Unravelling the Complexity Myth for Minimally Invasive Right Hepatectomy: Liver Parenchymal Features and Their Correlation to Objective Outcomes in Major Anatomical Resections

Minimally invasive approaches to major liver resection have been limited by presumed difficulty of the operation. While some concerns arise from mastering the techniques, factors such as tumor size and liver parenchymal features have anecdotally been described as surrogates for operative difficulty. These factors have not been systematically studied for minimally invasive right hepatectomy (MIRH). Seventy-five patients who underwent MIRH during 2007–2016 by the senior author were evaluated; these were compared to control group of open right hepatectomy. Demographics, operative, and post-operative variables were collected. Operative times and estimated blood loss, two objective parameters of operative difficulty were correlated to volume of hepatic resection, parenchymal transection diameter and liver parenchymal features using regression analysis. Thirty-eight (50.6%) resections were performed for malignant indications. Average tumor size was 5.7 cm (±3.6), mean operative time was 196 min (±74), and mean EBL was 220 mL (±170). Average transection diameter was 10.1 cm (±1.7). There was no correlation between operative difficulty with parenchymal transection diameter or presence of steatosis. Blood loss was higher with increased right hepatic lobe volume and body mass index. This analysis of a very defined anatomical resection suggests that the often quoted radiographic and pathologic features indicative of a challenging procedure were not significant in determining operative difficulty.