Precaval Right Renal Artery During Laparoscopic Donor Nephrectomy

Abstract

Since its introduction in 1995 (1), laparoscopic donor nephrectomy (LDN) has rapidly become the standard of care for the procurement of allografts from potential kidney donors (2). Preoperative evaluation of both the donor and recipient is extensive and often includes cross-sectional imaging to help determine if allograft harvest is feasible. Computed tomography (CT) with intravenous contrast is commonly utilized to evaluate not only which kidney to procure, but also to help plan the procurement. This “CT angiogram” allows visualization of the renal vasculature in order to determine the best operative approach, and to prevent unforeseen difficulties with adequate length of vasculature for anastomosis in the recipient. A healthy 29-year-old female underwent a preoperative workup for kidney donation, including an contrast- enhanced CT scan, which revealed an isolated finding of a single, precaval right renal artery (Fig. 1). The right kidney also had a simple cyst, while the left was larger, with multiple arteries and veins. These findings made the right kidney preferable for donation. CT imaging did not reveal any other anomalies, and we elected to proceed with a right LDN. During the procedure, after the gonadal vein was ligated and transected, the renal artery was mobilized, stapled, and transected at its junction with the aorta. This maneuver allowed for maximal length of the vasculature (both arterial and venous) for anastomosis in the recipient. Both the donor and the recipient tolerated their respective procedures well and had excellent postoperative outcomes.FIGURE 1.: A contrast-enhanced computed tomography image demonstrating the single right renal artery (A) passing anterior to the inferior vena cava.During the eighth week of gestation, the renal arteries develop from the lateral portion of an arterial plexus arising from the aorta. The posterior vessels of this plexus develop into lumbar arteries, while ventral vessels become mesenteric arteries. A precaval right renal artery is likely the result of a persistent caudal vessel, arising ventrally from the aorta after formation of the inferior vena cava (IVC), but before gonadal vein descent (3, 4). The prevalence of this anomaly has been reported between 0.8% (5) and 5% (6). The precaval artery is commonly an accessory to the lower pole, (3, 6) associated with an enlarged kidney or a bifid collecting system (4). We present a case of a precaval right renal artery during LDN without any of these associated findings. Usually during right donor nephrectomy, great care is taken to maximize renal vein length, often taking a cuff of IVC during its transection. However, the length of the renal artery can be suboptimal if its dissection is not adequate. Our common practice is to place the kidney in a “flipped” position and to dissect the renal artery to its origin at the aorta (7). By taking both renal vessels at their insertion/origin, maximum length for anastomosis can be successfully attained. In this case, however, dissection was actually facilitated by the presence of the right renal artery anterior to the IVC. After careful dissection exposed the vessels, the ligation and transection of the artery was performed without having to flip the kidney to work posteriorly. In our brief experience, a precaval right renal artery does not preclude a successful right laparoscopic donor nephrectomy. Bartholomew Radolinski Eric K. Diner Department of Urology Washington Hospital Center Washington, DC Seyed R. Ghasemian Departments of Urology and Transplantation Services Washington Hospital Center Washington, DC