Preoperative Assessment of Laparoscopic Live Kidney Donors by Gadolinium-Enhanced Magnetic Resonance Angiography C. Vallet, V. Bettschart, R. Meuli, J.-P. Wauters, and F. Mosimann K IDNEY transplantation from living related and unre- lated donors has become increasingly common due to the shortage of cadaveric organs. In this context, laparo- scopic nephrectomy is now often proposed to encourage donation because it offers the well-known advantages of minimally invasive surgery. 1–3 Before operation, a careful radiologic assessment is essential, however, because arterial and venous anatomy may be more difficult to appreciate during laparoscopy than at open surgery. The number, length, size, and location of the renal arteries and veins need to be determined, as well as anomalies of the urinary tract. Finally, rare contraindications to donation, such as a tumor or a malformation, must be excluded. 4,5 Potential living donors have traditionally undergone in- traarterial angiography. This “gold standard” technique is very accurate but requires arterial catheterization and injection of an iodinated contrast medium, and therefore the procedure is not free of complications. It is also relatively expensive and time-consuming, and requires ion- izing radiation. These disadvantages have prompted the use of a new noninvasive technique: three-dimensional (3D) gadolinium (Gd)-enhanced magnetic resonance angiogra- phy (MRA). Other MRA techniques without contrast have also been investigated but were found unreliable for detec- tion of all renal arteries. 6,7 MRA with Gd is a far superior method with regard to image quality and identification of accessory renal arteries. 8,9 The purpose of this study is to prospectively assess the accuracy of Gd-enhanced MRA to define renal vascular anatomy prior to laparoscopic nephrectomy in living kidney donors. PATIENTS AND METHODS From July 1999 to November 2000, eight consecutive patients were investigated as potential living kidney donors, using a Gd-enhanced MRA technique. Seven women and one man were assessed, aged 26 to 53 years (mean 40.2 years). All underwent radiologic explo- ration only after history, physical examination, crossmatching, biochemistry and urine profiles, nuclear scanning, and a psychiatric interview had identified them as good candidates for donation. Magnetic resonance angiography was done using a 1.5-T super- conducting imager (Magnetom Vison and Symphony, Siemens, Erlangen, Germany) with the use of a body coil. Three sequences were performed: (a) initial axial T 2 -weighted with fat saturation to evaluate the renal parenchyma; (b) coronal T 2 HASTE with fat saturation for urinary tract anatomy; (c) axial T 1 gradient echo breath-hold fat saturation and coronal breath-hold contrast-en- hanced turbo 3D MRA for vascular anatomy. The MRA images were interpreted preoperatively by two radi- ologists for the number and branching of the renal arteries, as well as the presence of stenosis or anomalies of renal veins. Pathologic findings in the kidneys, urinary tract, and other organs were also reported. The Gd-enhanced MRA findings were compared with those encountered at surgery. Intraoperative findings were used as reference to define the sensitivity of the method. RESULTS Of the eight donors, one had to be excluded from the analysis due to language difficulties that obviated the breath-holding maneuver. MRA demonstrated that five donors had a single renal artery on both sides. Two patients had two arteries on one side. Two kidneys with a single artery showed early branch- ings at 12 and 20 mm of the aorta. No polar artery was seen. The seven donors had a single vein on both sides. There were no anomalies of the urinary tract except for one very mildly dilated renal pelvis. One donor had a large left ovarian vein. In addition, MRA examination showed one renal hemangiomyolipoma and one liver hemangioma. At surgery, the number of renal arteries was the same as at MRA in all but one case. In one donor, one of the two arteries described by the radiologists was in fact a polar vessel entrapping the pyeloureteral junction, a finding that explained the pelvis dilation described earlier. It was as- sumed that if this kidney was to remain in the donor, she might have become exposed to a risk of late renal failure. Therefore, this organ was chosen for harvesting. Before it was grafted, the polar artery was transposed posterior to the renal pelvis to avoid compression in the recipient. The number of renal veins found at surgery confirmed the results of MRA in all but one case in which a second right renal vein was found posterior to the artery. Departments of Surgery (C.V., V.B., F.M.), Radiology (R.M.), and Nephrology (J.-P.W.), University Hospital, Lausanne, Swit- zerland. Address reprint requests to Dr Ce ´ dric Vallet, Department of Surgery, Centre Hospitalier Universitaire Vaudois, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland E-mail: cedric. vallet@chuv.hospvd.ch © 2002 by Elsevier Science Inc. 0041-1345/02/$–see front matter 655 Avenue of the Americas, New York, NY 10010 PII S0041-1345(01)02913-X Transplantation Proceedings, 34, 795–796 (2002) 795