Short-term Outcomes after Minimally-invasive Liver Resection for Single Small Hepatocellular Carcinoma: An Analysis from the IGoMILS (Italian Group of Minimally Invasive Liver Surgery) Registry

Introduction: Safety of liver resection for hepatocellular carcinoma (HCC) improved over time, also in relation to the diffusion of minimally-invasive liver surgery (MILS). Aim of this study is to analyze short-term outcomes of MILS for solitary HCC < 3 cm at a nationwide level. Methods: Patients who underwent MILS for single HCC < 3 cm between November 2014 and December 2019 were identified from the IGoMILS Registry. Results: 748 patients underwent MILS: 73.5% were male (mean age 68.1 ± 9.6 years). 93% of patients were Child A, 6.9% Child B and 0.1% Child C; portal hypertension was present in 35.5% of cases. Mean HCC size was 2.1±6.3 cm, with 54.1% of tumors localized in the antero-medial segments and 45.9% in postero-superior segments. 85% of procedures were pure laparoscopic, 13.1% robotic and 1.9% performed by hybrid technique, with an overall conversion rate of 5.5%. 66.3% were wedge resections, 31.5% anatomic resections and 2.1% major hepatectomies. Intraoperative transfusions rate was 2.5%, with a mean blood loss of 182.4±283.3 ml. Mortality was nil. Overall morbidity rate was 23.3% (not significantly different between that following MILS inthe antero-lateral segments than that in the postero-superior segments: 21.7% vs. 25.1%; p=0.281, respectively) with 3.9% of major complications. Biliary fistula occurred in 2.4% of patients and ascites in 6.9%. Mean postoperative stay was 5.5 ± 4.5 days. Conclusions: MILS for HCC < 3 cm should be carefully evaluated in the therapeutic decision making process, being associated with low operative risk, even following difficult posterior segments resection.