MORPHOLOGIC AND MORPHOMETRIC VARIATION OF EXTRAHEPATIC PORTAL VEIN AMONG ETHIOPIAN CADAVERS

Abstract

ABSTRACT Introduction: The portal vein (PV) begins at the level of 2nd lumbar vertebrae and measures approximately 8cm long. In the lesser omentum the PV lies posterior to both common bile duct and hepatic artery. The main extrahepatic tributaries of portal vein are left gastric and posterior superior pancreatoduodenal vein. PV is formed posterior to the neck of pancreas, by the union of SMV and SV passes posterior to the first part of duodenum and anterior to IVC and enters the free border of lesser omentum. The vein then ascends towards the porta hepatis in the anterior margin of lesser omentum, at the porta hepatis it divides into right and left branches. Objective: To assess morphologic and morphometric variations of extrahepatic portal vein among Ethiopian cadavers. Method and materials: A descriptive study based on observation and morphometry was done on embalmed human cadavers. This study was carried out in the dissection rooms of the Departments of Human Anatomy of University of Gondar, Bahr Dar, Addis Ababa, Wello, Madawollabu, Wolkitie and Debre Markos Universities, St. Paul’s Millennium Medical College and Gambi Private Medical College. The study populations were 21 embalmed Ethiopian cadavers prepared for teaching purpose. The portal vein was cleaned and observed starting at its formation up to its termination at porta hepatis. The observations related to morphological variations of PV and its tributaries were captured and recorded and its relation with neck of pancreas was recorded. The length and diameter of PV for each case was measured with precisely calibrated, standard sliding vernier caliper. Result: Type I pattern of formation of Portal vein was observed in 17 cases (80.95%) while Type II Pattern was observed in 4 cadavers (19.04%). Of the 17 bodies having Type I pattern of formation11cases (52.38%) were reclassified as type Ia and 6 bodies (28.57%) as type Ib. The mean length and diameter of the portal vein of the 21 cadavers studied were 60.36 mm and 16.73 mm, respectively. Conclusion: According to the present study, of the three types described the type Ia was the predominant followed by type Ib and type II, respectively. The dimensions of portal vein are affected in portal hypertension and various other pathological conditions affecting the organs related to the portal system. Hence, our findings could be used as a base line for further research conducted in Ethiopia.