Experience-based transition to robotic surgery in an experienced program in minimally invasive hepatobiliary surgery.

BACKGROUND: The adoption of robotic techniques in liver surgery introduces significant challenges for their safe integration within hepatobiliary surgery units. This study is designed to investigate the complexities associated with establishing a robotic surgery program. METHODS: Data on robotic hepatobiliary surgeries were prospectively collected from October 2021 to October 2023. Historical cohorts from the institutional experiences for comparison were hand-assisted (HALS) and purely laparoscopic procedures (PLS). Inverse probability of treatment weighting and propensity score matching were employed to compare outcomes between PLS and robotic resections. The learning curve for robotic surgeries was evaluated by the cumulative sum method. RESULTS: In this study, 454 patients were enrolled (113 robotic surgeries, 157 HALS, and 184 PLS). The posterosuperior segments resections were significantly higher in the robotic group (47.8%) compared to PLS (31.5%) and HALS (35.7%). There were no conversions in the robotic group, in PLS 2.7% and HALS 3.8%. The degree of difficulty according to the median of the IWATE score and IMM score was significantly higher in the robot group (p < 0.001 and p = 0.008, respectively). No significant differences in short-term outcomes were observed between robotic procedures and PLS in a matched subset of patients. Operative efficiency and blood loss improved significantly after the 75th robotic surgery patient, with high-difficulty cases (IWATE ≥ 10) incorporated from the beginning. CONCLUSION: This study suggests that robotic liver surgery in units with prior experience in minimally invasive liver surgery offers benefits, such as a lower conversion rate and a higher rate of successful difficult resections.

Propensity Score-matched Analysis Comparing Robotic Versus Laparoscopic Minor Liver Resections of the Anterolateral Segments: an International Multi-center Study of 10,517 Cases.

OBJECTIVE: To compare the outcomes of robotic minor liver resections (RMLR) versus laparoscopic (L) MLR of the anterolateral segments. BACKGROUND: Robotic liver surgery has been gaining prominence over the years with increasing usage for a myriad of hepatic resections. Robotic liver resections(RLR) has demonstrated non-inferiority to laparoscopic(L)LR while illustrating advantages over conventional laparoscopy especially for technically difficult and major LR. However, the advantage of RMLR for the anterolateral(AL) (segments II, III, IVb, V and VI) segments, has not been clearly demonstrated. METHODS: Between 2008 to 2022, 15,356 of 29,861 patients from 68 international centres underwent robotic(R) or laparoscopic minor liver resections (LMLR) for the AL segments Propensity score matching (PSM) analysis was performed for matched analysis. RESULTS: 10,517 patients met the study criteria of which 1,481 underwent RMLR and 9,036 underwent LMLR. A PSM cohort of 1,401 patients in each group were identified for analysis. Compared to the LMLR cohort, the RMLR cohort demonstrated significantly lower median blood loss (75ml vs. 100ml, P<0.001), decreased blood transfusion (3.1% vs. 5.4%, P=0.003), lower incidence of major morbidity (2.5% vs. 4.6%, P=0.004), lower proportion of open conversion (1.2% vs. 4.5%, P<0.001), shorter post operative stay (4 days vs. 5 days, P<0.001), but higher rate of 30-day readmission (3.5% vs. 2.1%, P=0.042). These results were then validated by a 1:2 PSM analysis. In the subset analysis for 3,614 patients with cirrhosis, RMLR showed lower median blood loss, decreased blood transfusion, lower open conversion and shorter post operative stay than LMLR. CONCLUSION: RMLR demonstrated statistically significant advantages over LMLR even for resections in the AL segments although most of the observed clinical differences were minimal.

The role of resection in hepatocellular carcinoma BCLC stage B: A multi-institutional patient-level meta-analysis and systematic review.

PURPOSE: The Barcelona Clinic Liver Cancer (BCLC) staging schema is widely used for hepatocellular carcinoma (HCC) treatment. In the updated recommendations, HCC BCLC stage B can become candidates for transplantation. In contrast, hepatectomy is currently not recommended. METHODS: This systematic review includes a multi-institutional meta-analysis of patient-level data. Survival, postoperative mortality, morbidity and patient selection criteria for liver resection and transplantation in BCLC stage B are explored. All clinical studies reporting HCC patients with BCLC stage B undergoing liver resection or transplantation were included. RESULTS: A total of 31 studies with 3163 patients were included. Patient level data was available for 580 patients from 9 studies (423 after resection and 157 after transplantation). The overall survival following resection was 50 months and recurrence-free survival was 15 months. Overall survival after transplantation was not reached and recurrence-free survival was 45 months. The major complication rate after resection was 0.11 (95%-CI, 0.0-0.17) with the 90-day mortality rate of 0.03 (95%-CI, 0.03-0.08). Child-Pugh A (93%), minor resection (60%), alpha protein level less than 400 (64%) were common in resected patients. Resected patients were mostly outside the Milan criteria (99%) with mean tumour number of 2.9. Studies reporting liver transplantation in BCLC stage B were scarce. CONCLUSION: Liver resection can be performed safely in selected patients with HCC BCLC stage B, particularly if patients present with preserved liver function. No conclusion can done on liver transplantation due to scarcity of reported studies.

Efficacy of Self-Expandable Absorbable Stents during Liver Transplant to Minimize Early Biliary Complications.

OBJECTIVE: We analyzed the use of a self-expandable absorbable biliary stent (SEABS) to reduce biliary complications in liver transplant (LT). BACKGROUND: Complications related to biliary anastomosis are a still a challenge in LT with a high impact on the patient outcomes and hospital costs. METHODS: This non-randomized prospective study was conducted between July 2019 and September 2023 in adult LT patients with duct-to-duct biliary anastomoses. The primary endpoint was to assess early biliary complications at 90 days in LT patients with intraoperative SEABS versus no SEABS. We also compared overall biliary complications, costs and SEABS- adverse effects related. RESULTS: A total of 158 patients were included, 78 with SEABS and 80 no-SEABS (22 T-tube and 58 no-stent). There were no adverse effects related to SEABS. Early biliary complications (23.8 vs 2.6%, P <0.001) and hospital stay (19 vs 15 days, P= 0.001) were higher in no-SEABS. No-SEABS group required 63 ERCPs and 13 surgeries (including 2 LT) versus 35 ERCPs and 2 surgeries in SEABS group. After PSM between SEABS (n=58) vs no-SEABS (n=58), early biliary complications (40% vs 0%, P<.001) were higher in no-SEABS group. T-tube had more early biliary complications (22.7% vs 5%, P=0.23) compared SEABS high-risk biliary anastomosis. SEABS excess cost per patient was lower compared to T-Tube and no-stent (6.988€ vs 17.992€ vs 36.364€, P=0.036 and P=0.002, respectively). CONCLUSIONS: SEABS during biliary anastomosis in LT is feasible with no adverse effects and avoid the T-tube in high-risk biliary anastomoses. It use has been associated with less early biliary complications, hospital costs and reoperations or interventional treatments for biliary complications resolution.

Harmonizing Definitions and Perspectives in Extreme Liver Surgery: A Delphi Experts Consensus.

OBJECTIVE: To propose to our community a common language about extreme liver surgery. BACKGROUND: The lack of a clear definition of extreme liver surgery prevents convincing comparisons of results among centers. METHODS: We used a two-round Delphi methodology to quantify consensus among liver surgery experts. For inclusion in the final recommendations, we established a consensus when the positive responses (agree and totally agree) exceeded 70%. The study steering group summarized and reported the recommendations. In general, a five-point Likert scale with a neutral central value was used, and in a few cases multiple choices. Results are displayed as numbers and percentages. RESULTS: A two-round Delphi study was completed by 38 expert surgeons in complex hepatobiliary surgery. The surgeon´s median age was 58 years old (52-63) and the median years of experience was 25 years (20-31). For the proposed definitions of total vascular occlusion, hepatic flow occlusion and inferior vein occlusion, the degree of agreement was 97%, 81% and 84%, respectively. In situ approach (64%) was the preferred, followed by ante situ (22%) and ex situ (14%). Autologous or cadaveric graft for hepatic artery or hepatic vein repair were the most recommended (89%). The use of veno-venous bypass or portocaval shunt revealed the divergence depending on the case. Overall, 75% of the experts agreed with the proposed definition for extreme liver surgery. CONCLUSION: Obtaining a consensus on the definition of extreme liver surgery is essential to guarantee the correct management of patients with highly complex hepatobiliary oncological disease. The management of candidates for extreme liver surgery involves comprehensive care ranging from adequate patient selection to the appropriate surgical strategy.

Defining Global Benchmarks for Laparoscopic Right Posterior Sectionectomy/H67: An International Multicenter Study.

OBJECTIVE: We aimed to establish global benchmark outcomes indicators for L-RPS/H67. BACKGROUND: Minimally invasive liver resections has seen an increase in uptake in recent years. Over time, challenging procedures as laparoscopic right posterior sectionectomies (L-RPS)/H67 are also increasingly adopted. METHODS: This is a post hoc analysis of a multicenter database of 854 patients undergoing minimally invasive RPS (MI-RPS) in 57 international centers in 4 continents between 2015 and 2021. There were 651 pure L-RPS and 160 robotic RPS (R-RPS). Sixteen outcome indicators of low-risk L-RPS cases were selected to establish benchmark cutoffs. The 75th percentile of individual center medians for a given outcome indicator was set as the benchmark cutoff. RESULTS: There were 573 L-RPS/H67 performed in 43 expert centers, of which 254 L-RPS/H67 (44.3%) cases qualified as low risk benchmark cases. The benchmark outcomes established for operation time, open conversion rate, blood loss ≥500 mL, blood transfusion rate, postoperative morbidity, major morbidity, 90-day mortality and textbook outcome after L-RPS were 350.8 minutes, 12.5%, 53.8%, 22.9%, 23.8%, 2.8%, 0% and 4% respectively. CONCLUSIONS: The present study established the first global benchmark values for L-RPS/H6/7. The benchmark provided an up-to-date reference of best achievable outcomes for surgical auditing and benchmarking.

Factors Associated with and Impact of Open Conversion in Laparoscopic and Robotic Minor Liver Resections: An International Multicenter Study of 10,541 Patients.

INTRODUCTION: Despite the increasing widespread adoption and experience in minimally invasive liver resections (MILR), open conversion occurs not uncommonly even with minor resections and as been reported to be associated with inferior outcomes. We aimed to identify risk factors for and outcomes of open conversion in patients undergoing minor hepatectomies. We also studied the impact of approach (laparoscopic or robotic) on outcomes. METHODS: This is a post-hoc analysis of 20,019 patients who underwent RLR and LLR across 50 international centers between 2004-2020. Risk factors for and perioperative outcomes of open conversion were analysed. Multivariate and propensity score-matched analysis were performed to control for confounding factors. RESULTS: Finally, 10,541 patients undergoing either laparoscopic (LLR; 89.1%) or robotic (RLR; 10.9%) minor liver resections (wedge resections, segmentectomies) were included. Multivariate analysis identified LLR, earlier period of MILR, malignant pathology, cirrhosis, portal hypertension, previous abdominal surgery, larger tumor size, and posterosuperior location as significant independent predictors of open conversion. The most common reason for conversion was technical issues (44.7%), followed by bleeding (27.2%), and oncological reasons (22.3%). After propensity score matching (PSM) of baseline characteristics, patients requiring open conversion had poorer outcomes compared with successful MILR cases as evidenced by longer operative times, more blood loss, higher requirement for perioperative transfusion, longer duration of hospitalization and higher morbidity, reoperation, and 90-day mortality rates. CONCLUSIONS: Multiple risk factors were associated with conversion of MILR even for minor hepatectomies, and open conversion was associated with significantly poorer perioperative outcomes.

Impact of neoadjuvant chemotherapy on short-term outcomes after simple and complex minimally invasive minor hepatectomy for colorectal liver metastases: A propensity-score matched and coarsened exact matched study.

BACKGROUND: In the last three decades, minimally invasive liver resection has been replacing conventional open approach in liver surgery. More recently, developments in neoadjuvant chemotherapy have led to increased multidisciplinary management of colorectal liver metastases with both medical and surgical treatment modalities. However, the impact of neoadjuvant chemotherapy on the surgical outcomes of minimally invasive liver resections remains poorly understood. METHODS: A multicenter, international, database of 4998 minimally invasive minor hepatectomy for colorectal liver metastases was used to compare surgical outcomes in patients who received neoadjuvant chemotherapy with surgery alone. To correct for baseline imbalance, propensity score matching, coarsened exact matching and inverse probability treatment weighting were performed. RESULTS: 2546 patients met the inclusion criteria. After propensity score matching there were 759 patients in both groups and 383 patients in both groups after coarsened exact matching. Baseline characteristics were equal after both matching strategies. Neoadjuvant chemotherapy was not associated with statistically significant worse surgical outcomes of minimally invasive minor hepatectomy. CONCLUSION: Neoadjuvant chemotherapy had no statistically significant impact on short-term surgical outcomes after simple and complex minimally invasive minor hepatectomy for colorectal liver metastases.

Global Outcomes Benchmarks in Laparoscopic Liver Surgery for Segments 7 and 8: International Multicenter Analysis.

BACKGROUND: In recent years, there has been growing interest in laparoscopic liver resection (LLR) and the audit of the results of surgical procedures. The aim of this study was to define reference values for LLR in segments 7 and 8. STUDY DESIGN: Data on LLR in segments 7 and 8 between January 2000 and December 2020 were collected from 19 expert centers. Reference cases were defined as no previous hepatectomy, American Society of Anesthesiologists score less than 3, BMI less than 35 kg/m 2 , no chronic kidney disease, no cirrhosis and portal hypertension, no COPD (forced expiratory volume 1 <80%), and no cardiac disease. Reference values were obtained from the 75th percentile of the medians of all reference centers. RESULTS: Of 585 patients, 461 (78.8%) met the reference criteria. The overall complication rate was 27.5% (6% were Clavien-Dindo 3a or more) with a mean Comprehensive Complication Index of 7.5 ± 16.5. At 90-day follow-up, the reference values for overall complication were 31%, Clavien-Dindo 3a or more was 7.4%, conversion was 4.4%, hospital stay was less than 6 days, and readmission rate was <8.33%. Patients from Eastern centers categorized as low risk had a lower rate of overall complication (20.9% vs 31.2%, p = 0.01) with similar Clavien-Dindo 3a or more (5.5% and 4.8%, p = 0.83) compared with patients from Western centers, respectively. CONCLUSIONS: This study shows the need to establish standards for the postoperative outcomes in LLR based on the complexity of the resection and the location of the lesions.

Textbook outcome in patients with biliary duct injury during cholecystectomy.

BACKGROUND: Iatrogenic bile duct injury (BDI) during cholecystectomy is associated with a complex and heterogeneous management owing to the burden of morbidity until their definitive treatment. This study aimed to define the textbook outcomes (TOs) after BDI with the purpose to indicate the ideal treatment and to improve it management. METHODS: We collected data from patients with an BDI between 1990 and 2022 from 27 hospitals. TO was defined as a successful conservative treatment of the iatrogenic BDI or only minor complications after BDI or patients in whom the first repair resolves the iatrogenic BDI without complications or with minor complications. RESULTS: We included 808 patients and a total of 394 patients (46.9%) achieved TO. Overall complications in TO and non-TO groups were 11.9% and 86%, respectively (P < .001). Major complications and mortality in the non-TO group were 57.4% and 9.2%, respectively. The use of end-to-end bile duct anastomosis repair was higher in the non-TO group (23.1 vs 7.8, P < .001). Factors associated with achieving a TO were injury in a specialized center (adjusted odds ratio [aOR], 4.01; 95% CI, 2.68-5.99; P < .001), transfer for a first repair (aOR, 5.72; 95% CI, 3.51-9.34; P < .001), conservative management (aOR, 5.00; 95% CI, 1.63-15.36; P = .005), or surgical management (aOR, 2.45; 95% CI, 1.50-4.00; P < .001). CONCLUSION: TO largely depends on where the BDI is managed and the type of injury. It allows hepatobiliary centers to identify domains of improvement of perioperative management of patients with BDI.

Robotic Versus Laparoscopic Liver Resection in Various Settings: An International Multicenter Propensity Score Matched Study of 10.075 Patients.

OBJECTIVE: To compare the perioperative outcomes of robotic liver surgery (RLS) and laparoscopic liver surgery (LLS) in various settings. BACKGROUND: Clear advantages of RLS over LLS have rarely been demonstrated, and the associated costs of robotic surgery are generally higher than those of laparoscopic surgery. Therefore, the exact role of the robotic approach in minimally invasive liver surgery remains to be defined. METHODS: In this international retrospective cohort study, the outcomes of patients who underwent RLS and LLS for all indications between 2009 and 2021 in 34 hepatobiliary referral centers were compared. Subgroup analyses were performed to compare both approaches across several types of procedures: (1) minor resections in the anterolateral (2, 3, 4b, 5, and 6) or (2) posterosuperior segments (1, 4a, 7, 8), and (3) major resections (≥3 contiguous segments). Propensity score matching was used to mitigate the influence of selection bias. The primary outcome was textbook outcome in liver surgery (TOLS), previously defined as the absence of intraoperative incidents ≥grade 2, postoperative bile leak ≥grade B, severe morbidity, readmission, and 90-day or in-hospital mortality with the presence of an R0 resection margin in case of malignancy. The absence of a prolonged length of stay was added to define TOLS+. RESULTS: Among the 10.075 included patients, 1.507 underwent RLS and 8.568 LLS. After propensity score matching, both groups constituted 1.505 patients. RLS was associated with higher rates of TOLS (78.3% vs 71.8%, P < 0.001) and TOLS+ (55% vs 50.4%, P = 0.026), less Pringle usage (39.1% vs 47.1%, P < 0.001), blood loss (100 vs 200 milliliters, P < 0.001), transfusions (4.9% vs 7.9%, P = 0.003), conversions (2.7% vs 8.8%, P < 0.001), overall morbidity (19.3% vs 25.7%, P < 0.001), and microscopically irradical resection margins (10.1% vs. 13.8%, P = 0.015), and shorter operative times (190 vs 210 minutes, P = 0.015). In the subgroups, RLS tended to have higher TOLS rates, compared with LLS, for minor resections in the posterosuperior segments (n = 431 per group, 75.9% vs 71.2%, P = 0.184) and major resections (n = 321 per group, 72.9% vs 67.5%, P = 0.086), although these differences did not reach statistical significance. CONCLUSIONS: While both produce excellent outcomes, RLS might facilitate slightly higher TOLS rates than LLS.

Explainable artificial intelligence prediction-based model in laparoscopic liver surgery for segments 7 and 8: an international multicenter study.

BACKGROUND: Artificial intelligence (AI) is becoming more useful as a decision-making and outcomes predictor tool. We have developed AI models to predict surgical complexity and the postoperative course in laparoscopic liver surgery for segments 7 and 8. METHODS: We included patients with lesions located in segments 7 and 8 operated by minimally invasive liver surgery from an international multi-institutional database. We have employed AI models to predict surgical complexity and postoperative outcomes. Furthermore, we have applied SHapley Additive exPlanations (SHAP) to make the AI models interpretable. Finally, we analyzed the surgeries not converted to open versus those converted to open. RESULTS: Overall, 585 patients and 22 variables were included. Multi-layer Perceptron (MLP) showed the highest performance for predicting surgery complexity and Random Forest (RF) for predicting postoperative outcomes. SHAP detected that MLP and RF gave the highest relevance to the variables "resection type" and "largest tumor size" for predicting surgery complexity and postoperative outcomes. In addition, we explored between surgeries converted to open and non-converted, finding statistically significant differences in the variables "tumor location," "blood loss," "complications," and "operation time." CONCLUSION: We have observed how the application of SHAP allows us to understand the predictions of AI models in surgical complexity and the postoperative outcomes of laparoscopic liver surgery in segments 7 and 8.

Multimodal prehabilitation program in patients with resectable perihilar cholangiocarcinoma: keypoints for an implementation protocol and literature review.

BACKGROUND: Postoperative complications after perihilar cholangiocarcinoma surgical procedure are still very high. The implementation of a multimodal prehabilitation program could improve these outcomes. Based on our experience and that of the literature in hepatobiliary and pancreatic surgery, we propose a protocol to promote its implementation. METHODS: First, we performed a retrospective analysis of the implementation feasibility of a multimodal prehabilitation program in patients' candidates for elective perihilar cholangiocarcinoma surgery in our center. Second, we conducted a literature search of publications in PubMed until December 2022. Relevant data about hepato-pancreato-biliary surgery and prehabilitation programs in features and postoperative outcomes was analyzed. RESULTS: Since October 2020, 11 patients were evaluated for prehabilitation in our hospital. Two of them could not be resected intraoperatively due to disease extension. The median hospital stay was 10 days (iqr, 7-11). There were no major complications and 1 patient died. Of a total of 17 articles related to prehabilitation in hepato-biliary-pancreatic surgery, no reports focusing exclusively on perihilar cholangiocarcinoma were found. Six of the studies had nutritional therapies in addition to physical interventions, and 12 studies used home-based exercise therapy. CONCLUSIONS: Based on our experience and the data obtained from other studies, a prehabilitation program could be useful to improve perioperative physical and mental fitness in patients' candidates for elective perihilar cholangiocarcinoma surgery. However, more well-designed studies are needed to allow us to obtain more evidence.

Propensity Score-Matching Analysis Comparing Robotic Versus Laparoscopic Limited Liver Resections of the Posterosuperior Segments: An International Multicenter Study.

OBJECTIVE: The purpose of this study was to compare the outcomes of robotic limited liver resections (RLLR) versus laparoscopic limited liver resections (LLLR) of the posterosuperior segments. BACKGROUND: Both laparoscopic and robotic liver resections have been used for tumors in the posterosuperior liver segments. However, the comparative performance and safety of both approaches have not been well examined in the existing literature. METHODS: This is a post hoc analysis of a multicenter database of 5446 patients who underwent RLLR or LLLR of the posterosuperior segments (I, IVa, VII, and VIII) at 60 international centers between 2008 and 2021. Data on baseline demographics, center experience and volume, tumor features, and perioperative characteristics were collected and analyzed. Propensity score-matching (PSM) analysis (in both 1:1 and 1:2 ratios) was performed to minimize selection bias. RESULTS: A total of 3510 cases met the study criteria, of whom 3049 underwent LLLR (87%), and 461 underwent RLLR (13%). After PSM (1:1: and 1:2), RLLR was associated with a lower open conversion rate [10 of 449 (2.2%) vs 54 of 898 (6.0%); P =0.002], less blood loss [100 mL [IQR: 50-200) days vs 150 mL (IQR: 50-350); P <0.001] and a shorter operative time (188 min (IQR: 140-270) vs 222 min (IQR: 158-300); P <0.001]. These improved perioperative outcomes associated with RLLR were similarly seen in a subset analysis of patients with cirrhosis-lower open conversion rate [1 of 136 (0.7%) vs 17 of 272 (6.2%); P =0.009], less blood loss [100 mL (IQR: 48-200) vs 160 mL (IQR: 50-400); P <0.001], and shorter operative time [190 min (IQR: 141-258) vs 230 min (IQR: 160-312); P =0.003]. Postoperative outcomes in terms of readmission, morbidity and mortality were similar between RLLR and LLLR in both the overall PSM cohort and cirrhosis patient subset. CONCLUSIONS: RLLR for the posterosuperior segments was associated with superior perioperative outcomes in terms of decreased operative time, blood loss, and open conversion rate when compared with LLLR.

Liver Histology Predicts Liver Regeneration and Outcome in ALPPS: Novel Findings From A Multicenter Study.

BACKGROUND AND AIMS: Alterations in liver histology influence the liver's capacity to regenerate, but the relevance of each of the different changes in rapid liver growth induction is unknown. This study aimed to analyze the influence of the degree of histological alterations during the first and second stages on the ability of the liver to regenerate. METHODS: This cohort study included data obtained from the International ALPPS Registry between November 2011 and October 2020. Only patients with colorectal liver metastases were included in the study. We developed a histological risk score based on histological changes (stages 1 and 2) and a tumor pathology score based on the histological factors associated with poor tumor prognosis. RESULTS: In total, 395 patients were included. The time to reach stage 2 was shorter in patients with a low histological risk stage 1 (13 vs 17 days, P ˂0.01), low histological risk stage 2 (13 vs 15 days, P <0.01), and low pathological tumor risk (13 vs 15 days, P <0.01). Regarding interval stage, there was a higher inverse correlation in high histological risk stage 1 group compared to low histological risk 1 group in relation with future liver remnant body weight ( r =-0.1 and r =-0.08, respectively), and future liver remnant ( r =-0.15 and r =-0.06, respectively). CONCLUSIONS: ALPPS is associated with increased histological alterations in the liver parenchyma. It seems that the more histological alterations present and the higher the number of poor prognostic factors in the tumor histology, the longer the time to reach the second stage.

Impact of liver cirrhosis, severity of cirrhosis and portal hypertension on the difficulty of laparoscopic and robotic minor liver resections for primary liver malignancies in the anterolateral segments.

INTRODUCTION: We performed this study in order to investigate the impact of liver cirrhosis (LC) on the difficulty of minimally invasive liver resection (MILR), focusing on minor resections in anterolateral (AL) segments for primary liver malignancies. METHODS: This was an international multicenter retrospective study of 3675 patients who underwent MILR across 60 centers from 2004 to 2021. RESULTS: 1312 (35.7%) patients had no cirrhosis, 2118 (57.9%) had Child A cirrhosis and 245 (6.7%) had Child B cirrhosis. After propensity score matching (PSM), patients in Child A cirrhosis group had higher rates of open conversion (p = 0.024), blood loss >500 mls (p = 0.001), blood transfusion (p < 0.001), postoperative morbidity (p = 0.004), and in-hospital mortality (p = 0.041). After coarsened exact matching (CEM), Child A cirrhotic patients had higher open conversion rate (p = 0.05), greater median blood loss (p = 0.014) and increased postoperative morbidity (p = 0.001). Compared to Child A cirrhosis, Child B cirrhosis group had longer postoperative stay (p = 0.001) and greater major morbidity (p = 0.012) after PSM, and higher blood transfusion rates (p = 0.002), longer postoperative stay (p < 0.001), and greater major morbidity (p = 0.006) after CEM. After PSM, patients with portal hypertension experienced higher rates of blood loss >500 mls (p = 0.003) and intraoperative blood transfusion (p = 0.025). CONCLUSION: The presence and severity of LC affect and compound the difficulty of MILR for minor resections in the AL segments. These factors should be considered for inclusion into future difficulty scoring systems for MILR.