RESUMO
BACKGROUND: Difficulty scoring system (DSS) has been established for laparoscopic hepatectomy and serves as useful tools to predict difficulty and guide preoperative planning. Despite increased adoption of robotics and its unique technical characteristics compared with laparoscopy, no DSS currently exists for robotic hepatectomy. We aimed to introduce a new DSS for robotic hepatectomy. METHODS: A total of 328 patients undergoing a robotic hepatectomy were identified. After removing the first 24 major and 30 minor hepatectomies using cumulative-sum analysis, 274 patients were included in this study. Relevant clinical variables underwent linear regression using operative time and/or estimated blood loss (EBL) as markers for operative difficulty. Score distribution was analyzed to develop a difficulty-level grouping system. RESULTS: Of the 274 patients, neoadjuvant chemotherapy; tumor location, size, and type; the extent of parenchymal resection; the need for portal lymphadenectomy; and the need for biliary resection with hepaticojejunostomy were significantly associated with operative time and/or EBL. They were used to develop the difficulty scores from 1 to 49. Grouping system results were group 1 (less demanding/beginner), 1 to 8 (n = 39); group 2 (intermediate), 9 to 24 (n = 208); group 3 (more demanding/advanced), 25 to 32 (n = 17); and group 4 (most demanding/expert), 33 to 49 (n = 10). When stratified by group, age, previous abdominal operation, Child-Pugh score, operative duration, EBL, major resection, 30-day mortality, 90-day mortality, and length of stay were significantly different among the groups. CONCLUSION: In addition to established variables in laparoscopic systems, new factors such as the need for portal lymphadenectomy and biliary resection specific to the robotic approach have been identified in this new robotic DSS. Internal and external validations are the next steps in maturing this robotic DSS.