Robot-assisted liver resections. Lessons learned from 127 procedures: short-term and long-term outcomes and literature review.

Background Liver surgery greatly evolved over the last decades, with significant reduction in operative morbidity and mortality. Minimally invasive liver surgery demonstrated to be safe and feasible for selected patients with equivalent oncologic outcomes compared to open surgery, despite requiring specific technical skills. Recently, robotic technology was used also to perform liver surgery, showing interesting aspects, such as flexibility and precision of surgical instruments and 3D vision, which appeared very helpful in performing challenging minimally invasive procedures. The present paper is a retrospective analysis of a seven years’personal experience in robotic liver surgery. Materials and methods: Over the last 7 years, from September 2012 to September 2019, we treated 127 patients affected by both benign and malignant liver diseases using robotic-assisted surgery. Patients’ characteristics, surgical procedures data and post-operative parameters were collected in a dedicated database. A retrospective analysis was performed to evaluate the outcomes in the robotic series. Results: Seventy-five patients were males and 52 females. The mean age was 66.3 years (range 21- 89). Patients undergoing surgery for malignancy were 97 (76%): 67 liver metastases (colorectal and others), 22 hepatocellular carcinomas (HCC), 5 cholangiocarcinomas (CCC), 3 gallbladder cancers. In 13 of them the final pathologic examination revealed benign lesions. Patients who underwent surgery for benign disease were 30 (24%): 15 biliary cystadenomas, 6 hydatid cysts, 3 hemangiomas, 4 symptomatic simple giant liver cysts, one focal nodular hyperplasia (FNH) and one adenoma. The overall liver lesions removed by robotic approach were 198: 63% of patients had more than one lesion. The median tumor size was 24,8 mm (range 4-92). Major hepatic resections were 20 (15.7%). Lesions involving posterior or paracaval segments (segments: 1, 4a, 7, 8) were 66 over 198 (33.3%). Twenty-seven patients (21.3%) had a previous open abdominal surgery with significant abdominal adhesions. Associated abdominal or thoracic diseases (excluding adhesions) treated during liver resections were 71: 25 colo-rectal resections, 22 cholecistectomies, 7 lymphadenectomy, 6 gastric resections, 2 lung resections, and other procedures. Inflow vascular pedicle control (Pringle maneuver) was performed in 37.8%. Mean estimated blood loss was 55 ml (range 5-1200). Intraoperative or perioperative transfusion request occurred in 8 cases (6.3%). Conversion to open surgery occurred in 11 patients (8.7%). Clavien-Dindo 3-4 grade complications occurred in 8.7%. Only one postoperative biliary leakage was observed (0.8%). One case of postoperative 90-day mortality was reported, related to liver failure at 52th post-operative day in a cirrhotic man who underwent a right hepatectomy. Conclusions. Robotic liver surgery is a safe and feasible approach which may increase the possibility of minimally invasive liver resection even in cases considered challenging for conventional laparoscopy, in particular for: lesions located in right postero-lateral and para-caval segments, major liver resections and associated abdominal procedures. The robotic assistance is useful especially for vascular control during tissue dissection and for micro-suturing, when required. The current lack of dedicated robotic instruments, in particular for parenchyma dissection, remains one of the most important shortfall, as well as the high costs and the devices availability. Further clinical comparative studies between robotic and laparoscopic approach are necessary.