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.

Defining Global Benchmarks for Laparoscopic Right Posterior Sectionectomy/H67: An International Multicenter Study.

OBJECTIVE: We aimed to establish global benchmark outcomes indicators for L-RPS/H67. BACKGROUND: Minimally invasive liver resections has seen an increase in uptake in recent years. Over time, challenging procedures as laparoscopic right posterior sectionectomies (L-RPS)/H67 are also increasingly adopted. METHODS: This is a post hoc analysis of a multicenter database of 854 patients undergoing minimally invasive RPS (MI-RPS) in 57 international centers in 4 continents between 2015 and 2021. There were 651 pure L-RPS and 160 robotic RPS (R-RPS). Sixteen outcome indicators of low-risk L-RPS cases were selected to establish benchmark cutoffs. The 75th percentile of individual center medians for a given outcome indicator was set as the benchmark cutoff. RESULTS: There were 573 L-RPS/H67 performed in 43 expert centers, of which 254 L-RPS/H67 (44.3%) cases qualified as low risk benchmark cases. The benchmark outcomes established for operation time, open conversion rate, blood loss ≥500 mL, blood transfusion rate, postoperative morbidity, major morbidity, 90-day mortality and textbook outcome after L-RPS were 350.8 minutes, 12.5%, 53.8%, 22.9%, 23.8%, 2.8%, 0% and 4% respectively. CONCLUSIONS: The present study established the first global benchmark values for L-RPS/H6/7. The benchmark provided an up-to-date reference of best achievable outcomes for surgical auditing and benchmarking.

Propensity Score-matched Analysis Comparing Robotic Versus Laparoscopic Minor Liver Resections of the Anterolateral Segments: an International Multi-center Study of 10,517 Cases.

OBJECTIVE: To compare the outcomes of robotic minor liver resections (RMLR) versus laparoscopic (L) MLR of the anterolateral segments. BACKGROUND: Robotic liver surgery has been gaining prominence over the years with increasing usage for a myriad of hepatic resections. Robotic liver resections(RLR) has demonstrated non-inferiority to laparoscopic(L)LR while illustrating advantages over conventional laparoscopy especially for technically difficult and major LR. However, the advantage of RMLR for the anterolateral(AL) (segments II, III, IVb, V and VI) segments, has not been clearly demonstrated. METHODS: Between 2008 to 2022, 15,356 of 29,861 patients from 68 international centres underwent robotic(R) or laparoscopic minor liver resections (LMLR) for the AL segments Propensity score matching (PSM) analysis was performed for matched analysis. RESULTS: 10,517 patients met the study criteria of which 1,481 underwent RMLR and 9,036 underwent LMLR. A PSM cohort of 1,401 patients in each group were identified for analysis. Compared to the LMLR cohort, the RMLR cohort demonstrated significantly lower median blood loss (75ml vs. 100ml, P<0.001), decreased blood transfusion (3.1% vs. 5.4%, P=0.003), lower incidence of major morbidity (2.5% vs. 4.6%, P=0.004), lower proportion of open conversion (1.2% vs. 4.5%, P<0.001), shorter post operative stay (4 days vs. 5 days, P<0.001), but higher rate of 30-day readmission (3.5% vs. 2.1%, P=0.042). These results were then validated by a 1:2 PSM analysis. In the subset analysis for 3,614 patients with cirrhosis, RMLR showed lower median blood loss, decreased blood transfusion, lower open conversion and shorter post operative stay than LMLR. CONCLUSION: RMLR demonstrated statistically significant advantages over LMLR even for resections in the AL segments although most of the observed clinical differences were minimal.

Robotic and laparoscopic right lobe living donation compared to the open approach: A multicenter study on 1194 donor hepatectomies.

Due to the success of minimally invasive liver surgery, laparoscopic and robotic minimally invasive donor hepatectomies (MIDH) are increasingly performed worldwide. We conducted a retrospective, multicentre, propensity score-matched analysis on right lobe MIDH by comparing the robotic, laparoscopic, and open approaches to assess the feasibility, safety, and early outcomes of MIDHs. From January 2016 until December 2020, 1194 donors underwent a right donor hepatectomy performed with a robotic (n = 92), laparoscopic (n = 306), and open approach (n = 796) at 6 high-volume centers. Donor and recipients were matched for different variables using propensity score matching (1:1:2). Donor outcomes were recorded, and postoperative pain was measured through a visual analog scale. Recipients' outcomes were also analyzed. Ninety-two donors undergoing robotic surgery were matched and compared to 92 and 184 donors undergoing laparoscopic and open surgery, respectively. Conversions to open surgery occurred during 1 (1.1%) robotic and 2 (2.2%) laparoscopic procedures. Robotic procedures had a longer operative time (493 ± 96 min) compared to laparoscopic and open procedures (347 ± 120 and 358 ± 95 min; p < 0.001) but were associated with reduced donor blood losses ( p < 0.001). No differences were observed in overall and major complications (≥ IIIa). Robotic hepatectomy donors had significantly less pain compared to the 2 other groups ( p < 0.001). Fifty recipients of robotic-procured grafts were matched to 50 and 100 recipients of laparoscopic and open surgery procured grafts, respectively. No differences were observed in terms of postoperative complications, and recipients' survival was similar ( p =0.455). In very few high-volume centers, robotic right lobe procurement has shown to be a safe procedure. Despite an increased operative and the first warm ischemia times, this approach is associated with reduced intraoperative blood losses and pain compared to the laparoscopic and open approaches. Further data are needed to confirm it as a valuable option for the laparoscopic approach in MIDH.

The learning curve for robotic living donor right hepatectomy: Analysis of outcomes in two specialized centers.

Robotic surgery is an emerging minimally invasive option for living donor hepatectomy. Currently, there are no studies on the learning curve of robotic donor hepatectomy. Thus, we evaluated the learning curve for robotic donor right hepatectomy (RH). We retrospectively reviewed prospectively collected data from consecutive living donors who underwent robotic hepatectomy at two specialized centers between 2016 and 2022. We estimated the number of cases required to achieve stable operating times for robotic donor RH using cumulative sum (CUSUM) analysis. The complication rates were similar between the two centers (22.8% vs. 26.7%; p=0.74). Most complications were graded as minor (70.4%). Analysis of the total operative time demonstrated that the learning curves reached a peak at the 17th case in Center 1 and the 9th case in Center 2. The average operation times for cases 1-17 versus 18-99 in Center 1 were 603 versus 438 minutes (p<0.001), and cases 1-9 versus 10-15 in Center 2 were 532 versus 418 minutes (p=0.002). Complication rates were lower after the learning curves were achieved, although this did not reach statistical significance. A comparison of outcomes between centers suggests that a standardized approach to this complex operation can be successfully transferred.

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.

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

INTRODUCTION: Despite the increasing widespread adoption and experience in minimally invasive liver resections (MILR), open conversion occurs not uncommonly even with minor resections and as been reported to be associated with inferior outcomes. We aimed to identify risk factors for and outcomes of open conversion in patients undergoing minor hepatectomies. We also studied the impact of approach (laparoscopic or robotic) on outcomes. METHODS: This is a post-hoc analysis of 20,019 patients who underwent RLR and LLR across 50 international centers between 2004-2020. Risk factors for and perioperative outcomes of open conversion were analysed. Multivariate and propensity score-matched analysis were performed to control for confounding factors. RESULTS: Finally, 10,541 patients undergoing either laparoscopic (LLR; 89.1%) or robotic (RLR; 10.9%) minor liver resections (wedge resections, segmentectomies) were included. Multivariate analysis identified LLR, earlier period of MILR, malignant pathology, cirrhosis, portal hypertension, previous abdominal surgery, larger tumor size, and posterosuperior location as significant independent predictors of open conversion. The most common reason for conversion was technical issues (44.7%), followed by bleeding (27.2%), and oncological reasons (22.3%). After propensity score matching (PSM) of baseline characteristics, patients requiring open conversion had poorer outcomes compared with successful MILR cases as evidenced by longer operative times, more blood loss, higher requirement for perioperative transfusion, longer duration of hospitalization and higher morbidity, reoperation, and 90-day mortality rates. CONCLUSIONS: Multiple risk factors were associated with conversion of MILR even for minor hepatectomies, and open conversion was associated with significantly poorer perioperative outcomes.

Intraindividual comparison of prognostic imaging features of HCCs between MRIs with extracellular and hepatobiliary contrast agents.

BACKGROUND & AIMS: Accumulating evidence suggests that certain imaging features of hepatocellular carcinoma (HCC) may have prognostic implications. This study aimed to intraindividually compare MRIs with extracellular contrast agent (ECA-MRI) and hepatobiliary agent (HBA-MRI) for prognostic imaging features of HCC and to compare the prediction of microvascular invasion (MVI) and early recurrence between the two MRIs. METHODS: The present study included 102 prospectively enrolled at-risk patients (median age, 61.0 years; 83 men) with surgically resected single HCC with both preoperative ECA-MRI and HBA-MRI between July 2019 and June 2023. The McNemar test was used to compare each prognostic imaging feature between the two MRIs. Significant imaging features associated with MVI were identified by multivariable logistic regression analysis, and early recurrence rates (<2 years) were compared between the two MRIs. RESULTS: The frequencies of prognostic imaging features were not significantly different between the two MRIs (p = .07 to >.99). Non-smooth tumour margin (ECA-MRI, odds ratio [OR] = 5.30; HBA-MRI, OR = 7.07) and peritumoral arterial phase hyperenhancement (ECA-MRI, OR = 4.26; HBA-MRI, OR = 4.43) were independent factors significantly associated with MVI on both MRIs. Two-trait predictor of venous invasion (presence of internal arteries and absence of hypoattenuating halo) on ECA-MRI (OR = 11.24) and peritumoral HBP hypointensity on HBA-MRI (OR = 20.42) were other predictors of MVI. Early recurrence rates of any two or more significant imaging features (49.8% on ECA-MRI vs 51.3% on HBA-MRI, p = .75) were not significantly different between the two MRIs. CONCLUSION: Prognostic imaging features of HCC may be comparable between ECA-MRI and HBA-MRI.

Comparison of Surgical Resection and Radiofrequency Ablation in Elderly Patients with Hepatocellular Carcinoma.

BACKGROUND/AIMS: The aim of this study was to examine whether the efficacy of radiofrequency ablation (RFA) and surgical resection (SR) are comparable for hepatocellular carcinoma (HCC) less than 3 cm in elderly individuals aged 65 years or older. METHODS: We used the National Health Insurance Service claims data in Korea, which was linked with liver cancer stage data from the Central Cancer Registry of the National Cancer Center, as well as death data from the National Statistical Office. Out of the 9213 registrants, we focused on 141 patients who underwent SR and 225 patients who underwent RFA when they were 65 years or older. To ensure comparability, a 1:1 propensity score (PS) matching was conducted. RESULTS: The SR group had lower performance status and better liver function compared to the RFA group. Tumor diameter was larger in the SR group than in the RFA group (2.1 cm vs. 1.7 cm), and the proportion of stage II cases was higher (62.4% vs. 33.8%). After PS matching, the mortality rate in the RFA group did not significantly differ from the SR group (HR 1.33, 95% CI 0.86-2.06, P = 0.19). Also, liver related mortality was similar between the SR and RFA group after matching (log rank P = 0.13). However, recurrence free survival was significantly longer in the SR group than RFA group before and after matching (log rank P = 0.03). CONCLUSION: In patients aged 65 years or older with resectable HCC, RFA demonstrates a therapeutic effect comparable to SR.

Defining Global Benchmarks for Laparoscopic Liver Resections: An International Multicenter Study.

OBJECTIVE: To establish global benchmark outcomes indicators after laparoscopic liver resections (L-LR). BACKGROUND: There is limited published data to date on the best achievable outcomes after L-LR. METHODS: This is a post hoc analysis of a multicenter database of 11,983 patients undergoing L-LR in 45 international centers in 4 continents between 2015 and 2020. Three specific procedures: left lateral sectionectomy (LLS), left hepatectomy (LH), and right hepatectomy (RH) were selected to represent the 3 difficulty levels of L-LR. Fifteen outcome indicators were selected to establish benchmark cutoffs. RESULTS: There were 3519 L-LR (LLS, LH, RH) of which 1258 L-LR (40.6%) cases performed in 34 benchmark expert centers qualified as low-risk benchmark cases. These included 659 LLS (52.4%), 306 LH (24.3%), and 293 RH (23.3%). The benchmark outcomes established for operation time, open conversion rate, blood loss ≥500 mL, blood transfusion rate, postoperative morbidity, major morbidity, and 90-day mortality after LLS, LH, and RH were 209.5, 302, and 426 minutes; 2.1%, 13.4%, and 13.0%; 3.2%, 20%, and 47.1%; 0%, 7.1%, and 10.5%; 11.1%, 20%, and 50%; 0%, 7.1%, and 20%; and 0%, 0%, and 0%, respectively. CONCLUSIONS: This study established the first global benchmark outcomes for L-LR in a large-scale international patient cohort. It provides an up-to-date reference regarding the "best achievable" results for L-LR for which centers adopting L-LR can use as a comparison to enable an objective assessment of performance gaps and learning curves.

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.

Left-sided Hepatectomy Leads to Less Postoperative Liver Failure and Comparable Overall Survival to Right-sided Hepatectomy in Type II or IV Perihilar Cholangiocarcinoma.

INTRODUCTION: Right-side hepatectomy (RH) is used in oncological resection for perihilar cholangiocarcinoma (PHC); however, the decision between performing left-side hepatectomy (LH) or RH is still controversial. We compared surgical and oncologic outcomes of LH and RH in PHC type II or IV where either hepatectomy was expected to have a negative margin. METHODS: From 2001 to 2020, 99 patients underwent major liver resection for type II or IV PHC. Patients with unilateral vascular invasion, unilateral tumor growth, and atrophy of unilateral liver were excluded. Preoperative characteristics, perioperative, and long-term outcomes were compared between the remaining RH and LH patients. RESULTS: After excluding 47 cases with side predominance, the RH group (n = 29) and LH group (n = 23) were compared. Clinical characteristics and disease severity did not differ between the groups. Portal vein embolization (RH: 48.3% vs. LH: 0.0%, p < 0.001) and days from diagnosis to operation (RH: 31.0 ± 16.2 vs. LH: 18.8 ± 13.4, p = 0.006) were significantly higher in the RH group. The RH group had statistically higher rate of postoperative hepatic failure (RH: 55.2% vs. LH: 21.7%, p = 0.015) and a higher mortality rate that was not significant (RH: 13.8% vs. LH: 0%, p = 0.120). The R0 resection rate (RH: 72.4% vs. LH: 78.3%, p = 0.629), median disease-free (p = 0.620), and overall (p = 0.487) survival did not differ between groups. R1 resection and lymph node metastasis were significant risk factors for disease-free survival in multivariate analysis. CONCLUSIONS: In type II or type IV PHC where either LH or RH was feasible, LH provided a shorter period of preoperative preparation, lower postoperative hepatic failure rate, similar R0 rate, and comparable long-term outcomes. LH should be considered a reasonable option in type II or IV PHC.

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.

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.

Propensity score-matched analysis of laparoscopic-assisted and hand-assisted laparoscopic liver resection versus pure laparoscopic liver resection: an international multicenter study.

BACKGROUND: Laparoscopic-assisted (LALR) and hand-assisted (HALR) liver resections have been utilized during the early adoption phase by surgeons when transitioning from open surgery to pure LLR. To date, there are limited data reporting on the outcomes of LALR or HALR compared to LLR. The objective was to compare the perioperative outcomes after LALR and HALR versus pure LLR. METHODS: This is an international multicentric analysis of 6609 patients undergoing minimal-invasive liver resection at 21 centers between 2004 and 2019. Perioperative outcomes were analyzed after propensity score matching (PSM) comparison between LALR and HALR versus LLR. RESULTS: 5279 cases met study criteria of whom 5033 underwent LLR (95.3%), 146 underwent LALR (2.8%) and 100 underwent HALR (1.9%). After 1:4 PSM, LALR was associated with inferior outcomes as evidenced by the longer postoperative stay, higher readmission rate, higher major morbidity rate and higher in-hospital mortality rate. Similarly, 1:6 PSM comparison between HALR and LLR also demonstrated poorer outcomes associated with HALR as demonstrated by the higher open conversion rate and higher blood transfusion rate. All 3 approaches technical variants demonstrated the same oncological radicality (R1 rate). CONCLUSION: LALR and HALR performed during the learning curve was associated with inferior perioperative outcomes compared to pure LLR.

An international multicentre propensity score matched analysis comparing between robotic versus laparoscopic left lateral sectionectomy.

BACKGROUND: Left lateral sectionectomy (LLS) is one of the most commonly performed minimally invasive liver resections. While laparoscopic (L)-LLS is a well-established technique, over traditional open resection, it remains controversial if robotic (R)-LLS provides any advantages of L-LLS. METHODS: A post hoc analysis of 997 patients from 21 international centres undergoing L-LLS or R-LLS from 2006 to 2020 was conducted. A total of 886 cases (214 R-LLS, 672 L-LLS) met study criteria. 1:1 and 1:2 propensity score matched (PSM) comparison was performed between R-LLS & L-LLS. Further subset analysis by Iwate difficulty was also performed. Outcomes measured include operating time, blood loss, open conversion, readmission rates, morbidity and mortality. RESULTS: Comparison between R-LLS and L-LLS after PSM 1:2 demonstrated statistically significantly lower open conversion rate in R-LLS than L-LLS (0.6% versus 5%, p = 0.009) and median blood loss was also statistically significantly lower in R-LLS at 50 (80) versus 100 (170) in L-LLS (p = 0.011) after PSM 1:1 although there was no difference in the blood transfusion rate. Pringle manoeuvre was also found to be used more frequently in R-LLS, with 53(24.8%) cases versus to 84(12.5%) L-LLS cases (p < 0.001). There was no significant difference in the other key perioperative outcomes such as operating time, length of stay, postoperative morbidity, major morbidity and 90-day mortality between both groups. CONCLUSION: R-LLS was associated with similar key perioperative outcomes compared to L-LLS. It was also associated with significantly lower blood loss and open conversion rates compared to L-LLS.

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.

Prognostic impact of R1 resection margin in synchronous and simultaneous colorectal liver metastasis resection: a retrospective cohort study.

BACKGROUND: A margin ≥ 1 mm is considered a standard resection margin for colorectal liver metastasis (CRLM). However, microscopic incomplete resection (R1) is not rare since aggressive surgical resection has been attempted in multiple and bilobar CRLM. This study aimed to investigate the prognostic impact of resection margins and perioperative chemotherapy in patients with CRLM. METHODS: A total of 368 of 371 patients who underwent simultaneous colorectal and liver resection for synchronous CRLM between 2006 and June 2017, excluding three R2 resections, were included in this study. R1 resection was defined as either abutting tumor on the resection line or involved margin in the pathological report. The patients were divided into R0 (n = 304) and R1 (n = 64) groups. The clinicopathological characteristics, overall survival, and intrahepatic recurrence-free survival were compared between the two groups using propensity score matching. RESULTS: The R1 group had more patients with ≥ 4 liver lesions (27.3 vs. 50.0%, P < 0.001), higher mean tumor burden score (4.4 vs. 5.8%, P = 0.003), and more bilobar disease (38.8 vs. 67.2%, P < 0.001) than the R0 group. Both R0 and R1 groups showed similar long-term outcomes in the total cohort (OS, P = 0.149; RFS, P = 0.414) and after matching (OS, P = 0.097, RFS: P = 0.924). However, the marginal recurrence rate was higher in the R1 group than in the R0 group (26.6 vs. 16.1%, P = 0.048). Furthermore, the resection margin did not have a significant impact on OS and RFS, regardless of preoperative chemotherapy. Poorly differentiated, N-positive stage colorectal cancer, liver lesion number ≥ 4, and size ≥ 5 cm were poor prognostic factors, and adjuvant chemotherapy had a positive impact on survival. CONCLUSIONS: The R1 group was associated with aggressive tumor characteristics; however, no effect on the OS and intrahepatic RFS with or without preoperative chemotherapy was observed in this study. Tumor biological characteristics, rather than resection margin status, determine long-term prognosis. Therefore, aggressive surgical resection should be considered in patients with CRLM expected to undergo R1 resection in this multidisciplinary approach era.

Outcomes of Robotic Living Donor Right Hepatectomy From 52 Consecutive Cases: Comparison With Open and Laparoscopy-assisted Donor Hepatectomy.

OBJECTIVE: To investigate the feasibility and safety of RLDRH. SUMMARY OF BACKGROUND DATA: Data for minimally invasive living-donor right hepatectomy, especially RLDRH, from a relatively large donor cohort that have not been reported yet. METHODS: From March 2016 to March 2019, 52 liver donors underwent RLDRH. The clinical and perioperative outcomes of RLDRH were compared with those of CODRH (n = 62) and LADRH (n = 118). Donor satisfaction with cosmetic results was compared between RLDRH and LADRH using a body image questionnaire. RESULTS: Although RLDRH was associated with longer operative time (minutes) (RLDRH, 493.6; CODRH, 404.4; LADRH, 355.9; P < 0.001), mean estimated blood loss (mL) was significantly lower (RLDRH, 109.8; CODRH, 287.1; LADRH, 265.5; P = 0.001). Postoperative complication rates were similar among the 3 groups (RLDRH, 23.1%; CODRH, 35.5%; LADRH, 28.0%; P = 0.420). Regarding donor satisfaction, body image and cosmetic appearance scores were significantly higher in RLDRH than in LADRH. After propensity score matching, RLDRH showed less estimated blood loss compared to those of CODRH (RLDRH, 114.7 mL; CODRH, 318.4 mL; P < 0.001), but complication rates were similar among the three groups (P = 0.748). CONCLUSIONS: RLDRH resulted in less blood loss compared with that of CODRH and similar postoperative complication rates to CODRH and LADRH. RLDRH provided better body image and cosmetic results compared with those of LADRH. RLDRH is feasible and safe when performed by surgeons experienced with both robotic and open hepatectomy.

Robotic Versus Laparoscopic Left and Extended Left Hepatectomy: An International Multicenter Study Propensity Score-Matched Analysis.

BACKGROUND: Controversies exist among liver surgeons regarding clinical outcomes of the laparoscopic versus the robotic approach for major complex hepatectomies. The authors therefore designed a study to examine and compare the perioperative outcomes of laparoscopic left hepatectomy or extended left hepatectomy (L-LH/L-ELH) versus robotic left hepatectomy or extended left hepatectomy (R-LH/R-ELH) using a large international multicenter collaborative database. METHODS: An international multicenter retrospective analysis of 580 patients undergoing L-LH/L-ELH or R-LH/R-ELH at 25 specialized hepatobiliary centers worldwide was undertaken. Propensity score-matching (PSM) was used at a 1:1 nearest-neighbor ratio according to 15 perioperative variables, including demographics, tumor characteristics, Child-Pugh score, presence of portal hypertension, multiple resections, histologic diagnosis, and Iwate difficulty grade. RESULTS: Before the PSM, 190 (32 %) patients underwent R-LH/R-ELH, and 390 (68 %) patients underwent L-LH/L-ELH. After the matching, 164 patients were identified in each arm without significant differences in demographics, preoperative variables, medical history, tumor pathology, tumor characteristics, or Iwate score. Regarding intra- and postoperative outcomes, the rebotic approach had significantly less estimated blood loss (EBL) (100 ml [IQR 200 ml] vs 200 ml [IQR 235 ml]; p = 0.029), fewer conversions to open operations (n = 4 [2.4 %] vs n = 13, [7.9 %]; p = 0.043), and a shorter hospital stay (6 days [IQR 3 days] vs 7 days [IQR 3.3 days]; p = 0.009). CONCLUSION: Both techniques are safe and feasible in major hepatic resections. Compared with L-LH/L-ELH, R-LH/R-ELH is associated with less EBL, fewer conversions to open operations, and a shorter hospital stay.