Preoperative evaluation of living renal donors with gadolinium-enhanced magnetic resonance angiography

BACKGROUND: Preoperative evaluation of living renal donors includes an intra-arterial digital subtraction angiography (DSA). Inasmuch as this technique is invasive, uses radiation and an iodine-containing contrast medium, an alternative technique would be preferable. The purpose of this study was to determine the accuracy of gadolinium-enhanced magnetic resonance (MR) angiography in the visualization of renovascular anatomy for the preoperative evaluation of renal donors. METHODS: Twenty-four consecutive potential renal donors underwent gadolinium-enhanced MR angiography before the standard of reference, intra-arterial DSA. Both modalities were evaluated in a blinded manner. The results were correlated with the surgical findings. RESULTS: Three MR angiograms were technically unacceptable because of inadequate breath-hold. The remaining 21 donors had 47 renal arteries, including 5 accessory renal arteries, which were all visualized by MR angiography. MR angiography failed to visualize one case of subtle fibromuscular dysplasia in the distal part of a renal artery. In one donor, a small accessory renal artery, which had not been visualized on DSA, was encountered during nephrectomy. CONCLUSION: Gadolinium-enhanced MR angiography is an accurate minimally invasive method for the detection of accessory renal arteries in the preoperative evaluation of potential renal donors. The accuracy for excluding stenosis in general is high; however, the depiction of stenosis that are located far distally, or in the branch vessels, is less accurate. Advantages of gadolinium-enhanced MR angiography over the currently used method, intra-arterial DSA, are the minimal invasive nature, lower costs, and superiority in detecting venous anomalies, renal cysts, and tumors.     

Gadolinium-enhanced three-dimensional magnetic resonance angiography versus conventional digital subtraction angiography: which modality is superior in evaluating living kidney donors?

This study evaluates the correlation of magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) with the operative vessel findings in living kidney donors. The intraoperative vessel findings of 52 living renal donors were compared with the preoperative diagnoses of each imaging technique. Sixty-seven arteries were found during explantation. Forty kidneys showed a single arterial blood supply, and 12 kidneys showed a multiple arterial blood supply. No advantage of either imaging method was found for arterial imaging. There were 55 veins identified during organ harvesting. MRA could not determine the venous system in one donor (1.9%) and failed to detect one small pole vein in another. DSA did not yield a venous diagnosis in seven patients (13.5%) and yielded misdiagnoses in four patients. The correct diagnosis of renal donor veins differed significantly in favor of MRA (kappa 0.79 vs. 0.45; P=0.008). MRA is superior to DSA in assessing the renal vasculature in living kidney donors.     

Can magnetic resonance angiogram be a reliable alternative for donor evaluation for laparoscopic nephrectomy?

BACKGROUND: While hand-assisted laparoscopic donor nephrectomy (HLDN) is less invasive, which can encourage kidney donation, it requires more exact information about the renal vascular anatomy because of its limited visual field during nephrectomy. MRA is also an attractive choice because of its minimal invasiveness; further, it is an outpatient-based procedure, it uses non-nephrotoxic contrast material and it has no radiation. The aim of our study was to evaluate the effectiveness of gadolinium enhanced three-dimensional MRA (GdE-3D MRA) in a group of potential live donors who were candidates for HLDN. METHODS: From September 2002 to December 2004, 40 potential live renal donors were evaluated prospectively with GdE-3D MRA, and this imaging modality was performed before the gold standard, the intra-arterial digital subtraction angiogram (IA-DSA), was carried out. All the images were reviewed in a blinded manner by the attending vascular radiologist. The MRA findings were compared with the DSA findings and the surgical findings as the reference methods. We evaluated the accuracy of MRA for imaging the renal architectures, and especially for imaging the renal accessory arteries and the early branching arteries that are important determinants for selection of the donor kidney. RESULTS: Both the MRA and DSA images showed consistent findings with the surgical findings in 92.5% of the 40 donors. There were no discrepant cases in depicting the main renal artery. MRA showed 100% specificity for imaging both the renal accessory arteries and the early branching arteries, when compared with the surgical findings. The kappa values for the MRA and DSA for the accessory arteries were all 0.66 compared with the intraoperative findings. MRA also depicted one huge renal cyst in one donor and many small renal cysts in the other donors that could not be imaged by DSA. There were no adverse events during the MRA procedure. None of the findings missed by MRA resulted in deleterious consequences at laparoscopic nephrectomy for the donor and graft. CONCLUSIONS: Our limited experience with GdE-3D MRA for imaging the renal structures in kidney donor evaluation for HLDN has been quite satisfactory.     

Magnetic resonance angiography for preoperative evaluation of potential kidney donors

BACKGROUND: Careful evaluation of the renovascular anatomy for living kidney donors is essential to optimize donor and recipient outcomes. Arteriography has been the standard for delineating the renovascular anatomy. However, this procedure is invasive. Magnetic resonance angiography (MRA) is an attractive, noninvasive alternative. The aim of this study was to evaluate the accuracy of MRA in potential living kidney donors. METHODS: A retrospective comparison of the preoperative MRA results with the intraoperative anatomy was performed in 189 living kidney donors. RESULTS: MRA interpretations correctly identified the vascular anatomy of the donor kidneys in 173 donors (91.5%). In the remaining 16 patients (8.5%), the MRA interpretation was inaccurate. In 10 patients, the MRA reported fewer arteries than the number encountered during the donor operation, whereas in six patients MRA reported more arteries than what found during operation. In seven patients, MRA supplied additional important anatomical information, including kidney size disparity, the presence of nephrolithiasis, the presence of a renal cyst, and renal artery stenosis. All kidneys were successfully transplanted. The misinterpretation of the MRA did not adversely affect the recipient outcome. CONCLUSION: The noninvasive MRA evaluation of donor renovascular anatomy is an acceptable substitute for traditional angiography.     

Assessment of live kidney donors by magnetic resonance angiography: reliability and impact on outcomes

Abstract: Background:  Kidney allograft retrieval from live donors requires accurate determination of kidney anatomy prior to surgery, particularly the arterial supply. Traditionally, conventional angiography has been used to obtain this information. Magnetic resonance angiography (MRA) offers a non-invasive, cost-effective alternative, but has been considered to be less accurate. Despite this criticism, many centers have moved to MRA screening of potential kidney donors. The objective of this study is to evaluate our experience of the reliability of MRA in determining the arterial anatomy of living kidney donors as compared to the intra-operative findings.
Methods:  We performed a retrospective review of gadolinium-enhanced, ultra-fast, three-dimensional, spoiled gradient-echo MRA in live kidney donors in the Southern Alberta Transplant Program and compared these results with the intra-operative findings during nephrectomy, as the gold standard.
Results:  Of the 66 patients, an accessory renal artery was found intra-operatively in eight cases; two of which were erroneously diagnosed as normal by MRA. The negative predictive value for MRA was 0.97, false-negative rate was 0.25, and sensitivity was 0.75. No patient experienced side-effects from the MRA procedure. No donor needed conversion to open nephrectomy because of an undetected accessory renal artery. One allograft with an accessory renal artery developed thrombosis of the lower pole of the kidney despite arterial reconstruction. Kidney function in the recipient of this allograft was excellent and there was no urinary leak.
Conclusion:  In our hands, MRA determined the vascular anatomy of potential kidney donors with an acceptable negative predictive value of 97%.     

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.     

Evaluating patients with renal failure for renal artery stenosis with gadolinium-enhanced magnetic resonance angiography

The incidence and prevalence of end-stage renal disease (ESRD) continues to increase, especially in the elderly population. The role of renovascular disease in contributing to ESRD is still not well defined. The objective of this study was to determine the utility of gadolinium (Gd)-enhanced magnetic resonance angiography (MRA) in evaluating elderly patients with renal insufficiency for renal artery stenosis (RAS). A 7-month prospective study conducted in a tertiary referral center evaluated 40 consecutive patients with progressive renal insufficiency (18 men and 22 women; mean age, 70 +/- 5.6 [standard deviation] years) and high clinical suspicion for renovascular disease with Gd-enhanced MRA. Digital subtraction angiography (DSA) was obtained in only those patients with significant RAS detected by MRA. Twelve patients had significant RAS. Six of these patients had percutaneous transluminal renal angioplasty (PTRA), five patients had renal artery bypass surgery, and one patient had a stent placed after PTRA. Seventy-eight renal arteries were satisfactorily evaluated by MRA. Twenty-two renal arteries were evaluated by both MRA and DSA. Of the 12 significant stenoses detected by the MRA, 11 were confirmed by DSA and 1 was confirmed at the time of surgical revascularization. It is concluded that Gd-enhanced MRA is a useful test for the evaluation of RAS in patients with compromised renal function.     

False-negative magnetic resonance angiography with extracranial internal carotid artery stenosis

Magnetic resonance angiography (MRA) is increasingly used as a noninvasive means to assess internal carotid artery (ICA) stenosis. When used alone, however, MRA may not be sufficiently accurate in certain settings to determine whether ICA disease meets surgical criteria. Although MRA has been recognized to overestimate the degree of stenosis, the authors present two cases in which it severely underestimated arterial stenosis. Two male patients, 70 and 40 years old, respectively, were admitted with crescendo transient ischemic attacks. Their MRA studies suggested nonsurgical lesions of the ICA. After the patients continued to demonstrate clinical evidence of embolic disease, digital subtraction angiography (DSA) was performed on one patient, and the other received a gadolinium contrast-enhanced MRA. These tests revealed critical stenosis in each patient. Each was taken to the operating room for awake carotid endarterectomy with heparin anticoagulation and electroencephalographic monitoring. At surgery, both patients were found to have severely stenosed ICAs with complex plaques. MRA to determine whether ICA stenosis meets surgical criteria may not be sufficiently accurate in certain clinical settings. Additional imaging studies, such as confirmatory digital ultrasonography, MRA with gadolinium contrast, or DSA, may be required to determine the extent of carotid artery stenosis accurately.     

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.     

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.     

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.     

Pre-donation Assessment of Kidneys by Magnetic Resonance Angiography and Venography: Accuracy and Impact on Outcomes

Reports on the accuracy of magnetic resonance angiography (MRA) and magnetic resonance venography (MRV) in evaluating living donor renovasculature employ few patients or omit the consequences of inaccurate scans. We retrospectively compared intraoperative findings to MRA/MRV scans in 146 donor–recipient pairs. For detecting accessory arteries and early branching, MRA sensitivity was 57.6%, specificity 96.5%, false positive rate 3.5%, false negative rate 42.4%, positive predictive value 82.6%, negative predictive value 88.6% and overall accuracy 87.7%. By excluding clinically inconsequential accessory arteries, MRA sensitivity rose to 73.1%, specificity to 96.7% and overall accuracy to 92.5%. For MRVs, sensitivity was 56.2%, specificity 99%, false positive rate 1%, false negative rate 43.8%, positive predictive value 90%, negative predictive value 94.8% and accuracy 94.5%. Inaccurate scans were associated with prolonged donor and recipient operations and more frequently reconstructed arteries, but did not affect clinical outcomes. Because most missed accessory arteries are inconsequential, MRA is a useful, less invasive method for defining donor renovascular anatomy.     

Comparison of computerized tomography angiography and digital subtraction angiography in ruptured cerebral aneurysm surgery

Objective: The aim of the present study was to review the efficacy of 16‐row multislice computerized tomography angiography (CTA) in ruptured cerebral aneurysm surgery by comparison with conventional digital subtraction angiography (DSA). Methods: A systemic review of patients suffering from ruptured cerebral aneurysm was performed. We report the results obtained during the 19‐month period from April 2003 to October 2004. In total, 32 patients had undergone aneurysm surgeries, in which 11 patients had both DSA and CTA performed. Results: Among the 11 patients with both DSA and CTA performed, two aneurysms were missed in DSA in two patients. The sensitivity and specificity of CTA were 100%. The correlation of CTA with DSA in operative findings was 100%. Our CTA could detect the aneurysm size down to 2 mm in diameter. Conclusion: The diagnostic accuracy of 16‐row multislice CTA is promising and it compares well with DSA for detection and evaluation of ruptured cerebral aneurysms. It is safe and effective to establish treatment decision on the basis of CTA alone in the majority of cases.     

Imaging Modalities for Renal Artery Stenosis in Suspected Renovascular Hypertension: Prospective Intraindividual Comparison of Color Doppler US,CT Angiography,GD-Enhanced MR Angiography,and Digital Substraction Angiography

The aim of the study was to evaluate the diagnostic accuracy of Color Doppler US, CT Angiography (CTA), and GD-enhanced MR Angiography (MRA) compared with digital subtraction angiography (DSA) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. Fifty-eight patients with suspected renovascular hypertension were enrolled in the study. All patients underwent Color Doppler US, CTA and GD-enhanced MRA. DSA was the gold standard method for the number of renal arteries, existence and degree of stenosis, or evidence of fibromuscular dysplasia. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. Color Doppler US failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and positive and negative predictive accuracy were 75%, 89.6%, 60% and 94.6%, respectively, for color Doppler US; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for GD-enhanced MRA. CTA and GD-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions.     

Imaging modalities for renal artery stenosis in suspected renovascular hypertension: prospective intraindividual comparison of color Doppler US, CT angiography, GD-enhanced MR angiography, and digital substraction angiography

The aim of the study was to evaluate the diagnostic accuracy of Color Doppler US, CT Angiography (CTA), and GD-enhanced MR Angiography (MRA) compared with digital subtraction angiography (DSA) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. Fifty-eight patients with suspected renovascular hypertension were enrolled in the study. All patients underwent Color Doppler US, CTA and GD-enhanced MRA. DSA was the gold standard method for the number of renal arteries, existence and degree of stenosis, or evidence of fibromuscular dysplasia. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. Color Doppler US failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and positive and negative predictive accuracy were 75%, 89.6%, 60% and 94.6%, respectively, for color Doppler US; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for GD-enhanced MRA. CTA and GD-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions.     

Digital subtraction angiography for renal donor evaluation

A consecutive series of 52 living related renal donors were evaluated preoperatively by angiography. The preoperative angiographic interpretation was compared with the anatomy found at donor nephrectomy. Standard selective renal arteriography was found to be 100 per cent accurate in defining single (25) or multiple (1) renal arteries. Digital subtraction angiography (DSA) alone performed with an intra-arterial injection of contrast material was found to be 82 per cent accurate in determining the number of renal arteries. In five kidneys with multiple renal arteries, only two had the correct number of vessels identified. The errors are inherent in the DSA technology. DSA at the present time is not accurate enough to replace the standard arteriogram in the evaluation of the donor nephrectomy patient.     

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.     

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.     

Multi-detector row CT scanner angiography in the evaluation of living kidney donors

Renal vascular anomalies are frequent and are not usually problematic, especially when they have been identified and localised with preoperative imaging; computed tomography angiography is a fast and minimally invasive procedure that may afford accurate visualisation of arterial and venous anatomy. We report on our experience with the utilisation of multi-detector row angiography in the preoperative evaluation of living kidney donors. Nineteen living kidney donors underwent multidetector row scan angiography with 3D post-processing. The subjects were 12 male and 7 female donors with a mean age of 60 years. Renal vascular anomalies were identified in 52.6% of donors. A total of 10 supernumerary arteries were identified. Surgical correlation was available for 19 kidneys (17 left and 2 right). The donated kidneys were selected on the basis of CT scan and renal function. CT scan identified all 29 arteries including 10 double right or left arteries (100% specificity and sensitivity). Dual multi-phase multi-detector row CT angiography is a minimally invasive and highly accurate method for preoperative evaluation of renal donors. It affords comprehensive depiction of the arterial and venous anatomy of the kidney, which is particularly critical for planning and performing the donor nephrectomy, especially via a laparoscopic approach.     

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.