Impact of neoadjuvant chemotherapy on short-term outcomes after simple and complex minimally invasive minor hepatectomy for colorectal liver metastases: A propensity-score matched and coarsened exact matched study.

BACKGROUND: In the last three decades, minimally invasive liver resection has been replacing conventional open approach in liver surgery. More recently, developments in neoadjuvant chemotherapy have led to increased multidisciplinary management of colorectal liver metastases with both medical and surgical treatment modalities. However, the impact of neoadjuvant chemotherapy on the surgical outcomes of minimally invasive liver resections remains poorly understood. METHODS: A multicenter, international, database of 4998 minimally invasive minor hepatectomy for colorectal liver metastases was used to compare surgical outcomes in patients who received neoadjuvant chemotherapy with surgery alone. To correct for baseline imbalance, propensity score matching, coarsened exact matching and inverse probability treatment weighting were performed. RESULTS: 2546 patients met the inclusion criteria. After propensity score matching there were 759 patients in both groups and 383 patients in both groups after coarsened exact matching. Baseline characteristics were equal after both matching strategies. Neoadjuvant chemotherapy was not associated with statistically significant worse surgical outcomes of minimally invasive minor hepatectomy. CONCLUSION: Neoadjuvant chemotherapy had no statistically significant impact on short-term surgical outcomes after simple and complex minimally invasive minor hepatectomy for colorectal liver metastases.

Prognostic benefit of preoperative transarterial chemoembolization in upfront resectable large hepatocellular carcinoma: a multicentric propensity score based analysis of European high-volume centers.

BACKGROUND: Hepatocellular carcinoma (HCC) have a dismal prognosis and any effective neoadjuvant treatment has been validated to date. We aimed to investigate the role of neoadjuvant transarterial chemoembolization (TACE) in upfront resectable HCC larger than 5 cm. METHODS: This is a multicentric retrospective study comparing outcomes of large HCC undergoing TACE followed by surgery or liver resection alone before and after propensity-score matching (PSM). RESULTS: A total of 384 patients were included of whom 60 (15.6%) received TACE. This group did not differ from upfront resected cases neither in terms of disease-free survival (p = 0.246) nor in overall survival (p = 0.276). After PSM, TACE still did not influence long-term outcomes (p = 0.935 and p = 0.172, for DFS and OS respectively). In subgroup analysis, TACE improved OS only in HCC ≥10 cm (p = 0.045), with a borderline significance after portal vein embolization/ligation (p = 0.087) and in single HCC (p = 0.052). CONCLUSIONS: TACE should not be systematically performed in all resectable large HCC. Selected cases could however potentially benefit from this procedure, as patients with huge and single tumors or those necessitating of a PVE.

Robotic versus Laparoscopic Liver Resection in Various Settings: An International Multicenter Propensity Score Matched Study of 10.075 Patients.

OBJECTIVE: The aim of this study was to compare the perioperative outcomes of robotic liver surgery (RLS) and laparoscopic liver surgery (LLS) in various settings. SUMMARY BACKGROUND DATA: Clear advantages of RLS over LLS have rarely been demonstrated, and the associated costs of robotic surgery are generally higher than those of laparoscopic surgery. Therefore, the exact role of the robotic approach in minimally invasive liver surgery remains to be defined. METHODS: In this international retrospective cohort study, the outcomes of patients who underwent RLS and LLS for all indications between 2009 and 2021 in 34 hepatobiliary referral centers were compared. Subgroup analyses were performed to compare both approaches across several types of procedures: minor resections in the anterolateral (2, 3, 4b, 5, and 6) or posterosuperior segments (1, 4a, 7, 8), and major resections (≥3 contiguous segments). Propensity score matching (PSM) was used to mitigate the influence of selection bias. The primary outcome was textbook outcome in liver surgery (TOLS), previously defined as the absence of intraoperative incidents ≥grade 2, postoperative bile leak ≥grade B, severe morbidity, readmission, and 90-day or in-hospital mortality with the presence of an R0 resection margin in case of malignancy. The absence of a prolonged length of stay was added to define TOLS+. RESULTS: Among the 10.075 included patients, 1.507 underwent RLS and 8.568 LLS. After PSM, both groups constituted 1.505 patients. RLS was associated with higher rates of TOLS (78.3% vs. 71.8%, P<0.001) and TOLS+ (55% vs. 50.4%, P=0.026), less Pringle usage (39.1% vs. 47.1%, P<0.001), blood loss (100 vs. 200 milliliters, P<0.001), transfusions (4.9% vs. 7.9%, P=0.003), conversions (2.7% vs 8.8%, P<0.001), overall morbidity (19.3% vs. 25.7%, P<0.001) and R0 resection margins (89.8% vs. 86%, P=0.015), but longer operative times (190 vs. 210 min, P=0.015). In the subgroups, RLS tended to have higher TOLS rates, compared to LLS, for minor resections in the posterosuperior segments (n=431 per group, 75.9% vs. 71.2%, P=0.184) and major resections (n=321 per group, 72.9% vs. 67.5%, P=0.086), although these differences did not reach statistical significance. CONCLUSIONS: While both producing excellent outcomes, RLS might facilitate slightly higher TOLS rates than LLS.

Propensity Score-Matching Analysis Comparing Robotic Versus Laparoscopic Limited Liver Resections of the Posterosuperior Segments: An International Multicenter Study.

OBJECTIVE: The purpose of this study was to compare the outcomes of robotic limited liver resections (RLLR) versus laparoscopic limited liver resections (LLLR) of the posterosuperior segments. BACKGROUND: Both laparoscopic and robotic liver resections have been used for tumors in the posterosuperior liver segments. However, the comparative performance and safety of both approaches have not been well examined in the existing literature. METHODS: This is a post hoc analysis of a multicenter database of 5446 patients who underwent RLLR or LLLR of the posterosuperior segments (I, IVa, VII, and VIII) at 60 international centers between 2008 and 2021. Data on baseline demographics, center experience and volume, tumor features, and perioperative characteristics were collected and analyzed. Propensity score-matching (PSM) analysis (in both 1:1 and 1:2 ratios) was performed to minimize selection bias. RESULTS: A total of 3510 cases met the study criteria, of whom 3049 underwent LLLR (87%), and 461 underwent RLLR (13%). After PSM (1:1: and 1:2), RLLR was associated with a lower open conversion rate [10 of 449 (2.2%) vs 54 of 898 (6.0%); P =0.002], less blood loss [100 mL [IQR: 50-200) days vs 150 mL (IQR: 50-350); P <0.001] and a shorter operative time (188 min (IQR: 140-270) vs 222 min (IQR: 158-300); P <0.001]. These improved perioperative outcomes associated with RLLR were similarly seen in a subset analysis of patients with cirrhosis-lower open conversion rate [1 of 136 (0.7%) vs 17 of 272 (6.2%); P =0.009], less blood loss [100 mL (IQR: 48-200) vs 160 mL (IQR: 50-400); P <0.001], and shorter operative time [190 min (IQR: 141-258) vs 230 min (IQR: 160-312); P =0.003]. Postoperative outcomes in terms of readmission, morbidity and mortality were similar between RLLR and LLLR in both the overall PSM cohort and cirrhosis patient subset. CONCLUSIONS: RLLR for the posterosuperior segments was associated with superior perioperative outcomes in terms of decreased operative time, blood loss, and open conversion rate when compared with LLLR.

Trends in the characteristics and perioperative outcomes of patients undergoing laparoscopic and open resections for benign liver lesions: An international multicenter retrospective cohort study of 845 patients.

BACKGROUND: Solid benign liver lesions (BLL) are increasingly discovered, but clear indications for surgical treatment are often lacking. Concomitantly, laparoscopic liver surgery is increasingly performed. The aim of this study was to assess if the availability of laparoscopic surgery has had an impact on the characteristics and perioperative outcomes of patients with BLL. METHODS: This is a retrospective international multicenter cohort study, including patients undergoing a laparoscopic or open liver resection for BLL from 19 centers in eight countries. Patients were divided according to the time period in which they underwent surgery (2008-2013, 2014-2016, and 2017-2019). Unadjusted and risk-adjusted (using logistic regression) time-trend analyses were performed. The primary outcome was textbook outcome (TOLS), defined as the absence of intraoperative incidents ≥ grade 2, bile leak ≥ grade B, severe complications, readmission and 90-day or in-hospital mortality, with the absence of a prolonged length of stay added to define TOLS+. RESULTS: In the complete dataset comprised of patients that underwent liver surgery for all indications, the proportion of patients undergoing liver surgery for benign disease remained stable (12.6% in the first time period, 11.9% in the second time period and 12.1% in the last time period, p = 0.454). Overall, 845 patients undergoing a liver resection for BLL in the first (n = 374), second (n = 258) or third time period (n = 213) were included. The rates of ASA-scores≥3 (9.9%-16%,p < 0.001), laparoscopic surgery (57.8%-77%,p < 0.001), and Pringle maneuver use (33.2%-47.2%,p = 0.001) increased, whereas the length of stay decreased (5 to 4 days,p < 0.001). There were no significant changes in the TOLS rate (86.6%-81.3%,p = 0.151), while the TOLS + rate increased from 41.7% to 58.7% (p < 0.001). The latter result was confirmed in the risk-adjusted analyses (aOR 1.849,p = 0.004). CONCLUSION: The surgical treatment of BLL has evolved with an increased implementation of the laparoscopic approach and a decreased length of stay. This evolution was paralleled by stable TOLS rates above 80% and an increase in the TOLS + rate.

Impact of Liver Cirrhosis, Severity of Cirrhosis, and Portal Hypertension on the Difficulty and Outcomes of Laparoscopic and Robotic Major Liver Resections for Primary Liver Malignancies.

BACKGROUND: Minimally invasive liver resections (MILR) offer potential benefits such as reduced blood loss and morbidity compared with open liver resections. Several studies have suggested that the impact of cirrhosis differs according to the extent and complexity of resection. Our aim was to investigate the impact of cirrhosis on the difficulty and outcomes of MILR, focusing on major hepatectomies. METHODS: A total of 2534 patients undergoing minimally invasive major hepatectomies (MIMH) for primary malignancies across 58 centers worldwide were retrospectively reviewed. Propensity score (PSM) and coarsened exact matching (CEM) were used to compare patients with and without cirrhosis. RESULTS: A total of 1353 patients (53%) had no cirrhosis, 1065 (42%) had Child-Pugh A and 116 (4%) had Child-Pugh B cirrhosis. Matched comparison between non-cirrhotics vs Child-Pugh A cirrhosis demonstrated comparable blood loss. However, after PSM, postoperative morbidity and length of hospitalization was significantly greater in Child-Pugh A cirrhosis, but these were not statistically significant with CEM. Comparison between Child-Pugh A and Child-Pugh B cirrhosis demonstrated the latter had significantly higher transfusion rates and longer hospitalization after PSM, but not after CEM. Comparison of patients with cirrhosis of all grades with and without portal hypertension demonstrated no significant difference in all major perioperative outcomes after PSM and CEM. CONCLUSIONS: The presence and severity of cirrhosis affected the difficulty and impacted the outcomes of MIMH, resulting in higher blood transfusion rates, increased postoperative morbidity, and longer hospitalization in patients with more advanced cirrhosis. As such, future difficulty scoring systems for MIMH should incorporate liver cirrhosis and its severity as variables.

Single-Center Retrospective Study Comparing Double Vein Embolization via a Trans-Jugular Approach with Liver Venous Deprivation via a Trans-Hepatic Approach.

PURPOSE: To compare safety, technical and clinical outcomes of double vein embolization (DVE) via a trans-jugular approach with liver venous deprivation (LVD) via a trans-hepatic approach. MATERIALS AND METHODS: A single-center retrospective analysis was conducted on patients undergoing simultaneous portal and hepatic veins embolization in view of a major hepatectomy (June 2019-November 2022). Hepatic vein embolization was performed either by transjugular plug (DVE) or by transhepatic plug followed by glue injection (LVD). Inclusion criteria were availability of pre-procedural CT scan, and availability of CT scans acquired 10 days and 25 days post-procedure. Comparative data included complication rate, fluoroscopy time, dose area product (DAP), Future Liver Remnant volume and function increase (FLR-V and FLR-F increase, respectively) and clinical outcomes. RESULTS: Thirty-six patients (n = 14 DVE; n = 22 LVD) were included. No baseline significant differences were observed among the two groups. One grade-3 complication (2.8%) was observed in the LVD group; one case of technical failure (2.8%) was observed in the DVE group. Fluoroscopy time and DAP were similar between DVE and LVD (29 ± 17.7 vs. 25 ± 8.2 min, p = 0.97; 105.1 ± 63.5 vs. 143.4 ± 79.5 Gy·cm2, p = 0.15). No differences arose at either time-point in FLR-V increase (46.7 ± 23.1% vs. 48.2 ± 28.2%, 52.9 ± 30.9% vs. 53.2 ± 29%, respectively, p = 0.9). FLR-F increase also did not differ significantly (62.8 ± 55.2 vs. 67.4 ± 57.5, p = 0.9). No differences in drop-out rate from surgery were observed. (28.6% vs. 27.3%, p = 0.93). One case of grade-B post-hepatectomy liver failure (2.8%) was observed in the LVD group. CONCLUSION: LVD via transhepatic approach and DVE via transjugular approach seem equally safe and effective. Level of Evidence Level 3, Retrospective Cohort Study.

Impact of liver cirrhosis and portal hypertension on minimally invasive limited liver resection for primary liver malignancies in the posterosuperior segments: An international multicenter study.

INTRODUCTION: To assess the impact of cirrhosis and portal hypertension (PHT) on technical difficulty and outcomes of minimally invasive liver resection (MILR) in the posterosuperior segments. METHODS: This is a post-hoc analysis of patients with primary malignancy who underwent laparoscopic and robotic wedge resection and segmentectomy in the posterosuperior segments between 2004 and 2019 in 60 centers. Surrogates of difficulty (i.e, open conversion rate, operation time, blood loss, blood transfusion, and use of the Pringle maneuver) and outcomes were compared before and after propensity-score matching (PSM) and coarsened exact matching (CEM). RESULTS: Of the 1954 patients studied, 1290 (66%) had cirrhosis. Among the cirrhotic patients, 310 (24%) had PHT. After PSM, patients with cirrhosis had higher intraoperative blood transfusion (14% vs. 9.3%; p = 0.027) and overall morbidity rates (20% vs. 14.5%; p = 0.023) than those without cirrhosis. After coarsened exact matching (CEM), patients with cirrhosis tended to have higher intraoperative blood transfusion rate (12.1% vs. 6.7%; p = 0.059) and have higher overall morbidity rate (22.8% vs. 12.5%; p = 0.007) than those without cirrhosis. After PSM, Pringle maneuver was more frequently applied in cirrhotic patients with PHT (62.2% vs. 52.4%; p = 0.045) than those without PHT. CONCLUSION: MILR in the posterosuperior segments in cirrhotic patients is associated with higher intraoperative blood transfusion and postoperative morbidity. This parameter should be utilized in the difficulty assessment of MILR.

A "cui prodest" evaluation on the development of a minimally invasive liver surgery program: a differential benefit analysis of open and laparoscopic approach for left and right hemihepatectomies.

BACKGROUND: The correlation between technical feasibility and short-term clinical advantage provided by laparoscopic over open technique for major hepatectomies is unclear. This monocentric retrospective study investigates the possible differences in the benefit provided by minimally invasive approach between left and right hepatectomy, deepening the concept of differential benefit in the setting of anatomical major resections. METHODS: All hemihepatectomies performed from January 2004 to December 2021 were identified in the institutional database. A propensity score method was used to match minimal invasive (MILS) and open pairs in the left hemihepatectomies (LH) and right hemihepatectomies (RH) groups with a 1:1 ratio to adjust any potential selection bias. The differential benefit for left and right hepatectomy provided by laparoscopic over open technique was evaluated in a pure analysis (i.e., including cases converted to open) and a risk-adjusted analysis (i.e., after excluding open conversion from the laparoscopic series). RESULTS: The analysis of the risk-adjusted differential benefit demonstrated better result of the MILS in the RH group than in the LH group, in terms of blood loss (∆ blood loss - 150 and - 350, respectively; differential benefit: 200 mL, p < 0.05), morbidity (∆ rate of morbidity - 11.3% and - 18.1%, respectively; differential benefit: 6.8%, p < 0.05) and length of stay, LOS (∆ LOS - 1 day and - 3 days, respectively; differential benefit: 2 days, p < 0.05). CONCLUSION: While MILS is associated with improved clinical outcomes both in left and right hepatectomy procedures, the greater advantage provided by laparoscopy was documented in patients undergoing right hepatectomy, i.e. for more technically demanding procedures. A MILS program should include the broadest range of liver resections to ensure the full benefits of the laparoscopic technique.

E-AHPBA-ESSO-ESSR Innsbruck consensus guidelines for preoperative liver function assessment before hepatectomy.

BACKGROUND: Posthepatectomy liver failure (PHLF) contributes significantly to morbidity and mortality after liver surgery. Standardized assessment of preoperative liver function is crucial to identify patients at risk. These European consensus guidelines provide guidance for preoperative patient assessment. METHODS: A modified Delphi approach was used to achieve consensus. The expert panel consisted of hepatobiliary surgeons, radiologists, nuclear medicine specialists, and hepatologists. The guideline process was supervised by a methodologist and reviewed by a patient representative. A systematic literature search was performed in PubMed/MEDLINE, the Cochrane library, and the WHO International Clinical Trials Registry. Evidence assessment and statement development followed Scottish Intercollegiate Guidelines Network methodology. RESULTS: Based on 271 publications covering 4 key areas, 21 statements (at least 85 per cent agreement) were produced (median level of evidence 2- to 2+). Only a few systematic reviews (2++) and one RCT (1+) were identified. Preoperative liver function assessment should be considered before complex resections, and in patients with suspected or known underlying liver disease, or chemotherapy-associated or drug-induced liver injury. Clinical assessment and blood-based scores reflecting liver function or portal hypertension (for example albumin/bilirubin, platelet count) aid in identifying risk of PHLF. Volumetry of the future liver remnant represents the foundation for assessment, and can be combined with indocyanine green clearance or LiMAx® according to local expertise and availability. Functional MRI and liver scintigraphy are alternatives, combining FLR volume and function in one examination. CONCLUSION: These guidelines reflect established methods to assess preoperative liver function and PHLF risk, and have uncovered evidence gaps of interest for future research.

Liver surgery is an effective treatment for liver tumours. Liver failure is a major problem in patients with a poor liver quality or having large operations. The treatment options for liver failure are limited, with high death rates. To estimate patient risk, assessing liver function before surgery is important. Many methods exist for this purpose, including functional, blood, and imaging tests. This guideline summarizes the available literature and expert opinions, and aids clinicians in planning safe liver surgery.

Impact of Tumor Size on the Difficulty of Laparoscopic Major Hepatectomies: An International Multicenter Study.

INTRODUCTION: Although tumor size (TS) is known to affect surgical outcomes in laparoscopic liver resection (LLR), its impact on laparoscopic major hepatectomy (L-MH) is not well studied. The objectives of this study were to investigate the impact of TS on the perioperative outcomes of L-MH and to elucidate the optimal TS cutoff for stratifying the difficulty of L-MH. METHODS: This was a post-hoc analysis of 3008 patients who underwent L-MH at 48 international centers. A total 1396 patients met study criteria and were included. The impact of TS cutoffs was investigated by stratifying TS at each 10-mm interval. The optimal cutoffs were determined taking into consideration the number of endpoints which showed a statistically significant split around the cut-points of interest and the magnitude of relative risk after correction for multiple risk factors. RESULTS: We identified 2 optimal TS cutoffs, 50 mm and 100 mm, which segregated L-MH into 3 groups. An increasing TS across these 3 groups (≤ 50 mm, 51-100 mm, > 100 mm), was significantly associated with a higher open conversion rate (11.2%, 14.7%, 23.0%, P < 0.001), longer operating time (median, 340 min, 346 min, 365 min, P = 0.025), increased blood loss (median, 300 ml,  ml, 400 ml, P = 0.002) and higher rate of intraoperative blood transfusion (13.1%, 15.9%, 27.6%, P < 0.001). Postoperative outcomes such as overall morbidity, major morbidity, and length of stay were comparable across the three groups. CONCLUSION: Increasing TS was associated with poorer intraoperative but not postoperative outcomes after L-MH. We determined 2 TS cutoffs (50 mm and 10 mm) which could optimally stratify the surgical difficulty of L-MH.

Radial and longitudinal margins in surgery of perihilar cholangiocarcinoma: When R1 definition is associated with different prognosis.

BACKGROUND: Infiltrated margins of resection (R1) and lymph node invasion are dominant negative predictors of survival in patients with a resectable perihilar cholangiocarcinoma. Less clear is whether survival predictors stratify differently between R0 (tumor-free margins) and R1 patients and whether the prognosis of the latter patients is influenced by the pattern of neoplastic infiltration (ie, radial versus longitudinal infiltration). We retrospectively evaluated a series of reported resected perihilar cholangiocarcinoma to obtain insights on the predictive power of these histologic features. METHODS: The study includes 264 patients with perihilar cholangiocarcinoma treated between 2004 and 2019 in our center and followed up for >18 months. There were 176 patients with R0 (66.6%) and 88 patients with R1 (33.3%), 31 with radial infiltration only, 30 with longitudinal infiltration only, and 27 with both infiltration patterns. In all patients, the criteria for resection was the absence of metastatic involvement (ie, distant organ metastases, liver metastases, and lymph node metastases beyond the hepatoduodenal ligament). Histopathologic specimens of the resected tumors were centrally reviewed by a pathologist unaware of the clinical outcomes. RESULTS: Three- and 5-year long-term survival were significantly better in R0 (respectively) compared to R1 patients (55% and 42% vs 42% and 18%, respectively, P < .05). In R1 patients with radial infiltration only and those with radial + longitudinal infiltration, both disease-free and overall survival were worse than those with longitudinal infiltration only (median disease-free survival of 18 and 23 months, respectively, P < .05, median overall survival of 33 and 39 months, respectively, P < .05). At multivariable analysis, nodal status, side of hepatectomy, grading, and presence of radial margin infiltration were associated with long-term outcome. CONCLUSION: Radial infiltration of resection margins enhances the negative prognostic value of R1 margins in perihilar cholangiocarcinoma patients and should specifically be accounted for in the prediction of the outcome of adjuvant therapy.

Survival benefit of second line therapies for recurrent hepatocellular carcinoma: repeated hepatectomy, thermoablation and second-line transplant referral in a real life national scenario.

BACKGROUND: Despite second-line transplant(SLT) for recurrent hepatocellular carcinoma(rHCC) leads to the longest survival after recurrence(SAR), its real applicability has never been reported. The aim was to compare the SAR of SLT versus repeated hepatectomy and thermoablation(CUR group). METHODS: Patients were enrolled from the Italian register HE.RC.O.LE.S. between 2008 and 2021. Two groups were created: CUR versus SLT. A propensity score matching (PSM) was run to balance the groups. RESULTS: 743 patients were enrolled, CUR = 611 and SLT = 132. Median age at recurrence was 71(IQR 6575) years old and 60(IQR 53-64, p < 0.001) for CUR and SLT respectively. After PSM, median SAR for CUR was 43 months(95%CI = 37 - 93) and not reached for SLT(p < 0.001). SLT patients gained a survival benefit of 9.4 months if compared with CUR. MilanCriteria(MC)-In patients were 82.7% of the CUR group. SLT(HR 0.386, 95%CI = 0.23 - 0.63, p < 0.001) and the MELD score(HR 1.169, 95%CI = 1.07 - 1.27, p < 0.001) were the only predictors of mortality. In case of MC-Out, the only predictor of mortality was the number of nodules at recurrence(HR 1.45, 95%CI= 1.09 - 1.93, p = 0.011). CONCLUSION: It emerged an important transplant under referral in favour of repeated hepatectomy or thermoablation. In patients with MC-Out relapse, the benefit of SLT over CUR was not observed.

Robo-Lap Approach for Anatomical Resections of Postero-Superior Liver Segments by Indocyanine Green Fluorescence: Intraoperative Navigation Based on Vascular Landmarks.

Cornerstones elements of surgical technique to achieve a good efficacy and safety profile in robotic anatomical resections of postero-superior segments have not yet reached an adequate level of standardization. In this technical note, surgical details to perform anatomical resections of postero-superior segments of the liver (Sg7 and Sg8) based on the identification of vascular landmarks and assisted by use of negative staining with indocyanine green (ICG) fluorescence will be described. In Sg7 segmentectomy, dorsal approach to portobiliary pedicle is suggested, followed by root to periphery approach to right hepatic vein along the negative staining demarcation line by indocyanine green. In Sg8 segmentectomy, root to periphery approach to middle hepatic vein allows comfortable indentification of Sg8 portobiliary pedicle. Approach to right hepatic vein is made easier by negative staining demarcation line. Robo-Lap approach allows to perform these procedures with an adequate level of safety and reproducibility.

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.

Robotic versus laparoscopic liver resection for huge (≥10 cm) liver tumors: an international multicenter propensity-score matched cohort study of 799 cases.

Background: The use of laparoscopic (LLR) and robotic liver resections (RLR) has been safely performed in many institutions for liver tumours. A large scale international multicenter study would provide stronger evidence and insight into application of these techniques for huge liver tumours ≥10 cm. Methods: This was a retrospective review of 971 patients who underwent LLR and RLR for huge (≥10 cm) tumors at 42 international centers between 2002-2020. Results: One hundred RLR and 699 LLR which met study criteria were included. The comparison between the 2 approaches for patients with huge tumors were performed using 1:3 propensity-score matching (PSM) (73 vs. 219). Before PSM, LLR was associated with significantly increased frequency of previous abdominal surgery, malignant pathology, liver cirrhosis and increased median blood. After PSM, RLR and LLR was associated with no significant difference in key perioperative outcomes including media operation time (242 vs. 290 min, P=0.286), transfusion rate rate (19.2% vs. 16.9%, P=0.652), median blood loss (200 vs. 300 mL, P=0.694), open conversion rate (8.2% vs. 11.0%, P=0.519), morbidity (28.8% vs. 21.9%, P=0.221), major morbidity (4.1% vs. 9.6%, P=0.152), mortality and postoperative length of stay (6 vs. 6 days, P=0.435). Conclusions: RLR and LLR can be performed safely for selected patients with huge liver tumours with excellent outcomes. There was no significant difference in perioperative outcomes after RLR or LLR.

Robotic versus laparoscopic liver resections for hepatolithiasis: an international multicenter propensity score matched analysis.

INTRODUCTION: Minimally invasive liver resection (MILR) is widely recognized as a safe and beneficial procedure in the treatment of both malignant and benign liver diseases. Hepatolithiasis has traditionally been reported to be endemic only in East Asia, but has seen a worldwide uptrend in recent decades with increasingly frequent and invasive endoscopic instrumentation of the biliary tract for a myriad of conditions. To date, there has been a woeful lack of high-quality evidence comparing the laparoscopic (LLR) and robotic (RLR) approaches to treatment hepatolithiasis. METHODS: This is an international multicenter retrospective analysis of 273 patients who underwent RLR or LRR for hepatolithiasis at 33 centers in 2003-2020. The baseline clinicopathological characteristics and perioperative outcomes of these patients were assessed. To minimize selection bias, 1:1 (48 and 48 cases of RLR and LLR, respectively) and 1:2 (37 and 74 cases of RLR and LLR, respectively) propensity score matching (PSM) was performed. RESULTS: In the unmatched cohort, 63 (23.1%) patients underwent RLR, and 210 (76.9%) patients underwent LLR. Patient clinicopathological characteristics were comparable between the groups after PSM. After 1:1 and 1:2 PSM, RLR was associated with less blood loss (p = 0.003 in 1:2 PSM; p = 0.005 in 1:1 PSM), less patients with blood loss greater than 300 ml (p = 0.024 in 1:2 PSM; p = 0.027 in 1:1 PSM), and lower conversion rate to open surgery (p = 0.003 in 1:2 PSM; p < 0.001 in 1:1 PSM). There was no significant difference between RLR and LLR in use of the Pringle maneuver, median Pringle maneuver duration, 30-day readmission rate, postoperative morbidity, major morbidity, reoperation, and mortality. CONCLUSION: Both RLR and LLR were safe and feasible for hepatolithiasis. RLR was associated with significantly less blood loss and lower open conversion rate.

Propensity-score Matched and Coarsened-exact Matched Analysis Comparing Robotic and Laparoscopic Major Hepatectomies: An International Multicenter Study of 4822 Cases.

OBJECTIVE: To compare the outcomes between robotic major hepatectomy (R-MH) and laparoscopic major hepatectomy (L-MH). BACKGROUND: Robotic techniques may overcome the limitations of laparoscopic liver resection. However, it is unknown whether R-MH is superior to L-MH. METHODS: This is a post hoc analysis of a multicenter database of patients undergoing R-MH or L-MH at 59 international centers from 2008 to 2021. Data on patient demographics, center experience volume, perioperative outcomes, and tumor characteristics were collected and analyzed. Both 1:1 propensity-score matched (PSM) and coarsened-exact matched (CEM) analyses were performed to minimize selection bias between both groups. RESULTS: A total of 4822 cases met the study criteria, of which 892 underwent R-MH and 3930 underwent L-MH. Both 1:1 PSM (841 R-MH vs. 841 L-MH) and CEM (237 R-MH vs. 356 L-MH) were performed. R-MH was associated with significantly less blood loss {PSM:200.0 [interquartile range (IQR):100.0, 450.0] vs 300.0 (IQR:150.0, 500.0) mL; P = 0.012; CEM:170.0 (IQR: 90.0, 400.0) vs 200.0 (IQR:100.0, 400.0) mL; P = 0.006}, lower rates of Pringle maneuver application (PSM: 47.1% vs 63.0%; P < 0.001; CEM: 54.0% vs 65.0%; P = 0.007) and open conversion (PSM: 5.1% vs 11.9%; P < 0.001; CEM: 5.5% vs 10.4%, P = 0.04) compared with L-MH. On subset analysis of 1273 patients with cirrhosis, R-MH was associated with a lower postoperative morbidity rate (PSM: 19.5% vs 29.9%; P = 0.02; CEM 10.4% vs 25.5%; P = 0.02) and shorter postoperative stay [PSM: 6.9 (IQR: 5.0, 9.0) days vs 8.0 (IQR: 6.0 11.3) days; P < 0.001; CEM 7.0 (IQR: 5.0, 9.0) days vs 7.0 (IQR: 6.0, 10.0) days; P = 0.047]. CONCLUSIONS: This international multicenter study demonstrated that R-MH was comparable to L-MH in safety and was associated with reduced blood loss, lower rates of Pringle maneuver application, and conversion to open surgery.