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

OBJECTIVE: To compare the perioperative outcomes of robotic liver surgery (RLS) and laparoscopic liver surgery (LLS) in various settings. BACKGROUND: 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: (1) minor resections in the anterolateral (2, 3, 4b, 5, and 6) or (2) posterosuperior segments (1, 4a, 7, 8), and (3) major resections (≥3 contiguous segments). Propensity score matching 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 propensity score matching, 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 microscopically irradical resection margins (10.1% vs. 13.8%, P = 0.015), and shorter operative times (190 vs 210 minutes, P = 0.015). In the subgroups, RLS tended to have higher TOLS rates, compared with 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 produce excellent outcomes, RLS might facilitate slightly higher TOLS rates than LLS.

Laparoscopic versus open right hepatectomy for colorectal liver metastases after portal vein embolization: international multicentre study.

BACKGROUND: Laparoscopic liver surgery is increasingly used for more challenging procedures. The aim of this study was to assess the feasibility and oncological safety of laparoscopic right hepatectomy for colorectal liver metastases after portal vein embolization. METHODS: This was an international retrospective multicentre study of patients with colorectal liver metastases who underwent open or laparoscopic right and extended right hepatectomy after portal vein embolization between 2004 and 2020. The perioperative and oncological outcomes for patients who underwent laparoscopic and open approaches were compared using propensity score matching. RESULTS: Of 338 patients, 84 patients underwent a laparoscopic procedure and 254 patients underwent an open procedure. Patients in the laparoscopic group less often underwent extended right hepatectomy (18% versus 34.6% (P = 0.004)), procedures in the setting of a two-stage hepatectomy (42% versus 65% (P < 0.001)), and major concurrent procedures (4% versus 16.1% (P = 0.003)). After propensity score matching, 78 patients remained in each group. The laparoscopic approach was associated with longer operating and Pringle times (330 versus 258.5 min (P < 0.001) and 65 versus 30 min (P = 0.001) respectively) and a shorter length of stay (7 versus 8 days (P = 0.011)). The R0 resection rate was not different (71% for the laparoscopic approach versus 60% for the open approach (P = 0.230)). The median disease-free survival was 12 (95% c.i. 10 to 20) months for the laparoscopic approach versus 20 (95% c.i. 13 to 31) months for the open approach (P = 0.145). The median overall survival was 28 (95% c.i. 22 to 48) months for the laparoscopic approach versus 42 (95% c.i. 35 to 52) months for the open approach (P = 0.614). CONCLUSION: The advantages of a laparoscopic over an open approach for (extended) right hepatectomy for colorectal liver metastases after portal vein embolization are limited.

Is prolonged operative time associated with postoperative complications in liver surgery? An international multicentre cohort study of 5424 patients.

BACKGROUND: The relation between operative time and postoperative complications in liver surgery is unclear. The aim of this study is to assess the impact of operative time on the development of postoperative complications in patients who underwent minimally invasive or open liver resections of various anatomical extent and technical difficulty levels. METHODS: In this retrospective cohort study, patients that underwent a right hemihepatectomy (RH), technically major resection (anatomically minor resection in segment 1, 4a, 7 or 8; TMR) or left lateral sectionectomy (LLS) between 2000 and 2022 were extracted from a multicenter database comprising the prospectively maintained databases of 31 centers in 13 countries. Minimally invasive procedures performed during the learning curve were omitted. Logistic regression models, performed separately for 9 different groups based on stratification by procedure type and allocated surgical approach, were used to assess the association between the fourth quartile of operative time (25% of patients with the longest operative time) and postoperative complications. RESULTS: Overall, 5424 patients were included: 1351 underwent RH (865 open, 373 laparoscopic and 113 robotic), 2821 TMR (1398 open, 1225 laparoscopic and 198 robotic), and 1252 LLS (241 open, 822 laparoscopic and 189 robotic). After adjusting for potential confounders (age, BMI, gender, ASA grade, previous abdominal surgery, disease type and extent, blood loss, Pringle, intraoperative transfusions and incidents), the fourth quartile of operative time, compared to the first three quartiles, was associated with an increased risk of postoperative complications after open, laparoscopic and robotic TMR (aOR 1.35, p = 0.031; aOR 1.74, p = 0.001 and aOR 3.11, p = 0.014, respectively), laparoscopic and robotic RH (aOR 1.98, p = 0.018 and aOR 3.28, p = 0.055, respectively) and solely laparoscopic LLS (aOR 1.69, p = 0.019). CONCLUSIONS: A prolonged operative time is associated with an increased risk of postoperative complications, although it remains to be defined if this is a causal relationship.

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.

The differential benefit of laparoscopic over open minor liver resection for lesions situated in the anterolateral or posterosuperior segments.

Background: It is well known that laparoscopic liver surgery can offer advantages over open liver surgery in selected patients. However, what type of procedures can benefit most from a laparoscopic approach has been investigated poorly thus far. The aim of this study is thus to define the extent of advantages of laparoscopic over open liver surgery for lesions in the anterolateral (AL) and posterosuperior (PS) segments. Methods: In this international multicentre retrospective cohort study, laparoscopic and open minor liver resections for lesions in the AL and PS segments were compared after propensity score matching. The differential benefit of laparoscopy over open liver surgery, calculated using bootstrap sampling, was compared between AL and PS resections and expressed as a Delta of the differences. Results: After matching, 3,040 AL and 2,336 PS resections were compared, encompassing open and laparoscopic procedures in a 1:1 ratio. AL and PS laparoscopic liver resections were more advantageous in comparison to open in terms of blood loss, transfusion rate, complications, and length of stay. However, AL resections benefitted more from laparoscopy than PS in terms of overall and severe complications (D-difference were 4.8%, P=0.046 and 3%, P=0.046) and blood loss (D-difference was 195 mL, P<0.001). Similar results were observed in the subset for high-volume centres, while in recent years no significant differences were found in the differential benefit between AL and PS segments. Conclusions: The advantage of laparoscopic over open liver surgery is greater in the AL segments than in the PS segments.

Simultaneous resection of colorectal cancer and synchronous liver metastases: what determines the risk of unfavorable outcomes? An international multicenter retrospective cohort study.

BACKGROUND: The use of a simultaneous resection (SIMR) in patients with synchronous colorectal liver metastases (sCRLM) has increased over the past decades. However, it remains unclear when a SIMR is beneficial and when it should be avoided. The aim of this retrospective cohort study was therefore to compare the outcomes of a SIMR for sCRLM in different settings, and to assess which factors are independently associated with unfavorable outcomes. METHODS: To perform this retrospective cohort study, patients with sCRLM undergoing SIMR (2004-2019) were extracted from an international multicenter database, and their outcomes were compared after stratification according to the type of liver and colorectal resection performed. Factors associated with unfavorable outcomes were identified through multivariable logistic regression. RESULTS: Overall, 766 patients were included, encompassing colorectal resections combined with a major liver resection (n=122), minor liver resection in the anterolateral (n=407), or posterosuperior segments ('Technically major', n=237). Minor and technically major resections, compared to major resections, were more often combined with a rectal resection (29.2 and 36.7 vs. 20.5%, respectively, both P=0.003) and performed fully laparoscopic (22.9 and 23.2 vs. 6.6%, respectively, both P = 0.003). Major and technically major resections, compared to minor resections, were more often associated with intraoperative transfusions (42.9 and 38.8 vs. 20%, respectively, both P = 0.003) and unfavorable incidents (9.6 and 9.8 vs. 3.3%, respectively, both P≤0.063). Major resections were associated, compared to minor and technically major resections, with a higher overall morbidity rate (64.8 vs. 50.4 and 49.4%, respectively, both P≤0.024) and a longer length of stay (12 vs. 10 days, both P≤0.042). American Society of Anesthesiologists grades ≥3 [adjusted odds ratio (aOR): 1.671, P=0.015] and undergoing a major liver resection (aOR: 1.788, P=0.047) were independently associated with an increased risk of severe morbidity, while undergoing a left-sided colectomy was associated with a decreased risk (aOR: 0.574, P=0.013). CONCLUSIONS: SIMR should primarily be reserved for sCRLM patients in whom a minor or technically major liver resection would suffice and those requiring a left-sided colectomy. These findings should be confirmed by randomized studies comparing SIMR with staged resections.

Indications, trends, and perioperative outcomes of minimally invasive and open liver surgery in non-obese and obese patients: An international multicentre propensity score matched retrospective cohort study of 9963 patients.

BACKGROUND: Despite the worldwide increase of both obesity and the use of minimally invasive liver surgery (MILS), evidence regarding the safety and eventual benefits of MILS in obese patients is scarce. The aim of this study was therefore to compare the outcomes of non-obese and obese patients (BMI 18.5-29.9 and BMI≥30, respectively) undergoing MILS and OLS, and to assess trends in MILS use among obese patients. METHODS: In this retrospective cohort study, patients operated at 20 hospitals in eight countries (2009-2019) were included and the characteristics and outcomes of non-obese and obese patients were compared. Thereafter, the outcomes of MILS and OLS were compared in both groups after propensity-score matching (PSM). Changes in the adoption of MILS during the study period were investigated. RESULTS: Overall, 9963 patients were included (MILS: n = 4687; OLS: n = 5276). Compared to non-obese patients (n = 7986), obese patients(n = 1977) were more often comorbid, less often received preoperative chemotherapy or had a history of previous hepatectomy, had longer operation durations and more intraoperative blood loss (IOBL), paralleling significantly higher rates of wound- and respiratory-related complications. After PSM, MILS, compared to OLS, was associated, among both non-obese and obese patients, with less IOBL (200 ml vs 320 ml, 200 ml vs 400 ml, respectively), lower rates of transfusions (6.6% vs 12.8%, 4.7% vs 14.7%), complications (26.1% vs 35%, 24.9% vs 34%), bile leaks(4% vs 7%, 1.8% vs 4.9%), liver failure (0.7% vs 2.3%, 0.2% vs 2.1%), and a shorter length of stay(5 vs 7 and 4 vs 7 days). A cautious implementation of MILS over time in obese patients (42.1%-53%, p < .001) was paralleled by stable severe morbidity (p = .433) and mortality (p = .423) rates, despite an accompanying gradual increase in surgical complexity. CONCLUSIONS: MILS is increasingly adopted and associated with perioperative benefits in both non-obese and obese patients.