Laparoscopic Liver Resection Difficulty Score-a Validation Study

Risk factor analysis of conversion in laparoscopic liver resection for intrahepatic cholangiocarcinoma

BACKGROUND

The risk factors of patients with intrahepatic cholangiocarcinoma (ICC) requiring conversion to open surgery have not been adequately studied. This study aimed to determine the risk factors and postoperative outcomes of conversion in patients with ICC.

METHODS

From May 2014 to September 2022, Unplanned conversions were compared with successful LLRs.

RESULTS

153 patients with ICC initially underwent LLR, of which 41 (26.8%) required conversion to open surgery. Multivariate analysis for those factors that were statistically significant or confirmed by clinical studies, tumor proximity to the major vessels (OR 6.643, P < 0.001), and previous upper abdominal surgery (OR 3.140, P = 0.040) were independent predictors of unplanned conversions. Compared to successful LLRs, unplanned conversions showed longer operative times (300.0 vs. 225.0 min, P < 0.001), more blood loss (500.0 vs. 200.0 mL, P < 0.001), higher transfusion rates (46.3% vs. 11.6%, P < 0.001), longer length of stays (13.0 vs. 8.0 days, P < 0.001), and higher rates of major morbidity (39.0% vs. 11.6%, P < 0.001). However, there was no statistically significant difference in 30-day or 90-day mortality between the conversion group and the laparoscopic group.

CONCLUSION

Conversion during LLR should be anticipated in ICC patients with prior upper abdominal surgery or tumor proximity to major vessels as features.

Evolution of laparoscopic liver resection in the last two decades: lessons from 2000 cases at a referral Korean center

BACKGROUND AND AIMS

Laparoscopic liver resection (LLR) has evolved to become the standard surgical approach in many referral centers worldwide. The aim of this study was to analyze how LLR evolved at a single high-volume referral center since its introduction, more than two decades ago.

METHODS

Data from all consecutive LLR between January 2003 and September 2022 at the Seoul National University Bundang Hospital were analyzed. Perioperative outcomes were compared between three time periods, with major technological innovations considered as landmarks: before introduction of laparoscopic-US and CUSA (2003-2006), before (2006-2015) and after (2015-2022) introduction of high-definition scope.

RESULTS

During the analyzed time periods the number of technically challenging procedures increased from 39.2 to 61.1% (p < 0.001). The most recent period showed shorter median operation time (from 267.5' to 175', p < 0.001), lower median estimated blood loss (EBL) (from 500 to 300 ml, p < 0.001), lower intraoperative transfusions (from 33.8 to 9.3%, p < 0.001), shorter median postoperative hospital stay (from 12 to 6 days, p < 0.001). The time period, a technical major resection and an underlying liver cirrhosis were found to be the associated with longer operation time (p < 0.001) in the multivariable linear regression analysis, while tumor size, technically major surgeries and liver cirrhosis were associated with higher EBL (p < 0.001).

CONCLUSION

During the last two decades, the indications for patients undergoing LLR have expanded significantly, including more and more challenging procedures and frail patients. Despite such challenges, perioperative outcomes improved, although technically major procedures, cirrhotic patients and huge tumors have still to be considered challenging situations.

Awake robotic liver surgery: A case report

BACKGROUND

In recent years, minimally invasive liver resection has become a standard of care for liver tumors. Considering the need to treat increasingly fragile patients, general anesthesia is sometimes avoided due to respiratory complications. Therefore, surgical treatment with curative intent is abandoned in favor of a less invasive and less radical approach. Epidural anesthesia has been shown to reduce respiratory complications, especially in elderly patients with pre-existing lung disease.

CASE SUMMARY

A 77-year-old man with hepatitis-C-virus-related chronic liver disease underwent robotic liver resection for hepatocellular carcinoma. The patient was suffering from hypertension, diabetes and chronic obstructive pulmonary disease. The National Surgical Quality Improvement Program score for developing pneumonia was 9.2%. We planned a combined spinal-epidural anesthesia with conscious sedation to avoid general anesthesia. No modification of the standard surgical technique was necessary. Hemodynamics were stable and bleeding was minimal. The postoperative course was uneventful.

CONCLUSION

Robotic surgery in locoregional anesthesia with conscious sedation could be considered a safe and suitable approach in specialized centers and in selected patients.

External validation of the Japanese difficulty score for laparoscopic hepatectomy in patients undergoing robotic-assisted hepatectomy

INTRODUCTION

The Japanese difficulty score (JDS) categorizes laparoscopic hepatectomy into low, intermediate, and high complexity procedures, and correlates with operative and postoperative outcomes. We sought to perform a validation study to determine if the JDS correlates with operative and postoperative indicators of surgical complexity for patients undergoing robotic-assisted hepatectomy.

METHODS

Retrospective review of 657 minimally invasive hepatectomy procedures was performed between January 2008 through March 2019. Outcomes included operative time, estimated blood loss (EBL), blood transfusion, complications, post-hepatectomy liver failure (PHLF), length of stay, 30-day readmission, and 30-day and 90-day mortality. Patients were grouped based on JDS defined as: low (< 4), intermediate (4-6), and high (7 +) complexity procedures. Statistical comparisons were analyzed by ANOVA or χ2 test.

RESULTS

241 of 657 patients underwent robotic-assisted resection. Of these patients, 137 were included in the analysis based on JDS: 25 low, 58 intermediate, and 54 high. High JDS was associated with more major resections (≥ 4 contiguous segments) versus minor resections (median JDS 8 vs. 5, P < 0.0001). High JDS was associated with significantly longer operative times, higher EBL, and more blood transfusions. High JDS was associated with higher rates of PHLF at 16.7%, compared with 5.2% intermediate and 0.0% low, (P = 0.018). Complication rates, 30-day readmissions, and mortality rates were similar between groups. Median LOS was longer in patients with high JDS compared with intermediate and low (4 days vs. 3 days vs. 2 days; P = 0.0005).

DISCUSSION

Higher JDS was associated with multiple indicators of operative complexity, including greater extent of resection, increased operative time, EBL, blood transfusion, PHLF, and LOS. This validation study supports the ability of the JDS to categorize patients undergoing robotic-assisted hepatectomy by complexity.

Robotic approach together with an enhanced recovery programme improve the perioperative outcomes for complex hepatectomy

Objective

Robotic surgery has more advantages than traditional surgical approaches to complex liver resection; however, the robotic approach is invariably associated with increased cost. Enhanced recovery after surgery (ERAS) protocols are beneficial in conventional surgeries.

Methods

The present study investigated the effects of robotic surgery combined with an ERAS protocol on perioperative outcomes and hospitalization costs of patients undergoing complex hepatectomy. Clinical data from consecutive robotic and open liver resections (RLR and OLR, respectively) performed in our unit in the pre-ERAS (January 2019-June 2020) and ERAS (July 2020-December 2021) periods were collected. Multivariate logistic regression analysis was performed to determine the impact of ERAS and surgical approaches-alone or in combination-on LOS and costs.

Results

A total of 171 consecutive complex liver resections were analyzed. ERAS patients had a shorter median LOS and decreased total hospitalization cost, without a significant difference in the complication rate compared with the pre-ERAS cohort. RLR patients had a shorter median LOS and decreased major complications, but with increased total hospitalization cost, compared with OLR patients. Comparing the four combinations of perioperative management and surgical approaches, ERAS + RLR had the shortest LOS and the fewest major complications, whereas pre-ERAS + RLR had the highest hospitalization costs. Multivariate analysis found that the robotic approach was protective against prolonged LOS, whereas the ERAS pathway was protective against high costs.

Conclusions

The ERAS + RLR approach optimized postoperative complex liver resection outcomes and hospitalization costs compared with other combinations. The robotic approach combined with ERAS synergistically optimized outcome and overall cost compared with other strategies, and may be the best combination for optimizing perioperative outcomes for complex RLR.

Delimiting Low Level of Difficulty Scoring System Based on the Extent of Resection Difficulty Scoring System for Laparoscopic Liver Resection

Background: The difficulty scoring system based on the extent of resection (DSS-ER) is a common tool for assessing the difficulty and risk of laparoscopic liver resection (LLR), but DSS-ER fails to comprehensively and accurately assess low level for beginners. Methods: The 93 cases of LLRs for primary liver cancer in the general surgery department of the Second Affiliated Hospital of Guangxi Medical University from 2017 to 2021 were retrospectively analyzed. The low level of DSS-ER difficulty scoring system was reclassified into three grades. The intraoperative and postoperative complications were compared among different groups. Results: There were significant differences in the operative time, blood loss, intraoperative allogeneic blood transfusion, conversion to laparotomy, and allogeneic blood transfusion among the different groups. Meanwhile, the postoperative complications were mainly pleural effusion and pneumonia, and the incidence of grade III was higher compared with other two grades. No significant difference existed in the postoperative biliary leakage and liver failure among three grades. Conclusions: This reclassified low level of DSS-ER difficulty scoring system has certain clinical value for LLR beginners to complete the corresponding learning curve.

Association of standardized liver volume and body mass index with outcomes of minimally invasive liver resections

INTRODUCTION

While minimally invasive liver resections (MILR) have demonstrated advantages in improved post-operative recovery, widespread adoption is hampered by inherent technical difficulties. Our study attempts to analyze the role of anthropometric measures in MILR-related outcomes.

METHODS

Between 2012 and 2020, 676 consecutive patients underwent MILR at the Singapore General Hospital of which 565 met study criteria and were included. Patients were stratified based on Body Mass Index (BMI) as well as Standardized Liver Volumes (SLV). Associations between BMI and SLV to selected peri-operative outcomes were analyzed using restricted cubic splines.

RESULTS

A BMI of ≥ 29 was associated with increase in blood loss [Mean difference (MD) 69 mls, 95% CI 2 to 137] as well as operative conversions [Relative Risk (RR) 1.63, 95% CI 1.02 to 2.62] among patients undergoing MILR while a SLV of 1600 cc or higher was associated with an increase in blood loss (MD 30 mls, 95% CI 10 to 49). In addition, a BMI of ≤ 20 was associated with an increased risk of major complications (RR 2.25, 95% 1.16 to 4.35). The magnitude of differences observed in these findings increased with each unit change in BMI and SLV.

CONCLUSION

Both BMI and SLV were useful anthropometric measures in predicting peri-operative outcomes in MILR and may be considered for incorporation in future difficulty scoring systems for MILR.

A machine learning analysis of difficulty scoring systems for laparoscopic liver surgery

INTRODUCTION

In the last decade, several difficulty scoring systems (DSS) have been proposed to predict technical difficulty in laparoscopic liver resections (LLR). The present study aimed to investigate the ability of four DSS for LLR to predict operative, short-term, and textbook outcomes.

METHODS

Patients who underwent LLR at a single tertiary referral center from January 2014 to June 2020 were included in the present study. Four DSS for LLR (Halls, Hasegawa, Kawaguchi, and Iwate) were investigated to test their ability to predict operative and postoperative complications. Machine learning algorithms were used to identify the most important DSS associated with operative and short-term outcomes.

RESULTS

A total of 346 patients were included in the analysis, 28 (8.1%) patients were converted to open surgery. A total of 13 patients (3.7%) had severe (Clavien-Dindo ≥ 3) complications; the incidence of prolonged length of stay (> 5 days) was 39.3% (n = 136). No patients died within 90 days after the surgery. According to Halls, Hasegawa, Kawaguchi, and Iwate scores, 65 (18.8%), 59 (17.1%), 57 (16.5%), and 112 (32.4%) patients underwent high difficulty LLR, respectively. In accordance with a random forest algorithm, the Kawaguchi DSS predicted prolonged length of stay, high blood loss, and conversions and was the best performing DSS in predicting postoperative outcomes. Iwate DSS was the most important variable associated with operative time, while Halls score was the most important DSS predicting textbook outcomes. No one of the DSS investigated was associated with the occurrence of complication.

CONCLUSIONS

According to our results DDS are significantly related to surgical complexity and short-term outcomes, Kawaguchi and Iwate DSS showed the best performance in predicting operative outcomes, while Halls score was the most important variable in predicting textbook outcome. Interestingly, none of the DSS showed any correlation with or importance in predicting overall and severe postoperative complications.

Perioperative Outcomes of Laparoscopic Liver Resection and Risk Factors for Adverse Events

PURPOSE

The perioperative outcomes and risk factors associated with adverse events (AEs) after initial laparoscopic liver resection (LLR) are unclear. We studied the outcomes of LLR and identified the predictive factors for AEs.

MATERIALS AND METHODS

Data from 100 adults who underwent LLR between April 2014 and February 2020 were reviewed. Baseline characteristics, surgery details, intraoperative data, and postoperative outcomes were tabulated. The AEs included conversion to open surgery, morbidity, and mortality.

RESULTS

Major and minor LLRs accounted for 16% and 84% of cases, respectively. Of the indications for LLR, 88% were malignancies. Conversion to open surgery was necessary for 7% of the patients, the overall morbidity rate was 21%, the major morbidity rate was 7%, and the 90-day mortality rate was 1%. Although the incidence of AEs was higher after major LLR (37.5%) than after minor LLR (21.4%), the difference was not statistically significant (P=0.095); the rate of AEs in the resection of posterosuperior segments (43.7%) did not significantly differ from that of the anteroinferior segments (19.2%; P=0.095). Multivariable analysis revealed that the significant predictors of AEs included American Society of Anesthesiologists (ASA) class III (odds ratio, 5.76; 95% confidence interval, 1.74-19.1; P=0.003) and an operative time longer than 5 hours (odds ratio, 9.20; 95% confidence interval, 2.41-35.07; P<0.001).

CONCLUSION

To improve outcomes in LLR, patients with ASA class III and those in whom surgery is expected to last longer than 5 hours should be taken into account for better patient selection.

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.

A retrospective and prospective study to establish a preoperative difficulty predicting model for video-assisted thoracoscopic lobectomy and mediastinal lymph node dissection

Background

In previous studies, the difficulty of surgery has rarely been used as a research object. Our study aimed to develop a predictive model to enable preoperative prediction of the technical difficulty of video-assisted thoracoscopic lobectomy and mediastinal lymph node dissection using retrospective data and to validate our findings prospectively.

Methods

Collected data according to the designed data table and took the operation time as the outcome variable. A nomogram to predict the difficulty of surgery was established through Lasso logistic regression. The prospective datasets were analyzed and the outcome was the operation time.

Results

This retrospective study enrolled 351 patients and 85 patients were included in the prospective datasets. The variables in the retrospective research were selected by Lasso logistic regression (only used for modeling and not screening), and four significantly related influencing factors were obtained: FEV1/FVC (forced expiratory volume in the first second/forced vital capacity) (p < 0.001, OR, odds ratio = 0.89, 95% CI, confidence interval = 0.84–0.94), FEV1/pred FEV1 (forced expiratory volume in the first second/forced expiratory volume in the first second in predicted) (p = 0.076, OR = 0.98, 95% CI = 0.95–1.00), history of lung disease (p = 0.027, OR = 4.00, 95% CI = 1.27–15.64), and mediastinal lymph node enlargement or calcification (p < 0.001, OR = 9.78, 95% CI = 5.10–19.69). We used ROC (receiver operating characteristic) curves to evaluate the model. The training set AUC (area under curve) value was 0.877, the test set’s AUC was 0.789, and the model had a good calibration curve. In a prospective study, the data obtained in the research cohort were brought into the model again for verification, and the AUC value was 0.772.

Conclusion

Our retrospective study identified four preoperative variables that are correlated with a longer surgical time and can be presumed to reflect more difficult surgical procedures. Our prospective study verified that the variables in the prediction model (including prior lung disease, FEV1/pred FEV1, FEV1/FVC, mediastinal lymph node enlargement or calcification) were related to the difficulty.

A systematic review and meta-analysis of randomized controlled trials comparing laparoscopic and open liver resection

BACKGROUND/PURPOSE

The dissemination of laparoscopic liver resection (LLR) has been based on non-randomized studies and reviews of these. Aim of this study was to evaluate if the randomized evidence comparing LLR to open liver resection (OLR) supports these findings.

METHODS

A prospectively registered (reviewregistry866) systematic review and meta-analysis following Cochrane and PRISMA guidelines comparing LLR to OLR for benign and malignant diseases was performed via Medline, Web of Science, CENTRAL up to 31.12.2020. The main outcome was postoperative complications. Risk of bias was assessed with the Cochrane Risk of Bias tool 2.0, certainty of evidence was assessed using the GRADE approach.

RESULTS

The search yielded 2080 results. 13 RCTs assessing mostly minor liver resections with 1457 patients were included. There were reduced odds of experiencing any complication (Odds ratio (OR) [95% confidence interval (CI)]: 0·42 [0·30, 0·58]) and severe complications (OR[CI]: 0·51 [0·31, 0·84]) for patients undergoing LLR. LOS was shorter (Mean difference (MD) [CI]: -2·90 [-3·88, -1·92] days), blood loss was lower (MD: [CI]: -115·41 [-146·08, -84·75] ml), and functional recovery was better for LLR. All other outcomes showed no significant differences.

CONCLUSIONS

LLR shows significant postoperative benefits. RCTs assessing long-term outcomes and major resections are needed.

Impact of introduction of an enhanced recovery protocol on the outcomes of laparoscopic liver resections: A propensity-score matched study

BACKGROUND

Presently, data on the impact of enhanced recovery protocols on the outcomes of laparoscopic liver resection remain limited. We performed propensity matched analysis comparing the outcomes between patients undergoing laparoscopic liver resection before and after the introduction of an enhanced recovery protocol.

METHODS

Between 2013 and 2019, 462 consecutive patients underwent laparoscopic liver resection by 3 surgeons of which 360 met the study inclusion criteria. There were 89 patients who underwent surgery under an enhanced recovery protocol and 271 without an enhanced recovery protocol. One-to-one propensity matched analysis was performed for 84 enhanced recovery protocol patients and 84 nonenhanced recovery protocol patients.

RESULTS

Comparisons between propensity matched cohorts revealed that patients who received laparoscopic liver resection with enhanced recovery protocol had reduced median blood loss (200 vs 300 mL, P = .013), postoperative stay (3 vs 4 days, P = .003), and lower open conversion rates (0% vs 8.3%, P = .008). There was no difference in other key perioperative outcomes such as operation time, postoperative morbidity, postoperative major morbidity, and 30-day readmission rates.

CONCLUSION

A combined approach of enhanced recovery protocol and laparoscopic liver resection was associated with improved perioperative outcomes as opposed to laparoscopic liver resection alone.

Impact of tumor size on the difficulty of minimally invasive liver resection

INTRODUCTION

We performed this study in order to investigate the impact of tumour size on the difficulty of MILR, as well as to elucidate the optimal tumour size cut-off/s to distinguish between 'easy' and 'difficult' MILRs.

MATERIALS AND METHODS

This is retrospective review of 603 consecutive patients who underwent MILR between 2006 and 2019 of which 461 met the study inclusion criteria. We first conducted an exploratory analysis to visualize the associations between tumor size and various surrogates of laparoscopic difficulty in order to determine to optimal tumor size cutoff for stratification. Visual inspection of flexible spline-based models as well as quantitative evidence determined that perioperative outcomes differed between patients with tumor size of 30-69 mm and tumours ≥70 mm. These cutoffs were used for further downstream analyses.

RESULTS

The cohort of 461 patients was divided into 3 groups based on tumour diameter size. Patients with larger tumours experienced longer operating times ((P_{Group 2 vs 1}<0.001, P_{Group 3 vs 1}<0.001, P_{Group 3 vs 2}<0.001), higher blood loss (P_{Group 2 vs 1}<0.001, P_{Group 3 vs 1}<0.001, P_{Group 3 vs 2}<0.001), as well as significantly longer hospital stay (P_{Group 2 vs 1}<0.001, P_{Group 3 vs 1}<0.001, P_{Group 3 vs 2}<0.001). There was a monotonic trend towards increasing blood transfusion rates (P = 0.006), overall morbidity (P = 0.029) and 90-day mortality rates (P = 0.047) with increasing tumour size.

CONCLUSION

Although tumour size of 30 mm serves as an optimal cut-off for predicting difficult resections as per the Iwate criteria, a trichotomy (<30 mm, 30-69 mm, ≥70 mm) may provide additional granularity. Further large-scale prospective studies are needed to corroborate these findings.

Evaluation of the Iwate Model for Predicting the Difficulty of Laparoscopic Liver Resection: Does Tumor Size Matter?

BACKGROUND

This study aimed to externally validate the Iwate scoring model and its prognostic value for predicting the risks of intra- and postoperative complications of laparoscopic liver resection.

METHODS

Consecutive patients who underwent pure laparoscopic liver resection between 2008 and 2019 at a single tertiary center were included. The Iwate scores were calculated according to the original proposition (four difficulty levels based on six indices). Intra- and postoperative complications were compared across difficulty levels. Fitting the obtained data to the cumulative density function of the Weibull distribution and a linear function provided the mean risk curves for intra- and postoperative complications, respectively.

RESULTS

The difficulty levels of 142 laparoscopic liver resections were scored as low, intermediate, advanced, and expert level in 41 (28.9%), 53 (37.3%), 32 (22.5%), and 16 (11.3%) patients, respectively. Intraoperative complications were detected in 26 (18.3%) patients and its rates (2.4%, 7.5%, 34.3%, and 62.5%) increased gradually with statistically significant values among difficulty levels (P ˂ 0.001). Major postoperative complications occurred in 21 (14.8%) patients and its rates (4.8%, 5.6%, 28.1%, 43.7%; P ˂ 0.001) showed the same trend as for intraoperative complications. Then, the mean risk curves of both complications were obtained. Due to outliers, a new threshold for a tumor size index was proposed at 38 mm. The repeated analysis showed improved results.

CONCLUSIONS

The Iwate scoring model predicts the probability of complications across difficulty levels. Our proposed tumor size threshold (38 mm) improves the quality of the prediction. The model is upgraded by a probability of complications for every difficulty score.

Validation and comparison of the Iwate, IMM, Southampton and Hasegawa difficulty scoring systems for primary laparoscopic hepatectomies

BACKGROUND

Various difficulty scoring systems (DSS) have been formulated to grade the complexity of laparoscopic hepatectomies (LH). This study aims to externally validate and compare 4 contemporary DSS including the Iwate, Institut Mutualiste Montsouris (IMM), Southampton and Hasegawa DSS in predicting the intraoperative technical difficulty and postoperative outcomes after LH.

METHODS

Retrospective review of 548 consecutive patients who underwent LH of which 455 met the study inclusion criteria. Outcomes measures of technical difficulty included operation time, Pringles maneuver, blood loss and blood transfusion rate. Postoperative outcomes measured included morbidity, major morbidity and postoperative hospital stay.

RESULTS

There was a statistically significant progressive increase in blood loss, blood transfusion rate, operation time and postoperative stay associated with all 4 DSS. There was also good calibration with respect to blood loss, operation time, Pringles maneuver, open conversion rate, postoperative morbidity, postoperative major morbidity and postoperative stay for all 4 DSS. The Southampton score demonstrated the poorest calibration in terms of operation time and discrimination in terms of application of Pringles maneuver and major morbidity amongst all 4 systems.

CONCLUSION

All 4 DSS significantly correlated with outcome measures associated with intraoperative technical difficulty and postoperative outcomes. The Southampton DSS was the poorest system in our cohort of patients.

Laparoscopic Liver Resection Should Be a Standard Procedure for Hepatocellular Carcinoma with Low or Intermediate Difficulty

BACKGROUND

To investigate the feasibility of laparoscopic liver resection (LLR) for hepatocellular carcinoma (HCC), we compared the outcome between LLR and conventional open liver resection (OLR) in patient groups with different IWATE criteria difficulty scores (DS).

METHODS

We retrospectively reviewed 607 primary HCC patients (LLR: 81, OLR: 526) who underwent liver resection in Linkou Chang Gung Memorial hospital from 2012 to 2019. By using 1:1 propensity score-matched (PSM) analysis, their baseline characteristics and the DS stratified by the IWATE criteria were matched between the LLR and OLR. Their perioperative and oncologic outcomes were compared.

RESULTS

After 1:1 PSM, 146 patients (73 in LLR, 73 in OLR) were analyzed. Among them, 13, 41, 13 and 6 patients were classified as low, intermediate, advanced and expert DS group, respectively. Compared to OLR, the LLR had shorter hospital stay (9.4 vs. 11.5 days, p = 0.071), less occurrence of surgical complications (16.4% vs. 30.1%, p = 0.049), lower rate of hepatic inflow control (42.5% vs. 65.8%, p = 0.005), and longer time of inflow control (70 vs. 51 min, p = 0.022). The disease-free survival (DFS) and overall survivals were comparable between the two groups. While stratified by the DS groups, the LLR tended to have lower complication rate and shorter hospital stay than OLR. The DFS of LLR in the intermediate DS group was superior to that of the OLR (p = 0.020). In the advanced and expert DS groups, there were no significant differences regarding outcomes between the two groups.

CONCLUSION

We have demonstrated that with sufficient experience and technique, LLR for HCC is feasible and the perioperative outcome is favorable. Based on the current study, we suggest LLR should be a standard procedure for HCC with low or intermediate difficulty. It can provide satisfactory postoperative recovery and comparable oncological outcomes. Further larger scale prospective studies are warranted to validate our findings.

Surgical outcomes of 118 complex laparoscopic liver resections: a single- center experience

BACKGROUND

Indications for laparoscopic liver resection (LLR) are continuously expanding. The Japanese Society of Hepato-Biliary-Pancreatic Surgery defines highly difficult hepatectomy as a procedure involving one or more sections (except for left lateral sectionectomy) or anatomical segmentectomy. This study aimed to assess the outcomes of complex LLR procedures and compare their technical difficulties, about which only a little is known to date.

METHODS

We performed a retrospective review of the operative outcomes of 118 consecutive patients who underwent pure laparoscopic complex hepatectomy. The surgical outcomes, including operative times, blood loss amounts, and postoperative morbidity rates, were compared among complex LLR procedures.

RESULTS

The overall median operative time was 280 minutes, and the median intraoperative blood loss was 86 mL. Two patients required conversion to open laparotomy (1.7%). The postoperative major morbidity rate was 11.0% Posterosuperior segmentectomy, right hemihepatectomy, and anterior sectionectomy required the longest operative times. Anterior and posterior sectionectomy resulted in the highest blood loss, and right hemihepatectomy and anterior sectionectomy resulted in the most complications.

CONCLUSIONS

The surgical difficulties associated with complex LLR procedures vary. It is critical to recognize the specific risks and cautionary points to ensure patient safety and provide proper systemic training to surgeons.

A novel difficulty grading system for laparoscopic living donor nephrectomy

Background

Several difficulty grading systems have been developed as a useful tool for selecting patients and training surgeons in laparoscopic procedures. However, there is little information on predicting the difficulty of laparoscopic donor nephrectomy (LDN). The aim of this study was to develop a grading system to predict the difficulty of LDN.

Methods

Data of 1741 living donors, who underwent pure or hand-assisted LDN between 1994 and 2018 were analyzed. Multivariable analyses were performed to identify factors associated with prolonged operative time, defined as a difficulty index with 0 to 8. The difficulty of LDN was classified into three levels based on the difficulty index.

Results

Multivariable analyses identified that male (odds ratio [OR] 1.69, 95% CI 1.37–2.09, P < 0.001), BMI > 28 (OR 1.36, 95% CI 1.08–1.72, P = 0.009), pure LDN (OR 1.99, 95% CI 1.53–2.60, P < 0.001), multiple renal arteries (OR 2.38, 95% CI 1.83–3.10, P < 0.001) and multiple renal veins (OR 2.18, 95% CI 1.52–3.16, P < 0.001) were independent risk factors influencing prolonged operative time. The difficulty index based on these factors was calculated and categorized into three levels: low (0–2), intermediate (3–5), and high (6–8) difficulty. Operative time was significantly longer in the high difficulty group (225 min) than in the low (169 min, P < 0.001) and intermediate difficulty group (194 min, P < 0.001). The conversion rate was higher in the high difficulty group (4.4%) than in the low (2.1%, P = 0.04) and the intermediate difficulty group (3.0%, P = 0.27). No significant difference in major complications was found between the groups.

Conclusion

We developed a novel grading system with simple preoperative donor factors to predict the difficulty of LDN. This grading system may help surgeons in patient selection to advance their experiences and/or teach fellows from simple to difficult LDN.

Robotic Liver Resection

Robotic surgery has rapidly evolved. It is particularly attractive as an alternative minimally invasive approach in liver surgery because of improvements in visualization and articulated instruments. Limitations include increased operative times and lack of tactile feedback, but these have not been shown in studies. Considerations unique to robotic surgery, including safety protocols, must be put in place and be reviewed at the beginning of every procedure to ensure safety in the event of an emergent conversion. Despite the lack of early adoption by many hepatobiliary surgeons, robotic liver surgery continues to evolve and find its place within hepatobiliary surgery.

The external validation of a difficulty scoring system for predicting the risk of intraoperative complications during laparoscopic liver resection

BACKGROUND

This study aimed to externally validate and upgrade the recent difficulty scoring system (DSS) proposed by Halls et al. to predict intraoperative complications (IOC) during laparoscopic liver resection (LLR).

METHODS

The DSS was validated in a cohort of 128 consecutive patients undergoing pure LLRs between 2008 and 2019 at a single tertiary referral center. The validated DSS includes four difficulty levels based on five risk factors (neoadjuvant chemotherapy, previous open liver resection, lesion type, lesion size and classification of resection). As established by the validated DSS, IOC was defined as excessive blood loss (> 775 mL), conversion to an open approach and unintentional damage to surrounding structures. Additionally, intra- and postoperative outcomes were compared according to the difficulty levels with usual statistic methods. The same five risk factors were used for validation done by linear and advanced nonlinear (artificial neural network) models. The study was supported by mathematical computations to obtain a mean risk curve predicting the probability of IOC for every difficulty score.

RESULTS

The difficulty level of LLR was rated as low, moderate, high and extremely high in 36 (28.1%), 63 (49.2%), 27 (21.1%) and 2 (1.6%) patients, respectively. IOC was present in 23 (17.9%) patients. Blood loss of >775 mL occurred in 8 (6.2%) patients. Conversion to open approach was required in 18 (14.0%) patients. No patients suffered from unintentional damage to surrounding structures. Rates of IOC (0, 9.5, 55.5 and 100%) increased gradually with statistically significant value among difficulty levels (P < 0.001). The relations between the difficulty level, need for transfusion, operative time, hepatic pedicle clamping, and major postoperative morbidity were statistically significant (P < 0.05). Linear and nonlinear validation models showed a strong correlation (correlation coefficients 0.914 and 0.948, respectively) with the validated DSS. The Weibull cumulative distribution function was used for predicting the mean risk probability curve of IOC.

CONCLUSION

This external validation proved this DSS based on patient's, tumor and surgical factors enables us to estimate the risk of intra- and postoperative complications. A surgeon should be aware of an increased risk of complications before starting with more complex procedures.