Analysis of economic impact of laparoscopic liver resection according to surgical difficulty

Predicting the complexity of minimally invasive liver resection for hepatocellular carcinoma using machine learning

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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

Gradual expansion of the indications for minimally invasive liver resection to include highly complex procedures may improve postoperative outcomes

Aim: Liver resection is performed in patients with benign and malignant liver tumors. Advancements in surgical instruments and improved perioperative management have enabled safe laparoscopic and robotic liver resections. Herein, we aimed to evaluate the patients who underwent minimally invasive liver resection (MISLR) and compare their short-term outcomes with those of patients who underwent open liver resection (OLR), according to surgical complexity.

Methods: Data of patients who underwent liver resection at our institution from January 2011 to August 2023 were obtained from a prospectively maintained database. We gradually expanded the indications for MISLR from technically less demanding procedures to intermediate- and high-complexity MISLRs. The procedures were categorized into three grades (low, intermediate, and high) according to the liver resection complexity classification.

Results: Of the 1,866 patients who underwent liver resection, 953 were included in the analysis. Of the 953 patients, 781 underwent OLR and 172 underwent MISLR. The operative time and estimated blood loss increased with the increase in surgical complexity in the MISLR group, which was similar to finding in the OLR group. The complication rate also increased with the increase in surgical complexity in the OLR group (low complexity vs. high complexity, 34.8% vs. 50.1%). However, the complication rate was steadily low and approximately 10% across all complexity grades in the MISLR group.

Conclusion: Careful selection and gradual expansion of the indications of MISLR may facilitate improved postoperative outcomes in patients undergoing highly complex MISLRs.

Outcomes after laparoscopic or open liver resection for nonalcoholic fatty liver disease-associated hepatocellular carcinoma: a propensity score-matching study

BACKGROUND

Laparoscopic liver resection (LLR) is rapidly gaining popularity; however, its efficacy for nonalcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC) (NAFLD-HCC) has been not evaluated. The purpose of this study was to compare short- and long-term outcomes between LLR and open liver resection (OLR) among patients with NAFLD-HCC.

METHODS

We used a single-institution database to analyze data for patients who underwent LLR or OLR for NAFLD-HCC from January 2007 to December 2022. We performed propensity score-matching analyses to compare overall postoperative complications, major morbidities, duration of surgery, blood loss, transfusion, length of stay, recurrence, and survival between the two groups.

RESULTS

Among 210 eligible patients, 46 pairs were created by propensity score matching. Complication rates were 28% for OLR and 11% for LLR (p = 0.036). There were no significant differences in major morbidities (15% vs. 8.7%, p = 0.522) or duration of surgery (199 min vs. 189 min, p = 0.785). LLR was associated with a lower incidence of blood transfusion (22% vs. 4.4%, p = 0.013), less blood loss (415 vs. 54 mL, p < 0.001), and shorter postoperative hospital stay (9 vs. 6 days, p < 0.001). Differences in recurrence-free survival and overall survival between the two groups were not statistically significant (p = 0.222 and 0.301, respectively).

CONCLUSIONS

LLR was superior to OLR for NAFLD-HCC in terms of overall postoperative complications, blood loss, blood transfusion, and postoperative length of stay. Moreover, recurrence-free survival and overall survival were comparable between LLR and OLR. Although there is a need for careful LLR candidate selection according to tumor size and location, LLR can be regarded as a preferred treatment for NAFLD-HCC over OLR.

External validation of different difficulty scoring systems of laparoscopic liver resection for hepatocellular carcinoma

BACKGROUND

Several difficulty scoring systems (DSSs) have been proposed for evaluating difficulty of laparoscopic liver resection (LLR) and no study has validated their performance in a hepatocellular carcinoma (HCC)-only cohort at the same time.

METHODS

All cases with HCC that underwent LLR from January 2015 to December 2020 in our center were retrospectively collected. Performance of the IWATE-DSS, Halls-DSS, Hasegawa-DSS, and Kawaguchi-DSS in predicting perioperative outcomes was evaluated. Subgroup analyses were conducted to compare perioperative outcomes between surgeons on the learning curve and surgeons that have gone through the learning curve.

RESULTS

For all four DSSs, there were significant distributions of applying bleeding control, surgical time, estimated blood loss, postoperative major complications, and postoperative hospital stay among different groups of each DSS (P all < 0.05). Conversion to laparotomy or not was significantly distributed in different groups of the IWATE-DSS (P = 0.006) and Halls-DSS (P = 0.022), while it was not in the Hasegawa-DSS (P = 0.056) and Kawaguchi-DSS (P = 0.183). Trend tests showed that the conversion rates increased with higher DSS points in the IWATE-DSS (P < 0.001) and the Kawaguchi-DSS (P = 0.021), while not in the Halls-DSS (P = 0.064) and the Hasegawa-DSS (P = 0.068). In the medium and advanced/expert difficulty-level subgroups defined by the IWATE-DSS, there were larger estimated blood loss (P in medium-difficulty group = 0.009; P in the advanced/expert difficulty group = 0.004) and longer postoperative hospital stay (P in the medium-difficulty group = 0.012; P in the advanced/expert group = 0.035) in the learner-performed cases.

CONCLUSIONS

All DSSs performed well in predicting applying bleeding control, surgical time, estimated blood loss, postoperative major complications, and postoperative hospital stay, while only the IWATE-DSS was able to predict whether conversion to laparotomy or not for HCC patients underwent LLR. The IWATE-DSS was also able to help surgeons on the LLR learning curve choose cases and guide clinical practices.

Postoperative fever after liver resection: Incidence, risk factors, and characteristics associated with febrile infectious complication

Purpose

To evaluate the incidence and risk factors of postoperative fever (POF) after liver resection. In patients with POF, predictors of febrile infectious complications were determined.

Methods

A total of 797 consecutive patients undergoing liver resection from January 2015 to December 2019 were retrospectively investigated. POF was defined as body temperature ≥ 38.0°C in the postoperative period. POF was characterized by time of first fever, the highest temperature, and frequency of fever. The Institut Mutualiste Montsouris (IMM) classification was used to stratify surgical difficulty, from grade I (low), grade II (intermediate) to grade III (high). Postoperative leukocytosis was defined as a 70% increase of white blood cell count from the preoperative value. Multivariate analysis was performed to identify risk factors for POF and predictors of febrile infectious complications.

Results

Overall, 401 patients (50.3%) developed POF. Of these, 10.5% had the time of first fever > postoperative day (POD) 2, 25.9% had fever > 38.6°C, and 60.6% had multiple fever spikes. In multivariate analysis, risk factors for POF were: IMM grade III resection (OR 1.572, p = 0.008), Charlson Comorbidity Index score > 3 (OR 1.872, p < 0.001), and serum albumin < 3.2 g/dL (OR 3.236, p = 0.023). 14.6% patients developed infectious complication, 21.9% of febrile patients and 7.1% of afebrile patients (p < 0.001). Predictors of febrile infectious complications were: fever > 38.6°C (OR 2.242, p = 0.003), time of first fever > POD2 (OR 6.002, p < 0.001), and multiple fever spikes (OR 2.039, p = 0.019). Sensitivity, specificity, positive predictive value and negative predictive value for fever > 38.6°C were 39.8%, 78.0%, 33.7% and 82.2%, respectively. A combination of fever > 38.6°C and leukocytosis provided high specificity of 95.2%.

Conclusion

In this study, we found that IMM classification, CCI score, and serum albumin level related with POF development in patients undergone liver resection. Time of first fever > POD2, fever > 38.6°C, and multiple fever spikes indicate an increased risk of febrile infectious complication. These findings may aid decision-making in patients with POF who require further diagnostic workup.