[Left hepatic artery: anatomical variations and clinical implications]

The presence of a left hepatic artery (LHA) is an anatomical variation related to the persistence after fetal maturation of one of the two embryonic hepatic arteries, who disappear in the modal liver arterial vascularisation (liver vascularisation by a unique hepatic artery originating from the celiac trunk). When present, LHA is originating from the left gastric artery and runs through the pars condensa of the lesser omentum. Its frequency is varying from 12 to 34% according to the different study methods: 14 to 27% in anatomical series, 12 to 20% in angiographic studies and 12 to 24% in liver transplantation series. Laparoscopic detection has the highest sensitivity with reported rates from 18 to 34% of cases. LHA is irrigating a variable liver territory from a part of the left lobe to the whole liver in less than 1% of cases. A satisfactory knowledge of these anatomical variations is mandatory in liver surgery and during liver transplantation but also each time the pars condensa is approached during gastric surgery, hiatal surgery for gastroesophageal reflux and for bariatric surgery. Due to existing anastomosis between liver arteries, LHA ligation is feasible in most cases with a subsequent and transitory elevation of liver enzymes. On the contrary, in case of a unique LHA for the whole liver, the safety of its ligation is not demonstrated.