Right liver tumors involving the right adrenal gland or which are located close to the inferior vena cava (IVC) often make it difficult to mobilize the right liver during laparoscopic surgery. As an alternative approach, retroperitoneoscopy offers a relatively easy approach to the dorsal aspect of the right side of the liver and area around the IVC. Therefore, we combined laparoscopic liver resection with retroperitoneoscopy ("retlap liver resection") to exploit the benefits of these methods. The preceding retroperitoneoscopy can be used to obtain a dorsal margin, which is difficult to achieve using laparoscopy alone. In such cases, a retroperitoneoscopic approach can be applied to the dorsal side of the adrenal gland, without mobilizing the right liver. Six patients underwent retlap liver resection between 2020 and 2022 without operative complications. Because no previous reports have described laparoscopic liver resection with retroperitoneoscopy, we introduce our approach and provide a video of the procedure.

We aimed to investigate the differences in surgical difficulty between laparoscopic partial liver resections of segments 7 and 8.

We analyzed 173 patients who underwent partial liver resections of segments 7 or 8 between 2010 and 2022 at two institutions. We investigated differences in the surgical outcomes of each procedure using propensity score matching. We compared these outcomes with those of open partial liver resections for segments 7 and 8 to determine whether the differences were unique to the laparoscopic approach.

Thirty and 54 patients underwent laparoscopic partial liver resections of segments 7 and 8. In the matched cohort (22 in each group), the operation time was significantly longer (377 vs. 278 min, P = 0.020) and the proportion of postoperative complications significantly higher in segment 7 (27% vs. 0%, P = 0.008). Forty-one and 48 patients underwent open partial liver resections of segments 7 and 8, respectively. There were no significant differences in the surgical outcomes between the segments in the matched cohort (20 in each group).

Laparoscopic partial liver resections of segment 7 may be more challenging than that of segment 8. This difference in difficulty was not observed in open partial liver resections.

Hepatocellular carcinoma arises in the setting of cirrhosis in most cases, requiring multidisciplinary input to define resectability. In this regard, more precise surgical management considers patient factors and anatomical states, including resection margins, tumour biology, and perioperative therapy. Together with advances in surgical techniques, this integrated approach has resulted in considerable improvements in patient morbidity and oncological outcomes. Despite this, recurrence rates in hepatocellular carcinoma remain high. As the systemic treatment landscape in hepatocellular carcinoma continues to evolve and locoregional options are increasingly used, we review current and future opportunities to individualise the surgical management of patients with hepatocellular carcinoma.

Robotic surgical approaches have demonstrated improved outcomes in primary hepatectomies. However, data on their effectiveness in redo hepatectomies (subsequent liver resections) are limited. This study aims to compare the outcomes of patients undergoing primary and redo robotic hepatectomies, with additional analysis comparing outcomes of robotic versus open redo hepatectomies. With IRB approval, we prospectively followed 101 patients from a parent population of 465, who were classified as either primary (non-redo) or redo robotic hepatectomy patients between 2013 and 2023. A Propensity Score Matched (PSM) analysis was conducted to compare perioperative variables between the two cohorts, using age, sex, BMI, IWATE score, tumor size, and tumor type as matching variables. Data are presented as median (mean ± standard deviation). Significance was accepted at p ≤ 0.05. After 3:1 PSM analysis (3 primary patients to 1 robotic redo patient), no significant differences were observed in pre-, intra-, or postoperative variables, except for the Model for End-Stage Liver Disease (MELD) score (p = 0.022). Additional analysis comparing robotic and open redo hepatectomies showed similar perioperative outcomes, with the robotic approach demonstrating comparable safety and feasibility. Length of stay, blood loss, operative duration, morbidity, and mortality showed no significant differences between the two groups. Major complications (Clavien-Dindo score ≥ III) occurred in 4% of non-redo patients, with none observed in the redo group. The findings suggest that patients undergoing redo robotic hepatectomies achieve outcomes comparable to those of primary hepatectomy patients. This indicates the potential of robotic platforms to mitigate the added complexities and risks associated with redo hepatectomies. Further multi-center collaboration is necessary to validate these findings.

Robotic surgery is becoming more and more widespread. Despite its diffusion, parenchymal transection still remains a matter of debate. Up to now, in minimally invasive surgery, most of liver resection were performed laparoscopically with the support of ultrasonic dissector. The absence of robotic ultrasonic dissector is replaced by the hybrid (Robo-lap) technique in which the use of laparoscopic ultrasonic dissector is merged with the use of robotic energy devices in order to perform parenchymotomy. On the other side, some surgical groups perform liver resection using only Da Vinci energy devices, focusing on the simultaneous use of the double bipolar forceps (Maryland and bipolar) and applying the clamp-crush technique during robotic resection (MAMBA-Moisture Assisted Multiple BipolAr). Aim of our study is to compare intra- and post-operative outcomes of these two techniques.

We collected a multicenter retrospective database, including 1070 consecutive robotic liver resection in 10 European Hospital Centers. Among these, 921 patients underwent liver resection for malignancies. Perioperative data for each patient were analyzed. Patients were also divided in two groups according to parenchymal transection technique (MAMBA vs robo-lap). Perioperative data were compared between 2 groups before and after 1:1 Propensity Score Matching.

755 resection were performed by MAMBA technique, 166 resection by Robo-lap. After PSM, 91 patients were included in each group. There were no significant differences between two groups regarding operative time, estimated blood loss, conversion rate, and post-operative complications.

MAMBA technique is a valid alternative in robotic liver parenchymal transection, overcoming the lack of ultrasound devices.

Robotic liver surgery, as part of minimally invasive liver surgery (MILS), offers advantages like enhanced dexterity and stable camera and instrument control. However, the learning curve - particularly the number of cases required for proficiency - remains underexplored. This study analyzes 100 consecutive robotic liver resections performed by a single surgeon to assess the learning curve and outcomes.

This retrospective analysis reviewed data from the Magdeburg registry of minimally invasive liver surgery (MD-MILS) from June 2013 to July 2024, to identify surgeons who performed at least 100 robotic liver resections. Operation time and Iwate difficulty score were used as indicators of surgical proficiency and learning progression.

One surgeon fulfilled the inclusion criteria of performing 100 robotic liver resections. Of these, 41 (41%) were major and 59 (59%) were minor liver resections. A significant reduction in average operation time was observed across the series, decreasing from an initial average of 450 min to approximately 300 min by the 100th operation. Similarly, the Iwate difficulty score showed a significant upward trend, reflecting the increasing technical challenges of the procedures. The learning curve was divided into four distinct phases: Competency (Cases 1-20), Proficiency (Cases 21-30), Early Mastery (Cases 31-65), and Full Mastery (Cases 66-100), highlighting the progression in skill acquisition and case complexity. Major complications (21%), such as bile leak, bilioma, and pulmonary embolism, were observed during the study period.

Over 100 robotic liver resections, significant learning curve progression was evident, with marked improvements in operation time and handling of complex cases. The results suggest that approximately 65 cases are needed for a surgeon experienced in open and laparoscopic liver surgery to achieve consistent proficiency in robotic liver resections. These findings underscore the importance of standardized training protocols to support the learning curve in robotic liver surgery.

Despite technical advancements, minimally invasive liver surgery (MILS) for hepatocellular carcinoma (HCC) remains challenging. Nonetheless, effective tools to assess MILS complexity are still lacking. Machine learning (ML) models could improve the accuracy of such tools.

Patients who underwent curative-intent MILS for HCC were identified using an international database. An XGBoost ML model was developed to predict surgical complexity using clinical and radiological characteristics.

Among 845 patients, 186 (22.0 %) were classified as high-risk patients. In this subgroup, median Charlson Comorbidity Index (CCI) (5.0, IQR 3.0-7.0 vs. 2.0, IQR 2.0-5.0, p < 0.001) and tumor burden score (TBS) (median 4.12, IQR 3.0-5.1 vs. 4.22, IQR 3.2-7.1, p < 0.001) were higher. The model was able to effectively predict complexity of surgery in both the training and testing cohorts with high discriminating power (ROC-AUC: 0.86, 95%CI 0.82-0.89 vs. 0.73, 95%CI 0.65-0.81). The most influential variables were CCI, TBS, BMI, extent of resection, and sex. Patients predicted to have a complex surgery were more likely to develop severe complications (OR 4.77, 95%CI 1.82-13.9, p = 0.002). An easy-to-use calculator was developed.

Preoperative ML-prediction of complex MILS for HCC may improve preoperative planning, resource allocation, and patient outcomes.

Laparoscopic repeat liver resection (LRLR) is still a challenging technique and requires a careful selection of indications. However, the current difficulty scoring system is not suitable for selecting indications. The purpose of this study is to develop the indication model for LRLR using machine learning and to identify factors associated with open conversion (OC).

Patients who underwent repeat hepatectomy (2017-2021) at Samsung Medical Center 2021 were investigated. Multiple indication models were developed using machine learning techniques (random forest, SVM, XGB) and logistic regression. The predictive performance of these models was compared, and risk factors associated with OC were analyzed.

Among 221 patients (110 LRLR, 111 ORLR), the ORLR group had a higher previous open approach rate (75.7% vs. 38.2%, p<0.001). Twice previous abdominal surgery was the only independent OC risk factor (OR 6.56, p=0.009). The indication model showed moderate predictive power (random forest AUC=0.779, logistic regression AUC=0.725, p=0.710). Important variables were previous laparoscopic approach, present subsegmentectomy, and left-sided tumor location.

The performance of the indication model for LRLR showed moderate predictive power in both machine learning and logistic regression. The important variables for LRLR were previous laparoscopic approach, present subsegmentectomy, and left side location.

Minimally invasive liver surgery (MILS) still appears to be adopted with significant variability. We aimed to investigate the diffusion, indications, and short-term outcomes of MILS compared to the open approach.

A prospective registry of all liver resections performed for any indication and using any technique between January 1, 2017, and December 31, 2019, was established (BReLLS) and analyzed.

A total of 1342 consecutive liver resections were included, 684 (51%) MILS and 658 (49%) open procedures. MILS was not attempted due to technical complexity in the 46.2% of cases, followed by previous abdominal surgery (22.5%). Patients undergoing MILS had a higher proportion of benign indications and of hepatocellular carcinomas, patients affected by liver cirrhosis with portal hypertension and a lower proportion of major hepatectomies (all p < 0.001). After propensity-score matching, MILS showed better results in terms of surgery duration (p < 0.001), blood loss (p = 0.015), complication rate (p < 0.001), rate of Clavien-Dindo grade ≥ 3 complications (p = 0.012), comprehensive complication index (p < 0.001), length of stay (p < 0.001), readmissions (p = 0.016). Centers performing over 50 liver resections per year had a higher proportion of overall MILS cases (p < 0.001), a similar proportion of major resections (p = 0.362), but a higher prevalence of MILS major resections (p = 0.004), lower 90-day mortality rates (p < 0.001), lower overall complication rates (p < 0.001), and shorter hospital length of stay (p < 0.001).

MILS was the preferred technique in half of the cases, particularly in patients with cirrhosis and portal hypertension, and benign lesions. It provided superior short-term outcomes compared to the open approach for both minor and major liver resections in selected patients.

Laparoscopic transcystic bile duct exploration (LTCBDE) represents a secure and efficacious approach for managing common bile duct (CBD) stones, particularly in patients concurrently undergoing laparoscopic cholecystectomy (LC). The decision to proceed with LTCBDE hinges on real-time assessment of the intraoperative cholangiogram (IOC), which is highly operator-dependent and poorly interpreted. No established criteria exist to guide the evaluation of IOCs for LTCBDE. This study aims to ascertain the concordance among surgeons, experienced in LTCBDE, on critical aspects of IOC interpretation.

A retrospective collection of IOC images of 40 patients who underwent LC, IOC, and LTCBDE at a tertiary university hospital between 2017 and 2018 was undertaken. Two hepato-pancreato-biliary (HPB) and 2 acute care surgery (ACS) specialists independently reviewed the images. They were tasked with assessing IOC features hypothesized to influence duct exploration and stone extraction complexity, along with overall suitability for LTCBDE based exclusively on the IOC images. Agreement percentages were calculated and Kappa inter-rater reliability statistics were assessed.

The overall agreement percentages concerning IOC features ranged between 52.5% and 82.5% with agreements surpassing 75% deemed robust. Maximum agreement was achieved in the interpretation of cystic duct morphology, whether straight or characterized by spiral valves. The concurrence for amenability of LTCBDE also demonstrated substantial accord among surgeons (ACS: 92.5%, HPB: 95%, total: 87.5%). Consistently high agreement was evident within specialty groups.

Anatomical attributes displayed superior agreement levels, as opposed to variables necessitating measurements. We recommend the development of a structured approach for the interpretation of IOC to facilitate surgical education in LTCBDE.

Hepatocellular carcinoma (HCC) remains a significant global health challenge, with over 800,000 new cases diagnosed annually. This comprehensive review examines current surgical approaches and emerging multidisciplinary strategies in HCC treatment. While traditional surgical criteria, such as the Barcelona Clinic Liver Cancer (BCLC) staging system, have been relatively conservative, recent evidence from high-volume Asian centers supports more aggressive surgical approaches in carefully selected patients. The review discusses the evolution of selection criteria, including the new "Borderline Resectable HCC" classification system, which provides more explicit guidance for surgical decision-making. Technical innovations have significantly enhanced surgical precision, including three-dimensional simulation, intraoperative navigation systems, and the advancement of minimally invasive approaches. The review evaluates the ongoing debate between anatomical versus non-anatomical resection and examines the emerging role of robotic surgery. In liver transplantation, expanded criteria beyond the Milan criteria show promising outcomes, while the integration of novel biomarkers and imaging techniques improves patient selection. The role of preoperative and adjuvant therapies is increasingly important, with recent trials demonstrating the potential of immune checkpoint inhibitors combined with anti-VEGF agents in both settings. Despite these advances, postoperative recurrence remains a significant challenge. The review concludes that successful HCC treatment requires a personalized approach, integrating surgical expertise with emerging technologies and systemic therapies while considering individual patient factors and regional variations in practice patterns.

Both laparoscopic hepatectomy (LH) and robotic hepatectomy (RH) have been performed for tumors in nearly all liver segments. However, few studies have compared the outcomes of patients who underwent open hepatectomy (OH), LH and RH for the treatment of Barcelona Clinic Liver Cancer (BCLC) stage 0-A HCC in S7/8.

The clinical data of patients who underwent S7/8 resection for the treatment of BCLC stage 0-A HCC in the First Affiliated Hospital of Guangxi Medical University from July 2017 to July 2023 were retrospectively collected. To minimize selection bias, propensity score matching (PSM) analysis was performed using American Society of Anesthesiology (ASA), tumor size, body mass index (BMI), alpha-fetoprotein (AFP), tumor location, age, number of tumors, platelet (PLT), and Viral hepatitis.

A total of 401 patients met the study criteria. After PSM, 61 OH (28.6%), 74 LH (34.8%), and 78 RH (36.6%) were included. RH group had the least blood loss among the three groups (OH, 300 vs. LH, 215 vs. RH, 100 mL, P < 0.001). Conversion rate was significantly lower in RH group compared to LH group [LH, 10 (13.5%) vs. RH, 1 (1.3%), P = 0.003]. Although minimally invasive group (RH + LH) took slightly longer operative time (OH, 233 vs. LH, 255.5 vs. RH, 257 min, P = 0.068), there was no statistical difference. The minimally invasive group had fewer postoperative hospital stay (OH, 8 vs. LH, 6 vs. RH, 6 days, P < 0.001). The minimally invasive group had lower rates of surgical complications (OH, 37.7% vs. LH, 20.3% vs. RH, 11.5%). However, there were no statistically significant variations observed in the disease-free survival or overall survival rates among the three groups.

RH showed advantage over the OH and LH in short-term outcomes, and non-inferiority in survival outcomes for the treatment of BCLC stage 0-A HCC patients.

Laparoscopic liver resection (LLR) is a surgical procedure with varying degrees of difficulty depending on tumor status and surgical technique. Therefore, we aimed to evaluate the relationship between surgical difficulty levels and outcomes of LLR, particularly portal vein thrombosis (PVT).

We performed LLRs in 214 patients between January 2009 and December 2022. Among them, 200 patients who underwent pure LLR were allocated into three groups according to the Institut Mutualiste Montsouris (IMM) classification: Group I (n = 152), Group II (n = 26), and Group III (n = 22). The perioperative outcomes were also compared; risk factors for postoperative complications were evaluated.

The operation time was significantly longer (p < 0.001) and intraoperative blood loss was significantly higher (p < 0.001) in Group III than in Groups I and II. The rates of complications of Clavien-Dindo (CD) grade 2 or higher (19.1% vs. 34.6% vs. 63.6%, p < 0.001) and CD grade 3 or higher (5.3% vs. 11.5% vs. 22.7%, p = 0.015) were significantly higher and postoperative hospital stay (9 vs. 13 vs. 16 days, p < 0.001) was significantly longer in Group III than in Groups I and II. The IMM classification (odds ratio [OR], 5.727; 95% confidence interval [CI], 1.863-17.610; p = 0.002] and blood transfusion (OR, 6.410; 95% CI, 2.215-18.549; p < 0.001) were independent risk factors for CD grade 2 or higher complication using multivariate analysis. PVT was the most common complication in patients with CD of grade 2 or higher, occurring in 14 of 48 patients. Hepatitis viral status (OR: 7.552, p = 0.021 [non-B non-C for HCV]) and the IMM classification (OR: 58.767, p < 0.001[II vs. I]; OR: 40.535, p = 0.002 [III vs. I]) were independent risk factors for PVT using multivariate analysis.

The IMM classification could strongly predict postoperative complications, particularly PVT.

To assess technical difficulty scores for laparoscopic liver resections (LLR) in a large well-characterized cohort of low to high difficulty LLR.

Patients undergoing LLR and open liver resection (OLS) (2007-2022) at Massachusetts General Hospital were included. Patients were classified according to the technical difficulty scores Ban difficulty score, IWATE criteria, Hasegawa score, IMM score, and Southhampton score (SHH) and calibration of these scores in predicting postoperative outcome parameters was assessed.

301 patients underwent LLR. Median age was 59 years and 58.5% of the patients were female. Median lesion size was 42.2 mm, median operative time was 197.7 min, and median estimated blood loss was 400.5 ml. According to the different scoring systems, 18.9% (SHH) to 52.2% (IWATE) of the LLR were high difficulty. Overall intraoperative events according to the modified Satava classification grade II (6.6%) and grade III (2.7%) were low as was postoperative 90 days major morbidity (5.3%) and mortality (1.0%). The respective scores' calibration for predicting non-textbook outcomes, intraoperative events, operative time, major postoperative morbidity, blood transfusion rates, and length of hospital stay was moderate to good for the respective scores and best for the IWATE criteria.

Even high technical difficulty LLR can be performed with low postoperative morbidity and mortality rates. The scores evaluated performed well in predicting major liver surgery outome parameters. Among the different difficulty scoring systems, the IWATE criteria performed best.

Laparoscopic liver resection has advantages over open liver resection, including reduced blood loss and shorter hospital stays. Laparoscopic central hepatectomy (CH) is a highly challenging procedure, and such outcomes can only be achieved with a high level of expertise in laparoscopic liver surgery. Laparoscopic CH remains challenging, with safety and efficacy unclear. This study retrospectively evaluated the intra- and short-term outcomes of laparoscopic versus open CH and assessed safety and efficacy of laparoscopic surgery.

CH included anterior sectionectomy (AS) and central bisectionectomy (CBS) (excluding cases with biliary reconstruction). The study comprised 38 patients receiving CH in our department from January 2010 to November 2023.

The laparoscopic group included 14 cases and the open group 24. AS/CBS was performed in 14/10 open group cases and 6/8 laparoscopic group cases. Short-term surgical outcomes showed no significant between-group difference in operative time, but the laparoscopic group lost significantly less blood (250 vs. 985 mL; p = 0.001) and the transfusion rate was lower (14% vs. 46%; p = 0.004). Among postoperative outcomes, incidence of bile leakage was not significantly different (33% vs. 42%; p = 0.42), but the laparoscopic group had significantly less postoperative ascites (0% vs. 17%; p = 0.047), fewer surgical site infections (SSI) (0% vs. 21%; p = 0.02), and shorter postoperative hospital stay (14 vs. 30 days; p = 0.005). The risk factor for bile leakage in CH by univariate and multivariate analysis was tumor proximity to the right anterior Glissonean pedicle (OR = 6.84; 95% CI = 1.67-32.7; p = 0.01).

Laparoscopic CH could be performed safely. Compared to open surgery, laparoscopic CH was effective in reducing blood loss, postoperative ascites, SSIs, and shortening postoperative hospital stay. However, tumors close to the root of the right anterior Glissonean pedicle were considered a risk factor for postoperative bile leakage and require caution.

The Iwate difficulty scoring system (DSS) is one of the most widely validated DSS for laparoscopic liver resection (LLR). However, these studies only validated the 4 difficulty levels and did not validate the 12-point difficulty index of the system. To address current limitations in the studies validating the Iwate difficulty scoring system (DSS), we performed an international multicenter study to validate the Iwate DSS across both its four difficulty levels and 12-point difficulty index.

A retrospective cohort study of 22,252 patients undergoing LLR across 64 centers worldwide between 2005 and 2021 was performed. Baseline characteristics and perioperative outcomes were analyzed across the four difficulty levels and 12-point difficulty index of the Iwate DSS.

A total of 14,759 patients met the inclusion criteria. The main indications for LLR were hepatocellular carcinoma/intrahepatic cholangiocarcinoma (52.8 %), and metastatic tumors liver (26.5 %). In terms of underlying liver pathology, 5127 patients (34.8 %) had liver cirrhosis, and 1214 patients (8.3 %) had portal hypertension. Intraoperative outcomes (operation time, blood loss, blood transfusion, use of Pringles maneuver and open conversion) and postoperative outcomes (length of stay, morbidity, major complications, and 90-day mortality) significantly increased with stepwise increases across the four difficulty levels (P < 0.001) and 12-point difficulty index (P < 0.001). These trends remained significant following adjustment for baseline characteristics (P < 0.001).

The Iwate DSS 12-point difficulty index and four difficulty levels correlated well with LLR difficulty as determined by key surrogate perioperative measures.

The impact of body-cavity depth on open (OLR) and laparoscopic liver resection (LLR) of segment 7 remains unclear. Therefore, we investigated the influence of body-cavity depth at the upper-right portion of the abdomen on LLR and OLR of segment 7.

In total, 101 patients who underwent segment-7 liver resection over 2010-2023 were included. Body-cavity depth was measured from the abdominal-wall surface to the deepest site on the right side of the liver. Patients were categorized into shallow (< 18.4 cm) and deep (≥ 18.4 cm) populations based on median body-cavity depth. We compared surgical outcomes between OLR and LLR in shallow and deep populations after propensity-score adjustments.

In OLR and LLR groups, 27 and 22 patients in the shallow population, respectively, and 26 and 26 patients were included in the deep population, respectively, were included. The OLR group in the deep population had significantly greater blood loss than the corresponding LLR group (difference: 144 mL, 95% confidence interval (CI): [50, 238], P = 0.004). Other surgical outcomes, including operative time, were similar between groups. In the shallow population, the OLR group had significantly shorter operative time (difference: - 54 mL, 95% CI: [-101, - 6], P = 0.028) and similar blood loss than the LLR group.

For segment-7 liver resection, LLR is likely favorable for patients with a deep body cavity, with similar operative time and lower blood loss compared to OLR. Body-cavity depth could be a useful indicator for determining the suitable surgical approach for segment-7 liver resection.

Background: Liver cancer has a high mortality rate worldwide, and clinicians segment liver vessels in CT images before surgical procedures. However, liver vessels have a complex structure, and the segmentation process is conducted manually, so it is time-consuming and labor-intensive. Consequently, it would be extremely useful to develop a deep learning-based automatic liver vessel segmentation method. Method: As a segmentation method, UNet is widely used as a baseline, and a multi-scale block or attention module has been introduced to extract context information. In recent machine learning efforts, not only has the global context extraction been improved by introducing Transformer, but a method to reinforce the edge area has been proposed. However, the data preprocessing step still commonly uses general augmentation methods, such as flip, rotation, and mirroring, so it does not perform robustly on images of varying brightness or contrast levels. We propose a method of applying image augmentation with different HU windowing values. In addition, to minimize the false negative area, we propose TransRAUNet, which introduces a reverse attention module (RAM) that can focus edge information to the baseline TransUNet. The proposed architecture solves context loss for small vessels by applying edge module (RAM) in the upsampling phase. It can also generate semantic feature maps that allows it to learn edge, global context, and detail location by combining high-level edge and low-level context features. Results: In the 3Dricadb dataset, the proposed model achieved a DSC of 0.948 and a sensitivity of 0.944 in liver vessel segmentation. This study demonstrated that the proposed augmentation method is effective and robust by comparisons with the model without augmentation and with the general augmentation method. Additionally, an ablation study showed that RAM has improved segmentation performance compared to TransUNet. Compared to prevailing state-of-the-art methods, the proposed model showed the best performance for liver vessel segmentation. Conclusions: TransRAUnet is expected to serve as a navigation aid for liver resection surgery through accurate liver vessel and tumor segmentation.

Laparoscopic liver resection (LLR) is a difficult procedure that requires the scopist to have a high skill level. Scopists play an important role in ensuring an appropriate surgical field. This is the first study that focuses on the scopist's skills in perioperative outcomes of LLR.

Patients who underwent LLR from April 2018 to March 2023 were included in this study. The scopists were separated into expert (≥ 10 LLR procedures as a scopist) and beginner (< 10 LLR procedures as a scopist) groups. The effects of the scopists' skills on the perioperative outcomes of LLR between the two groups were examined retrospectively. In addition to listing baseline characteristics and perioperative outcomes, this study viewed video recordings to list intraoperative surgical manipulation factors as new attempts.

No significant differences were observed in the baseline characteristics or perioperative outcomes between the two groups. The duration of the time during which the surgical procedure was interrupted due to scope operation errors during the Pringle maneuver was significantly longer in the beginner group (71 vs. 198 s, p < 0.001).

The scope manipulation by the less experienced LLR scopists sometimes hindered the progress of the surgery. The scopist's skills may lead to an increased psychological burden on the surgeon and prolonged operative times.

This meta-analysis aimed to compare the efficacy of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) in treating gastric cancer (GC).

A comprehensive literature search across PubMed, MEDLINE, and Web of Science identified 86 eligible studies, including 68,755 patients (20,894 in the RG group and 47,861 in the LG group).

The analysis revealed that RG was associated with superior outcomes in several areas: more lymph nodes were harvested, intraoperative blood loss was reduced, postoperative hospital stays were shorter, and the time to first flatus and oral intake was shortened (all p < 0.001). Additionally, RG resulted in lower incidences of conversion to open surgery (OR = 0.62, p = 0.004), reoperation (OR = 0.68, p = 0.010), overall postoperative complications (OR = 0.82, p < 0.001), severe complications (OR = 0.65, p < 0.001), and pancreatic complications (OR = 0.60, p = 0.004). However, RG had longer operative times and higher costs (both p < 0.001). No significant differences were found between RG and LG in terms of resection margin distance, mortality, anastomotic leakage, or recurrence rates.

RG is a safe and effective surgical option for patients of GC, but further improvements in operative duration and costs are needed.

Caudate and posterosuperior hepatectomy are technically challenging resections, especially in a minimally invasive approach. We aimed to analyze the outcomes of isolated caudate resection (ICR), en-bloc caudate resection with right/left hepatic lobectomy (ECR), and posterosuperior segment resection (PSR) using our institutional database.

Following IRB approval, we prospectively followed 500 consecutive patients between 2013 and 2023 who underwent robotic hepatectomy. Posterosuperior segments include segment 4 ​A, 7, and 8. The data are presented as median (mean ​± ​standard deviation).

Of the 500 patients included in this study, 19 (4 ​%) underwent ICR, 65 (13 ​%) underwent ECR, and 131 (26 ​%) patients underwent PSR. ECR was associated with significantly longer operative time, increased EBL, and longer LOS when compared with those of ICR and PSR. The patients who underwent ICR had the shortest operation duration, lowest EBL, and shortest LOS compared to ECR and PSR.

Robotic resection of liver tumors located in difficult segments is safe and feasible with excellent clinical and oncological outcomes. With appropriate expertise, a minimally invasive approach to those operations should not be avoided.

Laparoscopic hepatectomy has minimally invasive advantages, but reports on laparoscopic right anterior sectionectomy (LRAS) are rare. Herein, we try to explore the benefits and drawbacks of LRAS by comparing it with open right anterior sectionectomy (ORAS). Between January 2015 and September 2023, 39 patients who underwent LRAS (n = 18) or ORAS (n = 21) were enrolled in the study. The patients' characteristics, intraoperative details, and postoperative outcomes were compared between the two groups. No significant differences in the preoperative data were observed between the two groups. The LRAS group had significantly lesser blood loss (P = 0.019), a shorter hospital stay (P = 0.045), and a higher rate of bile leak (P = 0.039) than the ORAS group. There was no significant difference in the operative time (P = 0.156), transfusion rate (P = 0.385), hospital expenses (P = 0.511), rate of other complications, postoperative white blood cell count, and alanine aminotransferase and aspartate aminotransferase levels between the two groups (P > 0.05). Beside, there was no significant difference in disease-free survival (P = 0.351) or overall survival (P = 0.613) in patients with hepatocellular carcinoma between the two groups. LRAS is a safe and feasible surgical procedure. It may be preferred for lesions in the right anterior lobe of the liver.

Laparoscopic hepatectomy has been widely accepted owing to its advantages as a minimally invasive surgery; however, laparoscopic segment 7 (S7) hepatectomy (LSH) has been rarely reported. We aimed to explore the safety and feasibility of LSH by comparing it with open surgical approaches.

Twenty-nine patients who underwent S7 hepatectomy between January 2016 and January 2023 were enrolled in this study. The patients' characteristics, intraoperative details, and postoperative outcomes were compared between the 2 groups.

No significant differences were observed in the preoperative data. The patients who underwent LSH had significantly shorter hospital stays ( P =0.016) but longer operative times ( P =0.034) than those who underwent open S7 hepatectomy. No significant differences in blood loss ( P =0.614), transfusion ( P =0.316), hospital expenses ( P =0.391), surgical margin ( P =0.442), rate of other complications, postoperative white blood cell count, and alanine aminotransferase and aspartate aminotransferase levels were noted between the 2 groups ( P >0.05). For hepatocellular carcinoma, the results showed no differences in either disease-free survival ( P =0.432) or overall survival ( P =0.923) between the 2 groups.

LSH is a safe and feasible surgical procedure that is efficient from an oncological point of view. It may be the preferred technique for lesions in the S7 of the liver.

Laparoscopic hepatectomy (LH) is reported to cause less bleeding than open hepatectomy (OH) in obese patients; however, there are no reports addressing this issue in terms of body size-corrected bleeding.

The subjects of this study were 31 obese and 149 non-obese patients who underwent LH and 32 obese and 245 non-obese patients who underwent OH. Bleeding corrected for body surface area (C-BL) was compared between the obese and non-obese patients who underwent each procedure. A multivariate analysis for increased C-BL was performed using the median C-BL for each procedure.

The median C-BL tended to be higher in the obese patients than in the non-obese patients who underwent LH, but there was no significant difference (72 vs. 42 mL/m2, P = 0.050). However, it was significantly higher in the obese patients than in the non-obese patients who underwent OH (542 vs. 333 mL/m2, P = 0.002). In a multivariate analysis, for OH, sectionectomy or more (OR 3.20, P < 0.001) and a high BMI (OR 2.76, P = 0.018) were found to be independent risk factors, whereas for LH, a high BMI was not (OR 1.58, P = 0.301).

Obesity was identified as a risk factor for increased bleeding with body size correction for OH, but the risk was reduced for LH.

Laparoscopic hepatectomy for colorectal liver metastases (CRLM) is performed worldwide. However, owing to a lack of palpatory information and difficulties associated with accurate intraoperative ultrasonographic diagnosis, the tumor may be exposed at the hepatic transection margin. This study aimed to investigate the pathological significance of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG)-guided laparoscopic hepatectomy and determine its usefulness in securing the resection margin for CRLMs.

Fifty-nine patients who underwent laparoscopic hepatectomy for CRLM using NIR fluorescence imaging between February 2017 and June 2021 at Sapporo Medical University Hospital were included. Generally, all patients received intravenous ICG (2.5 mg/body) as a fluorescence agent 1 to 2 days before surgery. During the surgical procedure, real-time NIR fluorescence imaging was repeatedly performed to assess the surgical margins.

Of the 94 tumors in 59 patients, laparoscopic NIR fluorescence imaging identified 56 tumors (59.6%) on the liver surface. Pathological analysis indicated clear margins in 96.6% (57/59) of patients. Examination of paraffin-embedded sections, which were successful in only 20 of 94 cases (21.3%), revealed that there were no tumor cells positive for NIR fluorescence, and the median distance of the continuous fluorescent signal from the tumor margin was 1.074 mm.

We demonstrated a high R0 rate using NIR fluorescence-guided hepatectomy. This technique has the potential to improve intraoperative tumor identification and tumor margin assurance and reduce the rate of positive resection margins in patients with CRLMs.

For intrahepatic duct (IHD) stones, laparoscopic liver resection (LLR) is currently a reliable treatment. However, the current LLR difficulty scoring system (DSS) is only available for patients with hepatocellular carcinoma.

To explore the development of a DSS for IHD stone patients with LLR and the validation of its reliability.

We used clinical data from 80 patients who received LLR for IHD stones. Forty-six of these patients were used in multiple linear regression to construct a scoring system. Another 34 patients from different centers were used as external validation. The completeness of our DSS was then evaluated in patients with varying degrees of surgical difficulty based on documented surgical outcomes in the study group of patients.

The following five predictors were ultimately included and scored by calculating the weighted contribution of each factor to the prediction of operative time in the training cohort: Location of stones, number of stones ≥ 3, stones located in the bile ducts of several grades, previous biliary surgery less than twice, distal bile duct atrophy. Subsequently, the data set was validated using a DSS developed from the variables. The following variables were identified as statistically significant in external validation: Operative time, blood loss, intraoperative transfusion, postoperative alanine aminotransferase, and Clavien-Dindo grading ≥ 3. These variables demonstrated statistically significant differences in patients with three or more grades.

Patients with IHD stones have varying degrees of surgical difficulty, and the newly developed DSS can be validated with external data to effectively predict risks and complications after LLR surgery.

The aim of this study was to investigate the perioperative outcomes of robotic liver surgery (RLS) and Open liver surgery (OLS) in a centre with a high number of operations.

A 1:1 propensity score matched (PSM) analysis of a retrospective database of RLS and OLS was performed. Cumulative sum (CUSUM) analysis was performed to identify learning curves.

After PSM analysis, operative time was significantly longer in the RLS group (p < 0.001). Estimated blood loss was significantly lower in the RLS group (p < 0.001). Transfusion rates were significantly lower in the RLS group. The length of hospital stay was shorter in the RLS group (3.5vs6.3 days, p < 0.001). Readmission rates were significantly lower in the RLS group (p < 0.049). CUSUM analysis showed a learning curve for at least 8 low-intermediate RLS procedures and 27 advanced-Expert RLS procedures.

RLS has many advantages, including being safe to perform, less blood loss and faster postoperative recovery compared with OLS.

Background: A difficulty scoring system was developed to estimate the surgical outcomes of laparoscopic liver surgery (LLS); however, the effect of the liver transection area (LTA) on LLS outcomes have not been previously examined. Therefore, this study investigated the predictive significance of the LTA for LLS. Methods: This retrospective study included 106 patients who underwent LLS in our hospital between January 2012 and December 2023. The association of the LTA with the surgical difficulty level and operative time was investigated. Multivariate analyses were performed to identify factors predicting surgical difficulty in LLS. Results: The median LTA and operative time were 62.5 (IQR, 36.0-91.8) cm2 and 250 (IQR, 195-310) minutes, respectively. The LTA was significantly associated with surgical difficulty as evaluated using the IWATE Criteria. Moreover, the LTA significantly correlated with operative time (r2 = 0.19, p < 0.001). The multivariable analyses found that the LTA (≥59 cm2) (odds ratio [OR], 6.07; 95% confidence interval [CI], 2.38-16.6; p < 0.001) and the type of LLS (≥segmentectomy) (OR, 3.79; 95% CI, 1.35-11.4; p = 0.01) were significant factors associated with surgical difficulty. Conclusions: The LTA is a useful parameter that reflects the difficulty of LLS.

The evolution of laparoscopic liver surgery, originating in the 1990s, has been marked by significant advancements and milestones, overcoming initial technical hurdles and gaining widespread acceptance within the surgical community as a precise and safe alternative to open procedures. Along this journey, numerous challenges emerged, leading to the accumulation of evidence and the development of guidelines aimed at assisting surgeons in determining the safety, suitability, and complexity of laparoscopic liver resection. This chapter provides a thorough examination of key aspects of laparoscopic liver resection, including difficulty scoring systems, criteria for patient selection, technical considerations, outcomes across different types of liver lesions, and the innovative solutions developed to address challenges, thus offering a comprehensive overview of laparoscopic liver resection, and highlighting its evolving significance in modern hepatobiliary surgery.

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.

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.

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.

Multiple risk factors were associated with conversion of MILR even for minor hepatectomies, and open conversion was associated with significantly poorer perioperative outcomes.