Can the left hepatic vein always be safely selectively clamped during hepatectomy? The contribution of anatomy

The minimization of blood loss is the main objective during hepatic resection to minimize perioperative mortality and morbidity. Selective clamping of the hepatic veins, combined with pedicle clamping, may make it possible to spare the non-resected territories from ischemia. These clamping procedures are particularly useful in the treatment of hepatic metastases of colorectal cancers, because preoperative chemotherapy may temporarily alter the hepatic parenchyma, increasing its susceptibility to ischemia. During left lobectomy or left hepatectomy, extraparenchymatous control of the left and median hepatic veins (the LHV and MHV, respectively) and of the common trunk (CT) requires exact knowledge of this anatomical region. Biometric analyses were carried out on extraparenchymatous portions of the LHV, MHV and CT of 20 fresh cadavers and 10 living subjects, to assess the feasibility of selective clamping without liver mobilization. Fourteen of the 20 cadaveric subjects (70%) had a common trunk between the LHV and the MHV. The extraparenchymatous portion of the LHV was between 4 and 13 mm long, depending on the presence or absence of a CT. The angle between the sagittal plane of the inferior vena cava and the LHV was about 18.3° on average, in the absence of liver mobilization. Selective clamping of the left hepatic vein was possible only when the extraparenchymatous portion of this vein was at least 6 mm long. The selective clamping of this vein is, therefore, less straightforward than that of the right hepatic vein, given the high frequency of a common trunk shared with the median hepatic vein and of a short extraparenchymatous segment.