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.

Sorted-Cell Sequencing on HCC Specimens Reveals EPS8L3 as a Key Player in CD24/CD13/EpCAM-Triple Positive, Stemness-Related HCC Cells.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a heterogeneous cancer with varying levels of liver tumor initiating or cancer stem cells in the tumors. We aimed to investigate the expression of different liver cancer stem cell (LCSC) markers in human HCCs and identify their regulatory mechanisms in stemness-related cells. METHODS: We used an unbiased, single-marker sorting approach by flow cytometry, fluorescence-activated cell sorting, and transcriptomic analyses on HCC patients' resected specimens. Knockdown approach was used, and relevant functional assays were conducted on the identified targets of interest. RESULTS: Flow cytometry on a total of 60 HCC resected specimens showed significant heterogeneity in the expression of LCSC markers, with CD24, CD13, and EpCAM mainly contributing to this heterogeneity. Concomitant expression of CD24, CD13, and EpCAM was detected in 32 HCC samples, and this was associated with advanced tumor stages. Transcriptomic sequencing on the HCC cells sorted for these individual markers identified epidermal growth factor receptor kinase substrate 8-like protein 3 (EPS8L3) as a common gene associated with the 3 markers and was functionally validated in HCC cells. Knocking down EPS8L3 suppressed the expression of all 3 markers. To search for the upstream regulation of EPS8L3, we found SP1 bound to EPS8L3 promoter to drive EPS8L3 expression. Furthermore, using Akt inhibitor MK2206, we showed that Akt signaling-driven SP1 drove the expression of the 3 LCSC markers. CONCLUSIONS: Our findings suggest that Akt signaling-driven SP1 promotes EPS8L3 expression, which is critical in maintaining the downstream expression of CD24, CD13, and EpCAM. The findings provide insight into potential LCSC-targeting therapeutic strategies.

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.

The Hong Kong consensus statements on unresectable hepatocellular carcinoma: narrative review and update for 2021.

Background and Objective: Hong Kong, like many parts of Asia, faces a high burden of hepatocellular carcinoma (HCC) caused by high endemic rates of hepatitis B virus infection. Hong Kong clinicians have developed a high level of expertise in HCC treatment across surgical, transarterial, ablative, radiotherapeutic and systemic modalities. This publication summarizes the latest evidence-based recommendations on how these modalities should be used. Methods: In two meetings held in 2020, a multidisciplinary panel of surgeons, oncologists and interventional radiologists performed a narrative review of evidence on the management of HCC, with an emphasis on treatment of HCC not amenable to surgical resection. Close attention was paid to new evidence published since the previous version of these statements in 2018. Key Content and Findings: The expert panel has formulated 60 consensus statements to guide the staging and treatment of unresectable HCC. Since the previous version of these statements, considerable additions have been made to the recommendations on use of targeted therapies and immunotherapies because of the large volume of new evidence. Conclusions: Our consensus statements offer guidance on how to select HCC patients for surgical or non-surgical treatment and for choosing among non-surgical modalities for patients who are not candidates for resection. In particular, there is a need for more evidence to aid physicians in the selection of second-line systemic therapies, as currently most data are limited to patients with disease progression on first-line sorafenib.

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.

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 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.

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.

Impact of neoadjuvant chemotherapy on the difficulty and outcomes of laparoscopic and robotic major liver resections for colorectal liver metastases: A propensity-score and coarsened exact-matched controlled study.

BACKGROUND: Minimal invasive liver resections are a safe alternative to open surgery. Different scoring systems considering different risks factors have been developed to predict the risks associated with these procedures, especially challenging major liver resections (MLR). However, the impact of neoadjuvant chemotherapy (NAT) on the difficulty of minimally invasive MLRs remains poorly investigated. METHODS: Patients who underwent laparoscopic and robotic MLRs for colorectal liver metastases (CRLM) performed across 57 centers between January 2005 to December 2021 were included in this analysis. Patients who did or did not receive NAT were matched based on 1:1 coarsened exact and 1:2 propensity-score matching. Pre- and post-matching comparisons were performed. RESULTS: In total, the data of 5189 patients were reviewed. Of these, 1411 procedures were performed for CRLM, and 1061 cases met the inclusion criteria. After excluding 27 cases with missing data on NAT, 1034 patients (NAT: n = 641; non-NAT: n = 393) were included. Before matching, baseline characteristics were vastly different. Before matching, the morbidity rate was significantly higher in the NAT-group (33.2% vs. 27.2%, p-value = 0.043). No significant differences were seen in perioperative outcomes after the coarsened exact matching. After the propensity-score matching, statistically significant higher blood loss (mean, 300 (SD 128-596) vs. 250 (SD 100-400) ml, p-value = 0.047) but shorter hospital stay (mean, 6 [4-8] vs. 6 [5-9] days, p-value = 0.043) were found in the NAT-group. CONCLUSION: The current study demonstrated that NAT had minimal impact on the difficulty and outcomes of minimally-invasive MLR for CRLM.

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

BACKGROUND: Tumor size (TS) represents a critical parameter in the risk assessment of laparoscopic liver resections (LLR). Moreover, TS has been rarely related to the extent of liver resection. The aim of this study was to study the relationship between tumor size and difficulty of laparoscopic left lateral sectionectomy (L-LLS). METHODS: The impact of TS cutoffs was investigated by stratifying tumor size at each 10 mm-interval. The optimal cutoffs were chosen taking into consideration the number of endpoints which show a statistically significant split around the cut-points of interest and the magnitude of relative risk after correction for multiple risk factors. RESULTS: A total of 1910 L-LLS were included. Overall, open conversion and intraoperative blood transfusion were 3.1 and 3.3%, respectively. The major morbidity rate was 2.7% and 90-days mortality 0.6%. Three optimal TS cutoffs were identified: 40-, 70-, and 100-mm. All the selected cutoffs showed a significant discriminative power for the prediction of open conversion, operative time, blood transfusion and need of Pringle maneuver. Moreover, 70- and 100-mm cutoffs were both discriminative for estimated blood loss and major complications. A stepwise increase in rates of open conversion rate (Z = 3.90, P < .001), operative time (Z = 3.84, P < .001), blood loss (Z = 6.50, P < .001), intraoperative blood transfusion rate (Z = 5.15, P < .001), Pringle maneuver use (Z = 6.48, P < .001), major morbidity(Z = 2.17, P = .030) and 30-days readmission (Z = 1.99, P = .047) was registered as the size increased. CONCLUSION: L-LLS for tumors of increasing size was associated with poorer intraoperative and early postoperative outcomes suggesting increasing difficulty of the procedure. We determined three optimal TS cutoffs (40-, 70- and 100-mm) to accurately stratify surgical difficulty after L-LLS.

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.

Comparison Between Minimally Invasive Right Anterior and Right Posterior Sectionectomy vs Right Hepatectomy: An International Multicenter Propensity Score-Matched and Coarsened-Exact-Matched Analysis of 1,100 Patients.

BACKGROUND: The role of minimally invasive right anterior and right posterior sectionectomy (MI-RAS/MI-RPS) for right-sided liver lesions remains debatable. Although technically more demanding, these procedures might result in faster recovery and lower postoperative morbidity compared with minimally invasive right hemihepatectomy. STUDY DESIGN: This is an international multicenter retrospective analysis of 1,114 patients undergoing minimally invasive right hemihepatectomy, MI-RAS, and MI-RPS at 21 centers between 2006 and 2019. Minimally invasive surgery included pure laparoscopic, robotic, hand-assisted, or a hybrid approach. A propensity-matched and coarsened-exact-matched analysis was performed. RESULTS: A total of 1,100 cases met study criteria, of whom 759 underwent laparoscopic, 283 robotic, 11 hand-assisted, and 47 laparoscopic-assisted (hybrid) surgery. There were 632 right hemihepatectomies, 373 right posterior sectionectomies, and 95 right anterior sectionectomies. There were no differences in baseline characteristics after matching. In the MI-RAS/MI-RPS group, median blood loss was higher (400 vs 300 mL, p = 0.001) as well as intraoperative blood transfusion rate (19.6% vs 10.7%, p = 0.004). However, the overall morbidity rate was lower including major morbidity (7.1% vs 14.3%, p = 0.007) and reoperation rate (1.4% vs 4.6%, p = 0.029). The rate of close/involved margins was higher in the MI-RAS/MI-RPS group (23.4% vs 8.9%, p < 0.001). These findings were consistent after both propensity and coarsened-exact matching. CONCLUSIONS: Although technically more demanding, MI-RAS/MI-RPS is a valuable alternative for minimally invasive right hemihepatectomy in right-sided liver lesions with lower postoperative morbidity, possibly due to the preservation of parenchyma. However, the rate of close/involved margins is higher in these procedures. These findings might guide surgeons in preoperative counselling and in selecting the appropriate procedure for their patients.

Limited liver resections in the posterosuperior segments: international multicentre propensity score-matched and coarsened exact-matched analysis comparing the laparoscopic and robotic approaches.

BACKGROUND: Limited liver resections (LLRs) for tumours located in the posterosuperior segments of the liver are technically demanding procedures. This study compared outcomes of robotic (R) and laparoscopic (L) LLR for tumours located in the posterosuperior liver segments (IV, VII, and VIII). METHODS: This was an international multicentre retrospective analysis of patients who underwent R-LLR or L-LLR at 24 centres between 2010 and 2019. Patient demographics, perioperative parameters, and postoperative outcomes were analysed; 1 : 3 propensity score matching (PSM) and 1 : 1 coarsened exact matching (CEM) were performed. RESULTS: Of 1566 patients undergoing R-LLR and L-LLR, 983 met the study inclusion criteria. Before matching, 159 R-LLRs and 824 L-LLRs were included. After 1 : 3 PSM of 127 R-LLRs and 381 L-LLRs, comparison of perioperative outcomes showed that median blood loss (100 (i.q.r. 40-200) versus 200 (100-500) ml; P = 0.003), blood loss of at least 500 ml (9 (7.4 per cent) versus 94 (27.6 per cent); P < 0.001), intraoperative blood transfusion rate (4 (3.1 per cent) versus 38 (10.0 per cent); P = 0.025), rate of conversion to open surgery (1 (0.8 per cent) versus 30 (7.9 per cent); P = 0.022), median duration of Pringle manoeuvre when applied (30 (20-46) versus 40 (25-58) min; P = 0.012), and median duration of operation (175 (130-255) versus 224 (155-300); P < 0.001) were lower in the R-LLR group compared with the L-LLR group. After 1 : 1 CEM of 104 R-LLRs with 104 L-LLRs, R-LLR was similarly associated with significantly reduced blood loss and a lower rate of conversion to open surgery. CONCLUSION: Based on a matched analysis of well selected patients, both robotic and laparoscopic access could be undertaken safely with good outcomes for tumours in the posterosuperior liver segments.

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.

Utility of the Iwate difficulty scoring system for laparoscopic right posterior sectionectomy: do surgical outcomes differ for tumors in segments VI and VII?

INTRODUCTION: The Iwate Score (IS) have not been well-validated for specific procedures, especially for right posterior sectionectomy (RPS). In this study, the utility of the IS was determined for laparoscopic (L)RPS and the effect of tumor location on surgical outcomes was investigated. METHODS: Post-hoc analysis of 647 L-RPS performed in 40 international centers of which 596L-RPS cases met the inclusion criteria. Baseline characteristics and perioperative outcomes of patients stratified based on the Iwate score were compared to determine whether a correlation with surgical difficulty existed. A 1:1 Mahalanobis distance matching was utilized to investigate the effect of tumor location on L-RPS outcomes. RESULTS: The patients were stratified into 3 levels of difficulty (31 intermediate, 143 advanced, and 422 expert) based on the IS. When using a stepwise increase of the IS excluding the tumor location score, only Pringle's maneuver was more frequently used in the higher surgical difficulty level (35.5%, 54.6%, and 65.2%, intermediate, advanced, and expert levels, respectively, Z = 3.34, p = 0.001). Other perioperative results were not associated with a statistical gradation toward higher difficulty level. 80 of 85 patients with a segment VI lesion and 511 patients with a segment VII lesion were matched 1:1. There were no significant differences in the perioperative outcomes of the two groups including open conversion, operating time, blood loss, intraoperative blood transfusion, postoperative stay, major morbidity, and mortality. CONCLUSION: Among patients undergoing L-RPS, the IS did not significantly correlate with most outcome measures associated with intraoperative difficulty and postoperative outcomes. Similarly, tumor location had no effect on L-RPS outcomes.

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

BACKGROUND: Despite the rapid advances that minimally invasive liver resection has gained in recent decades, open conversion is still inevitable in some circumstances. In this study, we aimed to determine the risk factors for open conversion after minimally invasive left lateral sectionectomy, and its impact on perioperative outcomes. METHODS: This is a post hoc analysis of 2,445 of 2,678 patients who underwent minimally invasive left lateral sectionectomy at 45 international centers between 2004 and 2020. Factors related to open conversion were analyzed via univariate and multivariate analyses. One-to-one propensity score matching was used to analyze outcomes after open conversion versus non-converted cases. RESULTS: The open conversion rate was 69/2,445 (2.8%). On multivariate analyses, male gender (3.6% vs 1.8%, P = .011), presence of clinically significant portal hypertension (6.1% vs 2.6%, P = .009), and larger tumor size (50 mm vs 32 mm, P < .001) were identified as independent factors associated with open conversion. The most common reason for conversion was bleeding in 27/69 (39.1%) of cases. After propensity score matching (65 open conversion vs 65 completed via minimally invasive liver resection), the open conversion group was associated with increased operation time, blood transfusion rate, blood loss, and postoperative stay compared with cases completed via the minimally invasive approach. CONCLUSION: Male sex, portal hypertension, and larger tumor size were predictive factors of open conversion after minimally invasive left lateral sectionectomy. Open conversion was associated with inferior perioperative outcomes compared with non-converted cases.

An international multicenter propensity-score matched and coarsened-exact matched analysis comparing robotic versus laparoscopic partial liver resections of the anterolateral segments.

BACKGROUND: Robotic liver resections (RLR) may have the ability to address some of the drawbacks of laparoscopic liver resections (LLR) but few studies have done a head-to-head comparison of the outcomes after anterolateral segment resections by the two techniques. METHODS: A retrospective study was conducted of 3202 patients who underwent minimally invasive LR of the anterolateral liver segments at 26 international centres from 2005 to 2020. Two thousand six hundred and six cases met study criteria of which there were 358 RLR and 1868 LLR cases. Perioperative outcomes were compared between the two groups using a 1:3 Propensity Score Matched (PSM) and 1:1 Coarsened Exact Matched (CEM) analysis. RESULTS: Patients matched after 1:3 PSM (261 RLR vs 783 LLR) and 1:1 CEM (296 RLR vs 296 LLR) revealed no significant differences in length of stay, readmission rates, morbidity, mortality, and involvement of or close oncological margins. RLR surgeries were associated with significantly less blood loss (50 mL vs 100 ml, P < .001) and lower rates of open conversion on both PSM (1.5% vs 6.8%, P = .003) and CEM (1.4% vs 6.4%, P = .004) compared to LLR. Though PSM analysis showed RLR to have a longer operating time than LLR (170 minutes vs 160 minutes, P = .036), this difference proved to be insignificant on CEM (167 minutes vs 163 minutes, P = .575). CONCLUSION: This multicentre international combined PSM and CEM study showed that both RLR and LLR have equivalent perioperative outcomes when performed in selected patients at high-volume centres. The robotic approach was associated with significantly lower blood loss and allowed more surgeries to be completed in a minimally invasive fashion.

Propensity Score-Matched Analysis Comparing Robotic and Laparoscopic Right and Extended Right Hepatectomy.

Importance: Laparoscopic and robotic techniques have both been well adopted as safe options in selected patients undergoing hepatectomy. However, it is unknown whether either approach is superior, especially for major hepatectomy such as right hepatectomy or extended right hepatectomy (RH/ERH). Objective: To compare the outcomes of robotic vs laparoscopic RH/ERH. Design, Setting, and Participants: In this case-control study, propensity score matching analysis was performed to minimize selection bias. Patients undergoing robotic or laparoscopic RH/EHR at 29 international centers from 2008 to 2020 were included. Interventions: Robotic vs laparoscopic RH/ERH. Main Outcomes and Measures: Data on patient demographics, tumor characteristics, and short-term perioperative outcomes were collected and analyzed. Results: Of 989 individuals who met study criteria, 220 underwent robotic and 769 underwent laparoscopic surgery. The median (IQR) age in the robotic RH/ERH group was 61.00 (51.86-69.00) years and in the laparoscopic RH/ERH group was 62.00 (52.03-70.00) years. Propensity score matching resulted in 220 matched pairs for further analysis. Patients' demographics and tumor characteristics were comparable in the matched cohorts. Robotic RH/ERH was associated with a lower open conversion rate (19 of 220 [8.6%] vs 39 of 220 [17.1%]; P = .01) and a shorter postoperative hospital stay (median [IQR], 7.0 [5.0-10.0] days; mean [SD], 9.11 [7.52] days vs median [IQR], 7.0 [5.75-10.0] days; mean [SD], 9.94 [8.99] days; P = .048). On subset analysis of cases performed between 2015 and 2020 after a center's learning curve (50 cases), robotic RH/ERH was associated with a shorter postoperative hospital stay (median [IQR], 6.0 [5.0-9.0] days vs 7.0 [6.0-9.75] days; P = .04) with a similar conversion rate (12 of 220 [7.6%] vs 17 of 220 [10.8%]; P = .46). Conclusion and Relevance: Robotic RH/ERH was associated with a lower open conversion rate and shorter postoperative hospital stay compared with laparoscopic RH/ERH. The difference in open conversion rate was associated with a significant decrease for laparoscopic but not robotic RH/ERH after a center had mounted the learning curve. Use of robotic platform may help to overcome the initial challenges of minimally invasive RH/ERH.