A multimodal atlas of hepatocellular carcinoma reveals convergent evolutionary paths and 'bad apple' effect on clinical trajectory.

BACKGROUND & AIMS: Hepatocellular Carcinoma (HCC) is a highly fatal cancer characterized by high intra-tumor heterogeneity (ITH). A panoramic understanding of its tumor evolution, in relation to its clinical trajectory, may provide novel prognostic and treatment strategies. METHODS: Through the Asia-Pacific Hepatocellular Carcinoma (AHCC) trials group (NCT03267641), we recruited one of the largest prospective cohorts of HCC with over 600 whole genome and transcriptome samples from 123 treatment-naïve patients. RESULTS: Using a multi-region sampling approach, we revealed seven convergent genetic evolutionary paths governed by the early driver mutations, late copy number variations and viral integrations, which stratify patient clinical trajectories after surgical resection. Furthermore, such evolutionary paths shaped the molecular profiles, leading to distinct transcriptomic subtypes. Most significantly, although we found the coexistence of multiple transcriptomic subtypes within certain tumors, patient prognosis was best predicted by the most aggressive cell fraction of the tumor, rather than by overall degree of transcriptomic ITH level - a phenomenon we termed the 'bad apple' effect. Finally, we found that characteristics throughout early and late tumor evolution provide significant and complementary prognostic power in predicting patient survival. CONCLUSIONS: Taken together, our study generated a comprehensive landscape of evolutionary history for HCC and provided a rich multi-omics resource for understanding tumor heterogeneity and clinical trajectories. CLINICAL TRIAL NUMBER: NCT03267641 (Observational cohort) IMPACT AND IMPLICATIONS: This prospective study, utilizing comprehensive multi-sector, multi-omics sequencing and clinical data from surgically resected HCC, reveals critical insights into the role of tumor evolution and intra-tumor heterogeneity (ITH) in determining the prognosis of Hepatocellular Carcinoma (HCC). These findings are invaluable for oncology researchers and clinicians, as they underscore the influence of distinct evolutionary paths and the 'bad apple' effect, where the most aggressive tumor fraction dictates disease progression. These insights not only enhance prognostic accuracy post-surgical resection but also pave the way for developing personalized therapies tailored to specific tumor evolutionary and transcriptomic profiles. The co-existence of multiple sub-types within the same tumor prompts a re-appraisal of the utilities of depending on single samples to represent the entire tumor and suggests the need for clinical molecular imaging. This research thus marks a significant step forward in the clinical understanding and management of HCC, underscoring the importance of integrating tumor evolutionary dynamics and multi-omics biomarkers into therapeutic decision-making.

A genomic enhancer signature associates with hepatocellular carcinoma prognosis.

Background & Aims: Lifestyle and environmental-related exposures are important risk factors for hepatocellular carcinoma (HCC), suggesting that epigenetic dysregulation significantly underpins HCC. We profiled 30 surgically resected tumours and the matched adjacent normal tissues to understand the aberrant epigenetic events associated with HCC. Methods: We identified tumour differential enhancers and the associated genes by analysing H3K27 acetylation (H3K27ac) chromatin immunoprecipitation sequencing (ChIP-seq) and Hi-C/HiChIP data from the resected tumour samples of 30 patients with early-stage HCC. This epigenome dataset was analysed with previously reported genome and transcriptome data of the overlapping group of patients from the same cohort. We performed patient-specific differential expression testing using multiregion sequencing data to identify genes that undergo both enhancer and gene expression changes. Based on the genes selected, we identified two patient groups and performed a recurrence-free survival analysis. Results: We observed large-scale changes in the enhancer distribution between HCC tumours and the adjacent normal samples. Many of the gain-in-tumour enhancers showed corresponding upregulation of the associated genes and vice versa, but much of the enhancer and gene expression changes were patient-specific. A subset of the upregulated genes was activated in a subgroup of patients' tumours. Recurrence-free survival analysis revealed that the patients with a more robust upregulation of those genes showed a worse prognosis. Conclusions: We report the genomic enhancer signature associated with differential prognosis in HCC. Findings that cohere with oncofoetal reprogramming in HCC were underpinned by genome-wide enhancer rewiring. Our results present the epigenetic changes in HCC that offer the rational selection of epigenetic-driven gene targets for therapeutic intervention or disease prognostication in HCC. Impact and Implications: Lifestyle and environmental-related exposures are the important risk factors of hepatocellular carcinoma (HCC), suggesting that tumour-associated epigenetic dysregulations may significantly underpin HCC. We profiled tumour tissues and their matched normal from 30 patients with early-stage HCC to study the dysregulated epigenetic changes associated with HCC. By also analysing the patients' RNA-seq and clinical data, we found the signature genes - with epigenetic and transcriptomic dysregulation - associated with worse prognosis. Our findings suggest that systemic approaches are needed to consider the surrounding cellular environmental and epigenetic changes in HCC tumours.

Histone-lysine N-methyltransferase EHMT2 (G9a) inhibition mitigates tumorigenicity in Myc-driven liver cancer.

Hepatocellular carcinoma (HCC) is the third deadliest and sixth most common cancer in the world. Histone-lysine N-methyltransferase EHMT2 (also known as G9a) is a histone methyltransferase frequently overexpressed in many cancer types, including HCC. We showed that Myc-driven liver tumours have a unique H3K9 methylation pattern with corresponding G9a overexpression. This phenomenon of increased G9a was further observed in our c-Myc-positive HCC patient-derived xenografts. More importantly, we showed that HCC patients with higher c-Myc and G9a expression levels portend a poorer survival with lower median survival months. We demonstrated that c-Myc interacts with G9a in HCC and cooperates to regulate c-Myc-dependent gene repression. In addition, G9a stabilises c-Myc to promote cancer development, contributing to the growth and invasive capacity in HCC. Furthermore, combination therapy between G9a and synthetic-lethal target of c-Myc, CDK9, demonstrates strong efficacy in patient-derived avatars of Myc-driven HCC. Our work suggests that targeting G9a could prove to be a potential therapeutic avenue for Myc-driven liver cancer. This will increase our understanding of the underlying epigenetic mechanisms of aggressive tumour initiation and lead to improved therapeutic and diagnostic options for Myc-driven hepatic tumours.

Multi-region sampling with paired sample sequencing analyses reveals sub-groups of patients with novel patient-specific dysregulation in Hepatocellular Carcinoma.

BACKGROUND: Conventional differential expression (DE) testing compares the grouped mean value of tumour samples to the grouped mean value of the normal samples, and may miss out dysregulated genes in small subgroup of patients. This is especially so for highly heterogeneous cancer like Hepatocellular Carcinoma (HCC). METHODS: Using multi-region sampled RNA-seq data of 90 patients, we performed patient-specific differential expression testing, together with the patients' matched adjacent normal samples. RESULTS: Comparing the results from conventional DE analysis and patient-specific DE analyses, we show that the conventional DE analysis omits some genes due to high inter-individual variability present in both tumour and normal tissues. Dysregulated genes shared in small subgroup of patients were useful in stratifying patients, and presented differential prognosis. We also showed that the target genes of some of the current targeted agents used in HCC exhibited highly individualistic dysregulation pattern, which may explain the poor response rate. DISCUSSION/CONCLUSION: Our results highlight the importance of identifying patient-specific DE genes, with its potential to provide clinically valuable insights into patient subgroups for applications in precision medicine.

IFNγ-IL-17+ CD8 T cells contribute to immunosuppression and tumor progression in human hepatocellular carcinoma.

IL-17-producing CD8 (Tc17) T cells have been shown to play an important role in infection and chronic inflammation, however their implications in hepatocellular carcinoma (HCC) remain elusive. In this study, we performed cytometry by time-of-flight (CyTOF) and revealed the distinctive immunological phenotypes of two IFNγ+ and IFNγ- Tc17 subsets that were preferentially enriched in human HCC. Single-cell RNA-sequencing analysis further revealed regulatory circuits governing the different phenotypes of these Tc17 subsets. In particular, we discovered that IFNγ- Tc17 subset demonstrated pro-tumoral characteristics and expressed higher levels of CCL20. This corresponded to increased tumor infiltration of T regulatory cells (Treg) validated by immunohistochemistry in another independent HCC cohort, demonstrating the immunosuppressive functions of IFNγ- Tc17 subset. Most importantly, higher intra-tumoral proportions of IFNγ- Tc17 were associated with poorer prognosis in patients with HCC and this was further validated in The Cancer Genome Atlas (TCGA) HCC cohort. Taken together, this compendium of transcriptomic and proteomic data of Tc17 subsets sheds light on the immunosuppressive phenotypes of IFNγ- Tc17 and its implications in HCC progression.

Radiofrequency Ablation Versus Repeat Hepatectomy for Recurrent Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND: An updated systematic review and meta-analysis was conducted to compare radiofrequency ablation (RFA) versus repeat hepatectomy (RH) for patients with recurrent hepatocellular carcinoma (rHCC) after a previous liver resection. METHODS: PubMed, EMBASE, and Cochrane databases were searched from inception to October 2021 for randomized controlled trials and propensity-score matched studies. Individual participant survival data of disease-free survival (DFS) and overall survival (OS) were extracted and reconstructed followed by one-stage and two-stage meta-analysis. Secondary outcomes were major complications and length of hospital stay (LOHS). RESULTS: A total of seven studies (1317 patients) were analysed. In both one-stage and two-stage meta-analysis, there was no significant difference in OS between the RFA and RH cohorts (Hazard Ratio (HR) 1.15, 95% CI 0.98-1.36, P = 0.094 and HR 1.12, 95% CI 0.77-1.64, P = 0.474 respectively), while the RFA group had a higher hazard rate of disease recurrence compared to the RH group (HR 1.30, 95% CI 1.13-1.50, P < 0.001 and HR 1.31, 95% CI 1.09-1.57, P = 0.013, respectively). RFA was associated with fewer major complications and shorter LOHS versus RH (Odds Ratio 0.34, 95% CI 0.15-0.76, P = 0.009 and Weighted Mean Difference - 4.78, 95% CI - 6.30 to - 3.26, P < 0.001, respectively). CONCLUSIONS: RH may be associated with superior DFS for rHCC, at the expense of higher morbidity rate and longer LOHS. However, OS is comparable between both modalities. As such, these techniques may be utilized as complementary strategies depending on individual patient and disease factors. Large-scale, randomized, prospective studies are required to corroborate these findings.

Extending Surgical Resection for Hepatocellular Carcinoma Beyond Barcelona Clinic for Liver Cancer (BCLC) Stage A: A Novel Application of the Modified BCLC Staging System.

Objective: We aimed to prognosticate survival after surgical resection of HCC stratified by stage with amalgamation of the modified Barcelona Clinic Liver Cancer (BCLC) staging system and location of tumour. Methods: This single-institutional retrospective cohort study included patients with HCC who underwent surgical resection between 1st January 2000 to 30th June 2016. Participants were divided into 6 different subgroups: A-u) Within MC with Unilobar lesions; A-b) Within MC + Bilobar lesions; B1-u) Out of MC + within Up-To-7 + Unilobar lesions; B1-b) Out of MC + within Up-to-7 + Bilobar lesions; B2-u) Out of MC + Out of Up-To-7 + Unilobar lesions; B2-b) Out of MC + Out of Up-To-7 + Bilobar lesions. A separate survival analysis was conducted for solitary HCC lesions according to three subgroups: A-S (Within MC); B1-S (Out of MC + within Up-To-7); B2-S (Out of MC + out of Up-To-7). Results: A total of 794 of 1043 patients with surgical resection for HCC were analysed. Groups A-u (64.6%), A-b (58.4%) and B1-u (56.2%) had 5-year cumulative overall survival (OS) rates above 50% after surgical resection and median OS exceeding 60 months (P = 0.0001). The 5-year cumulative recurrence-free survival rates (RFS) were 40.4% (group A-u), 38.2% (group A-b), 36.3% (group B1-u), 24.6% (group B2-u), and 7.3% (group B2-b)(P=0.0001). For solitary lesions, the 5-year OS for the subgroups were A-S (65.1%), B1-S (56.0%) and B2-S (47.1%) (P = 0.0003). Compared to A-S, there was also a significant trend towards relatively poorer OS as the lesion sizes increased in B1-S (HR 1.46, 95% CI 1.03-2.08) and B2-S (HR 1.65, 95% CI 1.25-2.18). Conclusion: We adopted a novel approach combining the modified BCLC B sub-classification and dispersion of tumour to show that surgical resection in intermediate stage HCC can be robustly prognosticated. We found that size prognosticates resection outcomes in solitary tumours.

Defining the optimal time to appendectomy: A step toward precision surgery.

BACKGROUND: We aimed to investigate the association between time from admission to appendectomy on perioperative outcomes in order to determine optimal time-to-surgery windows. METHODS: We performed a retrospective review of all the appendectomies performed between July 2018 to May 2020. We first compared the perioperative outcomes using preselected time-to-surgery cut-offs, then determined optimal safe windows for surgery, and finally identified subgroups of patients who may require early intervention. RESULTS: Six hundred twenty-one appendectomies were performed in the time period. The patients with a time-to-surgery of ≥12 hours had a significantly longer length of stay (median 2 days [interquartile range 1-3] vs 3 days [interquartile range 2-4], mean difference = 0.74 [95% confidence interval 0.32-1.17, P = .0006]) and higher 30-day readmission risk (odds ratio 2.58, 95% confidence interval 1.12-5.96, P = .0266) versus those with a time-to-surgery of <12 hours. These differences persisted when the time-to-surgery was dichotomized by <24 or ≥24 hours. A time-to-surgery beyond 25 hours was associated with a 3.34-fold increased odds of open conversion (P = .040), longer operation time (mean difference 15.8 mins, 95% confidence interval 3.4-28.3, P = .013) and longer postoperative length of stay (mean difference 10.3 hours, 95% confidence interval 3.4-20.2, P = .042) versus a time-to-surgery of <25 hours. The patients with time-to-surgery beyond 11 hours had a 1.35-fold increased odds of 30-day readmission (95% confidence interval 1.02-5.43, P = .046) compared with those who underwent appendectomy before 11 hours. Older patients, patients with American Society of Anesthesiologist score II to III, and individuals with long duration of preadmission symptoms had higher risk of prolonged operation time, open conversion, increased length of stay, and postoperative morbidity with increasing time-to-surgery. CONCLUSION: This study identified the safe windows for appendectomy to be 11 to 25 hours from admission for most perioperative outcomes. However, certain patient subgroups may be less tolerant of surgical delays.

Dynamic phenotypic heterogeneity and the evolution of multiple RNA subtypes in hepatocellular carcinoma: the PLANET study.

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.

Trajectory of immune evasion and cancer progression in hepatocellular carcinoma.

Immune evasion is key to cancer initiation and later at metastasis, but its dynamics at intermediate stages, where potential therapeutic interventions could be applied, is undefined. Here we show, using multi-dimensional analyses of resected tumours, their adjacent non-tumour tissues and peripheral blood, that extensive immune remodelling takes place in patients with stage I to III hepatocellular carcinoma (HCC). We demonstrate the depletion of anti-tumoural immune subsets and accumulation of immunosuppressive or exhausted subsets along with reduced tumour infiltration of CD8 T cells peaking at stage II tumours. Corresponding transcriptomic modification occur in the genes related to antigen presentation, immune responses, and chemotaxis. The progressive immune evasion is validated in a murine model of HCC. Our results show evidence of ongoing tumour-immune co-evolution during HCC progression and offer insights into potential interventions to reverse, prevent or limit the progression of the disease.

Hypoxia-driven immunosuppression by Treg and type-2 conventional dendritic cells in HCC.

BACKGROUND AND AIMS: Hypoxia is one of the central players in shaping the immune context of the tumor microenvironment (TME). However, the complex interplay between immune cell infiltrates within the hypoxic TME of HCC remains to be elucidated. APPROACH AND RESULTS: We analyzed the immune landscapes of hypoxia-low and hypoxia-high tumor regions using cytometry by time of light, immunohistochemistry, and transcriptomic analyses. The mechanisms of immunosuppression in immune subsets of interest were further explored using in vitro hypoxia assays. Regulatory T cells (Tregs) and a number of immunosuppressive myeloid subsets, including M2 macrophages and human leukocyte antigen-DR isotype (HLA-DRlo ) type 2 conventional dendritic cell (cDC2), were found to be significantly enriched in hypoxia-high tumor regions. On the other hand, the abundance of active granzyme Bhi PD-1lo CD8+ T cells in hypoxia-low tumor regions implied a relatively active immune landscape compared with hypoxia-high regions. The up-regulation of cancer-associated genes in the tumor tissues and immunosuppressive genes in the tumor-infiltrating leukocytes supported a highly pro-tumorigenic network in hypoxic HCC. Chemokine genes such as CCL20 (C-C motif chemokine ligand 20) and CXCL5 (C-X-C motif chemokine ligand 5) were associated with recruitment of both Tregs and HLA-DRlo cDC2 to hypoxia-high microenvironments. The interaction between Tregs and cDC2 under a hypoxic TME resulted in a loss of antigen-presenting HLA-DR on cDC2. CONCLUSIONS: We uncovered the unique immunosuppressive landscapes and identified key immune subsets enriched in hypoxic HCC. In particular, we identified a potential Treg-mediated immunosuppression through interaction with a cDC2 subset in HCC that could be exploited for immunotherapies.

Outcomes of laparoscopic, robotic, and open pancreatoduodenectomy: A network meta-analysis of randomized controlled trials and propensity-score matched studies.

BACKGROUND: This network meta-analysis was performed to determine the optimal surgical approach for pancreatoduodenectomy by comparing outcomes after laparoscopic pancreatoduodenectomy, robotic pancreatoduodenectomy and open pancreatoduodenectomy. METHODS: A systematic search of the PubMed, EMBASE, Scopus, and Web of Science databases was conducted to identify eligible randomized controlled trials and propensity-score matched studies. RESULTS: Four randomized controlled trials and 23 propensity-score matched studies comprising a total of 4,945 patients were included for analysis. Operation time for open pancreatoduodenectomy was shorter than both laparoscopic pancreatoduodenectomy (mean difference -57.35, 95% CI 26.25-88.46 minutes) and robotic pancreatoduodenectomy (mean difference -91.08, 95% CI 48.61-133.56 minutes), blood loss for robotic pancreatoduodenectomy was significantly less than both laparoscopic pancreatoduodenectomy (mean difference -112.58, 95% CI 36.95-118.20 mL) and open pancreatoduodenectomy (mean difference -209.87, 95% CI 140.39-279.36 mL), both robotic pancreatoduodenectomy and laparoscopic pancreatoduodenectomy were associated with reduced rates of delayed gastric emptying compared with open pancreatoduodenectomy (odds ratio 0.59, 95% CI 0.39-0.90 and odds ratio 0.69, 95% CI 0.50-0.95, respectively), robotic pancreatoduodenectomy was associated with fewer wound infections compared with open pancreatoduodenectomy (odds ratio 0.35, 95% CI 0.18-0.71), and laparoscopic pancreatoduodenectomy patients enjoyed significantly shorter length of stay compared with open pancreatoduodenectomy (odds ratio 0.43, 95% CI 0.28-0.95). There were no differences in other outcomes. CONCLUSION: This network meta-analysis of high-quality studies suggests that when laparoscopic pancreatoduodenectomy and robotic pancreatoduodenectomy are performed in high-volume centers, short-term perioperative and oncologic outcomes are largely comparable, if not slightly improved, compared with traditional open pancreatoduodenectomy. These findings should be corroborated in further prospective randomized studies.

Continuous improvements in short and long-term outcomes after partial hepatectomy for hepatocellular carcinoma in the 21st century: Single institution experience with 1300 resections over 18 years.

INTRODUCTION: To investigate the changing trends in short- and long-term outcomes after partial hepatectomy(PH) for hepatocellular carcinoma(HCC) performed in the 21st century. METHODS: A retrospective review was conducted on 1300 consecutive patients who underwent PH for HCC. The study cohort was divided into 3 time periods(P): P1(2000-2005), P2(2006-2011) and P3(20012-2017). RESULTS: Comparison between the patients' baseline demographic features across the 3 periods demonstrated that patients were significantly older, had decreasing frequency of hepatitis B, increasing non-alcoholic fatty liver disease, lower alpha-feto protein(AFP) level, lower creatinine levels, less likely to undergo emergency surgery, less likely to undergo major hepatectomy, more likely to undergo repeat resection and minimally-invasive surgery. There was also an increase in operation time, decrease in blood loss, increase frequency in the use of Pringles manoeuvre, decrease liver failure, decrease length of stay and decrease postoperative mortality. HCC resected were of smaller size, less likely to demonstrate microvascular invasion and less likely to have close margins. This was associated with significant improvement in overall survival and recurrence free interval over time. Period of resection was an independent predictor of 90-day mortality and OS on multivariate analysis. CONCLUSION: We observed a continuous improvement in postoperative outcomes including postoperative mortality and long-term survival after PH for HCC over the past 18 years.

Resected pancreatic adenocarcinoma: An Asian institution's experience.

BACKGROUND: Pancreatic adenocarcinoma (PDAC) is highly lethal. Surgery offers the only chance of cure, but 5-year overall survival (OS) after surgical resection and adjuvant therapy remains dismal. Adjuvant trials were mostly conducted in the West enrolling fit patients. Applicability to a general population, especially Asia has not been described adequately. AIM: We aimed to evaluate the clinical outcomes, prognostic factors of survival, pattern, and timing of recurrence after curative resection in an Asian institution. METHODS AND RESULTS: The clinicopathologic and survival outcomes of 165 PDAC patients who underwent curative resection between 1998 and 2013 were reviewed retrospectively. Median age at surgery was 62.0 years. 55.2% were male, and 73.3% had tumors involving the head of pancreas. The median OS of the entire cohort was 19.7 months. Median OS of patients who received adjuvant chemotherapy was 23.8 months. Negative predictors of survival include lymph node ratio (LNR) of >0.3 (HR = 3.36, P = .001), tumor site involving the body or tail of pancreas (HR = 1.59, P = .046), presence of perineural invasion (PNI) (HR = 2.36, P = .018) and poorly differentiated/undifferentiated tumor grade (HR = 1.86, P = .058). The median time to recurrence was 8.87 months, with 66.1% and 81.2% of patients developing recurrence at 12 months and 24 months respectively. The most common site of recurrence was the liver. CONCLUSION: The survival of Asian patients with resected PDAC who received adjuvant chemotherapy is comparable to reported randomized trials. Clinical characteristics seem similar to Western patients. Hence, geographical locations may not be a necessary stratification factor in RCTs. Conversely, lymph node ratio and status of PNI ought to be incorporated.

Primary renal synovial sarcoma presenting with a retroperitoneal bleed.

Synovial sarcomas are most commonly localised in extremities, especially in the lower thigh and knee areas. Comprising less than 1% of all malignancies, retroperitoneal synovial sarcoma is very rare with primary synovial sarcoma of the kidney being even more infrequent and difficult to diagnose. We describe a case report of a renal synovial sarcoma in a young adult who was initially managed as a case of Wunderlich's syndrome secondary to what was believed to be a ruptured renal angiomyolipoma. After biopsy confirmation, the patient was eventually managed with neo-adjuvant chemotherapy followed by a right radical nephrectomy and right hepatectomy. Despite its rarity, synovial sarcoma should be considered as differential diagnosis of a bleeding retroperitoneal soft tissue mass detected in young adults.

Use of Reinforced Staplers Decreases the Rate of Postoperative Pancreatic Fistula Compared to Bare Staplers After Minimally Invasive Distal Pancreatectomies.

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 stump have been proposed with no robust evidence unanimously supporting one technique over the other. This study aims to compare the outcomes of minimally invasive distal pancreatectomy (MIDP) performed with reinforced stapler (RS) versus bare stapler (BS) with particular attention to the POPF. Methods: Retrospective review of 90 consecutive elective MIDP performed at a single institution between 2014 and 2019 was performed. The primary outcome was POPF as defined by the latest International Study Group of Pancreatic Fistula classification. MIDP with RS was adopted by two surgeons who subsequently performed all their consecutive surgeries with RS. Results: There were 25 and 65 patients who underwent MIDP with RS and BS, respectively. There were 8 (8.9%) open conversions and 17 (18.9%) patients experienced a POPF. Patients who underwent MIDP with RS had a significantly lower POPF rate (4% versus 24.6%, P = .025), lower major (>grade 2) morbidity rate (4% versus 21.5%, P = .046), and lower readmission rate (4% versus 27.7%, P = .014). On multivariate analysis, only the use of BS and obesity (body mass index ≥27.5) was independently associated with the development of a POPF. Conclusion: MIDP performed with RS was associated with a significantly lower rate of POPF, major morbidity, and readmissions compared to BS. The use of RS was protective against POPF.

Impact of liver cirrhosis on the difficulty of minimally-invasive liver resections: a 1:1 coarsened exact-matched controlled study.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.