Factors associated with and impact of open conversion on the outcomes of minimally invasive left lateral sectionectomies: An international multicenter study

Risk factors and outcomes of conversions in robotic and laparoscopic liver resections: A nationwide analysis

BACKGROUND

Unfavorable intraoperative findings or incidents during minimally invasive liver surgery may necessitate conversion to open surgery. This study aimed to identify predictors for conversion in minimally invasive liver surgery and gain insight into outcomes following conversions.

METHODS

This nationwide, retrospective cohort study compared converted and non-converted minimally invasive liver surgery procedures using data from 20 centers in the Dutch Hepatobiliary Audit (2014-2022). Propensity score matching was applied. Subgroup analyses of converted robotic liver resection versus laparoscopic liver resection and emergency versus non-emergency conversions were performed. Predictors for conversions were identified using backward stepwise multivariable logistic regression.

RESULTS

Of 3,530 patients undergoing minimally invasive liver surgery (792 robotic liver resection, 2,738 laparoscopic liver resection), 408 (11.6%) were converted (4.9% robotic liver resection, 13.5% laparoscopic liver resection). Conversion was associated with increased blood loss (580 mL [interquartile range 250-1,200] vs 200 mL [interquartile range 50-500], P < .001), major blood loss (≥500 mL, 58.8% vs 26.7%, P < .001), intensive care admission (19.0% vs 8.4%, P = .005), overall morbidity (38.9% vs 21.0%, P < .001), severe morbidity (17.9% vs 9.6%, P = .002), and a longer hospital stay (6 days [interquartile range 5-8] vs 4 days [interquartile range 2-5], P < .001) but not mortality (2.2% vs 1.2%, P = .387). Emergency conversions had increased intraoperative blood loss (1,500 mL [interquartile range 700-2,800] vs 525 mL [interquartile range 208-1,000], P < .001), major blood loss (87.5% vs 59.3%, P = .005), and intensive care admission (27.9% vs 10.6%, P = .029), compared with non-emergency conversions. Robotic liver resection was linked to lower conversion risk, whereas American Society of Anesthesiologists grade ≥3, larger lesion size, concurrent ablation, technically major, and anatomically major resections were risk factors.

CONCLUSION

Both emergency and non-emergency conversions negatively impact perioperative outcomes in minimally invasive liver surgery. Robotic liver resection reduces conversion risk compared to laparoscopic liver resection.

Robotic Versus Laparoscopic Liver Resection: A Nationwide Propensity Score Matched Analysis

Objective

To compare nationwide outcomes of robotic liver resection (RLR) with laparoscopic liver resection (LLR).

Background

Minimally invasive liver resection is increasingly performed using the robotic approach as this could help overcome inherent technical limitations of laparoscopy. It is unknown if this translates to improved patient outcomes.

Methods

Data from the mandatory Dutch Hepatobiliary Audit were used to compare perioperative outcomes of RLR and LLR in 20 centers in the Netherlands (2014-2022). Propensity score matching (PSM) was used to mitigate selection bias. Sensitivity analyses assessed the impact of the learning curve (≥50 procedures for LLR and ≥25 procedures for RLR), concurrent noncholecystectomy operations, high-volume centers, and conversion on outcomes.

Results

Overall, 792 RLR and 2738 LLR were included. After PSM (781 RLR vs 781 LLR), RLR was associated with less blood loss (median: 100 mL [interquartile range (IQR): 50-300] vs 200 mL [IQR: 50-500], P = 0.002), less major blood loss (≥500 mL,18.6% vs 25.2%, P = 0.011), less conversions (4.9% vs 12.8%, P < 0.001), and shorter hospital stay (median: 3 days [IQR: 2-5] vs 4 days [IQR: 2-6], P < 0.001), compared with LLR. There were no significant differences in overall and severe morbidity, readmissions, mortality, and R0 resection rate. Sensitivity analyses yielded similar results. When excluding conversions, RLR was only associated with a reduction in reoperations (1.1% vs 2.7%, P = 0.038).

Conclusion

In this nationwide analysis, RLR was associated with a reduction in conversion, blood loss and length of hospital stay without compromising patient safety, also when excluding a learning curve effect. The benefits of RLR seem to be mostly related to a reduction in conversions.

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

INTRODUCTION

Despite the increasing widespread adoption and experience in minimally invasive liver resections (MILR), open conversion occurs not uncommonly even with minor resections and as been reported to be associated with inferior outcomes. We aimed to identify risk factors for and outcomes of open conversion in patients undergoing minor hepatectomies. We also studied the impact of approach (laparoscopic or robotic) on outcomes.

METHODS

This is a post-hoc analysis of 20,019 patients who underwent RLR and LLR across 50 international centers between 2004-2020. Risk factors for and perioperative outcomes of open conversion were analysed. Multivariate and propensity score-matched analysis were performed to control for confounding factors.

RESULTS

Finally, 10,541 patients undergoing either laparoscopic (LLR; 89.1%) or robotic (RLR; 10.9%) minor liver resections (wedge resections, segmentectomies) were included. Multivariate analysis identified LLR, earlier period of MILR, malignant pathology, cirrhosis, portal hypertension, previous abdominal surgery, larger tumor size, and posterosuperior location as significant independent predictors of open conversion. The most common reason for conversion was technical issues (44.7%), followed by bleeding (27.2%), and oncological reasons (22.3%). After propensity score matching (PSM) of baseline characteristics, patients requiring open conversion had poorer outcomes compared with successful MILR cases as evidenced by longer operative times, more blood loss, higher requirement for perioperative transfusion, longer duration of hospitalization and higher morbidity, reoperation, and 90-day mortality rates.

CONCLUSIONS

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

Textbook outcome in liver surgery: open vs minimally invasive hepatectomy among patients with hepatocellular carcinoma

BACKGROUND

We sought to investigate whether minimally invasive hepatectomy (MIH) was superior to open hepatectomy (OH) in terms of achieving textbook outcome in liver surgery (TOLS) after resection of hepatocellular carcinoma (HCC).

METHODS

Patients who underwent resection of HCC between 2000 and 2020 were identified from an international database. TOLS was defined by the absence of intraoperative grade ≥2 events, R1 resection margin, posthepatectomy liver failure, bile leakage, major complications, in-hospital mortality, and readmission.

RESULTS

A total of 1039 patients who underwent HCC resection were included in the analysis. Although most patients underwent OH (n = 724 [69.7%]), 30.3% (n = 315) underwent MIH. Patients who underwent MIH had a lower tumor burden score (3.6 [IQR, 2.6-5.2] for MIH vs 6.1 [IQR, 3.9-10.1] for OH) and were more likely to undergo minor hepatectomy (84.1% [MIH] vs 53.6% [OH]) than patients who had an OH (both P < .001). After propensity score matching to control for baseline differences between the 2 cohorts, the incidence of TOLS was comparable among patients who had undergone MIH (56.6%) versus OH (64.8%) (P = .06). However, MIH was associated with a shorter length of hospital stay (6.0 days [IQR, 4.0-8.0] for MIH vs 9.0 days [IQR, 6.0-12.0] for OH). Among patients who had MIH, the odds ratio of achieving TOLS remained stable up to a tumor burden score of 4; after which the chance of TOLS with MIH markedly decreased.

CONCLUSION

Patients with HCC who underwent resection with MIH versus OH had a comparable likelihood of TOLS, although MIH was associated with a short length of stay.

Laparoscopic hepatectomy for hepatocellular carcinoma in patients with clinically significant portal hypertension: a systematic review and meta-analysis

OBJECTIVE

To compare the effects of laparoscopic hepatectomy (LH) on the short-term and long-term outcomes in hepatocellular carcinoma (HCC) patients with and without clinically significant portal hypertension (CSPH).

METHODS

A systematic literature search of the PubMed, EMBASE, and Cochrane databases was performed for articles published from inception to March 1, 2023. Meta-analysis of surgical and oncological outcomes was performed using a random effects model. Data were summarized as mean difference and risk ratio with 95% confidence intervals.

RESULTS

Five cohort studies with a total of 310 HCC patients were included (CSPH 143; Non-CSPH 167). In terms of surgical outcomes, estimated blood loss and the length of hospital stay were significantly lower in the Non-CSPH group than in the CSPH group. There were no significant differences between the two groups regarding other surgical outcomes, including the operative time, ratio of conversion to open surgery, and overall complication rate. In addition, there were also no significant differences between the two groups regarding the oncological outcomes, such as 1-, 3-, and 5-year overall survival.

CONCLUSIONS

HCC patients with and without CSPH who underwent LH had comparable surgical and oncological outcomes. LH is a safe and effective treatment for HCC patients with CSPH under the premise of rational screening of patients.

Robotic versus laparoscopic liver resection for liver malignancy: a systematic review and meta-analysis of propensity score-matched studies

OBJECTIVE

How different surgical procedures, including the robotic-assisted liver resection (RLR) and laparoscopic liver resection (LLR), can affect the prognosis of patients with liver malignancies is unclear. Thus, in this study, we compared the effects of RLR and LLR on the surgical and oncological outcomes in patients with liver malignancies through propensity score-matched cohort studies.

METHODS

The PubMed, Embase, and Cochrane databases were searched using Medical Subject Headings terms and keywords from inception until May 31, 2023. The quality of the included studies was assessed using the Newcastle-Ottawa quality assessment scale. The mean difference with 95% confidence interval (95% CI) was used for analysis of continuous variables; the risk ratio with 95% CI was used for dichotomous variables; and the hazard ratio with 95% CI was used for survival-related variables. Meta-analysis was performed using a random-effects model.

RESULTS

Five high-quality cohort studies with 986 patients were included (370 and 616 cases for RLR and LLR, respectively). In terms of surgical outcomes, there were no significant differences in the operation time, conversion rate to open surgery, overall complication rate, major complication rate, and length of hospital stay between the RLR and LLR groups. In terms of oncological outcomes, there were no significant differences in the 5-year overall survival and disease-free survival between the two groups.

CONCLUSION

Surgical and oncological outcomes are comparable between RLR and LLR on patients with liver malignancies. Therefore, the benefits of applying RLR in patients with liver malignancies need to be further explored.

Impact of liver cirrhosis, the severity of cirrhosis, and portal hypertension on the outcomes of minimally invasive left lateral sectionectomies for primary liver malignancies

BACKGROUND

The impact of cirrhosis and portal hypertension on perioperative outcomes of minimally invasive left lateral sectionectomies remains unclear. We aimed to compare the perioperative outcomes between patients with preserved and compromised liver function (noncirrhotics versus Child-Pugh A) when undergoing minimally invasive left lateral sectionectomies. In addition, we aimed to determine if the extent of cirrhosis (Child-Pugh A versus B) and the presence of portal hypertension had a significant impact on perioperative outcomes.

METHODS

This was an international multicenter retrospective analysis of 1,526 patients who underwent minimally invasive left lateral sectionectomies for primary liver malignancies at 60 centers worldwide between 2004 and 2021. In the study, 1,370 patients met the inclusion criteria and formed the final study group. Baseline clinicopathological characteristics and perioperative outcomes of these patients were compared. To minimize confounding factors, 1:1 propensity score matching and coarsened exact matching were performed.

RESULTS

The study group comprised 559, 753, and 58 patients who did not have cirrhosis, Child-Pugh A, and Child-Pugh B cirrhosis, respectively. Six-hundred and thirty patients with cirrhosis had portal hypertension, and 170 did not. After propensity score matching and coarsened exact matching, Child-Pugh A patients with cirrhosis undergoing minimally invasive left lateral sectionectomies had longer operative time, higher intraoperative blood loss, higher transfusion rate, and longer hospital stay than patients without cirrhosis. The extent of cirrhosis did not significantly impact perioperative outcomes except for a longer duration of hospital stay.

CONCLUSION

Liver cirrhosis adversely affected the intraoperative technical difficulty and perioperative outcomes of minimally invasive left lateral sectionectomies.

Risk Factors and Outcomes of Open Conversion During Minimally Invasive Major Hepatectomies: An International Multicenter Study on 3880 Procedures Comparing the Laparoscopic and Robotic Approaches

INTRODUCTION

Despite the advances in minimally invasive (MI) liver surgery, most major hepatectomies (MHs) continue to be performed by open surgery. This study aimed to evaluate the risk factors and outcomes of open conversion during MI MH, including the impact of the type of approach (laparoscopic vs. robotic) on the occurrence and outcomes of conversions.

METHODS

Data on 3880 MI conventional and technical (right anterior and posterior sectionectomies) MHs were retrospectively collected. Risk factors and perioperative outcomes of open conversion were analyzed. Multivariate analysis, propensity score matching, and inverse probability treatment weighting analysis were performed to control for confounding factors.

RESULTS

Overall, 3211 laparoscopic MHs (LMHs) and 669 robotic MHs (RMHs) were included, of which 399 (10.28%) had an open conversion. Multivariate analyses demonstrated that male sex, laparoscopic approach, cirrhosis, previous abdominal surgery, concomitant other surgery, American Society of Anesthesiologists (ASA) score 3/4, larger tumor size, conventional MH, and Institut Mutualiste Montsouris classification III procedures were associated with an increased risk of conversion. After matching, patients requiring open conversion had poorer outcomes compared with non-converted cases, as evidenced by the increased operation time, blood transfusion rate, blood loss, hospital stay, postoperative morbidity/major morbidity and 30/90-day mortality. Although RMH showed a decreased risk of conversion compared with LMH, converted RMH showed increased blood loss, blood transfusion rate, postoperative major morbidity and 30/90-day mortality compared with converted LMH.

CONCLUSIONS

Multiple risk factors are associated with conversion. Converted cases, especially those due to intraoperative bleeding, have unfavorable outcomes. Robotic assistance seemed to increase the feasibility of the MI approach, but converted robotic procedures showed inferior outcomes compared with converted laparoscopic procedures.

Impact of body mass index on the difficulty and outcomes of laparoscopic left lateral sectionectomy

INTRODUCTION

Currently, the impact of body mass index (BMI) on the outcomes of laparoscopic liver resections (LLR) is poorly defined. This study attempts to evaluate the impact of BMI on the peri-operative outcomes following laparoscopic left lateral sectionectomy (L-LLS).

METHODS

A retrospective analysis of 2183 patients who underwent pure L-LLS at 59 international centers between 2004 and 2021 was performed. Associations between BMI and selected peri-operative outcomes were analyzed using restricted cubic splines.

RESULTS

A BMI of >27kg/m2 was associated with increased in blood loss (Mean difference (MD) 21 mls, 95% CI 5-36), open conversions (Relative risk (RR) 1.13, 95% CI 1.03-1.25), operative time (MD 11 min, 95% CI 6-16), use of Pringles maneuver (RR 1.15, 95% CI 1.06-1.26) and reductions in length of stay (MD -0.2 days, 95% CI -0.3 to -0.1). The magnitude of these differences increased with each unit increase in BMI. However, there was a "U" shaped association between BMI and morbidity with the highest complication rates observed in underweight and obese patients.

CONCLUSION

Increasing BMI resulted in increasing difficulty of L-LLS. Consideration should be given to its incorporation in future difficulty scoring systems in laparoscopic liver resections.

Impact of tumor size on the difficulty of laparoscopic left lateral sectionectomies

BACKGROUND

Tumor size (TS) represents a critical parameter in the risk assessment of laparoscopic liver resections (LLR). Moreover, TS has been rarely related to the extent of liver resection. The aim of this study was to study the relationship between tumor size and difficulty of laparoscopic left lateral sectionectomy (L-LLS).

METHODS

The impact of TS cutoffs was investigated by stratifying tumor size at each 10 mm-interval. The optimal cutoffs were chosen taking into consideration the number of endpoints which show a statistically significant split around the cut-points of interest and the magnitude of relative risk after correction for multiple risk factors.

RESULTS

A total of 1910 L-LLS were included. Overall, open conversion and intraoperative blood transfusion were 3.1 and 3.3%, respectively. The major morbidity rate was 2.7% and 90-days mortality 0.6%. Three optimal TS cutoffs were identified: 40-, 70-, and 100-mm. All the selected cutoffs showed a significant discriminative power for the prediction of open conversion, operative time, blood transfusion and need of Pringle maneuver. Moreover, 70- and 100-mm cutoffs were both discriminative for estimated blood loss and major complications. A stepwise increase in rates of open conversion rate (Z = 3.90, P < .001), operative time (Z = 3.84, P < .001), blood loss (Z = 6.50, P < .001), intraoperative blood transfusion rate (Z = 5.15, P < .001), Pringle maneuver use (Z = 6.48, P < .001), major morbidity(Z = 2.17, P = .030) and 30-days readmission (Z = 1.99, P = .047) was registered as the size increased.

CONCLUSION

L-LLS for tumors of increasing size was associated with poorer intraoperative and early postoperative outcomes suggesting increasing difficulty of the procedure. We determined three optimal TS cutoffs (40-, 70- and 100-mm) to accurately stratify surgical difficulty after L-LLS.

Conversion of Minimally Invasive Liver Resection for HCC in Advanced Cirrhosis: Clinical Impact and Role of Difficulty Scoring Systems

BACKGROUND

Minimally invasive liver resections (MILRs) in cirrhosis are at risk of conversion since cirrhosis and complexity, which can be estimated by scoring systems, are both independent factors for. We aimed to investigate the consequence of conversion of MILR for hepatocellular carcinoma in advanced cirrhosis.

METHODS

After retrospective review, MILRs for HCC were divided into preserved liver function (Cohort-A) and advanced cirrhosis cohorts (Cohort-B). Completed and converted MILRs were compared (Compl-A vs. Conv-A and Compl-B vs. Conv-B); then, converted patients were compared (Conv-A vs. Conv-B) as whole cohorts and after stratification for MILR difficulty using Iwate criteria.

RESULTS

637 MILRs were studied (474 Cohort-A, 163 Cohort-B). Conv-A MILRs had worse outcomes than Compl-A: more blood loss; higher incidence of transfusions, morbidity, grade 2 complications, ascites, liver failure and longer hospitalization. Conv-B MILRs exhibited the same worse perioperative outcomes than Compl-B and also higher incidence of grade 1 complications. Conv-A and Conv-B outcomes of low difficulty MILRs resulted in similar perioperative outcomes, whereas the comparison of more difficult converted MILRs (intermediate/advanced/expert) resulted in several worse perioperative outcomes for patients with advanced cirrhosis. However, Conv-A and Conv-B outcomes were not significantly different in the whole cohort where "advanced/expert" MILRs were 33.1% and 5.5% in Cohort A and B.

CONCLUSIONS

Conversion in the setting of advanced cirrhosis can be associated with non-inferior outcomes compared to compensated cirrhosis, provided careful patient selection is applied (patients elected to low difficulty MILRs). Difficulty scoring systems may help in identifying the most appropriate candidates.

Hospital Volume and Textbook Outcomes in Minimally Invasive Hepatectomy for Hepatocellular Carcinoma

BACKGROUND

Hospital volume affects outcomes of patients who underwent resection for hepatocellular carcinoma (HCC). We sought to assess the impact of minimally invasive hepatectomy (MIH) volume on short- and long-term outcomes among patients with HCC.

METHODS

Patients who underwent MIH for HCC from 2010 to 2018 were identified from the National Cancer Database. Multivariable modeling with restricted cubic splines (RCS) was utilized to identify the MIH hospital volume threshold. Textbook outcome (TO) was defined as no conversion to open resection, negative margins after resection (R0), no extended length-of-stay, no readmission, and no 90-day mortality.

RESULTS

Among 3268 patients who underwent MIH for HCC, median age was 65.0 (IQR 59.0-72.0) and the majority was male (n = 2308, 70.6%). MIH hospital volume ranged from 1 to 87 cases, with a median of 13 (IQR 7-23). Overall, 2151 (60.9%) patients achieved TO after resection. While particularly high rates of achievement were found for no 90-day mortality (n = 3106, 95.0%), no readmission (n = 3153, 96.5%), and R0 resection (n = 3,017, 92.3%), other TO components including no conversion to open (n = 2778, 85.0%) and no prolonged LOS (n = 2584, 79.1%) were achieved less frequently. Patients treated at high-volume centers (≥50 MIH cases) were more likely to experience TO (high volume centers, n = 334, 68.7% vs. low volume centers, n = 1656, 59.5%, p < 0.001) and better long-term survival (5-year OS; high volume centers, 64.7% vs. low volume centers, 54.6%, p < 0.001).

CONCLUSIONS

MIH hospital volume was associated with a higher likelihood of achieving TO and improved long-term survival among patients undergoing resection of HCC.

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.