IWATE criteria are associated with perioperative outcomes in robotic hepatectomy: a retrospective review of 225 resections

Abstract

Background Robotic hepatectomy (RH) is increasingly utilized for minor and major liver resections. The IWATE criteria were developed to classify minimally invasive liver resections by difficulty. The objective of this study was to apply the IWATE criteria in RH and to describe perioperative and oncologic outcomes of RH over the last decade at our institution. Methods Perioperative and oncologic outcomes of patients who underwent RH between 2011 and 2019 were retrospectively collected. The difficulty level of each operation was assessed using the IWATE criteria, and outcomes were compared at each level. Univariate linear regression was performed to characterize the relationship between IWATE criteria and perioperative outcomes (OR time, EBL, and LOS), and a multivariable model was also developed to address potential confounding by patient characteristics (age, sex, BMI, prior abdominal surgery, ASA class, and simultaneous non-hepatectomy operation). Results Two hundred and twenty-five RH were performed. Median IWATE criteria for RH were 6 (IQR 5–9), with low, intermediate, advanced, and expert resections accounting for 23% (n = 51), 34% (n = 77), 32% (n = 72), and 11% (n = 25) of resections, respectively. The majority of resections were parenchymal-sparing approaches, including anatomic segmentectomies and non-anatomic partial resections. 30-day complication rate was 14%, conversion to open surgery occurred in 9 patients (4%), and there were no deaths within 30 days postoperatively. In the univariate linear regression analysis, IWATE criteria were positively associated with OR time, EBL, and LOS. In the multivariable model, IWATE criteria were independently associated with greater OR time, EBL, and LOS. Two-year overall survival for hepatocellular carcinoma and intrahepatic cholangiocarcinoma was 94% and 50%, respectively. Conclusion In conclusion, the IWATE criteria are associated with surgical outcomes after RH. This series highlights the utility of RH for difficult hepatic resections, particularly parenchymal-sparing resections in the posterosuperior sector, extending the indication of minimally invasive hepatectomy in experienced hands and potentially offering select patients an alternative to open hepatectomy or other less definitive liver-directed treatment options.

Pure laparoscopic versus robotic liver resections: Multicentric propensity score‐based analysis with stratification according to difficulty scores

“…In our study, the analysis was performed on a large cohort of patients and variables, which allowed us to add more detailed considerations. The Wakabayashi score has been externally validated on a cohort of LLR 29 and its criteria have been found associated with the outcomes of RALS 30 . Referring to this previous knowledge, in our study, the Wakabayashi system was referred to as the reference for the analysis and we found that the Gayet and Abu Hilal classifications had a high concordance with the system of reference through all the levels of difficulty (>90%).…”

“…The Wakabayashi score has been externally validated on a cohort of LLR 29 and its criteria have been found associated with the outcomes of RALS. 30 Referring to this previous knowledge, in our study, the Wakabayashi system was referred to as the reference for the analysis and we found that the Gayet and Abu Hilal classifications had a high concordance with the system of reference through all the levels of difficulty (>90%). Hence, we could conclude that both the Gayet and Abu Hilal classification systems are applicable to stratify RALR according to difficulty and to guide operative decisions.…”

Can the computed tomography texture analysis of colorectal liver metastases predict the response to first-line cytotoxic chemotherapy?

“…In this study, 45% of the procedures were classified as advanced and expert. These percentages are similar to those of Labadie et al [ 26 ] (43%) and lower than the data reported by Sucandy et al [ 27 ] (68.6%). As can be seen in Figure 3 showing the cases performed to date and their degree of difficulty, the 45% of RLRs performed were classified as advanced and expert.…”

“…To study the complexity of the RLRs performed, we employed the IWATE score. The effectiveness of the IWATE score as an indicator of operative difficulty in LLR has been demonstrated and several groups have previously considered that its usefulness in laparoscopic liver surgery could be extrapolated to the robotic approach[ 26 , 27 ]. In this study, 45% of the procedures were classified as advanced and expert.…”

Systematic review and meta‐analysis of difficulty scoring systems for laparoscopic and robotic liver resections

“…Twelve studies in the literature had supporting data for the Iwate DSS for MILR. [11][12][13]18,32,[33][34][35][36][37][38][39] Notably, the Iwate DSS was not formulated based on any data but as a modification of the Ban DSS based on expert opinion. Ten studies had supporting data for Iwate DSS for LLR against various outcome measures, 11,12,18,[32][33][34][35][36]38,39 of which eight studies 11,12,18,21,[32][33][34][35][36] published data that was amenable to pooling (Table 3).…”