Risk factors and consequences of conversion in laparoscopic major liver resection

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.

Circumstances and implications of conversion from minimally invasive to open liver resection: a multi-center analysis from the AMILES registry

BACKGROUND

Minimally invasive approaches to liver resection (MILR) are associated with favorable outcomes. The aim of this study was to determine the implications of conversion to an open procedure on perioperative outcomes.

METHODS

Patients who underwent MILR at 10 North American institutions were identified from the Americas Minimally Invasive Liver Resection (AMILES) database. Outcomes of patients who required conversion were compared to those who did not. Additionally, outcomes after conversion due to unfavorable findings (poor visualization/access, lack of progress, disease extent) versus intraoperative events (bleeding, injury, cardiopulmonary instability) were compared.

RESULTS

Of 1675 patients who underwent MILR, 102 (6.1%) required conversion. Conversion rate ranged from 4.4% for left lateral sectionectomy to 10% for right hepatectomy. The primary reason for conversion was unfavorable findings in 67 patients (66%) and intraoperative adverse events in 35 patients (34%). By multivariable analysis, major resection, cirrhosis, prior liver surgery, and tumor proximity to major vessels were identified as risk factors for conversion (p < 0.05). Patients who required conversion had higher blood loss, transfusion requirements, operative time, and length of stay, (p < 0.05). They also had higher major complication rates (23% vs. 5.2%, p < 0.001) and 30-day mortality (8.8% vs. 1.3%, p < 0.001). When compared to those who required conversion due to unfavorable findings, patients who required conversion due to intraoperative adverse events had significantly higher major complication rates (43% vs. 14%, p = 0.012) and 30-day mortality (20% vs. 3.0%, p = 0.007).

CONCLUSIONS

Conversion from MILR to open surgery is associated with increased perioperative morbidity and mortality. Conversion due to intraoperative adverse events is rare but associated with significantly higher complication and mortality rates, while conversion due to unfavorable findings is associated with similar outcomes as planned open resection. High-risk patients may benefit from early conversion in a controlled fashion if difficulties are encountered or anticipated.

Risk Factors and Long-Term Implications of Unplanned Conversion During Laparoscopic Liver Resection for Hepatocellular Carcinoma

Background: Laparoscopic liver resection (LLR) has become a widely used standardized operation for patients with hepatocellular carcinoma (HCC) in the field of hepatic surgery. However, the risk factors and long-term implications associated with unplanned conversion to an open procedure during the LLR have not been adequately studied. Methods: The study incorporated 96 patients with HCC. Risk factors of conversion and their prognosis were analyzed by comparing patients who successfully underwent LLR with those who required unplanned conversion. Results: In this study, the unplanned conversion rate for laparoscopic hepatectomy was 42.7%. Patients who underwent conversion had longer length of stay (8 versus 7 days, P < .001), longer operation time (297.73 versus 194.03 minutes, P = .000), a higher transfusion rate (29.3% versus 5.5%, P < .001), and more postoperative complications compared with patients who successfully underwent LLR. The two surgical maneuvers did not show substantial disparities in terms of total survival and disease-free survival rates. Risk factors of unplanned conversion contained tumor location (odds ratio [OR], 3.129; 95% confidence interval [CI]: 1.214-8.066; P = 0.018) and tumor size (OR, 2.652; 95% CI: 1.039-6.767; P = 0.041). Conclusions: The unplanned conversion during LLR for HCC was linked to unfavorable short-term prognosis, yet it did not influence long-term oncologic outcomes. Moreover, preoperative evaluation of tumor size and location may effectively reduce the probability of unplanned conversion during LLR.

Open Versus Laparoscopic Right Hepatectomy for Hepatocellular Carcinoma Following Sequential TACE-PVE: A Multicentric Comparative Study

BACKGROUND

Right hepatectomy (RH) for hepatocellular carcinoma (HCC) is ideally preceded by transcatheter arterial chemoembolization (TACE) and portal vein embolization (PVE). Laparoscopic approach improves short-term outcome and textbook outcome (TO), which reflects the "ideal" surgical outcome, after RH. However, laparoscopic RH on an underlying diseased liver and after TACE/PVE remains a challenging procedure. The aim of this study was to compare the outcomes in patients who underwent laparoscopic liver resection (LLR) or open liver resection (OLR) following TACE/PVE.

PATIENTS AND METHODS

All patients with HCC who underwent RH after TACE/PVE in five French centers were retrospectively included. Outcomes were compared between the LLR group and the OLR group using propensity score matching (PSM). Quality of surgical care was defined by TO.

RESULTS

Between 2005 and 2019, 117 patients were included (41 in LLR group, 76 in OLR group). Overall morbidity was comparable (51% versus 53%, p = 0.24). In LLR group, TO was completed in 66% versus 37% in OLR group (p = 0.02). LLR and absence of clamping were the only factors associated with TO completion [hazard ratio (HR) 4.27, [1.77-10.28], p = 0.001]. After PSM, 5-year overall survival (OS) and progression-free survival (PFS) were 55% in matched LLR versus 77% in matched OLR, p = 0.35, and 13% in matched LLR versus 17% in matched OLR, p = 0.97. TO completion was independently associated with a better 5-year OS (65.2% versus 42.5%, p = 0.007).

CONCLUSION

Major LLR after TACE/PVE should be considered as a valuable option in expert centers to increase the chance of TO, the latter being associated with a better 5-year OS.

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.

The Outcome of Conversion to Hand-Assisted Laparoscopic Surgery in Laparoscopic Liver Resection

BACKGROUND

Hand-assisted laparoscopic surgery (HALS) is known as a useful option. However, the outcome and predictor of conversion to HALS in laparoscopic liver resection (LLR) are unclear.

METHODS

Data from consecutive patients who planned pure LLR between 2011 and 2020 were retrospectively reviewed. Univariate and multivariate analyses were performed and compared pure LLR, HALS, and converted open liver resection (OLR).

RESULTS

Among the 169 LLRs, conversion to HALS was performed in 19 (11.2%) and conversion to OLR in 16 (9.5%). The most frequent reasons for conversion to HALS were failure to progress (11 cases). Subsequently, bleeding (3 cases), severe adhesion (2 cases), and oncological factors (2 cases) were the reasons. In the multivariable analysis, the tumor located in segments 7 or 8 (p = 0.002) was evaluated as a predictor of conversion to HALS. Pure LLR and HALS were associated with less blood loss than conversion to OLR (p = 0.005 and p = 0.014, respectively). However, there was no significant difference in operation time, hospital stay, or severe complications.

CONCLUSIONS

The predictor of conversion to HALS was a tumor located in segments 7 or 8. The outcome of conversion to HALS was not inferior to pure LLR in terms of bleeding, operation time, hospital stay, or severe complication.

Impact of shifting from laparoscopic to robotic surgery during 600 minimally invasive pancreatic and liver resections

BACKGROUND

Many centers worldwide are shifting from laparoscopic to robotic minimally invasive hepato-pancreato-biliary resections (MIS-HPB) but large single center series assessing this process are lacking. We hypothesized that the introduction of robot-assisted surgery was safe and feasible in a high-volume center.

METHODS

Single center, post-hoc assessment of prospectively collected data including all consecutive MIS-HPB resections (January 2010-February 2022). As of December 2018, all MIS pancreatoduodenectomy and liver resections were robot-assisted. All surgeons had participated in dedicated training programs for laparoscopic and robotic MIS-HPB. Primary outcomes were in-hospital/30-day mortality and Clavien-Dindo ≥ 3 complications.

RESULTS

Among 1875 pancreatic and liver resections, 600 (32%) were MIS-HPB resections. The overall rate of conversion was 4.3%, Clavien-Dindo ≥ 3 complications 25.7%, and in-hospital/30-day mortality 1.8% (n = 11). When comparing the period before and after the introduction of robotic MIS-HPB (Dec 2018), the overall use of MIS-HPB increased from 25.3 to 43.8% (P < 0.001) and blood loss decreased from 250 ml [IQR 100-500] to 150 ml [IQR 50-300] (P < 0.001). The 291 MIS pancreatic resections included 163 MIS pancreatoduodenectomies (52 laparoscopic, 111 robotic) with 4.3% conversion rate. The implementation of robotic pancreatoduodenectomy was associated with reduced operation time (450 vs 361 min; P < 0.001), reduced blood loss (350 vs 200 ml; P < 0.001), and a decreased rate of delayed gastric emptying (28.8% vs 9.9%; P = 0.009). The 309 MIS liver resections included 198 laparoscopic and 111 robotic procedures with a 3.6% conversion rate. The implementation of robotic liver resection was associated with less overall complications (24.7% vs 10.8%; P = 0.003) and shorter hospital stay (4 vs 3 days; P < 0.001).

CONCLUSION

The introduction of robotic surgery was associated with greater implementation of MIS-HPB in up to nearly half of all pancreatic and liver resections. Although mortality and major morbidity were not affected, robotic surgery was associated with improvements in some selected outcomes. Ultimately, randomized studies and high-quality registries should determine its added value.

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.

Intraoperative laparoscopic liver surface registration with preoperative CT using mixing features and overlapping region masks

PURPOSE

Laparoscopic liver resection is a minimal invasive surgery. Augmented reality can map preoperative anatomy information extracted from computed tomography to the intraoperative liver surface reconstructed from stereo 3D laparoscopy. However, liver surface registration is particularly challenging as the intraoperative surface is only partially visible and suffers from large liver deformations due to pneumoperitoneum. This study proposes a deep learning-based robust point cloud registration network.

METHODS

This study proposed a low overlap liver surface registration algorithm combining local mixed features and global features of point clouds. A learned overlap mask is used to filter the non-overlapping region of the point cloud, and a network is used to predict the overlapping region threshold to regulate the training process.

RESULTS

We validated the algorithm on the DePoLL (the Deformable Porcine Laparoscopic Liver) dataset. Compared with the baseline method and other state-of-the-art registration methods, our method achieves minimum target registration error (TRE) of 19.9 ± 2.7 mm.

CONCLUSION

The proposed point cloud registration method uses the learned overlapping mask to filter the non-overlapping areas in the point cloud, then the extracted overlapping area point cloud is registered according to the mixed features and global features, and this method is robust and efficient in low-overlap liver surface registration.

Risk factors and outcomes in patients undergoing minimally invasive hepatectomy with unplanned conversion: a contemporary NSQIP analysis

BACKGROUND

Minimally invasive techniques are growing for hepatectomies. Laparoscopic and robotic liver resections have been shown to differ in conversions. We hypothesize that robotic approach will have decreased conversion to open and complications despite being a newer technique than laparoscopy.

METHODS

ACS NSQIP study using the targeted Liver PUF from 2014 to 2020. Patients grouped based on hepatectomy type and approach. Multivariable and propensity scored matching (PSM) was used to analyze the groups.

RESULTS

Of 7767 patients who underwent hepatectomy, 6834 were laparoscopic and 933 were robotic. The rate of conversions was significantly lower in robotic vs laparoscopic (7.8% vs 14.7%; p < 0.001). Robotic hepatectomy was associated with decreased conversion for minor (6.2% vs 13.1%; p < 0.001), but not major, right, or left hepatectomy. Operative factors associated with conversion included Pringle (OR = 2.09 [95% CI 1.05-4.19]; p = 0.0369), and a laparoscopic approach (OR = 1.96 [95% CI 1.53-2.52]; p < 0.001). Undergoing conversion was associated with increases in bile leak (13.7% vs 4.9%; p < 0.001), readmission (11.5% vs 6.1%; p < 0.001), mortality (2.1% vs 0.6%; p < 0.001), length of stay (5 days vs 3 days; p < 0.001), and surgical (30.5% vs 10.1%; p < 0.001), wound (4.9% vs 1.5%; p < 0.001) and medical (17.5% vs 6.7%; p < 0.001) complications.

CONCLUSION

Minimally invasive hepatectomy with conversion is associated with increased complications, and conversion is increased in the laparoscopic compared to a robotic approach.

Indications for open hepatectomy in the era of laparoscopic liver resection: a high volume single institutional study

Background/Aim

Since the introduction of laparoscopy for liver resection in the 1990s, the performance of laparoscopic liver resection (LLR) has been steadily increasing. However, there is currently no data on the extent to which laparoscopy is used for liver resection. Herein, we investigated the extent to which laparoscopy is performed in liver resection and sought to determine whether surgeons prefer laparoscopy or laparotomy in the posterosuperior (PS) segment.

Methods

For this retrospective observational study, we enrolled patients who had undergone liver resection at the Samsung Medical Center between January 2020 and December 2021. The proportion of LLR in liver resection was calculated, and the incidence and causes of open conversion were investigated.

Results

A total of 1,095 patients were included in this study. LLR accounted for 79% of the total liver resections. The percentage of previous hepatectomy (16.2% vs. 5.9%, P<0.001) and maximum tumor size (median 4.8 vs. 2.8, P<0.001) were higher in the open liver resection (OLR) group. Subgroup analysis revealed that tumor size (median 6.3 vs. 2.9, P<0.001) and surgical extent (P<0.001) in the OLR group were larger than those in the LLR group. The most common cause of open conversion (OC) was adhesion (57%), and all OC patients had tumors in the PS.

Conclusions

We investigated the recent preference of practical surgeons in liver resection, and found that surgeons preferred OLR to LLR when treating a large tumor located in the PS.

Assessment of Factors Associated with Morbidity and Textbook Outcomes of Laparoscopic Liver Resection in Obese Patients: A French Nationwide Study

BACKGROUND

Liver surgeons need to know the expected outcomes of laparoscopic liver resection (LLR) in obese patients.

OBJECTIVE

The purpose of the present study is to assess morbidity, mortality and textbook outcomes (TO) after LLR in obese patients.

METHODS

This is a French multicenter study of patients undergoing LLR between 1996 and 2018. Obesity was defined by a BMI at or above 30 kg/m 2 . Short-term outcomes and TO were compared between obese (ob) and nonobese (non-ob) patients. Factors associated with severe morbidity and TO were investigated.

RESULTS

Of 3,154 patients included, 616 (19.5%) were obese. Ob-group patients had significantly higher American Society of Anesthesiologists (ASA) score and higher incidence of metabolic syndrome and chronic liver disease and were less likely to undergo major hepatectomy. Mortality rates were similar between ob and non-ob groups (0.8 vs 1.1%; p = 0.66). Overall morbidity and hospital stay were significantly increased in the ob group compared with the non-ob group (39.4 vs 34.7%, p = 0.03; and 9.5 vs 8.6 days, p = 0.02), whereas severe 90-day morbidity (at or above Clavien-Dindo grade III) was similar between groups (8% in both groups; p = 0.90). TO rate was significantly lower for the ob group than the non-ob group (58.3 vs 63.7%; p = 0.01). In multivariate analysis, obesity did not emerge as a risk factor for severe 90-day morbidity but was associated with a lower TO rate after LLR (odds ratio = 0.8, 95% CI 0.7-1.0; p = 0.03).

CONCLUSIONS

LLR in obese patients is safe and effective with acceptable mortality and morbidity. Obesity had no impact on severe morbidity but was a factor for failing to achieve TO after LLR.

Fast-track protocols in laparoscopic liver surgery: Applicability and correlation with difficulty scoring systems

BACKGROUND

Few series have reported the utility of fast-track protocols (FTP) in minimally invasive liver surgery.

AIM

To report the applicability of FTP in minimally invasive liver surgery and to correlate with difficulty scores.

METHODS

The series of patients undergoing minimally invasive liver surgery from 2014 was analyzed. Iwate, Southampton and Gayet’s scores were compared as predictors of FTP adherence. Accomplishment of FTP was considered within 24-h, 48-h and 72-h. Multivariate models were performed to define discharge < 24 h, < 72 h, complications and readmissions.

RESULTS

From 160 cases, 78 were candidates for FTP, of which 22 (28.2%), 19 (24.4%) and 14 (17.9%) were discharged in < 24-h, 48-h and 72-h, respectively (total = 71.5%). Iwate, Southampton and Gayet’s scores achieved area under the receiver operating characteristic values for < 24-h stay of 0.780, 0.687 and 0.698, respectively. Sensitivity and specificity values for the best score (Iwate) were 87.7% and 66.7%, respectively (cutoff = 5.5). In multivariate models, < 72 h stay and complications revealed body mass index as a risk factor independent from difficulty scores.

CONCLUSION

The development of aggressive FTP is feasible and < 24-h stay can be achieved even in moderate and advanced complexity cases. Difficulty scores, including body mass index value, may be useful to predict which cases may adhere to these protocols.

The risk factors of intraoperative conversion during laparoscopic hepatectomy: a systematic review and meta-analysis

PURPOSE

Intraoperative conversion to laparotomy is a challenge during laparoscopic hepatectomy; however, the risk factors of conversion have been poorly elucidated.

METHODS

In this systematic review and meta-analysis, we computed pooled odds ratios (ORs) with 95% confidence intervals (CIs) for each risk factor and evaluated heterogeneity using a L'Abbe plot, Galbraith radial plot, Cochran's Q test, and I². An extended funnel plot was used to evaluate the robustness of the results of meta-analysis. Sensitivity analysis and subgroup analysis were performed to determine sources of heterogeneity. Egger's test and Begg's test were used to assess publication bias.

RESULTS

A total of 25 eligible studies were enrolled in the meta-analysis. Higher body mass index (OR 1.346, 95% CI 1.055-1.717), hypertension (OR 1.387, 95% CI 1.100-1.749), male sex (OR 1.278, 95% CI 1.072-1.523), cirrhosis (OR 1.378, 95% CI 1.062-1.788), major resection (OR 2.041, 95% CI 1.748-2.382), posterosuperior tumor location (OR 2.420, 95% CI 1.923-3.044), and larger tumor diameter (OR 1.618, 95% CI 1.270-2.061) were found to be significantly related to intraoperative conversion during laparoscopic hepatectomy. Malignant tumor (OR 1.253, 95% CI 0.970-1.619), higher American Society of Anesthesiologists stage (OR 1.186, 95% CI 0.863-1.631), multiple tumors (OR 1.273, 95% CI 0.866-1.871), and abdominal surgery history (OR 1.236, 95% CI 0.589-2.597) were not associated with conversion. A history of abdominal surgery showed significant heterogeneity with an I² of 80.8% (p < 0.001). Subgroup analysis indicated that heterogeneity was caused by the different number of patients among enrolled studies.

CONCLUSIONS

In this systematic review and meta-analysis, we identified a number of factors associated with intraoperative conversion during laparoscopic hepatectomy. Our findings can help patient risk evaluation to reduce the laparotomy conversion rate in laparoscopic hepatectomy.

Risk factors and long-term implications of unplanned conversion during laparoscopic liver resection for hepatocellular carcinoma located in anterolateral liver segments

Purpose

The impact of conversion on perioperative and long-term oncologic outcomes is controversial. Thus, we compared these outcomes between laparoscopic (Lap), unplanned conversion (Conversion), and planned open (Open) liver resection for hepatocellular carcinoma (HCC) located in anterolateral (AL) liver segments and aimed to identify risk factors for unplanned conversion.

Methods

We retrospectively studied 374 patients (Lap, 299; Open, 62; Conversion, 13) who underwent liver resection for HCC located in AL segments between 2004 and 2018.

Results

Compared to the Lap group, the Conversion group showed greater values for operation time (p < 0.001), blood loss (p = 0.021), transfusion rate (p = 0.009), postoperative complication rate (p = 0.008), and hospital stay (p = 0.040), with a lower R0 resection rate (p < 0.001) and disease-free survival (p = 0.001). Compared with the Open group, the Conversion group had a longer operation time (p = 0.012) and greater blood loss (p = 0.024). Risk factors for unplanned conversion were large tumor size (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.05-1.74; p = 0.020), multiple tumors (OR, 5.95; 95% CI, 1.45-24.39; p = 0.013), and other organ invasion (OR, 15.32; 95% CI, 1.80-130.59; p = 0.013).

Conclusion

In conclusion, patients who experienced unplanned conversion during LLR for HCC located in AL segments showed poor perioperative and long-term outcomes compared to those who underwent planned laparoscopic and open liver resection. Therefore, open liver resection should be considered in patients with risk factors for unplanned conversion.

Performance of image guided navigation in laparoscopic liver surgery - A systematic review

BACKGROUND

Compared to open surgery, minimally invasive liver resection has improved short term outcomes. It is however technically more challenging. Navigated image guidance systems (IGS) are being developed to overcome these challenges. The aim of this systematic review is to provide an overview of their current capabilities and limitations.

METHODS

Medline, Embase and Cochrane databases were searched using free text terms and corresponding controlled vocabulary. Titles and abstracts of retrieved articles were screened for inclusion criteria. Due to the heterogeneity of the retrieved data it was not possible to conduct a meta-analysis. Therefore results are presented in tabulated and narrative format.

RESULTS

Out of 2015 articles, 17 pre-clinical and 33 clinical papers met inclusion criteria. Data from 24 articles that reported on accuracy indicates that in recent years navigation accuracy has been in the range of 8-15 mm. Due to discrepancies in evaluation methods it is difficult to compare accuracy metrics between different systems. Surgeon feedback suggests that current state of the art IGS may be useful as a supplementary navigation tool, especially in small liver lesions that are difficult to locate. They are however not able to reliably localise all relevant anatomical structures. Only one article investigated IGS impact on clinical outcomes.

CONCLUSIONS

Further improvements in navigation accuracy are needed to enable reliable visualisation of tumour margins with the precision required for oncological resections. To enhance comparability between different IGS it is crucial to find a consensus on the assessment of navigation accuracy as a minimum reporting standard.

The Italian Consensus on minimally invasive simultaneous resections for synchronous liver metastasis and primary colorectal cancer: A Delphi methodology

At the time of diagnosis synchronous colorectal cancer, liver metastases (SCRLM) account for 15-25% of patients. If primary tumour and synchronous liver metastases are resectable, good results may be achieved performing surgical treatment incorporated into the chemotherapy regimen. So far, the possibility of simultaneous minimally invasive (MI) surgery for SCRLM has not been extensively investigated. The Italian surgical community has captured the need and undertaken the effort to establish a National Consensus on this topic. Four main areas of interest have been analysed: patients' selection, procedures, techniques, and implementations. To establish consensus, an adapted Delphi method was used through as many reiterative rounds were needed. Systematic literature reviews were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses instructions. The Consensus took place between February 2019 and July 2020. Twenty-six Italian centres participated. Eighteen clinically relevant items were identified. After a total of three Delphi rounds, 30-tree recommendations reached expert consensus establishing the herein presented guidelines. The Italian Consensus on MI surgery for SCRLM indicates possible pathways to optimise the treatment for these patients as consensus papers express a trend that is likely to become shortly a standard procedure for clinical pictures still on debate. As matter of fact, no RCT or relevant case series on simultaneous treatment of SCRLM are available in the literature to suggest guidelines. It remains to be investigated whether the MI technique for the simultaneous treatment of SCRLM maintain the already documented benefit of the two separate surgeries.

Validation of the IWATE criteria as a laparoscopic liver resection difficulty score in a single North American cohort

BACKGROUND

Laparoscopic liver resection (LLR) involves a difficult learning curve, for which multiple difficulty scores have been proposed to assist with safe adaptation. The IWATE Criteria is a 4-level difficulty score shown to correlate with conversion to open surgery, estimated blood loss (EBL), and operative time in Japanese and French cohorts. We set out to validate the IWATE Criteria in a North American cohort, describe the evolution of our LLR program, and analyze the IWATE Criteria's ability to predict conversion to open surgery.

METHODS

Patients that underwent LLR between January 2006 and December 2019 were selected from a prospectively maintained database. Difficulty outcomes, including conversion to open surgery, EBL, operative time, and post-operative complications were analyzed according to IWATE difficulty level, both overall and between chronological eras. The IWATE Criteria's ability to predict conversion to open surgery was assessed with a receiver operating characteristic (ROC) analysis.

RESULTS

A total of 426 patients met inclusion criteria. Operative time, EBL, and conversion to open surgery increased in concordance with low to advanced IWATE difficulty. ROC analysis for conversion to open surgery demonstrated an overall area under the curve (AUC) of 0.694. Predictive performance was superior during the first two eras, with AUCs of 0.771 and 0.775; predictive value decreased as the LLR program gained experience, with AUCs of 0.708 and 0.551 for eras three and four.

CONCLUSIONS

This study validated the IWATE Criteria in a North American population distinct from previous Japanese and French cohorts, based on its correlation with operative time, EBL, and conversion to open surgery. The IWATE Criteria may be of utility for identification of LLR cases appropriate for surgeon experience, as well as determination of laparoscopic feasibility. Interval difficulty score recalibration may be warranted as surgeon perception of difficulty evolves.

Role of Surgical Approach to Synchronous Colorectal Liver Metastases: A Retrospective Analysis

PURPOSE

This study is a retrospective analysis of exploring the efficiency of surgical management on patients with synchronous colorectal liver metastasis (SCLM).

PATIENTS AND METHODS

Nine hundred fifty-three consecutive patients with SCLM from Weifang People's Hospital of Shandong Province between January 2006 and December 2015 were reviewed. The values of different factors were analyzed, such as different surgical indications of liver metastases, simultaneous or staged resection of primary colorectal cancer and liver metastases, and primary tumor resection (PTR) of asymptomatic patients with unresectable liver metastases.

RESULTS

Median survival time (47.3 months) and 5-year survival rate (31%) for patients with resected liver metastases were significantly superior to that of with nonoperative treatment (17.2 months, 4%, P<0.001); enlarging the standard of liver metastases resection can improve the resection rates (31.0% vs 13.6%, P<0.001); for patients with resectable liver metastases, the in-hospital cost for simultaneous resection group was lower than that in the staged resection group (36,698 vs 45,134 RMB, P<0.001); for patients of the asymptomatic primary tumor with unresectable liver metastases, PTR was associated with improved median survival (18.0 vs 15.0 months, P=0.006).

CONCLUSION

For patients with SCLM, liver resection is considered the best treatment; expanding indications of liver resection can improve the resection rates. Simultaneous resection of the primary tumor and liver metastases were indicated in patients with resectable SCLM; PTR was recommended for asymptomatic patients with unresectable hepatic metastases.

Body mass index and surgical outcomes in laparoscopic liver resections: a systematic review

BACKGROUND

Laparoscopic liver resection is gaining momentum; however, there is limited evidence on its efficacy and safety in obese patients. The aim of this study was to examine the relationship between BMI and outcomes after laparoscopic liver resection (LLR) using a systematic review of the existing literature.

METHODS

A systematic search of Medline (Ovid 1946-present), PubMed (NCBI), Embase (Ovid 1966-present) and Cochrane Library was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement for parameters of LLR and BMI. Operative, post-operative and oncological outcomes were recorded.

RESULTS

Of 1460 abstracts, seven retrospective studies were analysed, published between 2015 and 2017 (study periods 1998-2017). Total patient cohort were classified as 481 obese and 1180 non-obese with a median age range of 42.5-69.4 years. Variations existed in definitions of obesity (Asia BMI >25 kg/m² , Western BMI >30 kg/m² ). Rates of conversion were examined in four studies (0-31%) with one reporting BMI >28 kg/m² as an independent risk factor. Estimated blood loss and transfusion rates were similar. Operative time was increased in obese patients in one study (P = 0.02). Mortality rates ranged from 0% to 4.3% with no difference between BMI classes. No difference in major morbidity was demonstrated. Bile leak rates were increased in obese groups in one study (0-3.44%, P < 0.05). Wound infections were reported in five studies, with higher rates in obese patients (0-5.8% versus 0-1.9%). Tumour size was comparable in both groups. Completeness of resection was analysed in four studies with one study reporting increased R0 rates in obese patients (P = 0.012).

CONCLUSION

This systematic review highlights that current evidence shows LLR in obese patients is safe, however, further studies are required.

Predicting the Risk of Postoperative Complications in Patients Undergoing Minimally Invasive Resection of Primary Liver Tumors

Minimal-invasive techniques are increasingly applied in clinical practice and have contributed towards improving postoperative outcomes. While comparing favorably with open surgery in terms of safety, the occurrence of severe complications remains a grave concern. To date, no objective predictive system has been established to guide clinicians in estimating complication risks as the relative contribution of general patient health, liver function and surgical parameters remain unclear. Here, we perform a single-center analysis of all consecutive patients undergoing laparoscopic liver resection for primary hepatic malignancies since 2010. Among the 210 patients identified, 32 developed major complications. Several independent predictors were identified through a multivariate analysis, defining a preoperative model: diabetes, history of previous hepatectomy, surgical approach, alanine aminotransferase levels and lesion entity. The addition of operative time and whether conversion was required significantly improved predictions and were thus incorporated into the postoperative model. Both models were able to identify patients with major complications with acceptable performance (area under the receiver-operating characteristic curve (AUC) for a preoperative model = 0.77 vs. postoperative model = 0.80). Internal validation was performed and confirmed the discriminatory ability of the models. An easily accessible online tool was deployed in order to estimate probabilities of severe complication without the need for manual calculation.

Laparoscopic Major Hepatectomy: Do Not Underestimate the Impact of Specimen Extraction Site

BACKGROUND

In laparoscopic major hepatectomy, analysis of outcomes according to specimen extraction site remains poorly described. The aim was to compare postoperative outcomes according to specimen extraction site.

METHODS

From 2000 to 2017, all laparoscopic major hepatectomies were reviewed and postoperative outcomes were analyzed according to specimen extraction site: subcostal (Group 1), midline (Group 2), or suprapubic (Group 3) incision.

RESULTS

Among 163 patients, 15 (9.2%) belonged to Group 1, 49 (30.1%) in Group 2, and 99 (60.7%) in Group 3. The proportion of right-sided, left-sided, or central hepatectomies, mortality, and overall and severe complications were comparable between groups. Group 1 had larger tumors (61 vs. 38 vs. 47 mm; P = 0.014), higher operative time (338 vs. 282 vs. 260 min; P < 0.008), higher adjacent organ resection rate (46.6 vs. 16.3 vs. 7.1%; P < 0.001), and tended to increase pulmonary complications (40.0 vs. 12.2 vs. 18.2%; P = 0.064). In Group 2, a previous midline incision scar was more frequently used for specimen extraction site (65.3 vs. 26.6 and 30.3%, Group 1 and 3; P < 0.001). Postoperative incisional hernia was observed in 16.4% (n = 23) and was more frequent in Group 2 (26.6 vs. 6.6% and 10.1%, Group 1 and Group 3; P = 0.030). Finally, Group 2 (HR 2.63, 95% CI 1.41-3.53; P = 0.032) was the only independent predictive factor of postoperative incisional hernia.

CONCLUSIONS

While using a previous incision makes sense, the increased risk of postoperative incisional hernia after midline incision promotes the suprapubic incision.

Impact of liver cirrhosis on the difficulty of minimally-invasive liver resections: a 1:1 coarsened exact-matched controlled study

INTRODUCTION

The impact of liver cirrhosis on the difficulty of minimal invasive liver resection (MILR) remains controversial and current difficulty scoring systems do not take in to account the presence of cirrhosis as a significant factor in determining the difficulty of MILR. We hypothesized that the difficulty of MILR is affected by the presence of cirrhosis. Hence, we performed a 1:1 matched-controlled study comparing the outcomes between patients undergoing MILR with and without cirrhosis including the Iwate system and Institut Mutualiste Montsouris (IMM) system in the matching process.

METHODS

Between 2006 and 2019, 598 consecutive patients underwent MILR of which 536 met the study inclusion criteria. There were 148 patients with cirrhosis and 388 non-cirrhotics. One-to-one coarsened exact matching identified approximately exact matches between 100 cirrhotic patients and 100 non-cirrhotic patients.

RESULTS

Comparison between MILR patients with cirrhosis and non-cirrhosis in the entire cohort demonstrated that patients with cirrhosis were associated with a significantly increased open conversion rate, transfusion rate, need for Pringles maneuver, postoperative, stay, postoperative morbidity and postoperative 90-day mortality. After 1:1 coarsened exact matching, MILR with cirrhosis were significantly associated with an increased open conversion rate (15% vs 6%, p = 0.03), operation time (261 vs 238 min, p  < 0.001), blood loss (607 vs 314 mls, p  = 0.002), transfusion rate (22% vs 9%, p  = 0.001), need for application of Pringles maneuver (51% vs 34%, p  = 0.010), postoperative stay (6 vs 4.5 days, p  = 0.004) and postoperative morbidity (26% vs 13%, p  = 0.029).

CONCLUSION

The presence of liver cirrhosis affected both the intraoperative technical difficulty and postoperative outcomes of MILR and hence should be considered an important parameter to be included in future difficulty scoring systems for MILR.

Pure laparoscopic right hepatectomy: A risk score for conversion for the paradigm of difficult laparoscopic liver resections. A single centre case series

BACKGROUND

Converted laparoscopic hepatectomies are known to lose some advantages of the minimally-invasiveness, and factors are identified to predict patients at risk. Specific evidence for laparoscopic right hepatectomy is expected of usefulness in clinical practice, given its technical peculiarities. The purpose of the study was the identification of risk factors and the development of a risk score for conversion of laparoscopic right hepatectomy.

MATERIALS AND METHODS

Laparoscopic right hepatectomy performed at a single hepatobiliary surgical center were analyzed. The cohort was split in half to obtain a derivation and a validation set. Risk factors for conversion were identified by uni- and multivariable analysis. A "conversion risk score" was built assigning each factor 1 point and comparing the score with the conversion status for each patient. The accuracy was assessed by the area-under-the-receiver-operator-characteristic-curve.

RESULTS

Among 130 operations, 22 were converted (16.9%). Reasons were: 45.5% oncologic inadequacy, 31.8% bleeding, 9.1% adhesions, 9.1% biliostasis, 4.5% anaesthesiological problems. Independent risk factors for conversion were: previous laparoscopic liver surgery (Hazard Ratio 4.9, p 0.011), preoperative chemotherapy ( Hazard Ratio 6.2, p 0.031), malignant diagnosis (Hazard Ratio 3.3, p 0.037), closeness to hepatocaval confluence or inferior vena cava (Hazard Ratio 4.1, p 0.029), tumor volume (Hazard Ratio 2.9, p 0.024). Conversion rates correlated positively with the score, raising from 0 to 100% when the score increased from 0 to 5 (Spearman: p 0.032 in the derivation set, p 0.020 in the validation set). The risk of conversion showed a sharp increase passing from class 3 to 4, reaching a probability estimated between 60 and 71.4%. The score showed good accuracy (area-under-the-receiver-operator-characteristic-curve 0.82).

CONCLUSION

Specific risk factors for conversion are identified for laparoscopic right hepatectomy. This score may help in standardizing the choice of a pure laparoscopic or open approach for such challenging resections.

Relevance of blood loss as key indicator of the quality of surgical care in laparoscopic liver resection for colorectal liver metastases

BACKGROUND

The development of laparoscopic liver resection has led to the hypothesis that intraoperative blood loss may be a key indicator of surgical care quality. This study assessed short- and long-term results of patients according to three levels of intraoperative blood loss during laparoscopic liver resection for colorectal liver metastasis.

METHODS

All patients who underwent laparoscopic liver resection for colorectal liver metastasis between 2000 and 2018 were included. Difficulty of laparoscopic liver resection was defined according to the Institut Mutualiste Montsouris classification. Three levels of the extent of intraoperative blood loss were defined: massive (≥1,000 mL), substantial (≥75th percentile of intraoperative blood loss within each grade of difficulty), and normal intraoperative blood loss.

RESULTS

During study period, 317 patients underwent laparoscopic liver resection for colorectal liver metastasis. Among them, 213 (67.2%), 80 (25.2%), and 24 (7.6%) patients had normal, substantial, and massive intraoperative blood loss, respectively. Twenty-six patients (8.2%) required transfusion. Massive intraoperative blood loss came from a major hepatic vein in 54% of cases and were managed by laparoscopy in 83% of the cases. Laparoscopic liver resection difficulty grade (odds ratio = 3.15; P = .053) and number of colorectal liver metastasis (odds ratio = 1.24; P = .020) were independently associated with massive intraoperative blood loss. Risks factors for substantial intraoperative blood loss were bi-lobar colorectal liver metastasis (odds ratio = 3.12; P = .033) and sinusoidal obstruction syndrome (odds ratio = 3.27; P = .004). The level of intraoperative blood loss was not associated with severe complications nor overall and disease-free survival. Requirement of transfusion was associated with severe complications (odds ratio = 7.27; P = .002) and decreased 1-, 3-, and 5-year overall survival (87%, 68%, and 61% vs 95%, 88%, and 79%; P = .042).

CONCLUSION

The extent of intraoperative blood loss did not affect short- and long-term results of laparoscopic liver resection for colorectal liver metastasis. Massive intraoperative blood loss was often incidental and, 83% of the time, manageable by laparoscopy. Rather than intraoperative blood loss, transfusion is a better relevant indicator of laparoscopic liver resection surgical quality.

When should we choose a laparoscopic approach? A high-volume center recommendation score

Laparoscopic liver resection is a demanding procedure that is undergoing continuous development. The surgeon's skill is constantly improving, new surgical instruments are being introduced, and the indications for this procedure are expanding. However, there is still great concern about patient safety during the procedure and it is not commonly performed in many centers, although numerous studies have confirmed the safety and feasibility of laparoscopic liver techniques. Our center tries to use laparoscopy routinely for most cases and we do not consider conversion to open surgery to be a complication. We present our current opinion on patient selection for laparoscopic liver resection in the hope of encouraging more centers to adopt and develop this technique. Although laparoscopic liver resection is not an official standard of care, it should be considered according to the surgeon's experience and available resources.

Surgical and oncological outcomes after laparoscopic vs. open major hepatectomy for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

The short- and long-term prognoses are unclear following laparoscopic major hepatectomy (LMH) for hepatocellular carcinoma (HCC). We performed a meta-analysis to compare the surgical and oncological outcomes of LMH vs. open major hepatectomy (OMH) in patients with HCC.

METHODS

All studies comparing LMH with OMH for HCC published until April 2019 were identified independently by searching PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We analyzed data for surgical and oncological outcomes, namely, operative time, intraoperative blood loss, blood transfusion rate, postoperative morbidity, major complications, mortality, hospital stay, margin distance, negative margin rate, long-term overall survival, and corresponding disease-free survival (DFS).

RESULTS

We included 13 studies involving 1,225 patients with HCC (LMH: 534 patients; OMH: 691 patients) in the meta-analysis. Regarding short-term outcomes, the pooled data showed that LMH was associated with longer operative time [weighted mean difference (WMD): 72.14 min; 95% confidence interval (CI): 43.07-101.21; P<0.00001], less blood loss (WMD: -102.32 mL; 95% CI: -150.99 to -53.64; P<0.0001), shorter hospital stay (WMD: -3.77 d; 95% CI: -4.95 to -2.60; P<0.00001), lower morbidity [risk difference (RD): -0.01; 95% CI: -0.16 to -0.06; P<0.00001], and lower major complication rates (RD: -0.08; 95% CI: -0.11 to -0.05; P<0.00001). However, the need for blood transfusion (RD: -0.01; 95% CI: -0.06 to 0.05; P=0.78), mortality (RD: -0.01; 95% CI: -0.02 to 0.01; P=0.57), margin distance (WMD: 0.05 mm; 95% CI: -0.1 to 0.19; P=0.52), and negative margin rate (RD: 0.01; 95% CI: -0.03 to 0.05; P=0.65) were significantly comparable between the two groups. Regarding long-term outcomes, there was no difference in 3-year DFS [hazard ratio (HR): 0.99; 95% CI: 0.72-1.37; P=0.95], 3-year overall survival (HR: 1.25; 95% CI: 0.70-2.21; P=0.45), 5-year DFS (HR: 0.94; 95% CI: 0.64-1.38; P=0.76), and 5-year overall survival (HR: 0.94; 95% CI: 0.45-1.99; P=0.88).

CONCLUSIONS

LMH can be performed as safely as OMH in select patients and provides improved short-term surgical outcomes without affecting long-term survival. However, confirming our results requires more evidence from high-quality and prospective randomized controlled trials.

Minimally Invasive Donor Hepatectomy for Adult Living Donor Liver Transplantation: An International, Multi-Institutional Evaluation of Safety, Efficacy and Early Outcomes

OBJECTIVE

Evaluating the perioperative outcomes of minimally invasive (MIV) donor hepatectomy for adult live donor liver transplants in a large multi-institutional series from both Eastern and Western centers.

BACKGROUND

Laparoscopic liver resection has become standard practice for minor resections in selected patients in whom it provides reduced postoperative morbidity and faster rehabilitation. Laparoscopic approaches in living donor hepatectomy for transplantation, however, remain controversial because of safety concerns. Following the recommendation of the Jury of the Morioka consensus conference to address this, a retrospective study was designed to assess the early postoperative outcomes after laparoscopic donor hepatectomy. The collective experience of 10 mature transplant teams from Eastern and Western countries was reviewed.

METHODS

All centers provided data from prospectively maintained databases. Only left and right hepatectomies performed using a MIV technique were included in this study. Primary outcome was the occurrence of complications using the Clavien-Dindo graded classification and the Comprehensive Complication Index during the first 3 months. Logistic regression analysis was used to identify risk factors for complications.

RESULTS

In all, 412 MIV donor hepatectomies were recorded including 164 left and 248 right hepatectomies. Surgical technique was either pure laparoscopy in 175 cases or hybrid approach in 237. Conversion into standard laparotomy was necessary in 17 donors (4.1%). None of the donors died. Also, 108 experienced 121 complications including 9.4% of severe (Clavien-Dindo 3-4) complications. Median Comprehensive Complication Index was 5.2.

CONCLUSIONS

This study shows favorable early postoperative outcomes in more than 400 MIV donor hepatectomy from 10 experienced centers. These results are comparable to those of benchmarking series of open standard donor hepatectomy.

Unplanned conversion during minimally invasive liver resection for hepatocellular carcinoma: risk factors and surgical outcomes

Purpose

Unplanned conversion is sometimes necessary during minimally invasive liver resection (MILR) of hepatocellular carcinoma (HCC). The aims of this study were to compare surgical outcomes of planned MILR and unplanned conversion and to investigate the risk factors after unplanned conversion.

Methods

We retrospectively analyzed 286 patients who underwent MILR with HCC from January 2006 to December 2017. All patients were divided into a MILR group and an unplanned conversion group. The clinicopathologic characteristics and outcomes were compared between the 2 groups. In addition, surgical outcomes in the conversion group were compared with the planned open surgery group (n = 505). Risk factors for unplanned conversion were analyzed.

Results

Of the 286 patients who underwent MILR, 18 patients (6.7%) had unplanned conversion during surgery. The unplanned conversion group showed statistically more blood loss, higher transfusion rate and postoperative complication rate, and longer hospital stay compared to the MILR group, whereas no such difference was observed in comparison with the planned open surgery group. There were no significant differences in overall and disease-free survival among 3 groups. The right-sided sectionectomy (right anterior and posterior sectionectomy), central bisectionectomy and tumor size were risk factors of unplanned conversion.

Conclusion

Unplanned conversion during MILR for HCC was associated with poor perioperative outcomes, but it did not affect long-term oncologic outcomes in our study. In addition, when planning right-sided sectionectomy or central bisectionectomy for a large tumor (more than 5 cm), we should recommend open surgery or MILR with an informed consent for unplanned open conversions.

Comparison of manual and semi-automatic registration in augmented reality image-guided liver surgery: a clinical feasibility study

BACKGROUND

The laparoscopic approach to liver resection may reduce morbidity and hospital stay. However, uptake has been slow due to concerns about patient safety and oncological radicality. Image guidance systems may improve patient safety by enabling 3D visualisation of critical intra- and extrahepatic structures. Current systems suffer from non-intuitive visualisation and a complicated setup process. A novel image guidance system (SmartLiver), offering augmented reality visualisation and semi-automatic registration has been developed to address these issues. A clinical feasibility study evaluated the performance and usability of SmartLiver with either manual or semi-automatic registration.

METHODS

Intraoperative image guidance data were recorded and analysed in patients undergoing laparoscopic liver resection or cancer staging. Stereoscopic surface reconstruction and iterative closest point matching facilitated semi-automatic registration. The primary endpoint was defined as successful registration as determined by the operating surgeon. Secondary endpoints were system usability as assessed by a surgeon questionnaire and comparison of manual vs. semi-automatic registration accuracy. Since SmartLiver is still in development no attempt was made to evaluate its impact on perioperative outcomes.

RESULTS

The primary endpoint was achieved in 16 out of 18 patients. Initially semi-automatic registration failed because the IGS could not distinguish the liver surface from surrounding structures. Implementation of a deep learning algorithm enabled the IGS to overcome this issue and facilitate semi-automatic registration. Mean registration accuracy was 10.9 ± 4.2 mm (manual) vs. 13.9 ± 4.4 mm (semi-automatic) (Mean difference - 3 mm; p = 0.158). Surgeon feedback was positive about IGS handling and improved intraoperative orientation but also highlighted the need for a simpler setup process and better integration with laparoscopic ultrasound.

CONCLUSION

The technical feasibility of using SmartLiver intraoperatively has been demonstrated. With further improvements semi-automatic registration may enhance user friendliness and workflow of SmartLiver. Manual and semi-automatic registration accuracy were comparable but evaluation on a larger patient cohort is required to confirm these findings.

A Comparison of the Learning Curves of Laparoscopic Liver Surgeons in Differing Stages of the IDEAL Paradigm of Surgical Innovation: Standing on the Shoulders of Pioneers

OBJECTIVE

To compare the learning curves of the self-taught "pioneers" of laparoscopic liver surgery (LLS) with those of the trained "early adopters" in terms of short- and medium-term patient outcomes to establish if the learning curve can be reduced with specific training.

SUMMARY OF BACKGROUND DATA

It is expected that a wider adoption of a laparoscopic approach to liver surgery will be seen in the next few years. Current guidelines stress the need for an incremental, stepwise progression through the learning curve in order to minimize harm to patients. Previous studies have examined the learning curve in Stage 2 of the IDEAL paradigm of surgical innovation; however, LLS is now in stage 3 with specific training being provided to surgeons.

METHODS

Using risk-adjusted cumulative sum analysis, the learning curves and short- and medium-term outcomes of 4 "pioneering" surgeons from stage 2 were compared with 4 "early adapting" surgeons from stage 3 who had received specific training for LLS.

RESULTS

After 46 procedures, the short- and medium-term outcomes of the "early adopters" were comparable to those achieved by the "pioneers" following 150 procedures in similar cases.

CONCLUSIONS

With specific training, "early adapting" laparoscopic liver surgeons are able to overcome the learning curve for minor and major liver resections faster than the "pioneers" who were self-taught in LLS. The findings of this study are applicable to all surgical specialties and highlight the importance of specific training in the safe expansion of novel surgical practice.

Laparoscopic Versus Open Major Hepatectomy: Analysis of Clinical Outcomes and Cost Effectiveness in a High-Volume Center

BACKGROUND

Considering the increasing evidence on the feasibility of laparoscopic major hepatectomies (LMH), their clinical outcomes and associated costs were herein evaluated compared to open (OMH).

METHODS

Major contributors of perioperative expenses were considered. With respect to the occurrence of conversion, a primary intention-to-treat analysis including conversions in the LMH group (ITT-A) was performed. An additional per-protocol analysis excluding conversions (PP-A) was undertaken, with calculation of additional costs of conversion analysis.

RESULTS

One hundred forty-five LMH and 61 OMH were included (14.5% conversion rate). At the ITT-A, LMH showed lower blood loss (p < 0.001) and morbidity (global p 0.037, moderate p 0.037), shorter hospital stay (p 0.035), and a lower need for intra- and postoperative red blood cells transfusions (p < 0.001), investigations (p 0.004), and antibiotics (p 0.002). The higher intraoperative expenses (+ 32.1%, p < 0.001) were offset by postoperative savings (- 27.2%, p 0.030), resulting in a global cost-neutrality of LMH (- 7.2%, p 0.807). At the PP-A, completed LMH showed also lower severe complications (p 0.042), interventional procedures (p 0.027), and readmission rates (p 0.031), and postoperative savings increased to - 71.3% (p 0.003) resulting in a 29.9% cost advantage of completed LMH (p 0.020). However, the mean additional cost of conversion was significant.

CONCLUSIONS

Completed LMH exhibit a high potential treatment effect compared to OMH and are associated to significant cost savings. Despite some of these benefits may be jeopardized by conversion, a program of LMH can still provide considerable clinical benefits without cost disadvantage and appears worth to be implemented in high-volume centers.

Ultrasound Liver Map Technique for Laparoscopic Liver Resections

BACKGROUND

Laparoscopic liver resection (LLR) is reported as a safe procedure with potential advantages over open surgery albeit with inherent limitations, such as loss of haptic perception and spatial orientation. Ultrasound is considered the best tool to identify anatomic landmarks and the transection plane during liver surgery. The aim of this study was to analyse the outcomes of LLR performed with a standardized US guidance technique.

METHODS

We have standardized a 4-step technique for ultrasound-guided LLR: (1) compose a 3-D mind map by studying relationships among lesions and surrounding anatomic structures, (2) sketch the map on the liver surface, (3) check, and (4) correct the transection plane in real time.

RESULTS

Between 01/2006 and 12/2016, 190 consecutive patients treated with US-guided LLR were analysed. The indications for LLR included malignant tumours in 148 patients (81.8%). The procedures were classified according to a difficulty scale. There were 18 major hepatectomies (9.9%), 80 anatomic bi- and monosegmentectomies (44.2%), and 101 non-anatomic resections (55.8%). Redo resection was performed in 17 patients (9.4%), and multiple liver resections were performed in 25 patients (24.7%). Median intraoperative blood loss was 100 ± 154 mL. Overall and major morbidity rates were 14.9% and 1.6%, respectively. Mortality was nil.

CONCLUSIONS

Ultrasound liver map technique enables planning and real-time guidance during laparoscopic liver resections.

Effective prediction of postoperative complications for patients after open hepatectomy: a simplified scoring system based on perioperative parameters

BACKGROUND

The aim of the study was to develop a scoring system for the prediction of postoperative complications of open hepatectomy.

METHOD

All consecutive patients receiving open hepatectomy from 2015 to 2017 were included in the study. Univariate and multivariate analyses were used to confirm the risk factors for postoperative complications. Afterwards, a novel scoring system was developed to predict the postoperative complications.

RESULTS

The study included a total of 207 patients. For the test dataset, multivariate analysis indicated that diabetes, scale of surgery, serum potassium, and blood loss versus body weight were independent risk factors of the postoperative complications. The area under the curve (AUC) of the novel scoring system we proposed for prediction of postoperative complications of hepatectomy was 0.803, which is comparable with the AUCs of previous scoring systems. Furthermore, in the validation dataset, the corresponding AUC of the new scoring system was 0.717.

CONCLUSION

This novel and simplified scoring system can effectively predict the postoperative complications of open hepatectomy and could help identify patients who are at high risk of postoperative complications.

Robotic versus laparoscopic liver resection in complex cases of left lateral sectionectomy

BACKGROUND

Laparoscopic liver resection is recommended as the standard operation for left lateral sectionectomy (LLS). Robotic liver resection is theoretically better than laparoscopic liver resection in complex cases of liver resection. However, in a complex case of LLS, whether robotic LLS (R-LLS) is still better than laparoscopic LLS (L-LLS) is unclear. This study aims to assess the perioperative outcomes of R-LLS and L-LLS in the overall and in the subgroup of complex cases of LLS.

METHODS

From January 2015 to June 2017, the data on consecutive patients who underwent R-LLS were retrospectively compared with those who underwent L-LLS. Based on defined criteria for complex cases, the subgroup of such patients who underwent R-LLS were compared with the subgroup of patients who underwent L-LLS. The patient characteristics and surgical outcomes in the whole groups and subgroups of patients were analyzed.

RESULTS

The overall R-LLS and L-LLS groups showed no significance differences in operative time, intraoperative blood loss, postoperative hospital stay, blood transfusion and morbidity rates. The overall medical costs were significantly higher in the R-LLS group than in the L-LLS group (12786.4 vs. 7974.3 USD; p < 0.001). On subgroup analysis of the complex cases, the estimated blood loss was significantly less in the R-LLS subgroup than the L-LLS subgroup (131.9 vs. 320.8 ml, p = 0.003). The two subgroups showed no significant differences in postoperative hospital stay (4.7 vs. 5.3 days; p = 0.054) and operative times (126.4 vs. 110.8 min; p = 0.379). The R-LLS subgroup had significantly higher overall medical costs than the L-LLS subgroup (13536.9 vs. 9186.7 USD, p = 0.006).

CONCLUSION

The overall R-LLS group was comparable to the overall L-LLS group in perioperative outcomes. Although the overall medical costs in the robotic subgroup was higher, R-LLS might be a better choice for the subgroup of patients with complex cases when compared to L-LLS.

Ultrasound liver map technique for laparoscopic liver resections: perioperative outcomes are not impaired by technical complexity

Intraoperative liver ultrasound has a crucial role to guide open liver surgery. A 4-step ultrasound liver map technique for laparoscopic liver resection (LLR) has been standardized in our center. The aim of this study was to evaluate outcomes of our technique according to the hepatectomy technical complexity. A difficulty scale (DS) ranging from 1 to 10 was applied to each LLR. A cumulative sum control-chart analysis identified 3 periods of gradually increasing DS. Perioperative outcomes of the 3 periods were compared. 300 LLRs performed between 2006 and 2018 were analyzed. Median DS was 3 for first 100 cases (P1), 5 for cases 101-200 (P2) and 6 for cases 201-300 (P3). A significantly greater percentage of postero-superior segments resections (P1 11%, P2 36%, P3 46%, p < 0.001) were performed in P3. P3 LLRs had a significantly longer transection time (p < 0.001) and wider cut surface area (p < 0.001), but median blood losses were similar among the 3 periods (P1 100 cc, P2 100 cc, P3 140 cc). There were no differences among periods in overall morbidity (P1 12%, P2 17%, P3 17%), major morbidity (P1 1%, P2 2%, P3 3%) and length of hospital stay (5 days in all the three groups). Despite the increasing surgical complexity of LLR, ultrasound liver map technique allows good perioperative outcomes.

Laparoscopic Liver Resection Difficulty Score-a Validation Study

OBJECTIVE(S)

The technical complexity of laparoscopic liver resection (LLR) poses unique challenges distinct from open surgery. An objective scoring system was developed that preoperatively quantifies the difficulty of LRR to help guide surgeon decision-making regarding the feasibility and safety of minimally invasive approaches. The aim of this multiinstitutional study was to externally validate this scoring system.

METHODS

Patients who underwent LLR at two institutions were reviewed. LLR difficulty score (LDS) was calculated based on patient, tumor, and anatomic characteristics by two independent, blinded hepatobiliary surgeons. Surrogates of case complexity (e.g., conversion rate, operative time) were used for validation of this index.

RESULTS

From 2006 to 2016, 444 LLR were scored as low (n = 94), intermediate (n = 98), and high difficulty (n = 152) with respective conversion rates of 5.3%, 15.7%, and 25%. Cases of higher LDS correlated with larger mean blood loss (203 ml vs. 331 ml vs. 635 ml). Mean operative and Pringle maneuver used were associated with increasing LDS (155 min vs. 202 min vs. 315 min and 14.4% vs. 29.7% vs. 45.1% respectively). These operative surrogates of difficulty correlated significantly with the LDS (all p < 0.0001).

CONCLUSIONS

This comprehensive external validation of the LDS is robust and applicable in diverse patient populations. This LDS serves as a useful objective predictor of technical difficulty for LLR to help surgeons in selecting patients according to their individual operative experience and is valuable for preoperative risk estimation and stratification in randomized trials.

NRG Oncology/RTOG 0438: A Phase 1 Trial of Highly Conformal Radiation Therapy for Liver Metastases

PURPOSE

This study aimed to determine the feasibility and maximally tolerated dose of hypofractionated, conformal radiation therapy (RT) in patients with liver metastases.

METHODS AND MATERIALS

Nonsurgical patients with ≤5 liver metastases (sum of maximal diameter of all lesions ≤8 cm) were included in the study. There were 4 dose levels: 35 Gy, 40 Gy (starting level), 45 Gy, and 50 Gy, in 10 fractions. The clinical target volume included metastases identified on contrast computed tomography or magnetic resonance imaging with a 5-mm margin within the liver. The planning target volume margin ranged from 4 to 30 mm, depending on breathing motion. Dose-limiting toxicities were defined as RT-related grade ≥4 hepatic or gastrointestinal toxicities or thrombocytopenia occurring within 90 days of the start of RT.

RESULTS

A total of 26 patients with metastases from colorectal (8 patients), breast (7 patients) and other malignancies (11 patients) were enrolled between November 2005 and December 2010. Twenty-three patients were evaluable (8, 7, and 8 on the 40, 45, and 50 Gy dose levels, respectively). Two patients assigned to 50 Gy received 35 Gy owing to normal tissue limits, so 2 additional patients were treated to 50 Gy. There were no dose-limiting toxicities on any of the dose levels. On the 45 Gy dose level, 1 patient developed reversible grade 3 enteritis (37 days from RT start) and diarrhea (22 days); another patient developed grade 3 lymphopenia (23 days). At the 50 Gy dose level, 1 patient had grade 3 hyperglycemia (74 days), and another patient developed grade 3 lymphopenia (13 days), colonic hemorrhage (325 days), and colonic gastrointestinal obstruction (325 days). With a potential median follow-up of 66.1 months (range, 34.6-89.0 months), no other late toxicities were observed.

CONCLUSIONS

Treatment of liver metastases with 50 Gy in 10 fractions was feasible and safe in a multi-institutional setting.

A novel scoring system for conversion and complication in laparoscopic liver resection

Background

Although laparoscopic liver resection (LLR) has been increasingly popular worldwide, there is lack of predictive model to evaluate the feasibility and safety of LLR. The aim of this study was to establish a scoring system for predicting the possibility of conversion and complication, which could facilitate the patient selection for clinicians and communication with patients and their relatives during the informed consent process.

Methods

Consecutively 696 patients between August 1998 and December 2016 underwent LLR were recruited. The entire cohort was divided randomly into development and validation cohorts. The scoring system for conversion and complication were established according to risk factors identified from multiple logistic analysis. Subgroup analysis was performed to assess the clinical application. And the C-index and decision curve analysis (DCA) were conducted to evaluate the discrimination in comparison with other predictive models.

Results

Six hundred and ninety-six patients were enrolled eventually. The rate of conversion in the development and validation cohorts was 8.3% and 10.3%, respectively. Compared with 12.6% complication rate in the development cohort, 12.9% was concluded in the validation cohort. Upon on the identified risk factors, the risk stratification model was established and validated. Subsequent subgroup analysis indicated low risk patients presented superior surgical outcomes compared with high risk patients. Besides, the C-index and DCA implied our models had better capacities of predicting conversion and complication in comparison with previous scoring systems.

Conclusions

This novel scoring system presents the remarkable capacities of predicting conversion, complication in LLR. And thereby, it could be a useful instrument to facilitate the patient selection for clinicians and communication with patients and their relatives during the informed consent process.

Laparoscopic Versus Open Approach for Formal Right and Left Hepatectomy: A Propensity Score Matching Analysis

BACKGROUND

Laparoscopic liver surgery is expanding worldwide, but further evidence is needed to assess safety and efficacy of laparoscopic major hepatectomy. The study analyzes perioperative outcomes of pure laparoscopic versus open major hepatectomies matched by the propensity score method.

METHODS

From 2005 to 2017, 268 major hepatectomies were performed of which 73 were laparoscopic. After a 1:1 propensity score matching, 59 laparoscopic right and left hepatectomies were compared to 59 open. The matching was based on age, gender, year of procedure, BMI, ASA score, underlying liver disease, previous abdominal surgery, type of hepatectomy, preoperative chemotherapy, number, dimension and nature of lesions. An intention-to-treat analysis and a per-protocol analysis were carried out.

RESULTS

Mean surgical time was 315 min in the laparoscopic group and 292.5 min in the open group (p = 0.039); conversion rate in laparoscopy was 20.3%; blood loss was 480 ml (50-3000) versus 550 ml (50-2600), respectively, for laparoscopic and open (p = 0.577). Lengths of postoperative analgesia and hospital stay were shorter in the laparoscopic group (p = 0.0001 and 0.024, respectively). Postoperative complications occurred in 11.9% of laparoscopic cases and in 25.4% of open cases (p = 0.098). Median Comprehensive Complication Index was 26.2 (8.7-54.2) in the open group versus 20.9 (8.7-66.2) in open (p = 0.368). Per-protocol analysis showed a better trend in favor of laparoscopy concerning surgical time.

CONCLUSIONS

Laparoscopic major hepatectomies are safe and feasible procedures allowing a similar complication rate with a shorter hospital stay and diminished postoperative pain with respect to the standard approach.

Laparoscopic left hemihepatectomy is suitable as a first step in pure laparoscopic major hepatectomy

AIM

As a procedure, major laparoscopic liver resection (LLR) remains in the exploration phase. Previous studies have assessed major LLR en bloc, including hepatectomies of varying complexities; however, the number of segments alone does not convey the complexity of a resection. This study aimed to assess operative outcomes of LLR procedures with more than one sectionectomy, and to identify the best procedure as a first step when learning to carry out major LLR in order to make LLR a safer, more widely used procedure.

METHODS

We carried out a retrospective review of the operative outcomes of 120 consecutive patients who underwent pure LLR with more than one sectionectomy. Operative outcomes were compared according to the complexity classification recently published, and the learning curve for each LLR procedure was assessed and compared.

RESULTS

Operative outcomes, including operative time, blood loss, and the comprehensive complication index, were significantly stratified according to complexity. There were significant differences in operative outcomes among the medium complexity procedures. The operative time for left hemihepatectomy was the shortest, and the amount of blood loss was the lowest among the medium complexity LLR. Operative times for left hemihepatectomy shortened significantly with time and experience (r = -0.639), and the slope of the learning curve was steeper than for right hemihepatectomy and right posterior sectionectomy.

CONCLUSION

Left hemihepatectomy is suitable as a first step in pure laparoscopic major hepatectomy and, given its safety and rapid learning curve for surgeons, it could become the gold standard procedure.

Low conversion rate during minimally invasive major hepatectomy: Ten-year experience at a high-volume center

BACKGROUND

Minimally invasive approaches for major hepatectomy have been marred by significant rates of conversion and associated morbidity. This study aimed to determine risk factors for conversion as well as postoperative morbidity in patients undergoing minimally invasive right-sided hepatectomy (MIRH).

METHODS

Data for patients undergoing MIRH between 2008 and 2017 at Emory University were reviewed. Risk factors for conversion were determined using multivariate regression analysis. Outcomes of conversion patients were compared with those who underwent successful MIRH or elective open surgery.

RESULTS

Unplanned conversion occurred in 7 (6.25%) of 112 patients undergoing MIRH. Primary reason for conversion was difficult dissection secondary to inflammation and severe adhesions. No preoperative clinical factor was identified that predicted conversions. Converted cases had higher EBL and pRBC transfusion compared to non-converted cases however morbidity was similar to those undergoing primary open surgery.

CONCLUSION

Difficult dissection and adhesions remained the only clinically applicable parameter leading to unplanned conversions. While these did offset benefits of a successful minimally invasive approach, it did not increase risk of postoperative complications compared with planned open surgery.