Comparison between the difficulty of laparoscopic limited liver resections of tumors located in segment 7 versus segment 8: An international multicenter propensity-score matched study

Impact of tumor proximity to vessel on conversion in laparoscopic liver resection: A retrospective cohort study

BACKGROUND

Although various difficulty scoring systems have been proposed for laparoscopic liver resection (LLR), details remain uncertain regarding distance between the tumor and vessels as a factor of difficulty. We aimed to examine the risk factors for conversion to open hepatectomy in LLR, including distance between tumor and vessels.

METHODS

Between January 2012 and December 2022, 118 patients who underwent LLR were retrospectively enrolled and their perioperative characteristics were evaluated.

RESULTS

A total of 10 cases (8.5%) were converted to open hepatectomy during LLR. The conversion group had lower platelet count, shorter distance between the tumor and a medium vessel (defined as diameter of 5-10 mm), and greater tumor depth compared with the pure LLR group. Receiver-operating characteristic curve analysis identified 10 mm as the optimal cutoff value of tumor proximity to a medium vessel (sensitivity, 80.0%, specificity, 78.7%, AUC 0.817) for predicting conversion. In multivariate analysis, lower platelet count (p = .028) and tumor proximity within 10 mm to a medium vessel (p = .001) were independent risk factors for conversion in LLR.

CONCLUSIONS

Our study suggests tumor proximity within 10 mm to a medium vessel and lower platelet count as predictors of unfavorable intraoperative conversion in LLR.

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.

A safe and simple exposure and Pringle maneuver in laparoscopic anatomical liver resection of segment 7

BACKGROUND

Laparoscopic access to liver segment 7 (S7) is difficult for deep surgical situations and bleeding control. Herein, our proposed laparoscopic technique for S7 lesions using a self-designed tube method is introduced.

METHODS

Clinical data of patients who underwent laparoscopic anatomical liver resection of S7 (LALR-S7) with the help of our self-designed tube to improve the exposure of S7 and bleeding control in the Second Affiliated Hospital, Third Military Medical University (Army Medical University) from April 2019 to December 2021 were retrospectively analyzed to evaluate feasibility and safety.

RESULTS

Nineteen patients were retrospectively reviewed. The mean age was 51.3 ± 10.3 years; mean operation time, 194.5 ± 22.7 min; median blood loss, 160.0 ml (150.0-205.0 ml); and median length of hospital stay, 8.0 days (7.0-9.0 days). There was no case conversion to open surgery. Postoperative pathology revealed all cases of hepatocellular carcinoma (HCC). Free surgical margins were achieved in all patients. No major postoperative complications were observed. Patients with postoperative complications recovered after conservative treatment. During outpatient follow-up examination, no other abnormality was presented. All patients survived without tumor recurrence.

CONCLUSIONS

The preliminary clinical effect of our method was safe, reproducible and effective for LALR-S7. Further research is needed due to some limitations of this study.

Efficacy and safety of laparoscopic liver resection for hepatocellular carcinoma in segment 8: a propensity score-matched two-center study

BACKGROUND

The safety and efficacy of laparoscopic liver resection (LLR) have been reported worldwide. However, those of LLR for tumors located in Couinaud's segment 8 are not sufficiently investigated.

METHODS

We retrospectively analyzed 108 patients who underwent liver resection for hepatocellular carcinoma (HCC) in segment 8 at Kobe University Hospital and Hyogo Cancer Center between January 2010 and December 2021. The patients were categorized in LLR and open liver resection (OLR) groups, and 1:1 propensity score matching (PSM) was performed to compare surgical outcomes between the groups.

RESULTS

Forty-seven and 61 patients underwent LLR and OLR, respectively. After PSM, each group contained 34 patients. There was no significant difference in operation time between the groups (331 min vs. 330 min, P = 0.844). Patients in the LLR group had significantly less blood loss (30 mL vs. 468 mL, P < 0.001) and shorter length of postoperative hospital stay (10 days vs. 12 days, P = 0.015) than those in the OLR group. There was no significant difference in the occurrence of postoperative complications between the groups (12% vs. 9%, P = 0.690). Further, the 1-year cumulative incidence of recurrence was not significantly different between the groups (16% vs. 19%, P = 0.734).

CONCLUSIONS

The surgical outcomes and short-term prognosis of LLR were similar or better than those of OLR. LLR could be an effective and safe procedure, even for lesions located in segment 8, which is considered a difficult anatomical location for LLR.

Robotic Versus Laparoscopic Hepatectomy: A Single Surgeon Experience of 629 Consecutive Minimally Invasive Liver Resections

BACKGROUND

Robotic surgery has the potential to broaden the indications for minimally invasive liver surgery owing to its technical advantages. This paper compares our experience with robotic liver surgery (RLS) with conventional laparoscopic liver surgery (LLS).

METHODS

All consecutive liver resections between October 2011 and October 2022 were selected from our prospective database to be included in this cohort study. Patients who underwent RLS were compared with a LLS group for operative and postoperative outcomes.

RESULTS

In total, 629 patients were selected from our database, including 177 patients who underwent a RLS and 452 patients who had LLS. Colorectal liver metastasis was the main indication for surgery in both groups. With the introduction of RLS, the percentage of open resections decreased significantly (32.6% from 2011 to 2020 vs. 11.5% from 2020 onward, P < 0.001). In the robotic group, redo liver surgery was more frequent (24.3% vs. 16.8%, P = 0.031) and the Southampton difficulty score was higher (4 [IQR 4 to 7] vs. 4 [IQR 3 to 6], P = 0.02). Median blood loss was lower (30 vs. 100 ml, P < 0.001), and postoperative length of stay (LOS) was shorter in the robotic group (median 3 vs. 4 days, P < 0.001). There was no significant difference in postoperative complications. Cost related to the used instruments and LOS was significantly lower in the RLS group (median €1483 vs. €1796, P < 0.001 and €1218 vs. €1624, P < 0.001, respectively), while cost related to operative time was higher (median €2755 vs. €2470, P < 0.001).

CONCLUSIONS

RLS may allow for a higher percentage of liver resections to be completed in a minimally invasive way with lower blood loss and a shorter LOS.

Pure abdominal laparoscopic approach versus thoraco-abdominal laparoscopic approach: What is the best technique for liver resection in segment 7 and segment 8? An answer from the Institut Mutualiste Montsouris experience with short- and long-term outcome evaluation

BACKGROUND

Lesions in segments 7 and 8 are a challenge during standard laparoscopic liver resection. The addition of transthoracic trocars could be useful in the standard abdominal approach for laparoscopic liver resection. We report our experience with a thoraco-abdominal laparoscopic combined approach for liver resection with the aim of comparing short- and long-term outcomes.

METHODS

We reviewed 1,003 laparoscopic liver resections in a prospectively maintained, single-institution database. We compared patient outcomes intraoperatively and postoperatively. We analyzed the long-term outcomes of the colorectal liver metastasis subgroup. Propensity score matching 1:1 was performed based on the following variables: age, American Society of Anesthesiologists, body mass index, previous abdominal surgery, multiple or single liver resection, lesion >50 mm or <50 mm, presence of solitary or multiple lesions, T stage, and N stage.

RESULTS

The standard abdominal approach was used in 110 laparoscopic liver resections, and the thoraco-abdominal laparoscopic combined approach was used in 62 laparoscopic liver resections. The thoraco-abdominal laparoscopic combined approach was associated with better intraoperative results (less blood loss and no need for conversion to open surgery). The R1s rate for segmentectomy 7 and 8 was lower in the thoraco-abdominal laparoscopic combined approach in the entire group and in the colorectal liver metastasis subgroup. In the colorectal liver metastasis subgroup, the 3- and 5-year overall survival was 90% and 80% in the thoraco-abdominal laparoscopic combined approach group and 76% and 52% in the standard abdominal approach group, respectively (P = .02). In univariate and multivariate analysis, the thoraco-abdominal laparoscopic combined approach was a significant factor that positively affected disease-free survival and overall survival.

CONCLUSION

The thoraco-abdominal laparoscopic combined approach in laparoscopic liver resection in segments 7 and 8 is safe and feasible, and it has demonstrated better oncologic outcomes than the pure abdominal approach, especially in segmentectomy.