patients over 18 years undergoing resection of CRLM (< 5cm), with suspected close resection margins were included. Sample from resection base was collected using CUSA for the evaluation of R1p. Primary outcome was the correlation of R1s and R1p. Secondary endpoints were the rates of local recurrence, liver specific recurrence, overall morbidity, and post-operative hospital stay.
Results: 45 specimens and the corresponding CUSA samples from the base from 26 patients were analysed. 82% patients received neo-adjuvant chemotherapy. RAS mutation was positive in 14% of patients. Among the 45 specimens, 28(62%) had margin clearance of < 1mm, 1-4mm in 15%, 5-6mm in 13%, >9mm in 20%. However, only 5/28(17%) had tumour cells on the patient side (R1p). Overall, one patient had liver specific recurrence at 8 months. None of the others had local recurrence. Median post-operative hospital stay was 6.4 days.
Conclusion: Early results of this on-going study suggest poor correlation between R1s and R1p. Confirmation of the results from larger cohort might help in patient counselling, surveillance, and in pre-operative planning of the resection of bilobar metastases.
PL01-44 Surgery for Synchronous Colorectal Liver Metastases in 233 Consecutive Patients: Which One of the Three Different Strategies?
Arpad Ivanecz, Slovenia

A. Ivanecz1, I. Plahuta1, T. Magdalenić1, A. Stožer2, B. Krebs1, S. Potrč1
1Department of Abdominal and General Surgery, UMC Maribor, Slovenia, 2Institute of Physiology, University of Maribor, Medical Faculty, Slovenia

Introduction: This study aimed to investigate the surgical management and outcome of patients with primary colorectal cancer (CRC) and synchronous colorectal liver metastases (SCLM).
Method: Consecutive patients undergoing surgical treatment of CRC and SCLM between 2000 and 2019 were identified retrospectively from a prospectively collected database. Three surgical strategies were followed: the simultaneous resection (SR), the colorectal-first (CRF) and the liver-first (LF) approach.
Results: Of 233 patients, SRs were performed in 83 (35.6%) patients. CRF was used in 136 (58.4%) patients and 14 (6.0%) patients underwent LF.
Overall morbidity was present in 102 (43.75%) patients and did not reach statistical significance among approaches.
Bleeding grade B/C was observed in 30 (12.9%) patients. The difference among approaches ((9.6%), 17 (12.5%) and 5 (35.7%)) reached statistical significance (P=0.026). Liver failure grade B/C was observed in 24 (10.3%) patients. The difference among approaches (5 (6.0%), 14 (10.3%) and 5 (35.7%)) was statistically significant (P=0.003).
Mortality included 8 (3.4%) patients; 1 (1.2%) in SR, 5 (3.7%) in CRF and 2 (14.3%) in LF (P=0.044).
On the overall survival analysis, the SR approach has statistically significantly (P=0.006) longer survival (48.5 months vs. 32.7 months in CRF or 23.8 months in LF).
Conclusions: treatment strategy should be patient-tailored. SR is feasible when both diseases require limited surgical procedures. CRF is recommended when concurrent major hepatectomy and colorectal resections may increase postoperative morbidity and mortality. LF approach diminishes the risk of metastatic progression during the treatment of the CRC.
PL01-45 Concurrent Hepatic and Renal Metastases of a Meningeal Hemangiopericytoma: A Case Report and Review of the Literature
Rachael Galvin, United States

R. Galvin1, J. Stuppy2, E. Kortz1, S. Sen3
1Department of Surgery, Swedish Medical Center, United States, 2Rocky Vista University, United States, 3Sarah Cannon Research Institute at HealthONE, United States

Introduction: Hemangiopericytoma (HPC) is a rare phenotype of solitary fibrous tumors. While local recurrence and metastasis is common, concurrent renal and hepatic lesions have seldom been reported. We present the rare case of a patient with both renal and hepatic metastatic HPC, 14-years following successful meningeal HPC resection.
Case Presentation: A 65-year-old female with history of a meningeal HPC resected in 2005, presented to her PCP in 2019 with complaints of persistent epigastric pain. Abdominal CT demonstrated a large hypervascular mass in both the left kidney and left lobe of the liver. Biopsy of the liver mass was consistent with metastatic HPC. Left hepatectomy and left nephrectomy were performed. Final pathology demonstrated a 7.5 x 7 x 6 cm well-circumscribed mass in the left kidney and an 18 x 15 x 10.5 cm well-circumscribed mass with central necrosis and hemorrhage of the left liver. Immunohistochemistry for STAT6 was performed on both lesions and confirmed the diagnosis of HPC.
Conclusion: This case was unique due to the simultaneous extramedullary metastases involving both the kidney and the liver. To our knowledge, there have only been two other reported cases of HPC presenting with simultaneous hepatic and renal metastases. This case highlights the importance of ongoing research regarding optimal treatment strategies and effective surveillance of patients with HPC, given the potentially metastatic, complex, and recurrent nature of the disease.
PL01-46 Utilization and Impact of Surgical Treatment of Stage IV Pancreatic Ductal Adenocarcinoma: An Analysis of the National Cancer Database
Jennifer Underhill, United States

J. Underhill1, R. El-Diwany2, B. Reames3, Y. Li1, J. Cloyd1, M. Dillhoff1, A. Tsung1, T. Pawlik1, A. Ejaz1
1The Ohio State University Wexner Medical Center and James Comprehensive Cancer Center, United States, 2Johns Hopkins University School of Medicine, United States, 3University of Nebraska Medical Center, United States

Introduction: Patients with liver-only metastatic pancreatic adenocarcinoma (PDAC) have traditionally been offered palliative chemotherapy alone. Recent institutional studies have explored the role of surgical resection among patients with limited metastatic disease. National practice patterns and the impact of surgery among these patients remains unknown.
Methods: The National Cancer Database was queried for all patients with PDAC between 2010-2015. The primary outcome was overall survival from the time of diagnosis.
Results: We identified 312,426 patients who met the study criteria. One-half of patients (n=140,043, 50.4%) had stage IV disease. Patients with stage IV disease were more likely to be younger (OR 1.31, 95%CI: 1.29-1.33; P< 0.001) and have poorly (OR 2.16, 95%CI: 2.07-2.27; P< 0.001) or undifferentiated (OR: 2.20, 95%CI: 1.99-2.44; P< 0.001) tumors. Among stage IV patients with liver-only metastatic disease (n=46,542, 14.9%), 891 patients (1.9%) underwent pancreatic resection. Patients who underwent resection were more likely to be younger (OR 1.87, 95%CI: 1.57-2.22; P< 0.001) and treated at an academic/research center (OR 1.81, 95%CI: 1.34-2.45; P< 0.001). Median OS among patients who underwent resection was 10.74 months versus 3.4 months among patients who did not undergo resection. Patients who underwent surgical resection had a lower risk of death than those who did not undergo surgery (HR: 0.57, 95%CI: 0.50-0.64; P< 0.001).
Conclusion: Surgical resection in patients with liver-only metastatic PDAC is associated with improved overall survival. Further studies are needed to identify which patients benefit the most from surgical resection for liver-only stage IV PDAC.
PL01-47 Is a R0 Resection Always the Aim in Resection of Colorectal Liver Metastasis?
Martyn Stott, United Kingdom

M. Stott, T. Noone, A. Kausar
East Lancashire Hospitals NHS Trust, United Kingdom

Introduction: Colorectal cancer is the 3rdmost common cancer in the UK, with up to 50% developing colorectal liver metastases (CRLM). When suitable, surgical resection of CRLM offers a five year survival of 35%-58%. Evidence remains equivocal regarding a superior surgical technique for resection or if synchronous colon and liver resections show more favourable results. Resection margin status is important, with recent evidence suggesting that an R1 resection often reflects more aggressive tumour biology.
Methods: A retrospective review of a prospectively maintained database of a single UK regional HPB centre, plus electronic patient records, for a two year period between 2014-2015 was undertaken. Reported outcomes included surgical approach, resection margin status and survival.
Results: Four consultants undertook 86 resections. 76% were men with a mean age of 66 years. 48% received neoadjuvant and 49% received adjuvant chemotherapy. 43% were laparoscopic. 13% were synchronous resections with the colorectal primary. 65% were parenchymal sparing resections. 17% were R1 resections: 57% of open, 36% of laparoscopic, 33% of synchronous. Overall five year survival 42%. R1 resections mean survival was 859 days versus 1733 days for R0.
Conclusion: Despite small numbers, outcomes show a comparable overall five year survival rate to the literature. The majority of resections were open, with the highest R1 resection rate which probably reflects more complex disease. However, there appears to be a survival benefit of 2.4 years despite R1 resection. More data is required prior to commenting on the benefit of synchronous colon and liver resections.
PL01-48 IGFBP7 and POSTN Are Prognostic Biomarkers in the Cancer Associated Stroma of Colorectal Liver Metastases
Kai M Brown, Australia

K.M. Brown1,2,3, A. Xue3, A.J. Gill2,4,5, T.J. Hugh1,2,3
1Upper GI Surgery Unit, Department of Gastrointestinal Surgery, Royal North Shore Hospital, Australia, 2Northern Clinical School, University of Sydney, Australia, 3Cancer Surgery and Metabolism Research Group, Kolling Institute of Medical Research, Australia, 4Department of Anatomical Pathology, Royal North Shore Hospital, Australia, 5Cancer Diagnosis and Pathology Group, Kolling Institute of Medical Research, Australia

Introduction: Cancer associated stroma (CAS) is emerging as a key determinant of metastasis in colorectal cancer (CRC). A handful of proteins including CALD1, IGFBP7, POSTN, FAP, TGF-b and pSMAD2 from stromal gene signatures have been purported as prognostic after resection of primary CRC, however very little is known about the role of CAS in colorectal liver metastases (CRLM). This study aimed to assess the prognostic significance of the above stromal biomarker panel in CRLM.
Method: A retrospective analysis of a prospectively maintained database was performed. Epithelial and stromal CALD1, IGFBP7, POSTN, FAP, TGF-b and pSMAD2 expression was assessed by immunohistochemistry (IHC) on tissue microarrays. Multivariate Cox proportional hazards models were used to determine the prognostic value of the IHC stromal biomarker panel for predicting overall (OS) and disease-free survival (DFS) following CRLM resection.
Results: 124 CRLMs included in the IHC analysis. Median follow up in months was 45 months. Median and 5-year survival were 101 months and 65%, and 23 months and 34%, for OS and DFS, respectively. Multivariate hazards ratio plots for DFS and OS are shown below. After CRLM resection, stromal IGFBP7 was an independent predictor of poorer DFS and stromal IGFBP7 and POSTN were independent predictors of poorer OS.
Conclusions: This study has identified two novel prognostic stromal IHC biomarkers in CRLM that may be easily translated to the clinic. Furthermore, as POSTN has a number of inhibitors in pre-clinical evaluation, further studies are warranted investigating POSTN as a putative therapeutic target in CRLM.
[Hazard ratio plots for multivariate models of OS and DFS following CRLM resection]
PL01-49 Survival Benefits and Margin of Liver Metastasectomy in Colorectal Liver Metastasis
Cheuk Him Ho, Hong Kong

C.H. Ho1, K.W. Ma1, W.H. She1, T.T. Cheung2, A.C.Y. Chan2, W.C. Dai1, C.M. Lo2
1Surgery, Queen Mary Hospital, the University of Hong Kong, Hong Kong, 2Surgery, University of Hong Kong, Hong Kong

Background: Association between resection margin of hepatic resection for colorectal liver metastasis and survival outcome remains controversial. While a margin of 10mm had been the traditional standard, several studies had been published in the past with conflicting results.
Method: This is a retrospective review of 385 patients who underwent liver resection for colorectal liver metastasis in a single centre from 2000-2017. Survival data were correlated with demographics, liver resection margin, KRAS status, CEA levels and analysed for statistical significance using long-rank test and cox regression with multivariate analysis.
Result: There is statistically significant association between the width of liver resection margin and both overall and disease free survival. Microscopic margin of greater than 10 mm is associated with significant benefit in both disease free (9.8 vs 15.8 months P=0.001) & overall survival (43.9 vs 58.9 months P= 0.012). Cutoff for free resection margin beyond 14mm did not correlate with significant difference in survival. The other factors associated with survival benefits was CEA less than 5 on admission (95%CI 0.53-0.92 p=0.01).
Conclusion: Liver resection margin of greater than 1mm is an independent predictor of increased disease free survival. There is clinically and statistically significant improved survival if liver resection margin of greater than 10mm can be achieved.
PL01-50 Effect of Chemotherapy and Tumor Clearance in Hepatic Resections for Colorectal Liver Metastases
Mauro Andrés Perdomo Perez, Uruguay

M.A. Perdomo Perez1, G. Botto Nuñez2, J. Reid3, D.A. Gonzalez1, G.J. Maddern3
1Clinica Quirúrgica '3', Facultad de Medicina Udelar, Uruguay, 2Departamento de Métodos Cuantitativos Facultad de Medicina Universidad de la República, Uruguay, 3The University of Adelaide, Australia

Background: Colorectal cancer is the third most common cancer, and the second leading cause of cancer-related deaths. Up to 50% of patients with CRC will develop synchronic (10-20%) or metachronic (20-30%) CRLM. Currently, liver resection is the gold standard treatment for CRLM improving the prognosis significantly. Despite this, more than 50% of patients undergo recurrences after liver resections, most of them within the first 24 months after surgery.
Objective: To describe rates and patterns of recurrence following liver resections for CRLM at The Queen Elizabeth Hospital, Adelaide as well as characterize clinical, pathological and treatment-related factors that could work as predictors of recurrence and survival.
Methods: Retrospective analysis of a prospectively collected data base of 170 patients who underwent liver resections for CRLM at The Queen Elizabeth Hospital (Adelaide, Australia) between 2004 and 2017.
Results: The incidence rate was 49,4% (84 of 170 patients), and the recurrences occurred mainly during the first year after the resective procedure (average 359 days). The intercurrence of perioperative chemotherapy was associated with a higher recurrence rate and a lower survival time in the univariate and multivariate analysis. The benefit of a margin resection greater or equal to 1mm was established. The other studied variables showed no statistical association.
Conclusion: Despite the development of better diagnostic and therapeutic techniques for CRC and CRLM, its recurrence rate continues to be high and the survival time low. The role and impact of perioperative chemotherapy must continue to be studied in order to improve therapeutic outcomes for CRLM.
PL01-51 Immune Profiling of Histologic Growth Patterns of Colorectal Liver Metastases: Spatial Distribution and Phenotyping of T Lymphocytes, Cytotoxic T Cells and Tissue-resident Memory T Cells
Dora Lucia Vallejo Ardila, Australia

D.L. Vallejo Ardila1, T. Fifis1, D. Williams2, K.A. Walsh1, V. Muralidharan1, J. Banting3, C. Christophi1, M.V. Perini1
1Surgery, Austin Health, University of Melbourne, Australia, 2Pathology, Austin Health, University of Melbourne, Australia, 3Anaesthesia, Austin Health, University of Melbourne, Australia

Introduction: The nature of the of Colorectal Liver Metastases (CRCLM) display mainly three distinct histologic growths patterns that impact on disease progression and patient outcome after surgical resection. However limited studies indicate that immune cell infiltration is dictated by the CRCLM growth pattern.
Methods: 22 CRCLM specimens were assessed by histological evaluation, and Multiplex Immunohistochemistry (OPALTM) was used to examine density and distribution of T lymphocytes (CD3+), cytotoxic T cells (CD3+CD8+), resident memory T cells (CD3+CD8+CD103+)(TRM). Cell phenotyping algorithm was performed using inForm® software v3.5. The tissue segmentation algorithm determined the adjacent liver parenchyma (LP), invasive tumor margin (IM) and tumor core (TC) regions.
Results: Histological evaluation of the 22 CRCLM specimens defined 7 desmoplastic, 8 replacement and 7 pushing growth patterns. The evaluation of the entire cohort of CRCLM showed that the spatial distribution total T lymphocytes as well as cytotoxic and TRM were found in significantly higher levels at the IM when compared with LP or TC. There was no significant difference between the IM and TC in the T lymphocytes cell count displayed by replacement pattern, whereas the desmoplastic and pushing pattern showed higher accumulation in the IM compared to the TC. The highest cell count of cytotoxic T cells occurred in the IM for all three growth patterns but only significantly different from the TC in the desmoplastic and pushing pattern.
Conclusion: This study unveiled the spatial variation of immune profiles according to histologic growth patterns of CRCLM using a powerful systematic imaging approach.
[Multiplex Immunohistochemistry defines immune profile of histologic growth patterns of CRCLM]
PL01-52 Role of Tumor Borden Score to Predict the Prognosis in Patients Resected for Colorectal Liver Metastases after Preoperative Chemotherapy
Simone Conci, Italy

A. Ruzzenente, R. Ziello, S. Conci, F. Bagante, C. Tommaso, G. Isa, S. Dedoni, C. Iacono, A. Guglielmi
Department of Surgery, Division of General and Hepatobiliary Surgery, G.B. Rossi University Hospital, University of Verona, Italy

Background: Response of colorectal liver metastasis (CRLM) on preoperative chemotherapy (PreopChT) has been associated with a worse prognosis compared with patients who have responsive disease. Defining response can be challenging as traditional criteria largely assess only tumor size.
Methods: Patients who underwent hepatectomy after PreopChT for CRLM in a single institution between 2006 and 2018 were considered. This study aimed to define the role of initial tumor burden score (TBS) and its variations after chemotherapy on long-term outcomes.
Results: One-hundred and ninety-nine patients were included in the study. The PreopChT regimen were oxaliplatin- (44.3%), irinotecan-based (43.2%) or both (12.5%). Target therapy were used in 61.1% of the patients. The median TBS at diagnosis and after PreopCht were 4.8 (3.2-8.4) and 4.4 (2.9-6.8), respectively. The 5-year OS rate of patients with TBS< 6 and TBS>6 at diagnosis were 57.8% and 38.7% (p=0.011), respectively. The 5-year OS rate of patients with TBS< 6 and TBS>6 after PreopChT were 60.1% and 31.5% (p< 0.001), respectively. The 5-year OS rate of patients with Δ-TBS < -20% and Δ-TBS >-20% were 64.3% and 42.8% (p=0.009), respectively. At the multivariate analysis the independent prognostic factors resulted TBS >6 at diagnosis (HR 1.3, 95%CI 1.1-2.1, p=0.003), Δ-TBS < -20% (HR 1.7, 95%CI 1.4-3.3, p=0.009) and gene mutation of KRAS/RAS (HR 1.9, 95%CI 1.1-3.3, p=0.020).
Conclusions: Tumor burden at the diagnosis, variations in tumor burden due to chemotherapy, and tumor molecular profile seems to be the important factors prognostic for stratification of patients with CRLM receiving preoperative chemotherapy.
PL01-54 Cystic Liver Metastasis from a Pancreatic Adenocarcinoma; a Case Report
Nattawut Keeratibharat, Thailand

J. Chansangrat1, N. Keeratibharat2
1School of Radiology, Institute of Medicine, Suranaree University of Technology, Thailand, 2School of Surgery, Institute of Medicine, Suranaree University of Technology, Thailand

A 75-year-old female was presented to our hospital due to obstructive jaundice. Computed tomography demonstrated a pancreatic head mass that causing common bile duct and intrahepatic duct dilatation without evidence of advanced disease. She was underwent pyloric-preserving pancreatoduodenectomy and they discharge without complication. In operative finding, we found the 1-cm liver cyst at segment 5 and excisional biopsy was done. The pathological report revealed well-differentiated adenocarcinoma of head of pancreas without nodal metastasis and cystic metastasis well-differentiated adenocarcinoma of liver. Then we reviewed the imaging study, it showed a small cystic lesion without enhancing portion at liver segment 5 that mimics intrahepatic duct dilatation and a cystic lesion at segment 6 that previously seen in preoperative imaging study. The patient underwent chemotherapy with Gemcitabine. Six months after surgery, the computed tomography revealed increase sized of cystic lesion at segment 6 and development of ascites. Ten months after surgery, the patient was dead due to severe septicemia from urinary tract infection. The previous study show a range of spectrum of hepatic cystic liver metastasis with histopathologic confirmation of diagnosis.
Although the incidence of hepatic cystic liver metastasis from pancreatic cancer is extremely rare, care should be taken to when a cystic liver lesion was detected with pancreatic cancer.
PL01-55 Systematic Review Comparing the Effectiveness of Robotic Verse Laparoscopic Liver Surgery in Colorectal Liver Metastasis (CRLM)
Badriya Alaraimi, Oman

N. Merali1, H. Ashraf1, R. Lahiri1, B. Alaraimi2, V. Yip3
1Royal Surrey County Hospital, United Kingdom, 2General Surgery, Armed Forces Hospital, Oman, 3Royal London Hospital, United Kingdom

Introduction: Colorectal cancer (CRC) is the third most common cancer in the world. According to Cancer Research UK, 42,000 new cases are diagnosed in the UK every year. The liver is the most common site of metastasis with 15 to 25% of patients presenting with synchronous colorectal liver metastasis (CRLM) at the time of diagnosis. Modern chemotherapy has resulted in improved survival rates. Patients with resectable disease, surgical resection remain the only potentially curative treatment. This study aimed to evaluate the short and long-term outcomes and directly comparing the effectiveness of laparoscopic and robotic CRLM surgery.
Methodology: A literature search was performed and all studies that reported on operative characteristics, oncological outcomes for CRLM, morbidity or mortality and cost effectiveness on robotic or laparoscopic surgery were included. Present study was designed according to the PRISMA guidelines.
Results: From the initial 575 manuscripts identified, 17 studies (9 laparoscopic & 8 robotic) were included in the final qualitative synthesis. Our study shows that robotic surgery can be used safely for colorectal liver resections with a limited conversion rate, blood loss, and postoperative morbidity. However, robotic and laparoscopic liver resection displays similar safety and feasibility for CRLM.
Conclusion: Experienced Hepatobiliary surgeons can safely perform robotic surgery. Long-term oncological outcomes are unclear, but short-term perioperative results are comparable to those of laparoscopic liver resection. The main drawback of advanced robotic surgery is the associated cost and further studies are needed to clarify the exact role of robotics in liver surgery.
PL01-56 Follow up after Liver Resection for Colorectal Liver Metastases - How Long Is Long enough?
Nagappan Kumar, United Kingdom

N. Kumar1, D. O'Reilly1, T. Duncan1, Z. Kaposztas2, S. Junnarkar3
1Cardiff Liver Unit, University Hospital of Wales, United Kingdom, 2Moritz Kaposi Teaching General Hospital, Hungary, 3Tan Tock Seng Hospital, Singapore

Introduction: Liver resection for colorectal liver metastases (CRLM) is the most common operation in most liver units in the western world. There is no evidence based guidance on the length of follow up. Like many units, we follow patients for 10 years with yearly CT scans. As recurrences were uncommon after 5 years we analysed our data on timing of recurrence to decide on future follow up protocol.
Methods: We performed a retrospective review of a prospectively held database on all patients undergoing liver resection for CRLM at the Cardiff Liver Unit from January 2003 to December 2018 and censored at 30 June 2019 or death. Data on follow up was obtained from electronic databases in Wales and contacting the General Practitioners. We excluded patients who died perioperatively or did not complete a two stage liver resection. In case of recurrence in liver that was resected, time from the last resection was considered.
Results: We performed liver resections in 503 patients for CRLM. After the above exclusions there were 486 patients in the study. Male female ratio 324:162, median age 67 (21-93), median hospital stay 7 days (2-216), perioperative mortality 2%. The overall survival at 1,3,5 and 10 years was 93%,69%, 50% and 34%. The median follow up was 3 years (1 month-15 years). No patient developed recurrence at any site after 5 years of follow up.
Conclusion: Follow up after liver resection for CRLM for 5 years is adequate and longer follow up may not be cost effective.
PL01-57 Liver First Approach - Comparative Analysis of Surgical and Oncological Outcomes Using Propensity Score Matching
Piotr Zelga, United Kingdom

P. Zelga1, Y. Wang2, E. Huguet1, R. Praseedom1, S. Harper1, S.-S. Liau1, A. Balakrishnan1, A. Jah1
1HPB Surgery, Cambridge University Hospitals NHS Foundation Trust, United Kingdom, 2University of Cambridge and Addenbrooke's Hospital, United Kingdom

Introduction: Contrary to conventional approach (CA), the liver first approach (L1) to synchronous colorectal liver metastases (sCLRM) warrants hepatic resection prior to removal of the primary source. Such approach facilitates early introduction of systemic therapy and prevent the further spread of the disease. However, there are limited data comparing the outcomes of both approaches.
Method: From January 2015 to December 2018, patients who underwent liver resection for sCLRM were screened. Propensity score matching was performed with a 1:1 matching protocol. Log-rank test and Cox proportional hazards model were used in survival analyses, including at least one year follow-up.
Results: A total of 223 patients (L1, n= 30; CA, n=193) met the eligibility criteria and finished the follow-up. After matching, 60 patients were included (30 patients for each treatment group). Patient chosen by matching has higher primary disease burden (T3-T4, N1-2) and median of 3 liver metastases (range 1-7). No differences in rates of postoperative complications and mortality were observed. The L1 approach was completed in 22 patients (overall = 80%; 14/16 with unilobar and 8/14 with bilobar presentation). No significant difference was found between the L1 and CA in overall survival (p = 0.76) and disease free survival (p = 0.42). In 20% (n=6) of patients in L1 and 27% (n=8) in CA who completed the treatment recurrent disease was observed at the time of the last follow-up.
Conclusions: Comparable in oncologic outcomes to conventional approach, liver first is beneficial in a subgroup of patients with advanced primary disease and unilobar presentation of sCLRM.
PL01-58 Socioeconomic Deprivation Does Not Affect Short or Long Term Outcomes after Liver Resection for Colorectal Liver Metastases
Nagappan Kumar, United Kingdom

N. Kumar, N. Mowbray, A. Iqbal, U. Nawaz, D. O'Reilly
Cardiff Liver Unit, University Hospital of Wales, United Kingdom

Introduction: Socioeconomic deprivation (SED) is a well documented factor in poor outcomes following treatment for many primary cancers. We sought to examine if this is true for liver resections for colorectal liver metastases (CRLM).
Methods: We did a retrospective study on a prospectively held database at Cardiff Liver unit on all patients having liver resections for CRLM between January 2013 and December 2018. Data was censored at 30 June 2019 or death. Demography, ASA status, length of stay, morbidity, mortality, margin status, vascular and bile duct invasion, tumour burden score and deprivation status (using Welsh Index of Multiple Deprivation (WIMD) recorded. WIMD 1 is most deprived and 5 least deprived. We combined the quintiles 1&2 and 3&4 to compare deprived vs non deprived patients.
Results: 337 resections were perfomed in 275 patients. Males 66%. Median age 66(21-93), median hospital stay 7 days (2-216) and 90 day mortality of 2.4%. The overall survival(OS) was 90%, 70% and 52%. There was no difference in the baseline characterestics between the most (Q1&2) and least(Q3&4) deprived patients. The OS at 1,3,5 years for most and least deprived were 90%, 69%, 45% and 96%,72% and 60% respectively (P=0.26). There was no difference in the hospital stay, morbidity and mortality between the two groups. Only tumour burden and two stage procedure led to significantly poorer long term outcome.
Conclusion: SED does not appear to affect OS after liver resection for CRLM. However, this needs to be confirmed in a larger cohort to avoid Type II error.
PL01-59 Perioperative and Long-term Outcomes of Laparoscopic Liver Resections for Non-colorectal Liver Metastases
Ioannis Triantafyllidis, France

I. Triantafyllidis1,2, B. Gayet1, S. Tsiakyroudi1, N. Tabchouri1, M. Beaussier1, A. Sarran1, M. Lefevre1, C. Louvet1, D. Fuks1
1Institut Mutualiste Montsouris, France, 2Konstantopoulio-Patision General Hospital of Nea Ionia, Greece

Introduction: The aim of this study was to analyze the outcomes of patients undergoing laparoscopic liver resection (LLR) for non-colorectal liver metastases (NCRLMs).
Method: From a prospectively maintained database between 2000 and 2018, patients undergoing LLR for colorectal liver metastases (CRLMs) and NCRLMs were selected. Clinicopathologic, operative, short and long-term outcome data were collected, analyzed and compared among patients with CRLMs and NCRLMs.
Results: The primary tumor was colorectal in 354 (82.1%), neuroendocrine in 21 (4.9%) and non-colorectal, non-neuroendocrine in the remaining 56 (13%) patients. Major postoperative morbidity was 12.7%, 19% and 3.6 %, respectively (p=0.001), whereas the mortality was 0.6% for patients with CRLMs and zero for patients with NCRLMs. According to the survival analysis, 3- and 5-year recurrence-free survival (RFS) rates were 76.1% and 64.3% in CRLMs group, 57.1% and 42.3% in neuroendocrine liver metastases (NELMs) group, 33% and 20.8% in non-colorectal, non-neuroendocrine liver metastases (NCRNNELMs) group (p=0.001), respectively. Three and 5-year overall survival (OS) were 88.3% and 82.7% in CRLMs group, 85.7% and 70.6% in NELMs group, 71.4% and 52.9% in NCRNNELMs group (p=0.001), respectively. In total, 31.9% of patients with CRLMs, 9.5% with NELMs and 14.3% of patients with NCRNNELMs underwent repeat LLR for recurrent metastatic tumors.
Conclusions: LLR is safe and feasible in the context of a multimodal management where an aggressive surgical approach, necessitating even complex procedures for bilobar multifocal metastases and repeat hepatectomy for recurrences, is the mainstay and may be of benefit in the long-term survival, in selected patients with NCRNNELMs.
PL01-60 Failure to Cure Colorectal Liver Metastases Patients Quantified - The Impact of the Liver Surgical Specialist
Eduardo A. Vega, United States

E.A. Vega1, O. Salehi1, O. Kocyreva2, C. Conrad1
1Surgery, Tufts University, Saint Elizabeth Medical Center, United States, 2Medical Oncology, Saint Elizabeth Medical Center, Dana Farber Cancer Institute, Harvard University, United States

Background: Lack of Liver surgical specialist (LSS) may lead to a failure-to-cure in patients with possibly resectable CRLM. This study aimed to quantify the failure to cure rate due to non-inclusion of LSS.
Patients and methods: All patients who underwent chemotherapy with palliative intent for CRLM at a community oncology network between 2014-2018 were identified from a prospectively maintained cancer registry. Two LSS blinded towards patient management and outcome, reviewed pretreatment imaging and assigned each scan a newly developed resectability score. Nominal Group Technique and independent scores were combined to determine feasibility of curative intent resection. Inter-observer agreement was calculated using Kappa testing.
Results: This study included 49 palliative CRLM patients. Demographic factors were: 29 (59%) male, median age 68 (IQR 58-75), 9 (18%) rectal primary, 22 (70%) receiving oxaliplatin-base chemotherapy. Of 45 (91%) with CRLM, 3 had left-sided metastases only. The median number of CRLM was 8 (IQR 2-8). Agreement on resectability was 21 patients (45%). A lower median number of CRLM was found in the group considered to be resectable by LSS (2 vs 8; p=0.001). Of those, 6 had lung metastases and 1 peritoneal carcinomatosis. Of the unresectable patients, 10 had unresectable lung metastases with associated other metastases. Substantial agreements was found between liver surgeons (Kappa=0.814).
Conclusion: 45% of patients with tumors deemed unresectable by non-LSS providers were considered potentially resectable upon independent liver surgeon review. Despite the rapid evolution of the systemic treatment for CRLM, inclusion of a LSS may result in the highest immediate impact on cure rate.
PL01-62 Reverse ALPPS on Makuuchi Vein after Combined Systemic and Local Chemotherapy: Compound Existing CRLM Management Techniques to Achieve Surgical Resectability
Aisha Isaeva, Russian Federation

A. Kaprin1, L. Petrov2, G. Rukhadze2, A. Isaeva2
1General Director, National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Russian Federation, 2Abdominal Surgery, National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Russian Federation

Aims: The main aim of this report to show how incorporation of different techniques in CRLM management has created an opportunity for the resection of locally advanced hepatic tumors formerly considered unresectable.
Materials and methods: The current study reports the case of a 38 year-old patient with synchronous CRLM involving all three hepatic veins initially deemed unresectable. The patient developed systemic chemotherapy with molecularly targeted therapy and selective transarterial chemoembolization during 12 months. Subsequent imaging demonstrated a decrease in tumor size with unchanged involvement of the major hepatic veins. However, a right accessory hepatic vein (Makuuchi vein) remained free of disease. Left trisectionectomy by reverse-ALPPS technique with right accessory hepatic vein preservation has been performed.
Results: The patient was discharged on POD 14. At the most recent follow‐up (23 months), he had presented without evidence of disease.
Conclusions: Isolated CRLM where surgical resection is first‐line treatment, technical advances and surgical innovations can expand the spectrum of curative interventions. Meantime in patients as was presented only the combination of cross‐disciplinary techniques may transform primary irresectability. In this report, the simultaneous utilization of non surgical therapies and advanced surgical skills enabled resection for patients with complex tumors.
PL01-64 Intra-arterial Liver Isolation Chemotherapy via an Implantable Vascular Access Device to Facilitate Repeated Vascular Access for Patients with Hepatic Metastases from Colorectal Cancer (The SYS-CAPLIOX Trial)
Rodney Lane, Australia

N. Khin1, R. Lane1,2,3, T. Hugh4, C. Rogan5, K. Ho-Shon2, G. Marx6, S. Clarke7, C. Kyung1, S. Murphy1, D. Lane1, J. Verghis1, N. Pavlakis8
1AllVascular, St Leonards, Australia, 2Macquarie University, Sydney, Australia, 3Macquarie University Hospital, Sydney, Australia, 4The Tom Reeve Academic Surgical Clinic, St Leonards, Australia, 5Vascular Associates, Camperdown, Australia, 6Northern Clinical School, Wahroonga, Australia, 7Northern Clinical School, St Leonards, Australia, 8Northern Cancer Institute, St Leonards, Australia

Introduction: The SYS-CAPLIOX trial uses an implantable vascular access device (AVAS®) for repeated liver isolation intra-arterial oxaliplatin (LIOX) for patients with inoperable colorectal cancer with liver metastases (CRCLM). Similar to selective internal radiation therapy (SIRT), transarterial chemoembolization (TACE) and hepatic arterial infusion (HAI), the LIOX technique negates repeated vascular puncture and has reduced surgical morbidity and systemic leak.
Methods: Using standard endovascular techniques with balloon catheters, the AVAS allows simultaneous multi-catheter access into the arteries to administer intra-arterial infusion with the blood supply to the liver temporarily obstructed. The portal flow is indirectly obstructed via the coeliac axis and superior mesenteric arterial balloons while the venous outflow via positive-end-expiratory-pressure.
Results: The technique has previously been shown to be safe and feasible in a pilot study treating 10 patients in a salvage setting, with progressive disease, stable disease, and partial response seen in 4,3, and 3 patients respectively. With EU and TGA regulatory approval, the device has been implanted off-trial in a patient with inoperable CRCLM with no adverse device effect, malfunction or use error. The patient received 5 LIOX infusions after which the device was successfully explanted.
Conclusion: SIRT, TACE, and HAI lack of control of the portal flow can lead to significant washout of the infused agents into the pulmonary and systemic system. The LIOX treatment allows for the full absorption of anti-cancer agents that may be thwarted by intravenous administration.
The device is currently available for trial and off-trial use. The trial is registered (ACTRN12617001268336) and commenced recruitment in November 2019.