USE OF SPIRAL COMPUTERIZED TOMOGRAPHY IN LIEU OF ANGIOGRAPHY FOR PREOPERATIVE ASSESSMENT OF LIVING RENAL DONORS

PURPOSE: We evaluate whether spiral computerized tomography (CT) can be used in lieu of renal angiography for preoperative assessment of living renal donors, with special attention to multiplicity of renal vasculature. MATERIALS AND METHODS: A total of 47 living renal donor candidates were evaluated with spiral CT and all but 2 underwent donor nephrectomy. Patients were divided into early and late groups because there was a learning curve with spiral CT. In the early group 18 donors underwent renal angiography as well as spiral CT and 10 underwent nephrectomy after spiral CT only. In the late group 5 had dual radiographic evaluation for ambiguities in spiral CT interpretation and 12 underwent nephrectomy after spiral CT only. Spiral CT was performed and interpreted blind to angiographic results, and vice versa. RESULTS: Spiral CT identified 50 of 52 renal arteries (96%) found at surgery overall and 23 of 25 (92%) found at surgery after spiral CT only. Two accessory arteries were missed in the 10 early group donors evaluated with spiral CT only, yielding an early negative predictive value of 80%. Renal angiography identified another accessory artery missed by spiral CT in the early group. All 3 missed vessels were identified retrospectively. No arteries found at surgery were missed in the late group (negative predictive value 100%), although there were 2 false-positive results detected by spiral CT relative to renal angiography in 1 candidate renal unit. Overall accuracy to predict early renal artery division relative to surgical findings was 93% for spiral CT and 91% for renal angiography. However, early renal artery division was clinically significant for only 1 of 11 vessels found at surgery. Spiral CT demonstrated 4 anomalous venous returns and renal angiography identified none. However, spiral CT missed 2 accessory veins and identified only 1 of 2 fibromuscular dysplasia cases. Total cost for spiral CT and renal angiography was $886 and $2,905, respectively. CONCLUSIONS: Spiral CT is a reasonably good alternative to renal angiography for living renal donor assessment but there is a profound learning curve for performance and interpretation. Renal angiography is still the gold standard with respect to the identification of arterial multiplicity and fibromuscular dysplasia, and it should be used adjunctively in cases with spiral CT ambiguity. Neither spiral CT nor renal angiography is ideal for the assessment of early renal artery division which is seldom an issue. The benefits of spiral CT over renal angiography are potentially lower morbidity, improved donor convenience and reduced cost.     

Contrast enhanced spiral computerized tomography in live kidney donors: a single session for anatomical and functional assessment

PURPOSE: We evaluated contrast enhanced spiral computerized tomography (CT) as a single session for anatomical and functional assessment of potential live kidney donors. MATERIALS AND METHODS: The study included 80 consecutive kidney donors. In addition to routine donor evaluation, radiological imaging of the kidneys was performed with spiral CT, which was also used for selective determination of the glomerular filtration rate (GFR) of each kidney. All donors underwent 99mTc-mercaptoacetyltriglycine renal scan as a gold standard for GFR determination. Anatomical results of spiral CT were compared to operative findings at donor nephrectomy. Moreover, the results of CT GFR were compared with those of standard 99mTc-mercaptoacetyltriglycine GFR. RESULTS: Spiral CT detected major renal abnormalities that might be potentially significant for safe renal donation in 4 of the 80 donors (5%). Spiral CT had 100% sensitivity, 85.7% specificity and 97.2% overall accuracy for detecting the number of renal arteries. To identify the number of renal veins spiral CT had 100% sensitivity, 92.3% specificity and 98.6% overall accuracy. A comparison between the isotope GFR of each kidney with the corresponding CT GFR showed a perfect correlation (r = 0.54, p <0.001). For the right and left kidneys mean isotope clearance was not significantly different from that of mean CT clearance. CONCLUSIONS: Multidetector row spiral CT with contrast medium can provide accurate information regarding the anatomy of the urinary tract and vasculature of the kidney. Moreover, it can detect renal and vascular abnormalities that might be potentially significant for safe renal donation. In addition, it can accurately demonstrate selective GFR of each kidney. Therefore, we recommend spiral CT with contrast material as a single radiological diagnostic modality for the assessment of potential live kidney donors.     

Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors

OBJECTIVES: Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. METHODS: From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. RESULTS: A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. CONCLUSION: MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.     

Multispiral computed tomographic angiography of renal arteries of live potential renal donors: a review of 118 cases

OBJECTIVES: Review of the angiographic data of 118 live kidney donors was performed to assess the renal vessel anatomy; compare the findings with the perioperative findings using multislice spiral (MS) computed tomographic angiography (CTA) with the use of 50 mL of intravenous contrast; determine the sensitivity of this technique in the workup of live potential renal donors; and finally to discuss and compare the results of the present study with the reported results using single-slice spiral (SS) CTA, magnetic resonance angiography (MRA), and conventional angiography (CA). METHODS: Retrospective analysis of the angiographic data of 118 of prospective live kidney donors was performed. All donors underwent renal angiography on MSCTA scanning using 50 mL of intravenous contrast with 1.25-mm slice thickness followed by maximum intensity projection and virtual rendering techniques postprocessing algorithms. Analysis was made on imaging and intraoperatively for the number of renal arteries as well as their bifurcation pattern, location, vessel caliber, length, and venous anatomy, and these were then compared with each other. RESULTS: MSCTA showed clear delineation of the main renal arteries in all the donors with detailed vessel morphology. The study also revealed a 100% sensitivity in the detection of accessory renal vessels, which had an overall incidence of 26.67%, with the most common distribution in the perihilar region. CONCLUSIONS: The present study showed a 100% sensitivity and specificity in the visualization and detection of main and accessory renal vessels with the use of only 50 mL of intravenous contrast with similar results seen with CA which has so far been considered the "gold standard." The results on MSCTA were also better than those with the use of SSCTA and MRA in the workup of liver renal donors, with the above technique also proving to be more cost effective. The overall incidence of supernumerary vessels was the same as reported in the literature; however, a higher incidence of single aberrant vessels was seen on the right side, contrary to what has been suggested so far and was attributable to improved detection of accessory vessels less then 2 mm in diameter.     

Utility of CT angiography for evaluation of living kidney donors

We reviewed our initial experience with helical computed tomography (CT) angiography in the evaluation of living kidney donors which, until now, has necessitated arteriography. Nineteen donors (12 women, 7 men) have had their renal anatomy evaluated solely by CT angiography preoperatively.All scans demonstrated normal collecting systems and single ureters. Five donors (26%) had supernumerary renal arteries. Fourteen donors had single, 4 donors had two, and 1 donor had three renal arteries. Helical CT demonstrated small polar vessels in several donors. Two donors (10%) had supernumerary renal veins. Accuracy of vascular anatomy defined on CT was 90% when confirmed at operation. Anatomically all CT findings were consistent with operative findings except in 1 donor who was found to have a 0.8 cm lesion near the renal hilum.At our institution, the total charges for selective renal arteriography are $3845 and for helical CT with three-dimensional (3-D) reconstruction are $1546. The amount of contrast dye (approximately 100 mL) is equivalent. Patients uniformly reported that the CT scan was a convenient and painless procedure.The accuracy of helical CT angiography is equivalent to arteriography in assessing renal vascular anatomy (with the additional benefit of imaging venous and parenchymal anatomy). Charges for helical CT are 59% less. There is greater patient acceptance and potentially less morbidity associated with the non-invasive nature of helical CT. We believe that CT angiography is the radiologic procedure of choice for the assessment of renal anatomy in potential living kidney donors.     

Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors

OBJECTIVE: To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors. SUBJECTS AND METHODS: Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery. RESULTS: CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively. CONCLUSION: Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.     

Evaluation of live renal donors with three-dimensional contrast-enhanced magnetic resonance angiography in comparison to catheter angiography

BACKGROUND: Catheter angiography is traditionally used to determine renal arterial anatomy in live renal donors. Three-dimensional (3D) contrast-enhanced magnetic resonance imaging (MRA) has been suggested as a noninvasive replacement. We assessed the possibility of using MRA in live renal donors in Malaysia. METHODS: Twenty-six consecutive live renal donors were recruited from 2000 to 2002. All potential donors underwent evaluation of the renal arteries using both techniques. Angiographic findings from both modalities were subsequently compared with surgical findings at the time of donor nephrectomy. The total number and diameter of the arteries and the presence of early branching and renal abnormalities were noted. RESULTS: Both angiographic modalities were able to detect multiple renal arteries with catheter angiography having a sensitivity of 100% and MRA a sensitivity of 97%. MRA missed one 1-mm artery due to a low index of suspicion. Renal artery caliber measurements were not significantly different between the two methods. However, both techniques tended to overestimate the caliber of the renal arteries when compared with measurements taken at surgery. Early branching was found in two arteries at the time of surgery, but only one was detected by both techniques. Renal cysts seen on MR were not detected by catheter angiography. CONCLUSIONS: Our findings suggest that noninvasive MRA is a promising substitute for catheter angiography to evaluate the renal arteries of live donors.     

Pre-operative evaluation of living kidney donors using computerized tomographic angiography (CTA) and conventional angiography: comparison with intraoperative findings

This study was undertaken to assess the accuracy of computerized tomographic angiography (CTA) for the evaluation of renal vascular anatomy for pre-operative donor assessment in living kidney transplantation and to compare it with conventional angiography. CTA of 70 living donor kidney donors were analyzed by two blinded observers and compared with the intraoperative findings. Similarly, findings of formal angiography of 30 living donor kidney donors were compared with the intraoperative observations. In the CTA group, there were two patients each with two main renal veins discovered during surgery that had not been recorded on CTA. In the second group, there was one patient with unrevealed two main renal veins before surgery. In both groups, accessory renal arteries were diagnosed. Overall, the accuracy for renal main artery anatomy was 100% for both CTA and conventional angiography. Accuracy for renal main vein anatomy was 97.1% and 96.6% for CTA and conventional angiography, respectively. Hence, these two modalities had comparable results for assessment of main renal vasculature anatomy.     

64层螺旋CT血管成像及三维重建后处理技术对活体供肾血管的评估

目的 评价64层螺旋CT血管成像及三维重建后处理技术对活体供肾血管术前评估的临床价值.方法 回顾性分析2011年1月至2013年3月临沂市人民医院泌尿外科61例亲属活体肾移植供者术前64层螺旋CT血管成像及三维重建影像资料,观察供肾实质、肾动脉、肾静脉和肾盂、输尿管排泄系统,并与术中所见结果进行对照分析.结果 64层螺旋CT血管成像及三维重建图像基本清晰显示所有供者的双肾解剖结构及毗邻关系情况.肾实质密度及肾动脉管径、形态均正常,其中47例双肾均为单支肾动脉,4例左肾为2支肾动脉,5例右肾为2支肾动脉,5例双肾均为2支肾动脉.53例容积再现结合最大密度投影图像对输尿管排泄系统显示较好,49例表面遮盖成像图像较好地显示了肾动脉主干的起源、管径、形态及与周围组织的解剖关系,肾动脉CT仿真内镜成像能清晰显示腹主动脉、双肾动脉开口及肾动脉管腔.61例供者均行单侧肾切除术,术前血管成像结果与术中所见基本吻合.结论 64层螺旋CT血管成像及三维重建后处理技术能真实反映肾血管的解剖及毗邻关系,在某种程度上完全可以替代数字减影血管造影,可作为术前评估活体供肾血管的有效方法.     

100 living-related kidney donor evaluations using digital subtraction angiography

Intravenous digital subtraction angiography (IV-DSA) combined with excretory urography was used to evaluate the renal anatomy of 100 potential living-related kidney donors. Each of the 100 patients underwent subsequent nephrectomy to verify the number and distribution of renal vessels. For the entire series, 71 patients had bilateral single, 2 bilateral multiple and 27 multiple renal arteries on one side determined by angiography. Eleven patients required standard catheter angiography due to inadequate IV-DSA studies. Four patients who had a single artery imaged by IV-DSA were found to have an additional vessel at the operation. The overall accuracy of IV-DSA to identify the number of renal vessels was 96% (85/89). The sensitivity of the exam was 100% (94/94) and the specificity was 67% (4/6). It is concluded that IV-DSA combined with excretory urography is a safe, cost effective, and suitable method to image the renal anatomy of potential kidney donors. Thus about 90% of donors can be spared the risks and inconvenience of standard angiography, and the donor evaluation can now be performed on an outpatient basis.     

16层螺旋CT成像在活体肾移植供体术前评价中的价值

目的 探讨16层螺旋CT成像在活体肾移植供体术前评价中的价值. 方法 36例肾移植供体行16层CT平扫、动脉期、静脉期和排泄期检查.采用最大密度投影和容积再现技术处理图像,2位放射科医师独立评价每个供体血管和集尿系统的解剖结构.活体肾移植术中所见作为标准,计算16层CT评价肾血管和集尿系统的特异性和准确性. 结果 16层CT检查发现变异肾动脉7支,1支外科手术中确诊的副肾动脉被漏诊.16层CT检查正确诊断了外科手术发现的全部肾静脉和输尿管解剖变异,诊断肾动脉、肾静脉和输尿管解剖变异的特异性为100%(29/29)、100%(32/32)和100%(35/35),准确性分别为97%(36/37)、100%(36/36)和100%(36/36). 结论 16层CT检查评价活体移植肾的血管和集尿系统准确性较高,是一种很好的术前评价活体移植肾的无创性检查方法.     

Intravenous digital subtraction angiography in the evaluation of potential renal donors

Of 65 surgically removed donor kidneys intravenous digital subtraction angiography demonstrated accurately the number of renal arteries in 58 (89 per cent). All accessory vessels missed at digital subtraction angiography were small and their presence did not interfere with successful transplantation in those donated. Of 50 surgically removed donor kidneys examined with conventional aortography only before the routine use of intravenous digital subtraction angiography the number of renal arteries was demonstrated accurately in 46 (92 per cent). Intravenous digital subtraction angiography offers advantages over conventional aortography, including most importantly the routine performance on an outpatient basis, and decreased film cost and examination time. Although the accuracy of conventional aortography (92 per cent) in detecting the number of renal arteries is slightly greater than that for intravenous digital subtraction angiography (89 per cent), the advantages of the digital examination justify its use as the initial examination for the potential renal donor. Conventional aortography can be reserved for use in patients with equivocal or technically inadequate digital examinations.     

Evaluation of the vascular anatomy in potential living kidney donors with gadolinium‐enhanced magnetic resonance angiography: comparison with digital subtraction angiography and intraoperative findings

Asgari MA, Dadkhah F, Ghadian AR, Razzaghi MR, Noorbala MH, Amini E. Evaluation of the vascular anatomy in potential living kidney donors with gadolinium‐enhanced magnetic resonance angiography: comparison with digital subtraction angiography and intraoperative findings.
Clin Transplant 2011: 25: 481–485. © 2010 John Wiley & Sons A/S. Abstract: Background: X‐ray contrast arteriography has traditionally been used for pre‐operative evaluation in living kidney donors. However, magnetic resonance angiography (MRA) offers a non‐invasive alternative, which has been considered to be less accurate. This study was performed to determine whether MRA in the pre‐operative investigation of living kidney donors provides sufficient information. Methods: From December 2005 to December 2007, 173 potential live donors were evaluated in this study. Donors performed digital subtraction angiography (DSA) and those with one or more accessory arteries at least on one side recruited for further evaluation with three‐dimensional gadolinium‐enhanced MRA. Results: A total of 30 donors constituted the study population. When compared with DSA as the reference method, MRA detected 20 of 36 renal accessory arteries which indicates a sensitivity of 55.6%. The difference between MRA and DSA in identifying accessory renal arteries was significant (p‐value <0.001). Considering intraoperative findings as the standard of reference, MRA depicted correctly four of six (66.7%) accessory arteries on the transplanted kidneys. Conclusions: MRA has the advantage of avoiding exposure to ionizing radiation and is non‐invasive. These are important considerations in pre‐operative evaluation of a generally healthy donor population. However, MRA provides suboptimal accuracy in detecting small accessory arteries.     

Intravenous digital subtraction angiography and helical computed tomography in evaluation of living renal donors

OBJECTIVES: The present study was carried out to evaluate the accuracy of helical computed tomography (CT) and intravenous digital subtraction angiography (IV-DSA) on anatomical assessment of renal vasculature for living renal donors. METHODS: Forty-two healthy potential renal donors were prospectively evaluated and 35 subsequently underwent donor nephrectomy after helical CT and IV-DSA evaluation. The vascular and non-vascular findings were compared between the findings on helical CT, IV-DSA and surgery. RESULTS: Ten prehilar branches and five accessory renal arteries were found at nephrectomy. Overall, operative findings agreed with the findings by IV-DSA in 89% and by helical CT in 83%. In delineating accessory arteries, IV-DSA had a sensitivity of 60% and specificity of 97%, whereas helical CT had a sensitivity of 40% and specificity of 100%. In delineating prehilar branches, IV-DSA had a sensitivity of 90% and specificity of 100%, whereas helical CT had a sensitivity of 70% and specificity of 100%. Accessory arteries and prehilar branches that were not detected by helical CT or IV-DSA, were less than 2 mm in diameter and did not require vascular reconstruction. Renal veins were delineated in 63% by IV-DSA, whereas they were clearly imaged by helical CT in all cases, including a case with a circumaortic renal vein. Non-vascular findings were obtained in 64% by helical CT, including two renal tumors. None of these findings were obtained by IV-DSA. CONCLUSION: Helical CT and IV-DSA provide comparably sufficient information on renal artery vasculature. However, helical CT provides significantly more information on venous and non-vascular findings as a single-imaging modality.     

Incidence of donor renal fibromuscular dysplasia: does it justify routine angiography?

BACKGROUND: The use of digital subtraction angiography (DSA) versus helical CT angiography (CTA) or MR angiography (MRA) for live renal donor evaluation is still controversial. Although CTA and MRA can detect some proximal moderate to severe arterial changes caused by fibromuscular dysplasia (FMD), mild and distal moderate FMD are not detected well without angiography. METHODS: This is a retrospective chart review of all potential, normotensive live renal donors at our center from July 1995 to June 2001. One hundred fifty-nine patients completed the donor evaluation process and underwent DSA. RESULTS: Seven cases of FMD, an incidence of 4.4%, were discovered. These patients were eliminated from donation. The distribution of renal vessels for our 159 patients was single arteries bilaterally, 64.8%; single left with multiple right, 16.4%; double left with single right, 9.4%; and multiple bilateral arteries, 9.4%. Three of the seven FMD patients had bilateral disease. Two of the seven (28.6%) FMD patients have subsequently required antihypertensive medications, with one requiring angioplasty of a progressive FMD stenotic lesion. CONCLUSIONS: We are concerned that CTA or MRA may overlook mild cases of DSA-detectable FMD. All seven FMD patients had single left renal arteries and would have undergone left donor nephrectomy. This would have resulted in their remaining right native kidneys having mild to moderate FMD in six of seven patients and in four donor kidneys having mild to moderate FMD. The need for antihypertensive medications in two of these seven potential donors within 4 years of their evaluation supports previous literature reports.     

Imaging of hepatic arterial anatomy for depicting vascular variations in living related liver transplant donor candidates with multidetector computed tomography: comparison with conventional angiography

AIMS: The aim of this study was to evaluate liver arteries to depict variations by using multidetector computed tomography (CT) in donor candidates for living related liver transplantation. METHODS: Computed tomographic hepatic angiography was carried out using a multidetector 16-row CT scanner (Sensation 16; Siemens) in 48 candidates between April 2003 and August 2004. Multidetector CT was performed after intravenous injection of 150 mL of contrast material at a rate of 4 mL/s. Arterial phase images were acquired after contrast injection. Afterward, maximum intensity projections and volume-rendered images were produced from the axial image data. Twenty-eight of these patients underwent conventional catheter angiography. RESULTS: Excellent arterial opacification was shown on multidetector CT scans in all patients; arteries up to tertiary branches were identified with CT. Of 28 patients who had both multidetector CT angiography and conventional angiography, only a branch of hepatic artery originating from superior mesenteric artery that supplied the posterior segment of the right lobe was not identified on multidetector CT angiography. In 27 donors, hepatic arterial anatomy depicted at multidetector CT angiography was identical to that at conventional angiography. We identified hepatic vascular variants in 22 of 48 patients with multidetector CT. The most common arterial variant was an accessory hepatic artery arising from the left gastric artery. CONCLUSIONS: Preoperative imaging evaluation of hepatic vascular anatomy is crucial for surgical planning in living related transplant donors. Multidetector CT is useful to depict hepatic arterial anatomy with high accuracy.     

Assessment of the arteries in living kidney donors: correlation of magnetic resonance angiography with intraoperative findings

Comprehensive imaging evaluation of kidney donor anatomy is crucial for selecting candidates for living kidney transplantation and for determining the surgical technique to procure the renal graft. In 76 living renal donors we compared the results of preoperative magnetic resonance angiography (MRA) with the intraoperative findings of arterial anatomy. Donors were evaluated for the number of main renal arteries and the presence of any polar arteries. A total of 80 main renal arteries and five polar arteries were observed at MRA. At surgery, 90 main renal arteries and eight polar arteries were identified. MRA demonstrated a sensitivity, specificity, and overall accuracy of 18%, 98%, and 87%, respectively, for main arteries and 25%, 96%, and 88% for polar arteries. Eleven (14.5%) kidneys displayed more than one main artery and MRA only detected two cases. Eight kidneys had polar arteries and MRA only detected two cases. MRA is a reliable method for presurgical evaluation of renal arteries in potential donors, providing valuable information required by the surgeon. But, as the technique misses small-diameter vessels, it cannot be recommended as the sole diagnostic tool in unclear cases.     

Preoperative evaluation of living kidney donors using multirow detector computed tomography: comparison with digital subtraction angiography and intraoperative findings

To assess the accuracy of multirow detector computed tomography (MDCT) for the evaluation of renal anatomy for preoperative donor assessment in living related kidney transplantation. MDCT-scans (4- and 16-slice-CT) of 51 consecutive living kidney donors (age, 51.6 +/- 9.7 years; range, 28-68 years) were analysed by three blinded observers and compared with digital subtraction angiography (DSA) and surgery. Contrast-enhanced MDCT was performed with 1 mm slice thickness reconstruction interval during arterial and venous phases. Supernumerary renal arteries, veins, early branching of vessels and abnormalities of the ureters were documented. The overall accuracy of computed tomography angiography (CTA) for detection and classification of surgically relevant arterial variants was 97% (99/102). The interpretation of 16-channel MDCT images was correct in all cases (accuracy, 100%), while the four-channel CTA had three incorrect results regarding the differentiation of early branching vessels from double renal arteries (accuracy, 93%). The overall accuracy of DSA was 91%. Renal vein abnormalities were correctly diagnosed with MDCT in 100% compared with 89% correct findings with DSA. There were three kidneys with incomplete ureter duplication, detected both with MDCT and DSA. MDCT demonstrated superior accuracy compared with non-selective DSA for the preoperative assessment of renal anatomy in living kidney donors; and for the distinction of supernumerary arteries versus early branching patterns, 16-channel CTA data were better than those of the four-channel system.     

Outpatient angiographic evaluation of living renal donors

A total of 71 potential living kidney donors was evaluated on an outpatient basis with either a modification of standard catheter angiography (30 patients) or intra-arterial digital subtraction angiography (41 patients). Both procedures provided accurate assessment of the main renal vasculature as proved at the time of donor nephrectomy. Neither technique was associated with any significant morbidity. We conclude that complete angiographic evaluation of potential kidney donors can be performed accurately and safely on an outpatient basis.