Variations in the bifurcation level of the abdominal aorta, formation level of the inferior vena cava, and insertion level of the left renal vein into the inferior vena cava and their clinical importance in laparoscopic surgery

Objective

It is important to minimize the risk of major vascular injury during pneumoperitoneum establishment in laparoscopic surgeries for patients with unusual variations in the levels of the abdominal aorta, the inferior vena cava (IVC), and the left renal vein, which will decrease the morbidity and mortality. The study aims to assess the variations regarding the bifurcation level of the abdominal aorta, formation level of the IVC, and insertion level of the left renal vein into the IVC.

Methods

This retrospective study was conducted on 100 patients (50 males and 50 females) referred to the Department of Radiology, Jordan University Hospital for abdomino-pelvic CT with intra-venous contrast from January 2018 to December 2019. The three vessels were determined on the axial plane, the coronal plane, and the midsagittal plane. The central vertebral body height as well as the distance of the level of the point of interest to the upper end plate of the vertebrae were measured. Afterwards, the results were classified into the following categories, upper end plate, lower end plate, intervertebral disc, upper half, and lower half of the vertebra.

Results

The aortic bifurcation was mainly found at the level of the L4 vertebral body (65, 65%). In the remaining cases, the bifurcation was found to be variably located spanning from L3 in 11 (11%) cases to 3 (3%) cases at L5. As for the iliocaval junction, the most common site was also at the level of L4 with 41 (41%) cases followed by 39 (39%) cases at the level of L5, and 20 (20%) cases at the intervertebral disc of L4/L5. The left renal vein most commonly joined the IVC at the level of L1 with 62 (62%) cases followed by 20 (20%) cases at the intervertebral disc T12/L1. There was wide variation in its entry to the IVC spanning from 4 (4%) cases at T12/L1 to 1 (1%) case at L4.

Conclusion

The anatomical variation of the major vessels can be found in the normal population. Therefore, sufficient investigation of the anatomical position of these vessels is essential for patients before laparoscopic surgery.