A major hepatectomy consists of the resection of 3 or more liver segments. Its indications are mainly secondary malignant lesions, then primary malignant lesions, benign lesions and septic resections. Around a hundred major hepatectomies are carried out every year in Strasbourg. This surgery is burdened by 4.5% mortality at day 90 and 20 to 50% morbidity. The main intraoperative risks are hemorrhage and hemodynamic instability. Surgical vascular clamping helps reduce the risk of bleeding but is responsible for sometimes major hemodynamic variations, ischemia-reperfusion syndromes and can lead to acute post-operative liver failure. Recent literature attests to the safety of liver resection without vascular clamping, which is why it is less and less practiced. Different elements are identified as independent risk factors for morbidity and mortality: the presence of cirrhosis, portal embolization, history of renal or cardiac failure, duration of vascular clamping, resected liver volume, transfusion of products labile blood and associated surgical procedures. Given the significant risk of intra- and post-operative complications, it seems relevant to analyze pre- and intra-operative data in order to highlight risk factors for vascular clamping. This would allow better anticipation of complications, patient information, adaptation of intraoperative monitoring and postoperative surveillance and perhaps a reduction in complications. This study also makes it possible to take stock of the epidemiology around hepatectomies performed at the STRASBOURG University Hospital.