Anatomical Variation of the Glissonean Pedicle of the Right Liver

PURPOSE Many studies have been conducted to date regarding whether the right hepatic vein is the accurate border that divides the anterior and posterior section of the right liver. It has been reported that the Glisson pedicle of the right liver may be an anatomical variation that does not have a consistent morphology. We analyzed the relationship between the true borders of the anterior and posterior sections, and the right hepatic vein, based on cadaver dissection and MD-CT image analysis of the anatomical variation of the Glisson pedicle of the right liver. METHODS Sixteen cadaver livers were available for dissection from the Department of Anatomy, and pre-operative MD-CTs of 20 donor livers who underwent living donor liver transplantation prior to December 2009, were obtained. We analyzed the 3D-relationship between the branches of the Glisson pedicles and the right hepatic vein of the right liver. They were divided into 3 groups according to the sliding pattern of the branches of the Glisson pedicle origin. When all segmental branches of the anterior pedicle arise from the main trunk of the anterior pedicle and all branches of posterior pedicle arise from the main trunk of posterior pedicle, it was designated as Group A (Normal Group). When a portion of the segmental branches of the anterior pedicle arises from the main trunk of the posterior pedicle, it was designated as Group B (Posterior dominant group). When a portion of the branches of the posterior pedicle arises from the main trunk of the anterior pedicle, it was designated as Group C (Anterior dominant group). RESULTS Among the 16 cadaver liver dissections, 6 cases were in Group A, 5 in Group B, and 3 in Group C. Two cases were excluded from the study because the inferior right hepatic vein was the main draining vein of the right liver. The analysis of preoperative MD-CT of the 20 donor livers showed that there were 13, 4, and 3 patients in Groups A, B, and C, respectively. CONCLUSION According to Couinaud's theory of anatomy, the right hepatic vein serves as the border between the anterior and posterior sections of the right liver. But, due to the frequent anatomical variations, an adequate understanding of the anatomical variations of the right Glisson pedicle should be necessary for liver surgery.