A single left renal vein draining into the common iliac vein.

Several variations of the anatomy of the left renal vein have been reported. Rare variants are frequently overlooked in the preoperative assessment but can lead to complications during surgery. We describe a kidney donor with a rare anomaly of a single main left renal vein draining into the left common iliac vein.

INTRODUCTION

Renal transplantation surgery has become frequent due to the superiority of transplant over dialysis.[1] Preoperative renal vascular anatomy mapping of the donor and utilizing advanced radiological imaging may improve the outcome of surgery. In this report, we describe a case of a kidney donor with a single left renal vein draining to the left common iliac vein.

CASE REPORT

A 21-year-old woman presented to our service to donate a kidney for her father. Renal computed tomography angiography was performed. The study revealed a single main left renal vein, coursing in the left para-aortic space and heading toward the bony pelvis [Figure 1]. During open donor nephrectomy, the left renal vein was tracked to the pelvis where it joined the left common iliac vein. There were three tributaries to the renal vein: the left adrenal, ovarian, and lumbar veins. The harvested kidney was successfully transplanted into the recipient.

Figure 1

CT angiogram image demonstrating the left renal vein draining into the common iliac vein (arrowhead)

DISCUSSION

The most common course of the left renal vein is posterior to the superior mesenteric artery, anterior to the aorta, and cranial to the inferior mesenteric artery, where it drains into the inferior vena cava.[2] There are several reports of variations in the left renal vein drainage; common variants include a retroaortic left renal vein and circumaortic left renal vein with a reported incidence of 0.5%–3.1% and 0.02%, respectively.3 In this case, a single main left renal vein received drainage from the left suprarenal, ovarian, and lumbar veins as it traveled in the left para-aortic space caudally and eventually drained in the left common iliac vein.

Three previous reports describe this rare anomaly of the left renal vein; Brancatelli et al., in 2000, reported one case of the retroaortic left renal vein joining the left iliac vein,[4] Karaman et al. reported that only three of 1856 patients had such variations,[5] and Kawai et al. reported one case of two left renal veins: one retroaorta drained into the inferior vena cava and the other drained into the left common iliac vein.[2]

CONCLUSION

Renal vascular variants are not uncommon and can be a risk factor for injury in retroperitoneal surgery. Failure to recognize such variations could result in vascular injury and subsequent severe bleeding. In the present case, preoperative assessment and intraoperative awareness of this rare renal venous variation allowed the surgery to be carried on safely.