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Background Presently, data on the impact of enhanced recovery protocols on the outcomes of laparoscopic liver resection remain limited. We performed propensity matched analysis comparing the outcomes between patients undergoing laparoscopic liver resection before and after the introduction of an enhanced recovery protocol. Methods Between 2013 and 2019, 462 consecutive patients underwent laparoscopic liver resection by 3 surgeons of which 360 met the study inclusion criteria. There were 89 patients who underwent surgery under an enhanced recovery protocol and 271 without an enhanced recovery protocol. One-to-one propensity matched analysis was performed for 84 enhanced recovery protocol patients and 84 nonenhanced recovery protocol patients. Results Comparisons between propensity matched cohorts revealed that patients who received laparoscopic liver resection with enhanced recovery protocol had reduced median blood loss (200 vs 300 mL, P = .013), postoperative stay (3 vs 4 days, P = .003), and lower open conversion rates (0% vs 8.3%, P = .008). There was no difference in other key perioperative outcomes such as operation time, postoperative morbidity, postoperative major morbidity, and 30-day readmission rates. Conclusion A combined approach of enhanced recovery protocol and laparoscopic liver resection was associated with improved perioperative outcomes as opposed to laparoscopic liver resection alone.

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with high rates of recurrence post-resection. Repeat hepatectomy (RH) and radiofrequency ablation (RFA) are the mainstays for managing recurrent HCC following initial curative resection. This retrospective study aims to determine the average treatment effect of RH and RFA in patients with recurrent HCC. From 2000 to 2016, a total of 219 consecutive patients with recurrent HCC who underwent either RH or RFA were included in the study. The analysis was performed using inverse probability of treatment weighting (IPTW), and propensity score-matched (PSM) methods. The minor and major post-operative morbidity after propensity score-matched analysis for the RH group was 30.0% and 6.0%, respectively, and 19.2% and 0.0% (p = 0.1006), respectively, for the RFA group. After propensity score matching, the median OS for RH and RFA was 85.5 (IQR, 33.5–not reached) and 53.3 months (IQR, 27.5–not reached) (p = 0.8474), respectively. There was no significant difference in 90-day mortality between both groups (p = 0.1287). RH showed improved long-term overall survival over RFA at the third [71.3% versus 65.7% (p = 0.0432)], fifth [59.9% versus 45.4% (p = 0.0271)] and tenth [35.4% versus 32.2% (p = 0.0132)] year follow-up, respectively. Median time to recurrence was 11.1 (IQR, 5.0–33.2) and 28.0 months (IQR, 9.1–not reached) (p = 0.0225) for the RFA and RH group, respectively. RH confers a late survival benefit compared with RFA for patients with recurrent HCC despite a higher morbidity rate.

Background Various difficulty scoring systems (DSS) have been formulated to grade the complexity of laparoscopic hepatectomies (LH). This study aims to externally validate and compare 4 contemporary DSS including the Iwate, Institut Mutualiste Montsouris (IMM), Southampton and Hasegawa DSS in predicting the intraoperative technical difficulty and postoperative outcomes after LH. Methods Retrospective review of 548 consecutive patients who underwent LH of which 455 met the study inclusion criteria. Outcomes measures of technical difficulty included operation time, Pringles maneuver, blood loss and blood transfusion rate. Postoperative outcomes measured included morbidity, major morbidity and postoperative hospital stay. Results There was a statistically significant progressive increase in blood loss, blood transfusion rate, operation time and postoperative stay associated with all 4 DSS. There was also good calibration with respect to blood loss, operation time, Pringles maneuver, open conversion rate, postoperative morbidity, postoperative major morbidity and postoperative stay for all 4 DSS. The Southampton score demonstrated the poorest calibration in terms of operation time and discrimination in terms of application of Pringles maneuver and major morbidity amongst all 4 systems. Conclusion All 4 DSS significantly correlated with outcome measures associated with intraoperative technical difficulty and postoperative outcomes. The Southampton DSS was the poorest system in our cohort of patients.

INTRODUCTION Fluorescence imaging (FI) with indocyanine green (ICG) is increasingly implemented as an intraoperative navigation tool in hepatobiliary surgery to identify hepatic tumours. This is useful in minimally invasive hepatectomy, where gross inspection and palpation are limited. This study aimed to evaluate the feasibility, safety and optimal timing of using ICG for tumour localisation in patients undergoing hepatic resection. METHODS From 2015 to 2018, a prospective multicentre study was conducted to evaluate feasibility and safety of ICG in tumour localisation following preoperative administration of ICG either on Day 0–3 or Day 4–7. RESULTS Among 32 patients, a total of 46 lesions were resected: 23 were hepatocellular carcinomas (HCCs), 12 were colorectal liver metastases (CRLM) and 11 were benign lesions. ICG FI identified 38 (82.6%) lesions prior to resection. The majority of HCCs were homogeneous fluorescing lesions (56.6%), while CLRM were homogeneous (41.7%) or rim-enhancing (33.3%). The majority (75.0%) of the lesions not detected by ICG FI were in cirrhotic livers. Most (84.1%) of ICG-positive lesions detected were < 1 cm deep, and half of the lesions ≥ 1 cm in depth were not detected. In cirrhotic patients with malignant lesions, those given ICG on preoperative Day 0−3 and Day 4−7 had detection rates of 66.7% and 91.7%, respectively. There were no adverse events. CONCLUSION ICG FI is a safe and feasible method to assist tumour localisation in liver surgery. Different tumours appear to display characteristic fluorescent patterns. There may be no disadvantage of administering ICG closer to the operative date if it is more convenient, except in patients with liver cirrhosis.

Hepatic artery (HA) complications after liver transplant (LT) can lead to biliary complications, graft failure, and mortality. Although microsurgery has been established to improve anastomotic outcomes, it prolongs surgical time and has not reached widespread adoption at all transplant centers. We investigated the incidences of arterial, biliary complications and outcomes after using microsurgery to anastomose HA during LT. Retrospective cohort of consecutive LT performed from 2006 to 2018 was reviewed for operative details and postoperative outcomes. Cox-regression models were used to investigate the relationship between variables and outcomes. Eighty (62.5%) LTs (Group 1) were performed without and compared with 48 (Group 2) with microsurgical anastomosis of HA. Both groups were comparable in terms of arterial and biliary anastomoses performed. Incidence of early HA thrombosis was similar (6.2% vs 2.1%, P = .28). Group 2 had lower incidence of short- and long-term arterial complications, especially amongst living donor liver transplantations (LDLT) (5.3% vs 35.0%, P = .022). On multivariate analysis, microsurgery was associated with lower risk (hazard ratio [HR] 0.09, 95% confidence interval [CI] 0.01-0.71) of, and LDLT had higher risk (HR 4.23, 95% CI 1.46-12.27) of arterial complications. Biliary complications were associated with LDLT (HR 3.91, 95% CI 1.30-11.71) and dual biliary anastomoses (HR 5.26, 95% CI 1.15-24.08) but not with occurrence of HA complications. Worse patient survival was associated with the occurrence of any HA complication (HR 4.11, 95% CI 1.78-9.48). Hepatic arterial complications can be reduced using microsurgical techniques for the anastomosis, resulting in improved patient survival outcomes after liver transplantation.

Although numerous long non-coding RNAs (lncRNAs) were reported to be deregulated in Hepatocellular Carcinoma (HCC), experimentally characterized, and/or associated with patient's clinical characteristics, there is, thus far, minimal concerted research strategy to identify deregulated lncRNAs that modulate prognosis of HCC patients. Here, we present a novel strategy where we identify lncRNAs, which are not only de-regulated in HCC patients, but are also associated with pertinent clinical characteristics, potentially contributing to the prognosis of HCC patients. LOC101926913 (LOC) was further characterized because it is the most highly differentially expressed amongst those that are associated with the most number of clinical features (tumor-stage, vascular and tumor invasion and poorer overall survival). Experimental gain- and loss-of-function manipulation of LOC in liver cell-lines highlight LOC as a potential onco-lncRNA promoting cell proliferation, anchorage independent growth and invasion. LOC expression in cells up-regulated genes involved in GTPase-activities and downregulated genes associated with cellular detoxification, oxygen- and drug-transport. Hence, LOC may represent a novel therapeutic target, modulating prognosis of HCC patients through up-regulating GTPase-activities and down-regulating detoxification, oxygen- and drug-transport. This strategy may thus be useful for the identification of clinically relevant lncRNAs as potential biomarkers/targets that modulate prognosis in other cancers as well.

Objective To establish consensus recommendations for the use of fluorescence imaging with indocyanine green (ICG) in hepatobiliary surgery. Background ICG fluorescence imaging has gained popularity in hepatobiliary surgery in recent years. However, there is varied evidence on the use, dosage, and timing of administration of ICG in clinical practice. To standardize the use of this imaging modality in hepatobiliary surgery, a panel of pioneering experts from the Asia-Pacific region sought to establish a set of consensus recommendations by consolidating the available evidence and clinical experiences. Methods A total of 13 surgeons experienced in hepatobiliary surgery and/or minimally invasive surgery formed an expert consensus panel in Shanghai, China in October 2018. By the modified Delphi method, they presented the relevant evidence, discussed clinical experiences, and derived consensus statements on the use of ICG in hepatobiliary surgery. Each statement was discussed and modified until a unanimous consensus was achieved. Results A total of 7 recommendations for the clinical applications of ICG in hepatobiliary surgery were formulated. Conclusions The Shanghai consensus recommendations offer practical tips and techniques to augment the safety and technical feasibility of ICG fluorescence-guided hepatobiliary surgery, including laparoscopic cholecystectomy, liver segmentectomy, and liver transplantation.

The impact of liver cirrhosis on the difficulty of minimal invasive liver resection (MILR) remains controversial and current difficulty scoring systems do not take in to account the presence of cirrhosis as a significant factor in determining the difficulty of MILR. We hypothesized that the difficulty of MILR is affected by the presence of cirrhosis. Hence, we performed a 1:1 matched-controlled study comparing the outcomes between patients undergoing MILR with and without cirrhosis including the Iwate system and Institut Mutualiste Montsouris (IMM) system in the matching process. Between 2006 and 2019, 598 consecutive patients underwent MILR of which 536 met the study inclusion criteria. There were 148 patients with cirrhosis and 388 non-cirrhotics. One-to-one coarsened exact matching identified approximately exact matches between 100 cirrhotic patients and 100 non-cirrhotic patients. Comparison between MILR patients with cirrhosis and non-cirrhosis in the entire cohort demonstrated that patients with cirrhosis were associated with a significantly increased open conversion rate, transfusion rate, need for Pringles maneuver, postoperative, stay, postoperative morbidity and postoperative 90-day mortality. After 1:1 coarsened exact matching, MILR with cirrhosis were significantly associated with an increased open conversion rate (15% vs 6%, p = 0.03), operation time (261 vs 238 min, p

Objective Novel hepatoprotective strategies are needed to improve clinical outcomes during liver surgery. There is mixed data on the role of remote ischemic preconditioning (RIPC). We investigated RIPC in partial hepatectomy for primary hepatocellular carcinoma (HCC). Methods This was a Phase II, single-center, sham-controlled, randomized controlled trial (RCT). The primary hypothesis was that RIPC would reduce acute liver injury following surgery indicated by serum alanine transferase (ALT) 24 h following hepatectomy in patients with primary HCC, compared to sham. Patients were randomized to receive either four cycles of 5 min/5 min arm cuff inflation/deflation immediately prior to surgery, or sham. Secondary endpoints included clinical, biochemical and pathological outcomes. Liver function measured by Indocyanine Green pulse densitometry was performed in a subset of patients. Results 24 and 26 patients were randomized to RIPC and control groups respectively. The groups were balanced for baseline characteristics, except the duration of operation was longer in the RIPC group. Median ALT at 24 h was similar between groups (196 IU/L IQR 113.5–419.5 versus 172.5 IU/L IQR 115–298 respectively, p = 0.61). Groups were similar in secondary endpoints. Conclusion This RCT did not demonstrate beneficial effects with RIPC on serum ALT levels 24 h after partial hepatectomy.

Although hepatectomy is the mainstay of curative therapy for hepatocellular carcinoma (HCC), post-operative complications remain high. Presently there is conflicting data on the impact of morbidity on oncologic outcomes. We sought to identify predictors for the occurrence of post-hepatectomy complications, as well as to analyse the impact on overall survival (OS) and recurrence-free survival (RFS).We performed a retrospective review of 888 patients who underwent resection for HCC from 2001 to 2016 in our institution.A total of 237 patients (26.7%) developed 254 complications of Clavien-Dindo Grade ≥2. Hepatitis B (p = 0.0397), elevated ASA score (p = 0.0002), higher platelet counts (p = 0.0277), raised pre-operative APRI scores (p = 0.0105) and bloodloss (p 0.0001) were independently associated with the development of complications. After propensity-score matching, 458 patients were compared in a 1:1 ratio (229 with complications versus 229 without). Patients with complications had significantly longer median length of stay (9 days [IQR 7-15] versus 6 days [IQR 5-8], p 0.0001), higher 90-day mortality rates as well as inferior OS (p = 0.0139), but there was no difference in RFS (p = 0.4577). Age (p = 0.0006), elevated Child Pugh points (p 0.0001), microvascular invasion (p = 0.0002), multifocal tumours (p = 0.0002), R1 resection (p = 0.0443) and development of complications (p = 0.0091) were independent predictors of inferior OS.Post-operative morbidity affected both short-term and OS outcomes after hepatectomy for HCC. Hepatitis B, higher ASA scores, elevated preoperative APRI and increased blood loss were found to predict a higher likelihood of developing complications. This may potentially be mitigated by careful patient selection and adopting strict measures to minimise intraoperative bleeding.

Backgrounds/aims This study aims to describe our experience with minimally-invasive distal pancreatectomies, with emphasis on the comparison between robotic distal pancreatectomy (RDP) and laparoscopic distal pancreatectomy (LDP). Methods Retrospective review of 102 consecutive RDP and LDP from 2006 to 2019 was performed. Results There were 27 and 75 patients who underwent RDP and LDP, respectively. There were 12 (11.8%) open conversions and 16 (15.7%) patients had major (＞grade 2) morbidities. Patients who underwent RDP had significantly higher rates of splenic preservation (44.4% vs. 13.3%, p=0.002), higher rates of splenic-vessel preservation (40.7% vs. 9.3%, p=0.001), higher median difficulty score (5 vs. 3, p=0.002) but longer operation time (385 vs. 245 minutes, p＜0.001). The rate of open conversion tended to be lower with RDP (3.7% vs. 14.7%, p=0.175). Conclusions In our institution practice, both RDP and LDP were safe and effective. The use of RDP appeared to be complementary to LDP, allowing us to perform more difficult procedures with comparable postoperative outcomes.

Liver resection (LR) is the main modality of treatment for hepatocellular carcinoma (HCC) and colorectal liver metastasis (CRLM). Post-hepatectomy liver failure (PHLF) remains the most dreaded complication. We aim to create a prognostic score for early risk stratification of patients undergoing LR. Clinical and operative data of 472 patients between 2000 and 2016 with HCC or CRLM undergoing major hepatectomy were extracted and analysed from a prospectively maintained database. PHLF was defined using the 50–50 criteria. Liver cirrhosis and fatty liver were histologically confirmed in 35.6% and 53% of patients. 4.7% (n = 22) of patients had PHLF. A 90-day mortality was 5.1% (n = 24). Pre-operative albumin–bilirubin score (p = 0.0385), prothrombin time (p 7 and International Study Group for Liver Surgery criteria, intensive care unit admissions, length of stay, all complications, major complications, re-admissions and mortality (p

BACKGROUND Controversy exists regarding the safety and feasibility of minimally invasive resection for lesions in segments 7 or 8. We compare outcomes of minimally invasive surgery (MIS) and Open parenchymal sparing liver resections at two high-volume centers. METHODS From 2003 to 2016 we identified patients who underwent MIS or Open resections for lesions in segments 7 or 8 at two institutions (MSKCC and SGH). Outcomes were compared using univariate and multivariate analyses. RESULTS Two-hundred and forty-five patients underwent resection of lesions in segments 7 or 8 (MIS 30% and Open 70%). Compared to the Open group, the MIS group had longer operative time (223 ± 88 vs 188 ± 72 minutes, P = .003), lower blood loss (297 ± 287 vs 448 ± 670 mL, P = .03), and shorter mean length of stay (5.2 ± 7.4 vs 8.3 ± 11.7 days, P

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are the most common primary liver cancers. With the increasing incidence of ICC over the past two decades in Asia, it is essential to differentiate between HCC and ICC. However, ICC may mimic the radiological appearance of HCC on computed tomography scans (CT) and magnetic resonance imaging (MRI), leading to misdiagnosis of ICC. The objective of this study is to evaluate and describe the association of specific pre-operative imaging characteristics (arterial enhancement, portal venous washout) in patients with histologically proven resected ICC in our centre. Data on patients with histology-proven ICC and mixed hepatocellular-cholangiocarcinomas (HCC-CC) who had undergone surgical resection at Singapore General Hospital (SGH) were identified from a prospectively maintained database. Pre-operative cross-sectional imaging reports were analysed. Ninety-one patients underwent resection between 1 January 2000 and 31 December 2016. Among those with no risk factors for HCC, a significant percentage of patients with ICC (24.3%) show imaging characteristics of both arterial phase hyperenhancement and non-peripheral venous washout. Among patients with risk factors for HCC, between 20.0 and 33.3% of patients with pure ICC fulfilled the imaging criteria for HCC, and this proportion was generally even higher in the mixed HCC-CC group. A significant proportion of patients with pure ICC showed pre-operative imaging characteristics which fulfilled the diagnostic criteria for HCC. The differential of ICC should be borne in mind in populations where both malignancies are endemic.

Long non-coding RNAs (lncRNAs) are often aberrantly expressed in Hepatocellular Carcinoma (HCC). We hypothesize that lncRNAs modulate HCC prognoses through differential deregulation of key lncRNAs affecting important gene network in key cancer pathways associated with pertinent clinical phenotype. Here, we present a novel approach integrating lncRNA-mRNA expression profiles with clinical characteristics to identify lncRNA signatures in clinically-relevant co-expression lncRNA-mRNA networks residing in pertinent cancer pathways. Notably one network, associated with poorer prognosis, comprises five up-regulated lncRNAs significantly correlated (|Pearson Correlation Coefficient|≥ 0.9) with 91 up-regulated genes in the cell-cycle and Rho-GTPase pathways. All 5 lncRNAs and 85/91 (93.4%) of the correlated genes were significantly associated with higher tumor-grade while 3/5 lncRNAs were also associated with no tumor capsule. Interestingly, 2/5 lncRNAs that are correlated with numerous genes in this oncogenic network were experimentally shown to up-regulate genes involved in cell-cycle and transcriptional regulation. Another network comprising 4 down-regulated lncRNAs and 8 down-regulated metallothionein-family genes are significantly associated with tumor invasion. The identification of these key lncRNAs signatures that deregulate important network of genes in key cancer pathways associated with pertinent clinical phenotype may facilitate the design of novel therapeutic strategies targeting these ‘master’ regulators for better patient outcome.

Pancreatic neuroendocrine neoplasms (PNENs) are increasingly prevalent with modern imaging, and surgical excision remains mainstay of treatment. This study aims to perform a propensity-score-matched (PSM) comparison of perioperative and oncologic outcomes following minimally invasive pancreatectomy (MIP) versus open pancreatectomy (OP) for PNEN. A retrospective review was performed on patients who underwent curative-intent surgery for PNEN at Singapore General Hospital from 1997 to 2018. A 1:1 PSM was performed between MIP and OP, after which both groups were balanced for baseline variables. We studied 134 patients who underwent surgery (36 MIP and 98 OP) for PNEN. Propensity-score-matched comparison between 35 MIP and 35 OP patients revealed that the MIP group had a longer operating time (MD = 75.0, 95% CI 15.2 to 134.8, P = 0.015), lower intraoperative blood loss (MD = − 400.0, 95% CI − 630.5 to − 169.5, P = 0.001), shorter median postoperative stay (MD = − 1.0, 95% CI − 1.9 to − 0.1, P = 0.029) and shorter median time to diet (MD = − 1.0, 95% CI − 1.9 to − 0.1, P = 0.039). There were no differences between both groups for short-term adverse outcomes and oncologic clearance. Overall survival (HR = 0.84, 95% CI 0.28 to 2.51, P = 0.761) and disease-free survival (HR = 0.57, 95% CI 0.20 to 1.64, P = 0.296) were comparable. MIP is a safe and feasible approach for PNEN and is associated with a lower intraoperative blood loss, decreased postoperative stay and time to oral intake, at the expense of a longer operative time compared to OP.

Introduction: This study aims to evaluate the impact of first assistant surgeon experience on the outcomes of laparoscopic hepatectomies in a university-affiliated teaching hospital. Methods: This ...

Background The evidence is conflicting regarding the effect of delays from the time of diagnosis to surgery on the survival in patients with hepatocellular carcinoma. We sought to investigate the impact of time to surgery on overall survival for patients who underwent curative resection for primary hepatocellular carcinoma. Methods We performed a retrospective review of all patients who underwent liver resection for primary hepatocellular carcinoma between the years 2000 and 2015. Using 30-, 60-, and 90-day cutoffs, we investigated the effect of time to surgery on survival outcomes by dichotomizing the patients and using inverse probability of treatment weighting to ensure comparability. We also investigated time to surgery in prognostic subgroups by modeling the statistical interaction between time to surgery and the relevant prognostic variable in multivariable Cox models. Results A total of 863 patients underwent liver resection for primary hepatocellular carcinoma during the study period. Using 30-, 60-, and 90-day cutoffs, time to surgery did not have a significant bearing on overall survival. For elderly patients (>70 years), patients with Child-Pugh B liver disease, American Society of Anesthesiologists status 2/3, tumor size >5cm, tumor size ≥10cm and presence of extrahepatic invasion, hazard ratio decreased and overall survival improved as time to surgery increased. However, for patients with liver cirrhosis or portal hypertension, increasing time to surgery was found to portend higher risks of death. Conclusion Time to surgery does not have a significant bearing on overall survival, and modest delays even appear to be associated with improved survival in specific subsets of patients. The importance of these findings is that patients with hepatocellular carcinoma should be fully optimized before and not rushed to surgery because of concerns of tumor progression and a diminished survival.

Repeat liver resection (RLR) for recurrent HCC (rHCC) is a widely accepted treatment modality. However, early recurrence rate is high, frequently resulting in futile resection. We performed this study to evaluate preoperative factors, including the value of inflammatory indices, in predicting early (1 year) recurrence in patients who underwent RLR for rHCC. This may help clinicians better select patients for RLR, while excluding cases in which RLR for rHCC would likely be futile.This is a retrospective study of 80 patients where 90 operative cases of RLR and 84 cases of early recurrence (1 year) post-RLR were evaluated. Preoperative predictors of early recurrence and overall survival (OS) were assessed.There were 31 (34.4%) early recurrences with a 5-year OS of 38.9%. Elevated platelet-to-lymphocyte ratio (PLR)103.6 was a significant independent preoperative predictor of both early recurrence, relative risk (RR) 4.284 (P = 0.001) and OS, RR 2.139 (P = 0.027), while alphafetoprotein (AFP) ≥ 200 was a significant independent preoperative predictor of early recurrence only, RR 11.655 (P = 0.030). Patients were followed-up at a median of 14.3 months with 54.8% developing intrahepatic recurrences and 19.4% developing extrahepatic recurrences.Both, elevated PLR and AFP ≥ 200 were independent predictors of early (1 year) recurrence after RLR for rHCC, while only an elevated PLR was an independent preoperative prognosticators of overall survival. Indication for RLR should be carefully discussed in patients with relapsed HCC with an elevated PLR, due to the potential of early recurrence and poor overall survival.

Intra-tumor heterogeneity (ITH) is a key challenge in cancer treatment, but previous studies have focused mainly on the genomic alterations without exploring phenotypic (transcriptomic and immune) heterogeneity. Using one of the largest prospective surgical cohorts for hepatocellular carcinoma (HCC) with multi-region sampling, we sequenced whole genomes and paired transcriptomes from 67 HCC patients (331 samples). We found that while genomic ITH was rather constant across stages, phenotypic ITH had a very different trajectory and quickly diversified in stage II patients. Most strikingly, 30% of patients were found to contain more than one transcriptomic subtype within a single tumor. Such phenotypic ITH was found to be much more informative in predicting patient survival than genomic ITH and explains the poor efficacy of single-target systemic therapies in HCC. Taken together, we not only revealed an unprecedentedly dynamic landscape of phenotypic heterogeneity in HCC, but also highlighted the importance of studying phenotypic evolution across cancer types. National Medical Research Council (NMRC) National Research Foundation (NRF) Published version This work is supported in part by the Singapore National Medical Research Council grants (TCR/015-NCC/2016, CIRG18may-0057l, NMRC/CSA-SI/0018/2017, and NMRC/ OFIRG/0064/2017) and the National Research Foundation, Singapore (NRF-NRFF2015-04). W.Z. is supported in part by the National Key R&D Program of China (2018YFC1406902 and 2018YFC0910400), the National Natural Science Foundation of China (31970566), and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDPB17). H.Y. is supported by the National Natural Science Foundation of China (32000407).

Introduction This study aimed to compare the perioperative outcomes of patients who underwent minimally invasive spleen-preserving distal pancreatectomy (MI-SPDP) versus open surgery SPDP (O-SPDP). It also aimed to determine the long-term vascular patency after spleen-saving vessel-preserving distal pancreatectomies (SSVDPs). Methods A retrospective review of 74 patients who underwent successful SPDP and met the study criteria was performed. Of these, 67 (90.5%) patients underwent SSVDP, of which 38 patients (21 open, 17 MIS) had adequate long-term post-operative follow-up imaging to determine vascular patency. Results Fifty-one patients underwent open SPDP, whereas 23 patients underwent minimally invasive SPDP, out of which 10 (43.5%) were laparoscopic and 13 (56.5%) were robotic. Patients who underwent MI-SPDP had significantly longer operative time (307.5 vs. 162.5 min, P = 0.001) but shorter hospital stay (5 vs. 7 days, P = 0.021) and lower median blood loss (100 vs. 200 cc, P = 0.046) compared to that of O-SPDP. Minimally-invasive spleen-saving vessel-preserving distal pancreatectomy (MI-SSVDP) was associated with poorer long-term splenic vein patency rates compared to O-SSVDP (P = 0.048). This was particularly with respect to partial occlusion of the splenic vein, and there was no significant difference between the complete splenic vein occlusion rates between the MIS group and open group (29.4% vs. 28.6%, P = 0.954). The operative time was statistically significantly longer in patients who underwent robotic surgery versus laparoscopic surgery (330 vs. 173 min, P = 0.008). Conclusion Adoption of MI-spleen-preserving distal pancreatectomy (SPDP) is safe and feasible. MI-SPDP is associated with a shorter hospital stay, lower blood loss but longer operation time compared to O-SPDP. In the present study, MI-SSVDP was associated with poorer long-term splenic vein patency rates compared to O-SSVDP.

Background: Postoperative pancreatic fistula (POPF) is the most common and important cause of morbidity after distal pancreatectomy. Various transection and closure techniques of the pancreatic stu...

The clinical relevance of immune landscape intratumoural heterogeneity (immune-ITH) and its role in tumour evolution remain largely unexplored. Here, we uncover significant spatial and phenotypic immune-ITH from multiple tumour sectors and decipher its relationship with tumour evolution and disease progression in hepatocellular carcinomas (HCC). Immune-ITH is associated with tumour transcriptomic-ITH, mutational burden and distinct immune microenvironments. Tumours with low immune-ITH experience higher immunoselective pressure and escape via loss of heterozygosity in human leukocyte antigens and immunoediting. Instead, the tumours with high immune-ITH evolve to a more immunosuppressive/exhausted microenvironment. This gradient of immune pressure along with immune-ITH represents a hallmark of tumour evolution, which is closely linked to the transcriptome-immune networks contributing to disease progression and immune inactivation. Remarkably, high immune-ITH and its transcriptomic signature are predictive for worse clinical outcome in HCC patients. This in-depth investigation of ITH provides evidence on tumour-immune co-evolution along HCC progression., Intratumoural heterogeneity is a feature of liver cancer. Here, the authors demonstrate that heterogeneity exists at the immune cell level in liver cancer and show that tumours with high intratumoural immune heterogeneity demonstrated an immune suppressive microenvironment, which was associated with tumour evolution and a poor prognosis.

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with high rates of recurrence post-resection. Repeat hepatectomy (RH) and radiofrequency ablation (RFA) are the mainstays for managing recurrent HCC following initial curative resection. This retrospective study aims to determine the average treatment effect of RH and RFA in patients with recurrent HCC.From 2000 to 2016, a total of 219 consecutive patients with recurrent HCC who underwent either RH or RFA were included in the study. The analysis was performed using inverse probability of treatment weighting (IPTW), and propensity score-matched (PSM) methods.The minor and major post-operative morbidity after propensity score-matched analysis for the RH group was 30.0% and 6.0%, respectively, and 19.2% and 0.0% (p = 0.1006), respectively, for the RFA group. After propensity score matching, the median OS for RH and RFA was 85.5 (IQR, 33.5-not reached) and 53.3 months (IQR, 27.5-not reached) (p = 0.8474), respectively. There was no significant difference in 90-day mortality between both groups (p = 0.1287). RH showed improved long-term overall survival over RFA at the third [71.3% versus 65.7% (p = 0.0432)], fifth [59.9% versus 45.4% (p = 0.0271)] and tenth [35.4% versus 32.2% (p = 0.0132)] year follow-up, respectively. Median time to recurrence was 11.1 (IQR, 5.0-33.2) and 28.0 months (IQR, 9.1-not reached) (p = 0.0225) for the RFA and RH group, respectively.RH confers a late survival benefit compared with RFA for patients with recurrent HCC despite a higher morbidity rate.

Background: Resection of colorectal liver metastases (CLM) has been established as the standard of care. This study aims to compare the change in clinicopathological characteristics of patients who underwent curative resection of CLM across two time periods – 2000 to 2010 (T1) and 2011 to 2016 (T2) and evaluate the prognostic impact of these characteristics on survival outcomes. Methods: Patients who undergo liver resection for CLM at Singapore General Hospital from January 2000 to December 2016 were identified from a prospectively maintained database. The primary end point was overall survival. ResultsThere were 183/318 (57.5%) patients and 135 /318 (42.5%) patients in T1 and T2 respectively. There was a lower proportion of patients who had nodal metastases from primary colorectal cancer and clinical risk score (CRS) less than 3 in T2 when compared to T1. There was no difference in survival between both time periods (HR 0.850 95% CI 0.601 – 1.201 p = 0.357). Independent predictors of survival for the cohort were CEA levels ≥200ng/ml, primary tumour grade and lymph nodal status. Independent predictors of poor survival in T1 were poorly differentiated colorectal cancer and nodal metastases while in T2, independent predictors of poor survival were multiple liver metastases and nodal metastases.Conclusion: Nodal metastases from primary colorectal cancer is an independent predictor of poor survival across time for resectable CLM. Although there is no difference in survival between the two time periods, patients with multiple liver metastases should be carefully considered prior to surgery as it is also an independent predictor of overall survival.

BACKGROUND Presently, there are limited studies analyzing the learning experience of minimally invasive distal pancreatectomies (MIDPs) and these frequently focused on a single surgeon or institution learning curve. This study aims to critically analyze the impact of individual surgeon experience on the outcomes of MIDP based on the collective experiences of multiple surgeons at a single institution. METHODS A retrospective review of 90 consecutive MIDP from 2006 to 2018 was performed. These cases were performed by 13 surgeons over various time periods. The cohort was stratified into 4 groups according to individual surgeon experience. The case experience of these surgeons was as follows

The impact of liver cirrhosis on the difficulty of minimal invasive liver resection (MILR) remains controversial and current difficulty scoring systems do not take in to account the presence of cirrhosis as a significant factor in determining the difficulty of MILR. We hypothesized that the difficulty of MILR is affected by the presence of cirrhosis. Hence, we performed a 1:1 matched-controlled study comparing the outcomes between patients undergoing MILR with and without cirrhosis including the Iwate system and Institut Mutualiste Montsouris (IMM) system in the matching process.Between 2006 and 2019, 598 consecutive patients underwent MILR of which 536 met the study inclusion criteria. There were 148 patients with cirrhosis and 388 non-cirrhotics. One-to-one coarsened exact matching identified approximately exact matches between 100 cirrhotic patients and 100 non-cirrhotic patients.Comparison between MILR patients with cirrhosis and non-cirrhosis in the entire cohort demonstrated that patients with cirrhosis were associated with a significantly increased open conversion rate, transfusion rate, need for Pringles maneuver, postoperative, stay, postoperative morbidity and postoperative 90-day mortality. After 1:1 coarsened exact matching, MILR with cirrhosis were significantly associated with an increased open conversion rate (15% vs 6%, p = 0.03), operation time (261 vs 238 min, p 0.001), blood loss (607 vs 314 mls, p = 0.002), transfusion rate (22% vs 9%, p = 0.001), need for application of Pringles maneuver (51% vs 34%, p = 0.010), postoperative stay (6 vs 4.5 days, p = 0.004) and postoperative morbidity (26% vs 13%, p = 0.029).The presence of liver cirrhosis affected both the intraoperative technical difficulty and postoperative outcomes of MILR and hence should be considered an important parameter to be included in future difficulty scoring systems for MILR.

OBJECTIVE(S): The technical complexity of laparoscopic liver resection (LLR) poses unique challenges distinct from open surgery. An objective scoring system was developed that preoperatively quantifies the difficulty of LRR to help guide surgeon decision-making regarding the feasibility and safety of minimally-invasive approaches. The aim of this multi-institutional study was to externally validate this scoring system. METHODS: Patients who underwent LLR at 2 institutions were reviewed. LLR difficulty score (LDS) was calculated based on patient, tumor, and anatomic characteristics by 2 independent, blinded hepatobiliary surgeons. Surrogates of case complexity (e.g. conversion rate, operative time) were used for validation of this index. RESULTS: From 2006-2016, 444 LLR were scored as low (n=94), intermediate (n=98), and high difficulty (n=152) with respective conversion rates of 5.3%, 15.7%, and 25%. Cases of higher LDS correlated with larger mean blood loss (203 ml vs. 331 ml vs. 635 ml). Mean operative and Pringle maneuver used were associated with increasing LDS (155 min vs. 202 min vs. 315 min and 14.4% vs. 29.7% vs. 45.1% respectively). These operative surrogates of difficulty correlated significantly with the LDS. (all p

Background: Epidemiological evidence suggests there are differences in gastroenteropancreatic neuroendocrine neoplasm (GEPNEN) among population groups. We aimed to contribute to the current evidence by evaluating the clinicopathological characteristics of GEPNEN in a multi-ethnic Asian group. Materials and Methods: This was a retrospective chart review of patients diagnosed with GEPNEN at a tertiary medical institution at Singhealth Outram Campus, Singapore, between 1995 and 2015. Results: Two hundred ninety-five patients were included in the evaluation, comprising Chinese (74.6%), Malay (4.4%), Indian (9.5%) and other (11.5%) ethnic backgrounds. The median age at diagnosis was 59 years; 52.5% were males. Distribution of disease stage at diagnosis was: localised (42.4%), regional (15.3%) and distant (38.0%). The three most common primary tumour sites were located in the pancreas (38.6%), rectum (19.7%) and stomach (9.5%), which varied significantly with ethnic background and age at diagnosis. Malay patients were younger (median 42 years) at diagnosis than Chinese (60 years). Patients with an appendiceal neuroendocrine neoplasm (NEN) (48 years) were younger compared to oesophageal NEN (66 years). Disease stage correlated with primary tumour site and grade (p < 0.001). Median overall survival (OS) for all GEPNEN was 10.2 years. Age at diagnosis, disease stage and grading were prognostic factors of OS in multivariable analyses. Conclusion: Our findings correspond with other studies that focus on GEPNEN incidences in Asian countries, with the pancreas, rectum and stomach being the most common primary tumour sites. Our findings suggest racial differences in primary tumour site and age at diagnosis. Further prospective population-based registries are required to understand these epidemiological differences.

Several studies published mainly from pioneers and early adopters have documented the evolution of minimally invasive hepatectomy (MIH). However, questions remain if these reported experiences are applicable and reproducible today. This study examines the changing trends, safety, and outcomes associated with the adoption of MIH based on a contemporary single-institution experience. This is a retrospective review of 400 consecutive patients who underwent MIH between 2006 and 2017 of which 360 cases (90%) were performed since 2012. To determine the evolution of MIH, the study population was stratified into four equal groups of 100 patients. Analyses were also performed of predictive factors and outcomes of open conversion. Four hundred patients underwent MIH of which 379 (94.8%) were totally laparoscopic/robotic. Eighty-eight (22.0%) patients underwent major hepatectomy and 160 (40.0%) had resection of tumors located in the posterosuperior segments. There were 38 (9.5%) open conversions. Comparison across the four groups demonstrated that patients were older, had higher ASA score, and had increased frequency of previous abdominal surgery and repeat liver resections. There was also an increase in the proportion of patients who underwent totally laparoscopic/robotic surgery, major liver resection, resection of ≥ 3 segments, and multiple resections. Comparison of outcomes demonstrated that there was a significant decrease in open conversion rate, longer operation time, and increased use of Pringles maneuver. The presence of cirrhosis and institution experience (1st 100 cases) were independent predictors of open conversion. Patients who required open conversion had significantly increased operation time, blood loss, blood transfusion rate, morbidity, and mortality. The case volume of MIH performed increased rapidly at our institution over time. Although the indications of MIH expanded to include higher risk patients and more complex hepatectomies, there was a decrease in open conversion rate and no change in other perioperative outcomes.

BACKGROUND Presently, the worldwide experience with robotic pancreatic surgery (RPS) is increasing although widespread adoption remains limited. In this study, we report our initial experience with RPS. METHODS This is a retrospective review of a single institution prospective database of 72 consecutive robotic hepatopancreatobiliary surgeries performed between 2013 and 2017. Of these, 30 patients who underwent RPS were included in this study of which 25 were performed by a single surgeon. RESULTS The most common procedure was robotic distal pancreatectomy (RDP) which was performed in 20 patients. This included eight subtotal pancreatectomies, two extended pancreatecto-splenectomies (en bloc gastric resection) and 10 spleen-saving-RDP. Splenic preservation was successful in 10/11 attempted spleen-saving-RDP. Eight patients underwent pancreaticoduodenectomies (five hybrid with open reconstruction), one patient underwent a modified Puestow procedure and one enucleation of uncinate tumour. Four patients had extended resections including two RDP with gastric resection and two pancreaticoduodenectomies with vascular resection. There was one (3.3%) open conversion and seven (23.3%) major (>Grade II) morbidities. Overall, there were four (13.3%) clinically significant (Grade B) pancreatic fistulas of which three required percutaneous drainage. These occurred after three RDP and one robotic enucleation. There was one reoperation for port-site hernia and no 30-day/in-hospital mortalities. The median post-operative stay was 6.5 (range: 3-36) days and there were six (20%) 30-day readmissions. CONCLUSION Our initial experience showed that RPS can be adopted safely with a low open conversion rate for a wide variety of procedures including pancreaticoduodenectomy.

Background Presently, the adoption of laparoscopic hepatectomy is rapidly increasingly worldwide. However, the application of robotic hepatectomy (RH) remains limited and its role remains undefined today. Methods A retrospective review of 43 consecutive patients who underwent RH at two institutions in the Singapore Health Services Group. Results Forty-three consecutive patients underwent 48 resections during the study period. Seven (16.3%) patients underwent major resections and seven (16.3%) underwent right posterior sectionectomies. Nineteen (44.2%) patients had tumours located in the difficult posterosuperior segments, five had multiple resections and three underwent repeat resections for recurrent tumours. RH was performed for malignant tumours in 32 (74%) patients and 16 (37.2%) had cirrhosis. Seven RH was performed with other concomitant procedures including three colectomies, three hilar lymphadenectomies and one portal vein ligation. The median operation time was 360 min (range 75-825) and the median blood loss was 300 mL (range 25-4500). There was one (2.3%) open conversion for bleeding. The median post-operative stay was 4 days (range 2-33) and there was one (2.3%) readmission. There was one (2.3%) major (>grade 2 morbidity) in a patient with concomitant anterior resection who underwent reoperation for anastomotic leak. There was no 90 day/in-hospital mortality. Comparison between RH for tumours in the anterolateral segments versus posterosuperior segments demonstrated no significant difference in perioperative outcomes. Conclusion Our initial experience demonstrated that RH is safe, feasible and associated with excellent post-operative outcomes. It can be performed successfully with low morbidity even for complex resections such as major hepatectomies, posterior sectionectomies, tumours in difficult posterosuperior segments and repeat liver resections.

Introduction: This study aims to study the changing trends and outcomes associated with the adoption of minimally invasive distal pancreatectomy (MIDP) at a single centre. Materials and Methods: Retrospective review of sixty consecutive patients who underwent MIDP from September 2006 to November 2016 at a single institution. To study the evolution of MIDP, the study population was divided into three groups consisting of twenty patients (Group I, Group II and Group III). Results: Sixty patients underwent MIDP with 11 (18.3%) requiring open conversions. The median operation time was 305 (range: 85–775) min and the median post-operative stay was 6 (range: 3–73) days. Fifteen procedures were spleen-saving pancreatectomies. Major post-operative morbidity (>Grade 2) occurred in 12 (20.0%) patients and there was no mortality or reoperations. There were 33 (55.0%) pancreatic fistulas, of which 15 (25.0%) were Grade B fistulas of which 12 (20.0%) required percutaneous drainage. Comparison between the three groups demonstrated a statistically significant increase in the frequency of procedures performed, increase in robotic-assisted procedures and proportion of asymptomatic tumours resected. There also tended to be non-significant decrease in open conversion rates from 25% to 5% between the three groups and increase in tumour size resected from 24 to 40 mm. Conclusion: Comparison between the three groups demonstrated that MIDP was performed with increased frequency. There was a statistically significant increase in the frequency of resections performed for asymptomatic tumours and resections performed through robotic assistance. There was also a non-significant trend towards a decrease in open conversions and increase in the size of tumours resected.

Background The veracity of the proportional hazards (PH) requirement is rarely scrutinized in most areas of cancer research, although fulfilment of this assumption underpins widely-used Cox survival models. We sought to critically appraise the existence of prognostic factors with time-dependent effects and to characterize their impact on survival among CLM patients. Methods Consecutive patients who underwent liver resection with curative intent for CLM at the Singapore General Hospital were identified from a prospectively-maintained database. We evaluated PH of 55 candidate variables, and parameters which departed significantly from proportionality were included in Cox models that incorporated an interaction term to account for time-dependent effects. As sensitivity analyses, we fitted Weibull mixture ‘cure’ models to handle long plateaus in the tails of survival curves, and also analyzed the restricted mean survival time. Results 318 consecutive patients who underwent curative liver resection for CLM between Jan 2000 and Nov 2016 were included in this analysis. Hazard ratios for tumor grade (poorly-versus well- and moderately-differentiated) were found to decrease from 3.135 (95% CI: 1.637–6.003) at 12 months to 2.048 (95% CI: 1.038–4.042) after 24 months, and ceased to be significant at 26 months. Compared to left-sided tumors, a right-sided tumor location was found to portend worse prognosis for the first 10 months after resection but subsequently confer a survival benefit due to a crossing of survival curves. Corroborating this observation, long-term cure fractions were estimated to be 25.5% (95% CI: 17.4%–33.6%) and 34.2% (95% CI: 17.4%–50.9%) among patients with left-sided and right-sided primary disease respectively. Conclusion Primary tumor sidedness and grade appear to exert time-varying prognostic effects in CLM patients undergoing curative liver resection.

Background Recurrent pyogenic cholangitis (RPC) has a high risk of disease recurrence. We present our experience with RPC and examine the factors associated with disease recurrence. Methods We performed a retrospective review of all patients with RPC treated at two tertiary institutions between January 1990 and December 2013. Patients with liver atrophy and/or abscess were categorized as being associated with parenchymal disease (PD). Results We studied 157 patients with a median age of 59.0 (interquartile range (IQR): 47.0-70.0) years and a median follow-up duration of 71.0 (IQR: 26.0-109.0) months. There were 64 (40.8%) and 93 (59.2%) patients with and without associated PD, respectively. Disease recurrence rate was 43.9% in our overall cohort through the course of follow-up. Surgical treatment was an independent prognostic factor for decreased disease recurrence risk (hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.18-0.87, P = 0.021). Stratified analysis revealed that liver resection was prognostic for lower risk of disease recurrence among patients with PD (HR 0.38, 95% CI 0.15-0.94, P = 0.036), while biliary bypass was prognostic for lower risk of disease recurrence among patients without PD (HR 0.30, 95% CI 0.15-0.61, P = 0.001). The overall post-operative complication rate among surgically treated patients was 31.1%, and the presence of bilobar stones was found to be independently associated with higher odds of post-operative complications (odds ratio 3.51, 95% CI 1.26-9.81, P = 0.017). Conclusion Surgical treatment is associated with decreased recurrence risk in RPC, but with significant post-operative morbidity. Where surgery is deemed appropriate, patients with and without PD are likely to benefit from liver resection and biliary bypass, respectively.

Background: Mirizzi syndrome (MS) occurs when gallstone impaction in Hartmann’s pouch results in extrinsic obstruction of the common bile duct, and fistulation may occur. Methods: We retrospectively reviewed electronic records of patients surgically treated for MS from November 2001 to June 2012. Patient presentations, diagnostic methods, treatments and complications were recorded. Results: Sixty-four patients were grouped according to a classification proposed by Beltran et al. [World J Surg 2008; 32: 2237–2243]. Forty-three (66.2%), 18 (27.7%) and 3 (4.6%) patients were classified as types I, II, and III respectively. Magnetic-resonance-cholangiopancreaticography was the most sensitive imaging modality, suggesting MS in 24 (88.9%), followed by CT scan (40%) and ultrasonography (11.4%). Forty-four underwent Endoscopic-retrograde-cholangiopancreaticography and 29 (65.9%) suggested the presence of MS. MS was accurately diagnosed pre-operatively in 48 (73.8%) patients. In type I, 40 (93.0%) patients underwent cholecystectomy, while 3 required hepaticojejunostomy. In type II, 12 (66.7%) underwent cholecystectomy and 5 (27.8%) required hepatico-enteric anastomosis. In type III, 1 underwent cholecystectomy and 2 (66.7%) required hepatico-enteric anastomosis. Laparoscopic cholecystectomy was attempted in 20 (30.8%) patients and 13 (65.0%) required conversion. Twenty-nine (44.6%) underwent intra-operative-cholangioscopy, 30 (46.2%) underwent intra-operative-cholangiogram and 41 (63.1%) underwent intra-operative T-tube placement. Six (9.2%) experienced intra-operative complications, 12 (18.5%) experienced post-operative complications and 10 (15.4%) experienced late complications. Conclusion: MS is a challenging condition and multimodal diagnostic approach has the greatest yield in achieving accurate pre-operative diagnosis. If suspicion is high, a trial of laparoscopic dissection with low threshold for open conversion is recommended.

Most studies analyzing the learning experience of laparoscopic liver resection (LLR) focused on the experience of one or two expert pioneering surgeons. This study aims to critically analyze the impact of individual surgeon experience on the outcomes of LLR based on the contemporary collective experiences of multiple surgeons at single institution.Retrospective review of 324 consecutive LLR from 2006 to 2016. The cases were performed by 10 surgeons over various time periods. Four surgeons had individual experience with20 cases, four surgeons with 20-30 cases, and two surgeons with90 cases. The cohort was divided into two groups: comparing a surgeon's experience between the first 20, 30, 40, and 50 cases with patients treated thereafter. Similarly, we performed subset analyses for anterolateral lesions, posterosuperior lesions, and major hepatectomies.As individual surgeons gained increasing experience, this was significantly associated with older patients being operated, decreased hand-assistance, larger tumor size, increased liver resections, increased major resections, and increased resections of tumors located at the posterosuperior segments. This resulted in significantly longer operation time and increased use of Pringle maneuver but no difference in other outcomes. Analysis of LLR for tumors in the posterosuperior segments demonstrated that there was a significant decrease in conversion rates after a surgeon had experience with 20 LLR. For major hepatectomies, there was a significant decrease in morbidity, mortality, and length of stay after acquiring experience with 20 LLR.LLR can be safely adopted today especially for lesions in the anterolateral segments. LLR for lesions in the difficult posterosuperior segments and major hepatectomies especially in cirrhosis should only be attempted by surgeons who have acquired a minimum experience with 20 LLR.

BACKGROUND Totally laparoscopic major hepatectomy (LMH) is a technically challenging procedure with limited studies mainly from high-volume expert centers reported. In this study, we report our initial experience with totally LMH. METHODS A retrospective review of a prospective database of 340 consecutive patients who underwent laparoscopic liver resection at a single institution was conducted. Thirty-one consecutive patients who underwent attempted totally LMH between March 2011 to December 2016 were identified. Major hepatectomies were defined as resection of ≥3 contiguous segments which included only right/left hepatectomies, extended hepatectomies or central hepatectomies. RESULTS The procedures included 11 right hepatectomies, one extended right hepatectomy, nine left hepatectomies (two including middle hepatic vein), two extended left hepatectomies, two left hepatectomies with caudate lobe and six central hepatectomies. The median tumor size was 40 (range, 12-100) mm and the median operation time was 435 (range, 245-585) min. Median blood loss was 500 (range, 100-1900) mls and 10 (32.3%) patients required blood transfusion. There were three (9.7%) open conversions of which two occurred during the first five cases. There was one (3.2%) major (>grade 2) morbidity and there were no 30-day/in-hospital mortalities or reoperations. The median postoperative stay was 5 (range, 3-14) days. CONCLUSION Our initial experience confirms the feasibility and safety of LMH. There was an increase in the number and proportion of LMH performed at our institution over time.

Background This article aims to validate and compare the performance of 6 prognostication systems—the World Health Organization 2010 grading criteria, the European Neuroendocrine Tumour Society and the American Joint Committee for Cancer staging systems, the Memorial Sloan Kettering Cancer Center staging and grading systems, as well as the Bilimoria criteria in a cohort of patients with pancreatic neuroendocrine neoplasms at a single institution. Methods A retrospective review of 176 patients with histologically proven pancreatic neuroendocrine neoplasm was performed. The prognostic ability of the various prognostication systems for pancreatic neuroendocrine neoplasm was assessed by analyzing the homogeneity, discriminatory ability, monotonicity of gradient, and Akaike information criteria. Results The 5-year overall survival for the 176 patients was 69% and 5-year recurrence-free survival in 119 patients who underwent curative resection was 78%. Comparison between the 6 prognostication systems demonstrated that the World Health Organization 2010 system had the lowest Akaike information criteria score and was hence the best prognostication system in predicting overall survival and recurrence-free survival rates in our cohort of patients. The European Neuroendocrine Tumour Society was superior to the American Joint Committee for Cancer in prognosticating overall survival rates for pancreatic neuroendocrine neoplasms, as there was a statistically significant difference in overall survival across the different stages when stratified by the European Neuroendocrine Tumour Society, while the use of the American Joint Committee for Cancer was limited to distinguishing between patients in stages I and II versus stages III and IV only. Conclusion All 6 prognostication systems were useful in the prognostication of pancreatic neuroendocrine neoplasm. The World Health Organization 2010 grading system was the best prognostication system in predicting both overall survival in our entire cohort of patients and recurrence-free survival in the subset of patients who underwent curative resection.