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.     

活体供肾术前评估中16层螺旋CT的价值

目的：评价16层螺旋CT三维重建在活体供肾血管、肾实质、泌尿系统评估中的实际应用价值.方法：回顾2004年以来41例活体肾移植供体临床资料,术前均行16层螺旋CT扫描,采集肾动脉期、静脉期以及排泄期的影像数据,采用MIP、VR、MPR和CRP等三维图像后处理技术,评估供体肾动脉、肾静脉、泌尿集合系统和肾实质情况,与术中所见相对照.结果：41例供肾动脉显示,34例双肾单支动脉供血,其中2例左肾动脉、3例右肾动脉分支较早;4例右肾见一支副肾动脉,3例左肾见一支副肾动脉;术中证实有1例右副肾动脉,1例左肾动脉早期分支未能在影像中显示清楚,准确率95.1%.41例供肾静脉显示,37例双肾静脉为单支,4例右侧双支肾静脉;术中证实5例右侧双支肾静脉未能在影像中显示,准确率87.8%;泌尿集合系统显影满意,1例左侧双肾盂双输尿管畸形.结论：16层螺旋CT三维重建能准确显示供体肾脏血管、泌尿集合系统、肾实质解剖及可能的病理情况,给临床肾移植术前评估提供有价值的帮助,可作为供体术前检查的首选方法.     

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.     

The use of spiral computed tomographic angiography for the assessment of living kidney donors

BACKGROUND: Recent reports suggest that spiral computed tomographic (CT) angiography can replace conventional angiography and intravenous urography for the assessment of potential kidney donors. The purpose of this study is to assess the accuracy of spiral CT in potential kidney donor workup. METHODS: Over a period of 1 year, from December 1995 to December 1996, 16 consecutive potential renal donors had intravenous pyelography, percutaneous transfemoral angiography with selective renal angiography and spiral CT angiography. The spiral CT and renal angiograms were assessed independently by two radiologists. The number of renal arteries, presence or absence of renal artery stenoses and associated parenchymal abnormalities were assessed. RESULTS: A total of 39 renal arteries were detected. Conventional transverse scans viewed in a cine loop format detected all 39 vessels, while the maximum intensity projection and shaded surface display demonstrated only 37. All 39 vessels were detected by the catheter angiography. With the exception of one potential donor with fibromuscular dysplasia, 15 donors were accepted. There was 100% accuracy between the two methods of visualization for the renal arteries. A simple renal cyst was noted in both spiral CT and conventional angiogram, while another had gallstones in spiral CT. CONCLUSIONS: Spiral CT angiography performed as an outpatient procedure is less invasive, less expensive, and provides good images of the arterial and venous anatomy. It has the potential to replace conventional catheter angiography and intravenous pyelogram in the assessment of potential renal donors.     

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.     

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%.     

Evaluation of MR-angiography for pre-operative assessment of living kidney donors

INTRODUCTION: Pre-operative magnetic resonance tomography (MR) and MR-angiography (MRA) have rendered favorable results for the assessment of renal anatomy preceding living-related kidney transplantation. However, limited value of MRA in the detection of accessory renal vasculature is reported. METHODS: We compared the results of pre-operative contrast-medium-enhanced MRA of the last 30 consecutively performed nephrectomies in living kidney donors with the intraoperative findings of vascular, parenchymal, and ureteral anatomy. RESULTS: Pre-operative MRA diagnosed a solitary renal artery in 24 cases (80%) and a normal venous, ureteral and parenchymal anatomy in all cases. Intraoperatively, the surgeon confirmed the normal pre-operative MRA findings of ureter and parenchyma. Yet, in 6 out of 30 patients (20%) vascular architecture differed from the pre-operative imaging: four of them, who had a radiologically regular anatomy, were found to have accessory vessels upon surgical preparation. In the fifth patient, MRA revealed an accessory lower polar artery, which was confirmed during surgery. An undiagnosed third arterial vessel, located behind the renal vein, led to an aortic bleeding. In the sixth case, the adrenal gland artery was misinterpreted as an accessory superior polar artery of the kidney in MRA. Additionally, a radiologically undetected inferior polar artery was dissected during nephrectomy and led to partial hypoperfusion of the graft. Subsequent retrospective reevaluation of the MRA by experienced radiologists was unable to identify the intraoperative anatomical discrepancies. Hence, sensitivity of MRA was 60% (6 out of 10 cases) for accessory renal vessel detection and 80% (24 out of 30 cases) for overall sensitivity in determining renal vessel number. DISCUSSION: MRA is a reliable method for the non-invasive investigation of living kidney donors and provides valuable information required by the surgeon. But, as the technique misses small diameter vessels, it cannot be recommended as sole diagnostic tool in unclear cases.     

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.     

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.     

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.     

多排螺旋CT血管成像评价肾动脉变异

目的探讨多排螺旋CT动脉成像（MSCTA）对肾动脉变异的诊断价值。方法分析298例肾动脉CT成像患者的肾动脉变异情况,并对男、女发生率和左、右肾发生率行χ2检验。结果肾动脉解剖变异发生率为60.47%（179/296）,其中单侧发生率为44.59%（132/296）,双侧发生率为15.88%（47/296）;异位开口发生率22.97%（68/296）;副肾动脉、早发支、肾极动脉的发生率分别为36.82%（109/296）、25.00%（74/296）、41.55%（163/296）。男性与女性、左肾与右肾的变异发生率没有明显差异（P〉0.05）。结论 MSCTA能够清晰显示供肾动脉各级分支数目、起点、走行和入肾部位,对于外科手术、尤其是肾移植具有重要的指导意义。     

多层螺旋CT血管成像评估多支肾动脉

目的探讨多层螺旋CT血管成像(MSCTA)评估多支肾动脉的可行性。方法回顾性分析460例患者腹部MSCTA资料,根据横断面图像,结合多平面重建(MPR)、最大密度投影(MIP)和容积再现(VR)等观察多支肾动脉数目、起源、走行、入肾位置及其分型。结果460例中,多支肾动脉发生率为30.65%(141/460),左肾、右肾发生率分别为21.08%(97/460)、17.83%(82/460),差异无统计学意义(P>0.05)。根据CT表现,多支肾动脉Ⅰ型(副肾动脉型)119例(119/460,25.86%),Ⅱ型(多支相仿型)22例(22/460,4.78%),男、女性间多支肾动脉发生率及其分型差异均无统计学意义(P均>0.05)。结论MSCTA可准确评估多支肾动脉并进行分型。     

多层螺旋CT血管成像在后腹腔镜肾蒂淋巴管结扎术中的应用

目的：评价多层螺旋CT血管成像（MSCTA）在后腹腔镜肾蒂淋巴管结扎术中的应用：方法：对3例术前超声诊断肾血管变异和2例未进行血管超声检查的乳糜尿患者,在后腹腔镜肾蒂淋巴管结扎术前行MSCTA肾血管扫描,比较MSCTA发现和术中所见,评价MSCTA检查对手术的指导意义。结果：5例MSCTA显示的血管数目、走行完全与术中所见一致。在MSCTA的指引下,2例患者肾脏的正常血管和3例患者的主要血管、变异血管被快速定位,血管周围淋巴管被顺利结扎。5例患者均顺利进行后腹腔镜手术治疗,无肾血管损伤。无血管畸形患者平均手术时间（67．5±17．7）min,肾血管畸形患者平均手术时间（91．7±22．5）min。术后乳糜尿消失。结论：MSCTA对后腹腔镜肾蒂淋巴管结扎术有重要的指导意义,特别是在肾血管存在变异的患者。     

MSCTCTA与DSA诊断肾癌的应用对照研究

目的探讨多层螺旋CT血管成像（MSCTA）与选择性肾动脉数字减影血管造影（DSA）对诊断肾癌的应用价值。方法对26例病理证实的肾癌患者的MSCTA与选择性肾动脉DSA影像特征进行对照分析。结果MSCTA对肾癌的肿瘤血供类型、肿瘤供血动脉来源的诊断符合率和肾动脉解剖显示正确率达到96．15％。选择性肾动脉DSA对肾癌的肿瘤血供类型、肿瘤供血动脉来源的诊断合率和肾动脉解剖显示正确率达到92．31％（P〉0．05）。结论MSCT（CTA）与DSA对诊断肾癌都具有较高的临床诊断价值；对指导肾癌的介入与外科手术治疗，MSCTA具有更高的实用价值。     

多层螺旋CT血管造影在血管压迫所致肾盂输尿管连接部梗阻中的诊断价值

目的探讨多层螺旋CT血管造影（CTA）对血管压迫所致肾盂输尿管连接部梗阻（UPJO）中的诊断价值。方法分析手术证实的16例血管压迫所致UPJO患者的CT血管造影图像,观察有无肾脏血管变异,肾盂输尿管连接部周围有无骑跨血管、血管的起源、大小及其与UPJO间的关系。结果16例UPJO中,肾动脉解剖变异12例,肾静脉解剖变异3例。CTA16例见19支血管压迫,其中动脉血管15支,静脉血管4支。单支血管压迫13例,双支血管压迫3例,包括副。肾动脉12例,迷走动脉3例,性腺静脉2例,副肾静脉2例。均与手术病理相吻合。结论多层螺旋CTA不但能够了解肾脏血管解剖及变异,并且在血管压迫所致UPJO的诊断及手术治疗方面具有重要价值。     

亲属活体肾移植供肾副肾动脉的处理及临床疗效分析

目的  探讨亲属活体肾移植供肾副肾动脉的处理及其临床疗效。方法  回顾性分析277例亲属活体肾移植供、受者的临床资料。根据术前CT血管造影（CTA）结果选择供肾,并在术中处理供肾副肾动脉。总结供者术中情况,受者术中处理、术后并发症情况及预后情况。结果  277例肾移植中,术前CTA检查发现83例供者存在副肾动脉,CTA判断准确率为95%。获取有副肾动脉的供肾58例,25例供肾副肾动脉经过血管修整重建吻合后,除1例与腹壁下动脉吻合者在关腹时发现吻合口血栓形成外,其余24例均吻合成功,血流充盈良好。术后均未发生出血、移植肾栓塞、输尿管坏死、尿瘘等并发症。移植受者和移植肾的1年存活率分别为94%和91%。单支肾动脉供肾与有副肾动脉供肾其受者的临床疗效比较,差异无统计学意义（P > 0.05）。结论  选择合适供肾,经血管修整重建吻合移植肾副肾动脉,可获得良好移植效果。     

Multidetector CT angiography in live donor renal transplantation: experience from 156 consecutive cases at a single centre

The performance of multidetector computed tomography (CT) angiography was assessed in the pre-operative evaluation of live renal donors. Between July 1998 and March 2006, 156 consecutive patients underwent open donor nephrectomy following pre-operative multidetector CT angiography (MDCTA). Operative notes were compared with radiological reports and discrepancies identified. MDCTA missed five of 28 accessory arteries (four visible with hindsight), accuracy of 96%. Of 30 early-branching renal arteries, eight were missed (all visible with hindsight), accuracy 95%. MDCTA missed only one of 13 venous anomalies (accuracy 97%) and also missed the only duplicated collecting system: both were undetectable with hindsight. Following modifications to image acquisition and interpretation sensitivity, negative-predictive value and accuracy were significantly increased. The results were compared with pooled data from published studies of live donor imaging. This study and previous studies of MDCTA had improved sensitivity for arterial and venous anomalies over single detector CT angiography and MR angiography. We conclude that multidetector CT angiography is an accurate modality in the pre-operative evaluation of live renal donors. Regular communication between the transplant surgeon and the radiologist is paramount to improve reporting of surgically relevant anatomy. Mechanisms should exist for auditing and improving pre-operative imaging in any live donor programme.     

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 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.