Role of MDCT Angiography in Selection and Presurgical Planning of Potential Renal Donors

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1 Genitourinary Imaging Original Research Chu et al. MDCT Angiography for Potential Renal Donors Genitourinary Imaging Original Research Linda C. Chu 1 Sheila Sheth 1 Dorry L. Segev 2 Robert A. Montgomery 2 Elliot K. Fishman 1 Chu LC, Sheth S, Segev DL, Montgomery RA, Fishman EK Keywords: CT angiography, renal donor, renal transplantation DOI: /AJR Received October 10, 2011; accepted after revision May 13, The Russell H. Morgan Department of Radiology and Radiological Science, JHOC 3254, Johns Hopkins Hospital, 601 North Caroline St, Baltimore, MD Address correspondence to E. K. Fishman (efishman@jhmi.edu). 2 Department of Transplant Surgery, Johns Hopkins Hospital, Baltimore, MD. CME This article is available for CME credit. AJR 2012; 199: X/12/ American Roentgen Ray Society Role of MDCT Angiography in Selection and Presurgical Planning of Potential Renal Donors OBJECTIVE. The purpose of this study was to determine the prevalence and types of renal and extrarenal abnormalities that preclude renal donation or lead to alteration of the surgical approach on the basis of abdominal CT angiography (CTA) in a large group of potential renal donors. MATERIALS AND METHODS. In this retrospective study, 654 potential renal donors undergoing dual-phase CTA were identified from January 2005 to January The CT reports were systemically reviewed by two radiologists to determine the presence of renal and extrarenal abnormalities. The operative notes of the renal donors were reviewed by one radiologist to determine whether the presence of renal pathology had affected the surgical approach. In the candidates who did not proceed to kidney donation, the reasons that precluded kidney donation were abstracted from the transplant database. RESULTS. Four hundred seventeen potential donors (269 men and 385 women; mean age, 44.0 years; age range, years) proceeded to renal donation and 237 did not. The most common renal abnormalities were cysts (34%) and renal stones (4.4%). Renal artery disease was identified in 3.4% of potential donors, including renal artery stenosis, possible fibromuscular dysplasia, and renal artery aneurysm. Suspicious renal masses were incidentally found in 0.5% of potential donors. The most common extrarenal pathology was an incidental adrenal nodule (2.6%). Other significant extrarenal pathology identified included gallbladder mass (0.2%), Crohn disease (0.2%), ovarian mass (0.2%), and possible sarcoidosis (0.2%). Although renal and extrarenal abnormalities were present in 41% of potential renal donors, abnormalities seen on CT only contributed to exclusion of 27 potential donors (4.1%). The most common reason for exclusion was the presence of renal stones or scarring (1.8%). Significant CT findings also contributed to the selection of the right kidney in 29 donors, most commonly due to presence of ipsilateral vascular disease or complex left vascular anatomy. CONCLUSION. Renal parenchymal and vascular abnormalities are common in asymptomatic potential kidney donors. Although most of these represent incidental CT findings, abnormalities can exclude potential renal donors and alter the surgical approach in a small minority of cases. L aparoscopic nephrectomy has become the preferred surgical procedure for procuring kidneys from living donors since its first introduction in 1995 [1]. The advances of the laparoscopic technique include reduction in postoperative pain, shorter recovery time, reduced length and cost of hospital stay, cosmesis, and higher degree of patient satisfaction [2, 3]. The left kidney is generally preferred for laparoscopic nephrectomy in living donors because of relative technical ease and a longer left venous pedicle [4]. Because of limited surgical FOV during laparoscopic nephrectomy, accurate preoperative evaluation of the renal anatomy is critical before donor nephrectomy. MDCT with 3D reconstruction is the technique of choice in the evaluation of potential renal donors because of the detailed visualization of renal parenchymal disease, arterial and venous anomalies, and collecting system abnormalities. The radiology and transplant surgery literature have focused on the performance of MDCT compared with surgery in the identification of renal vascular anomalies. Previous studies have shown that MDCT has 93 99% accuracy in the identification of accessory renal arteries, prehilar branching, and renal venous anomalies [5 9]. MDCT has also revealed renal parenchymal and urothelial abnormalities in 25 30% of potential kidney donors, most commonly AJR:199, November

2 Chu et al. renal cysts and renal calculi [10, 11]. However, few studies, to our knowledge, have focused on assessing how often these CT abnormalities impact renal donor selection and the surgical approach. A few previous studies reported that CT angiography (CTA) findings contributed to exclusion of % of potential renal donors [10, 12, 13]. The largest study to date by Lorenz et al. [10] of 1957 potential renal donors focused mainly on renal abnormalities and did not evaluate the effect of extrarenal abnormalities on renal donor selection. The effect of CT abnormalities on surgical approach (right vs left nephrectomy) was only briefly described by Sebastià et al. [12] in 199 potential renal donors. The purpose of our study was therefore to determine the prevalence of renal and extrarenal abnormalities and renal vascular variations in potential renal donors with a focus on CT findings that lead to exclusion from renal donation or alteration of the surgical approach. Materials and Methods Subjects This retrospective study was approved by our institutional review board. From January 2005 to January 2009, 654 consecutive potential living kidney donors (269 men and 385 women; mean age, 44.0 years; age range, years) underwent dual-phase CT angiography at our institution as part of a standard preoperative evaluation for renal donation and were included in this study. MDCT Protocol CT angiography (CTA) was performed using a 16-MDCT scanner (Sensation 16, Siemens Healthcare) or a 64-MDCT scanner (Sensation 64, Siemens Healthcare). After fasting for at least 2 3 hours, each potential renal donor ingested 1000 ml of water over a 15- to 20-minute period before scanning began. We injected 120 ml of iohexol (Omnipaque 350, GE Healthcare) through a peripheral venous catheter at a rate between 3.0 and 4.0 ml/s. Arterial phase images were acquired at seconds and venous phase at seconds. A delayed topogram was obtained at 4 5 minutes postinjection to evaluate for urinary tract duplication or obstruction. The area scanned extended from above the kidneys to just below the common iliac arteries on the arterial phase images and from above the kidneys to just below the top of the iliac crests on the venous phase images. All image data were reconstructed with a body soft-tissue algorithm in 0.75-mm and 5-mm-thick sections. All CT angiograms were interpreted in axial, sagittal, and coronal reformations. Threedimensional imaging with volume rendering and maximum intensity projection were used routinely in the evaluation of renal vessels as well as the renal parenchyma. Ascertainment of CT Findings All 654 CT examinations were technically adequate and were of diagnostic quality. The CT reports were systematically reviewed by two radiologists with 3 and 35 years of experience, and an electronic database was created to abstract the imaging findings. The CT findings were grouped into the following categories: renal abnormalities, renal vascular variations, and potentially significant extrarenal abnormalities warranting additional workup. Donor Characteristics The electronic medical record and the transplant database were reviewed for each potential renal donor to determine which donors proceeded to kidney donation and which donors were excluded. Of the donors who proceeded to kidney donation, the operative notes were reviewed to determine which kidney was selected (right vs left) and for what reasons if the right side was chosen. Of the potential donors who did not proceed to kidney donation, the medical and imaging factors that contributed to exclusion were abstracted from the transplant database, the medical record, and conversations with the team evaluating the donors. Results Renal Abnormalities on CT Angiography The most common abnormalities noted on CTA (Table 1) were Bosniak I or Bosniak II renal cysts (34%) followed by renal stones (4.4%) (Fig. 1), renal artery disease (3.4%) (Fig. 2), angiomyolipoma (1.4%), and focal scarring (1.2%). Suspicious renal masses were incidentally found in three potential donors (0.5%) (Fig. 3). Congenital renal abnormalities, including horseshoe kidney (0.2%) and solitary kidney (0.2%), were rare (Fig. 4). Polycystic kidney disease was incidentally noted in one potential donor (0.2%) (Fig. 5). Renal artery disease was identified in 22 potential donors (3.4%), including atherosclerosis in unilateral or bilateral renal arteries in 17 potential donors, possible fibromuscular dysplasia in four potential donors, and renal artery aneurysm in one potential donor. The presence of renal artery disease was more commonly found in potential donors older than 60 years (23.0%). Variations in Renal Vascular Anatomy On the CT angiograms, 66% of the left kidneys and 69% of the right kidneys had conventional arterial anatomy (Table 2), and 34% of the left kidneys and 31% of the right kidneys had accessory renal arteries or prehilar branching of renal arteries. The majority of left kidneys (90%) and right kidneys (94%) had conventional venous anatomy (Table 3). Circumaortic left renal vein was found in 7% of donors and retroaortic left renal vein was found in 2% of donors. Six percent of right kidneys had more than one renal vein, and fewer than 1% of left kidneys had more than one renal vein. Extrarenal Abnormalities on CT Angiography The most common extrarenal pathology was an incidental adrenal nodule, which was TABLE 1: Renal Pathology Identified on CT Angiography of 654 Potential Kidney Donors Potential Donors Pathology No. % Renal cysts Renal stones Renal artery disease Angiomyolipoma Focal renal scarring Suspicious renal mass Ureteropelvic junction obstruction Partial duplication of renal collecting system Malrotation Horseshoe kidney Solitary kidney Polycystic kidney disease AJR:199, November 2012

3 MDCT Angiography for Potential Renal Donors Fig year-old man who was potential renal donor. Coronal contrast-enhanced CT angiography image shows staghorn calculus within left renal pelvis. Moderate cortical thinning and contour deformity of left kidney and mild contour deformity of upper pole of right kidney are compatible with scarring and parenchymal loss. He was excluded from donation. found in 17 potential donors (2.6%). Four of these donors subsequently underwent concurrent adrenalectomy at the time of donor nephrectomy. Other significant extrarenal pathology identified included gallbladder mass (0.2%), Crohn disease (0.2%), and ovarian mass (0.2%). Hilar lymphadenopathy suspicious for sarcoidosis (0.2%) was incidentally seen on the basis of the topogram of one potential donor. Renal Donors Four hundred seventeen (63.8%) potential renal donors proceeded to kidney donation, and 237 (36.2%) did not. Of the 417 renal donors, 388 underwent left nephrectomy and 29 underwent right nephrectomy. Two of the donors underwent concurrent laparoscopic left nephrectomy and left adrenalectomy for incidentally identified left adrenal adenomas. Two of the donors underwent concurrent laparoscopic right nephrectomy and right adrenalectomy for incidentally identified right adrenal adenomas. In one donor with a single 5-mm right renal stone, ex vivo ureteroscopic lithotripsy and stone removal were performed after laparoscopic nephrectomy. The most common reason for selecting the right kidney was the presence of ipsilateral vascular disease or complex left vascular anatomy (11 donors) (Table 4). The right kidney was selected in six donors because of the presence of right renal artery atherosclerosis, fibromuscular dysplasia, or aneurysm. The right kidney was selected in five donors because of complex left renal arterial or venous anatomy. Other reasons for selecting the right kidney included the presence of right renal cysts (seven donors), right renal stones (three donors), mild degree of distal right urinary tract obstruction (two donors), right small (1 cm) angiomyolipoma (one donor), and presence of partial duplication of the left kidney (one donor). In two donors, the right kidney was selected because left nephrectomy would have been technically more challenging due to previous left-sided abdominal surgeries. Individuals Who Did Not Proceed to Renal Donation Two hundred thirty-seven of the potential renal donors did not proceed to renal donation. In 56 individuals, the potential recipient was deemed not to be a candidate. In 29 individuals, another living donor candidate was selected. In 29 additional individuals, the recipient received a deceased donor renal transplant. In 25 individuals, the donor declined to proceed for personal reasons. In six individuals, care of the donor-recipient pair was transferred to another facility. No reason was specified in six more individuals, and additional workup was pending in the remaining 18 individuals. Sixty-eight of the potential donors were excluded for medical reasons, which included medical contraindications, such as obesity, glucose intolerance, and borderline hypertension, as well as imaging contraindications. Significant imaging findings contributed to the exclusion of 27 potential donors (4.1%) (Figs. 6 and 7). These included the presence of renal stones in 10 potential donors (1.5%), the presence of renal scarring in six potential donors (0.9%), and the A Fig. 2 Renal artery disease in potential renal donors. A, 58-year-old woman who was potential renal donor. Oblique coronal CT image shows noncalcified atherosclerotic plaque within origin of left renal artery (arrow). Her urinalysis showed microhematuria and her kidney biopsy showed thin basement membrane disease. She elected not to proceed to renal donation. B, 60-year-old woman who was potential renal donor. Oblique coronal volume-rendered CT image shows beaded appearance of bilateral renal arteries, left greater than right, representing fibromuscular dysplasia. She did not proceed to donation. combination of renal stones or renal scarring in 12 potential donors (1.8%). The presence of a congenital renal abnormality included a horseshoe kidney, solitary kidney, malrotation, and polycystic kidney disease and contributed to exclusion of four potential donors (0.6%). The presence of a suspicious renal mass contributed to the exclusion of three potential donors (0.5%). Complex renal vascular variation (three left renal arteries and two or more right renal arteries) in two potential donors (0.3%) led to the selection of other potential donors with less complex vascular anatomy. The presence of ureteropelvic junction obstruction contributed to exclusion of one potential donor (0.2%). The presence of extrarenal pathology (gallbladder Fig year-old woman who was potential renal donor. Axial contrast-enhanced CT image shows enhancing mass within lower pole of right kidney (arrow), which is highly suspicious for renal cell carcinoma. She underwent partial nephrectomy, and pathology showed oncocytoma. She did not proceed to donation. B AJR:199, November

4 Chu et al. A B Fig. 4 Congenital renal abnormalities in potential renal donors. A, 54-year-old man who was potential kidney donor. Axial contrast-enhanced CT image shows horseshoe kidney with 5-mm renal calculus in right kidney (arrow). He was excluded from donation. B, 44-year-old man who was potential kidney donor. Axial contrast-enhanced CT image shows solitary right kidney. No kidney is identified within left renal fossa. He was excluded from donation. mass, Crohn disease, ovarian mass, and hilar lymphadenopathy) contributed to exclusion of four potential donors (0.6%). Discussion The goals of living-donor kidney transplantation are to maximize the benefit to the recipient while minimizing the short-term and long-term morbidities to the healthy donor. Potential kidney donors thus undergo a comprehensive preoperative evaluation, including imaging, medical, and psychosocial evaluation. In our study, 68 (10%) potential donors were excluded for medical contraindications, such as obesity, glucose intolerance, and borderline hypertension, as well as imaging-related contraindications. Although renal and extrarenal abnormalities were present in 41% of potential kidney donors, most of these were incidental findings and did not preclude donation. Imaging-related contraindications contributed to the exclusion of 4.1% of potential donors compared with % in previous studies [10, 12, 13]. Significant extrarenal abnormalities contributed to exclusion of 0.6% of potential donors compared with % in previous studies [12, 13]. The left kidney is generally preferred for laparoscopic nephrectomy in living donors because of relative technical ease and a longer left venous pedicle [4], and the left kidney is used almost exclusively (> 99%) in some institutions [14]. In attempts to maximize the donor pool, some centers procure the right kidney in up to 16 34% of renal donors, and have shown no significant adverse outcome compared with procurement of the left kidney [15 17]. In our study, imaging abnormalities, such as the presence of renal vascular abnormalities, renal cysts, and renal stones, contributed to the selection of the right kidney in 29 of the 417 renal donors (7.0%). A few CT findings represented absolute contraindications to donation. Lorenz et al. [10] previously reported absolute CT contraindications in 0.5% of potential renal donors, which included polycystic kidney disease, solitary or horseshoe kidney, and pelvic kidney. Our study similarly showed absolute CT contraindications in 0.5% of potential donors (horseshoe kidney, solitary kidney, and polycystic kidney disease). The other imaging findings, including renal mass, renal stone, renal scarring, malrotation, and ureteropelvic junction obstruction, represented relative contraindications that may preclude a potential donor from donation depending on the severity and nature of the abnormality and additional donor characteristics. Fig year-old man who was potential kidney donor. Coronal contrast-enhanced CT image shows bilateral polycystic kidneys. He was excluded from donation. Transplantation of a donor kidney containing a small renal cell carcinoma is controversial. A few small studies have reported transplantation of a kidney containing small renal cell carcinoma after donor nephrectomy and ex vivo excision of the tumor [18 21]. In our study, none of the potential donors with suspicious renal masses proceeded to donation. Renal stones and focal renal scarring frequently coexisted in potential renal donors and represented the most common radiographic abnormalities that contributed to the exclusion of potential renal donors. In our study, 34% of the candidates with renal stones were excluded from donation and 75% of the candidates with focal renal scarring were excluded from donation. The decision of whether candidates with renal stones are excluded is based on the size of the renal calculi and any history of renal stones or metabolic disease. In asymptomatic donors with no history of nephrolithiasis or metabolic disease, a kidney with small calculi (< 4 mm) may be safely donated [22]. Kidneys with multiple stones or a single stone larger than 5 mm are often excluded from donation until the calculi are removed and metabolic analysis is performed [12]. Ex vivo ureteroscopic lithotripsy and extraction can be performed without compromising ureteral integrity or renal allograft function [23]. Although renal vascular variations were common in our study, affecting more than 30% of the kidneys, most of these variations were incidental findings and only contributed to the exclusion of two potential renal donors (0.3%). Between 70% to 75% of individuals can be expected to have a single renal artery bilaterally. Multiple renal arteries were identified in 25% of the left kidneys and 23% of the right kidneys, which was similar 1038 AJR:199, November 2012

5 MDCT Angiography for Potential Renal Donors TABLE 2: Variations in Renal Arterial Anatomy Identified on CT Angiography of 654 Potential Kidney Donors Left Kidney Right Kidney Variation No. % No. % One renal artery One renal artery with prehilar branching Two renal arteries Two renal arteries with prehilar branching Three renal arteries TABLE 3: Variations in Renal Venous Anatomy Identified on CT Angiography of 654 Potential Kidney Donors Left Kidney Right Kidney Variation No. % No. % One renal vein One circumaortic renal vein One retroaortic renal vein Two renal veins Two retroaortic renal veins Three renal veins Four renal veins TABLE 4: Rationale for Selecting the Right Kidney in 29 Donors Who Underwent Right Nephrectomy Rationale No. of Donors Right renal cysts 7 Right renal artery disease 6 Complex left renal vascular anatomy 5 Right renal stones 3 Right urinary tract obstruction 2 Concurrent right adrenalectomy 2 Prior surgery in left abdomen 2 Right angiomyolipoma 1 Left kidney partial duplication 1 to previous reports [24 26]. In general, the presence of more than two arteries within a kidney may be a relative contraindication for procuring that kidney. In many centers, donation only proceeds if one of the three arteries is a small superior polar artery less than 2 mm in diameter. Such an artery may be sacrificed because the resultant volume of renal infarct does not substantially affect graft function [12]. Renal veins show a more uniform anatomic pattern than renal arteries. In our patients, 90% of left kidneys and 94% of right kidneys had a single renal vein. Previous reports showed single renal veins in 92 98% of left kidneys and 76 85% of right kidneys [11, 25]. Multiple renal veins were more common on the right (6%) than on the left (0.5%). Relatively common anatomic variants of the left renal vein include the circumaortic renal vein (7%) and the retroaortic vein (2%). Previous reports showed the circumaortic renal vein in % of left kidneys and retroaortic renal vein in % of left kidneys [11, 27]. The presence of venous anomalies did not contribute to the exclusion of potential renal donors. However, the presence of complex venous anatomy in the left kidney may lead to selection of the right kidney, which was the case in one of our donors. The presence of renal vascular disease led to selection of the right kidney in six donors and selection of the left kidney in 10 donors. In six other donors with renal artery disease who did not proceed to donation, there were comorbid medical conditions, such as renal insufficiency and glucose intolerance, that precluded donation. It was unclear if the CT findings of renal artery disease alone in these patients would have led to exclusion of these potential donors. In patients with unilateral renal artery atherosclerotic plaque, the atheromatous kidney may be donated, with endarterectomy or resection of the affected segment performed during backbench surgery. The presence of bilateral atherosclerotic renal artery disease almost always excludes donation [28], particularly in the case of partial obstruction at the orifice of both arteries. Bosniak I and Bosniak II renal cysts were the most common incidental renal abnormality (34%) and did not contribute to the exclusion of potential renal donors. Renal cysts are associated with a varying risk of malignancy according to the Bosniak grade [29]. Therefore, it is important to carefully assess for presence of solid components, septations, and calcifications on preoperative CT to avoid accidental transplantation of a kidney with a cystic renal cell carcinoma [30]. The presence of simple renal cysts (Bosniak I) is not associated with increased risk of complication or organ dysfunction and is therefore not a contraindication for kidney donation [31]. However, it is important to recognize that the presence of simple renal cysts may favor selection of the cyst-containing kidney in an effort to leave the donor with the more normal kidney. There are several limitations of our study. Our renal donor CT protocol does not include an unenhanced phase in an attempt to limit radiation dose to the potential renal donors. Because nephrolithiasis is an important finding in prospective renal donors, the omission of unenhanced imaging is a potential limitation of our technique. However, in our experience, the presence of nephrolithiasis and urolithiasis can be detected on arterial phase images with the use of maximumintensity-projection images, especially when calculi are more than several millimeters in diameter [32]. With widespread application of dual-energy CT in the near future, the virtual unenhanced images can potentially be used for the detection of renal calculi. In addition, several potential renal donors often undergo simultaneous preoperative evaluation for the same recipient. Forty-eight AJR:199, November

6 Chu et al. No Excluded (%) Renal Stone and/or Scarring 1/1 Horseshoe Kidney Renal Mass 1/1 Congenital Extrarenal Renal Pathology Abnormality 1/1 Solitary Kidney Polycystic Kidney Disease 3/3 Suspicious Renal Mass percent of the excluded renal donors were excluded because the recipient was not a candidate, the recipient received a cadaveric organ, or another donor candidate was selected. Medical contraindications to renal donation accounted for only 29% of the excluded potential donors. The reasons for exclusion of potential donors were often multifactorial, with both imaging contraindications and medical factors present in the same candidate. In these cases, it was not always clear how much weight the imaging abnormalities carried in the exclusion of these potential donors. Finally, there may be subtle differences in exclusionary criteria among different transplantation centers and among individual transplantation surgeons. Our imaging exclusion rate of 4.1% was slightly lower than the % on previous studies [10, 12, 13]. 6/8 Renal Scarring Renal Vascular Variation 1/2 Malrotation UPJ Obstruction 10/29 Renal Stone 1/3 UPJ Obstruction Fig. 6 Types of CT abnormalities that contributed to exclusion of 27 potential donors. UPJ = ureteropelvic junction. Angiomyolipoma In conclusion, CTA has been established as the technique of choice in the preoperative evaluation of renal donors, and it has a significant impact in identifying renal abnormalities and vascular variations that would preclude renal donation or alter the surgical approach. References 1. Ratner LE, Ciseck LJ, Moore RG, Cigarroa FG, Kaufman HS, Kavoussi LR. Laparoscopic live donor nephrectomy. Transplantation 1995; 60: Ratner LE, Kavoussi LR, Schulam PG, Bender JS, Magnuson TH, Montgomery R. Comparison of laparoscopic live donor nephrectomy versus the standard open approach. Transplant Proc 1997; 29: Ratner LE, Kavoussi LR, Sroka M, et al. Laparoscopic assisted live donor nephrectomy: a comparison with the open approach. Transplantation 1997; 63: /9 2/390 Renal Vascular Variation Fig. 7 Percentage of potential renal donors with given CT finding excluded from kidney donation. Number of renal donors with given CT finding is expressed as denominator, and number of renal donors excluded based on given CT finding is expressed as numerator. UPJ = ureteropelvic junction. 4. Ratner LE, Kavoussi LR, Chavin KD, Montgomery R. Laparoscopic live donor nephrectomy: technical considerations and allograft vascular length. Transplantation 1998; 65: Chai JW, Lee W, Yin YH, et al. CT angiography for living kidney donors: accuracy, cause of misinterpretation and prevalence of variation. Korean J Radiol 2008; 9: Laugharne M, Haslam E, Archer L, et al. Multidetector CT angiography in live donor renal transplantation: experience from 156 consecutive cases at a single centre. Transpl Int 2007; 20: Namasivayam S, Small WC, Kalra MK, Torres WE, Newell KA, Mittal PK. Multidetector-row CT angiography for preoperative evaluation of potential laparoscopic renal donors: how accurate are we? Clin Imaging 2006; 30: Sahani DV, Rastogi N, Greenfield AC, et al. Multi-detector row CT in evaluation of 94 living renal donors by readers with varied experience. Radiology 2005; 235: Raman SS, Pojchamarnwiputh S, Muangsomboon K, Schulam PG, Gritsch HA, Lu DS. Utility of 16-MDCT angiography for comprehensive preoperative vascular evaluation of laparoscopic renal donors. AJR 2006; 186: Lorenz EC, Vrtiska TJ, Lieske JC, et al. Prevalence of renal artery and kidney abnormalities by computed tomography among healthy adults. Clin J Am Soc Nephrol 2010; 5: Raman SS, Pojchamarnwiputh S, Muangsomboon K, Schulam PG, Gritsch HA, Lu DS. Surgically relevant normal and variant renal parenchymal and vascular anatomy in preoperative 16-MDCT evaluation of potential laparoscopic renal donors. AJR 2007; 188: Sebastià C, Peri L, Salvador R, et al. Multidetector CT of living renal donors: lessons learned from surgeons. RadioGraphics 2010; 30: Strang AM, Lockhart ME, Kenney PJ, et al. Computerized tomographic angiography for renal donor evaluation leads to a higher exclusion rate. J Urol 2007; 177: Leventhal JR, Paunescu S, Baker TB, et al. A decade of minimally invasive donation: experience with more than 1200 laparoscopic donor nephrectomies at a single institution. Clin Transplant 2010; 24: Bachir BG, Hussein M, Nasr R, Abu-Dargham R, Khauli RB. Evaluation of right versus left laparoscopic donor nephrectomy. Exp Clin Transplant 2011; 9: Keller JE, Dolce CJ, Griffin D, Heniford BT, Kercher KW. Maximizing the donor pool: use of right kidneys and kidneys with multiple arteries for live donor transplantation. Surg Endosc 2009; 23: Saad S, Paul A, Treckmann J, Nagelschmidt M, Heiss M, Arns W. Laparoscopic live donor nephrectomy for right kidneys: experience in a German 1040 AJR:199, November 2012

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