Safety of 'Isolated IVb (Inferior) Resection of the Liver' by Cadaver Dissection

Kim, In Gyu; Park, Jung Wook; Kim, Bong Wan; Wang, Hee Jung; Lee, Bong Hwa; Kim, Myung Wook

Abstract

PURPOSE
Healey divided segment IV of the live as the 'superior portion (IVa) ' and the 'inferior portion (IVb) '. On the contrary, Couinaud suggested that there was no useful purpose in dividing segment IV because of several reasons. Our goal is to evaluate the safety of the 'isolated IVb (inferior) resection of the liver' via performing the dissection of cadavers. METHODS: There were ten total cadavers. Cadaver dissection proceeded with respect to the Glissonian pedicle, the portal vein and the bile duct, respectively. The total number of Glissonian pedicles at segment IV was measured. The distance between the origins of the IVa and IVb branches was measured. Additional pedicles that were known to exist at segment IVa were also evaluated. RESULTS: The mean number of Glissonian pedicles in segment IV, IVa, and IVb was 5 (+/-1.3), 1.6 (+/-7), and 3.4 (+/-0.9), respectively. The mean distance between the origins of the IVa and IVb branches was 5.6 mm (+/-3.9 mm). Two of 10 cases had a very short distance between the origins that were considered as having common origin. Additional pedicles were identified at the Lt. main Glissonian pedicle in all the cases (8 cases: 1 each, 2 cases: 2 each). CONCLUSION: Considering the possible existence of a common origin of segment IVa and IVb Glissonian pedicles, there is the risk that the segment IVa will be injured during 'iso lated IVb resection'. Inevitable ligation of the additional pedicle of segment IVa from the Lt. main Glissonian pedicle can be made during the 'isolated IVb resection'. Therefore, we think that 'isolated IVb resection of the liver' can be safe only when the surgeon divides the branches of segment IVb with meticulous preservation of the IVa branches.