Gross anatomy of the retrohepatic segment of the inferior vena cava in northwest Indians.

BACKGROUND AND OBJECTIVES: Information regarding the size and position of the ostia of veins opening into the retrohepatic segment of inferior vena cava (HIVC) in northwest Indians is not available. Knowledge of gross anatomy of this segment is of importance in cases of segmental resection of the liver involving the groove for inferior vena cava (IVC) and when performing selective hepatic venography. We carried out this study to provide information on gross anatomy of HIVC in northwest Indians. METHODS: Livers were obtained from 500 adult autopsy subjects. The HIVC was opened posteriorly by a vertical cut and its circumference at the upper and lower cut ends was measured. To study the position of the ostia of the hepatic veins, HIVC was divided transversely into upper, middle and lower thirds. The anterior and anterolateral walls of HIVC were also divided into four equal parts longitudinally. The venous ostia were classified according to the size of their openings. In addition, in 100 livers the openings were injected with a 20 per cent solution of cellulose acetate butyrate (CAB) in acetone and veins were dissected. RESULTS: The HIVC extended upwards and to the left either obliquely (66.4%) or by describing a gentle curve (33.6%) in its upper half or upper third. Its average length was about 71 mm. Mean diameter at the upper cut end was about 19 mm. The posterior aspect of the upper half or upper one third of HIVC was covered by an extension of the caudate lobe completely (4%) or incompletely (7.4%). The ostia of the left, middle and right hepatic veins were large (>10 mm) and were located in the upper third segment of HIVC. In 87 per cent of specimens the left and middle hepatic veins had a common opening on the left anterior area. The ostium of the right hepatic vein was present in the right anterior area. INTERPRETATION AND CONCLUSION: In conclusion, our study provided gross measurements of HIVC in northwest Indians. A knowledge of the anatomy of HIVC and hepatic venous ostia will help the clinician interventional operator in planning the treatment by choosing a balloon of correct size and at correct site. The measurements helps in determining the fall in portal pressure with pharmacotherapy given for the prevention of variceal bleed.