Anatomy of the Middle Hepatic Vein Tributaries to Promote Safer Hepatic Vein-Guided Liver Resection.

Background In laparoscopic anatomic liver resection, an increasingly common procedure, the hepatic vein-guided approach is widely used although the hepatic vein tributaries can be a major source of bleeding in the event of inadvertent injury. This report describes the anatomy of the middle hepatic vein (MHV) including its tributaries based on reconstructed three-dimensional computed tomography images and provides anatomic data to enable safe middle hepatic vein-guided liver resection. Methods Following simulation modeling of the hepatic vasculatures, reconstructed MHV data was pooled from 35 healthy liver donors. Yields of the MHV tributaries were analyzed to enable MHV-guided liver resection. Results A total of 252 tributaries were identified in the 35 donors. The MHV yielded fewer tributaries from its anterior and posterior aspects than from its right-side and left-side aspects (40 [15.9%], 13 [5.2%], 93 [36.9%], and 106 [42.1%], respectively). The MHV tributaries from the anterior and posterior aspects were smaller in diameter than those from the right-side and left-side aspects (median, 3.0, 2.0, 4.8, and 4.0 mm, respectively). Discussion Our simulation revealed that MHV dissection from the anterior or posterior aspect poses a lower risk of injury to the MHV tributaries compared to dissection from either lateral aspect. In addition, MHV dissection from the anterior or posterior aspect allows for safer identification and isolation of the thick MHV tributaries originating from the lateral aspects. Ideally, the anterior or posterior aspect of the MHV should be accessed and exposed before the lateral aspects are dissected to minimize the risk of MHV tributary injury.