Donor renal angiography: its influence on the decision to use the right or left kidney

Protean Drainage Patterns of the Left Renal Vein: A Cadaveric and Retrospective Clinical Study on the Surgical Implications and Technical Feasibility

BACKGROUND

The diverse drainage patterns of the left renal vein (LRV), often with asymptomatic congenital anomalies, present considerable challenges in renal and retroperitoneal surgical contexts. The potential for significant bleeding and subsequent renal compromise upon vascular injury highlights the need for increased surgical awareness.

OBJECTIVE

This study investigates the LRV's variable anatomical drainage patterns and morphometry. It also evaluates the embryological factors contributing to these variations and discusses their surgical implications and technical considerations.

METHODS

Anatomical dissections were conducted on 21 adult human cadavers within the Department of Anatomy. Concurrently, a retrospective analysis was conducted on 15 patients who underwent various retroperitoneal surgical interventions in the Urology Department. Demographic variables and intraoperative findings were recorded and analyzed.

RESULTS

Dissection analysis predominantly identified preaortic LRVs in 18 cadavers. Notable anatomical variations included a circumaortic left renal vein (CLRV), a delayed preaortic confluence of extrahilar duo LRVs, and an extrahilar tetramerous confluence with a retroiliac topography. The majority of LRVs usually end in the inferior vena cava. However, an extrahilar tetramerous variant had an unusual drainage pathway. Out of 15 cases, three (20%) had a retroaortic left renal vein (RLRV). One patient with a nonfunctioning kidney had type 1 RLRV, and another patient with pelvic ureteric junction obstruction had type 4 retroiliac left renal vein (RILRV). In both of these patients, symptoms were relieved after surgery. In a young patient with left varicocele and microscopic hematuria who had type 2 RLRV, symptoms resolved spontaneously after a few months.

CONCLUSION

A thorough understanding of the variable anatomical drainage patterns of the LRV is crucial for surgeons. Accurate preoperative identification can provide valuable insights, potentially leading to improved surgical outcomes in renal procedures.

Is a Retroaortic Vein a Risk Factor in Laparoscopic Living Donor Nephrectomy?

INTRODUCTION

In living donor transplantation choosing the right donor and donor side for laparoscopic donor nephrectomy is a challenging task in clinical practice. Knowledge about anomalies in renal blood supply are crucial to evaluate the feasibility of the operative procedure. Few data so far exist whether the existence of a retroaortic left renal vein has an impact on living kidney transplantation outcome for donor and recipient.

MATERIALS AND METHODS

We retrospectively analyzed 221 patients who underwent laparoscopic living donor nephrectomy between 2011 and 2017 for existence of a retroaortic left renal vein. Clinical characteristics and operative outcomes for donors and recipients were analyzed.

RESULTS

221 patients underwent donor nephrectomy between 2011 and 2017; 11 patients (4.98%) showed the feature of a retroaortic left renal vein, and in 8 patients (72.7%) out of those 11 the left kidney was chosen for transplantation. Mean preoperative serum creatinine was 0.77 (0.49-0.98) mg/dL and 1.28 (0.97-1.64) mg/dL at discharge. In recipients mean serum creatinine preoperatively, after 1 week, 1 month,1 year, 2 and 3 years of follow-up was 10.36 (6.09-20.77) mg/dL, 1.71 (0.67-2.72), 1.33 (0.70-1.89), 1.31 (0.95-2.13), 1.31 (0.98-2.13) and 1.33 (1.03-1.84), respectively. Neither donors nor recipients suffered from any operative complications.

CONCLUSIONS

Laparoscopic living donor nephrectomy of a left kidney with retroaortic renal vein is safe for the donor, without limitation in the outcome for the recipient.

Laparoscopic donor nephrectomy in unusual venous anatomy - donor and recepient implications

OBJECTIVES

Laparoscopic donor nephrectomy is now a commonly performed procedure in most of renal transplantation centers. However, the suitability of laparoscopy for donors with abnormal venous anatomy is still a subject of debate.

MATERIALS AND METHODS

Between August 2007 and August 2014, 243 laparoscopic donor nephrectomies were performed in our institution. All donors were evaluated with preoperative three-dimensional spiral computed tomography (CT) angiography Thirteen (5.35%) donors had a left renal vein anomaly. A retrospective analysis was performed to collect donor and recipient demographics and perioperative data.

RESULTS

Four donors had a type I retroaortic vein, seven had type II retroaortic vein and a circumaortic vein was seen in three donors. The mean operative time was 114±11 minutes and mean warm ischemia time was 202±12 seconds. The mean blood loss was 52.7±18.4mL and no donor required blood transfusion. Mean recipient creatinine at the time of discharge was 1.15±0.18mg/dL, and creatinine at six months and one year follow-up was 1.12±0.13mg/dL and 1.2±0.14mg/dL, respectively. There were no significant differences in operative time, blood loss, warm ischemia time, donor hospital stay or recipient creatinine at 6 months follow-up, following laparoscopic donor nephrectomy in patients with or without left renal vein anomalies.

CONCLUSION

Preoperative delineation of venous anatomy using CT angiography is as important as arterial anatomy. Laparoscopic donor nephrectomy is safe and feasible in patients with retroaortic or circumaortic renal vein with good recipient outcome.

Influence of Renal Angiography in Living Potential Kidney Donors

The angiograms of 258 potential kidney donors were retrospectively reviewed to assess the influence of angiography for deciding whether or not to accept the potential donor for nephrectomy and which kidney to use for transplantation. Twenty-five potential donors were rejected. In only 8 of these was angiography necessary to reveal the pathology. Angiography was found to be important in deciding which kidney to donate. In 81 donors the right kidney was used for donation and in 50 this decision was based on findings at angiography.

Anomalies of the inferior vena cava and renal veins and implications for renal surgery

Abnormalities of the inferior vena cava (IVC) and renal veins are extremely rare. However, with the increasing use of computed tomography (CT), these anomalies are more frequently diagnosed. The majority of venous anomalies are asymptomatic and they include left sided IVC, duplicated IVC, absent IVC as well as retro-aortic and circumaortic renal veins. The embryological development of the IVC is complex and involves the development and regression of three sets of paired veins. During renal surgery, undiagnosed venous anomalies may lead to major complications. There may be significant hemorrhage or damage to vascular structures. In addition, aberrant vessels may be mistaken for lymphadenopathy and may be biopsied. In this review we discuss the embryology of the IVC and the possible anomalies of IVC and its tributaries paying particular attention to diagnosis and implications for renal surgery.

Prospective Evaluation of the Accuracy of MDCT Angiography for Living Kidney Donor

PURPOSE

In donor nephrectomy, it is important to understand the exact anatomy of the blood vessels during minimally invasive surgery. We prospectively analyzed the accuracy of the vessel structures obtained by use of 64-row multi-detector computed tomography (MDCT) angiography compared with the actual vessel structure observed during surgery.

MATERIALS AND METHODS

We analyzed 238 patients who underwent donor nephrectomy from July 2007 to August 2010. Before the operation, MDCT angiography was performed, and after the operation, the surgeons themselves wrote the protocol. The ipsilateral artery, the number of veins, the association with the run of the hilar vessel, and other vascular anomalies in computed tomography (CT) angiography and in the donor protocol were summarized.

RESULTS

Among 238 patients, nephrectomy was performed on the left side in 199 patients. The accuracy of MDCT for the artery and the vein was 93.3% and 92.4%, respectively. Accuracy did not differ significantly on the left and right sides (artery: p=0.124; vein: p=0.174). In 199 patients, the CT findings for the lumbar vein were compared with the surgical findings. The overall accuracy was shown to be 84.9%, and the accuracy of the group drained to the inferior vena cava (54%) was significantly different (p<0.01) from that of the group drained to the renal vein (98.6%). Thus, it may be necessary to pay close attention to the interpretation of the findings for the lumbar vein.

CONCLUSIONS

MDCT angiography is important for understanding the exact anatomy of blood vessels before minimally invasive surgery. We showed that 64-channel MDCT has high accuracy in the main vessel and hilar vessels. However, close attention to the interpretation of the CT findings for the lumbar vein may be required.

Retroperitoneoscopic donor nephrectomy for retroaortic renal vein draining into left common iliac vein

Laparoscopic donor nephrectomy (LDN) for both retroaortic and circumaortic veins is described. LDN for left retroaortic vein draining into the common iliac vein (CIV) is not described previously. We report 2 cases of laparoscopic harvesting of left kidney having retroaortic renal vein draining into the left CIV and successful transplantation.

Evaluation of Renal Transplant Donors with 16-Section Multidetector CT Angiography: Comparison of Contrast Media with Low and High Iodine Concentrations

PURPOSE

To compare the degree of contrast enhancement, image quality, and accuracy of renal computed tomographic (CT) angiography performed with a 16-detector row CT unit and equal iodine doses of low- and high-iodine-concentration contrast medium in the evaluation of renal transplant donors.

MATERIALS AND METHODS

Eighty donors scheduled to undergo renal CT angiography with 16-detector row CT were administered nonionic contrast media with two iodine concentrations. The first group (group A, n=40) received a contrast medium with 300 mg of iodine per milliliter, and the second group (group B, n=40) received a contrast medium with 370 mg of iodine per milliliter. An equal iodine dose of 550 mg per kilogram body weight was given to both groups. Contrast enhancement was quantified by measuring attenuation in the abdominal aorta and in both renal arteries. Subjective assessment of contrast enhancement, quality of reformatted images, and visualization of branch order of renal arteries were rated with a 5-point scale. The number of renal arteries and veins seen at CT was correlated with the results at surgery.

RESULTS

The mean enhancement values in group B were significantly greater (P<.001) than those in group A. The mean HU (+/-standard deviation) in groups A and B were 298+/-76 and 344+/-75, respectively, in the aorta, 284+/-74 and 331+/-71 in the right renal artery, and 285+/-72 and 329+/-73 in the left renal artery. The mean enhancement, image quality, and branch orders visualized were rated better in group B than in group A (P<.01). The accuracies for correctly identifying renal arteries and veins, respectively, were 91% and 95% for group A and 96% and 96% for group B.

CONCLUSION

Renal donor CT angiography with a contrast medium of 370 mg of iodine per milliliter provides greater enhancement and image quality compared with a contrast medium of 300 mg of iodine per milliliter. The diagnostic accuracies were similar.

Routine left robotic-assisted laparoscopic donor nephrectomy is safe and effective regardless of the presence of vascular anomalies

The classic approach to donor nephrectomy consists of preferential procurement of the kidney without vascular anomalies. We studied the effect of routine procurement of the left kidney regardless the presence of multiple arteries on the outcomes of robotic-assisted laparoscopic living donor nephrectomy (LLDN) with particular reference to the incidence of urological complications. From August 2000 to July 2005, 209 left LLDNs were performed. We analyzed the outcomes of donors and recipients in relation to the presence of multiple vessels versus normal anatomy. We divided the patients into two groups: group A (n = 148) with normal vascular anatomy and group B (n = 61) with vascular anomalies. In the donors, no significant difference in conversion to open surgery rate, blood loss, length of stay, was noted between the two groups; operative time and warm ischemia time were slightly higher in group B. One-year patient survival was 98% in both groups while the 1-year graft survival was 96.6% in group A and 96% in group B. Only one urological complication was noted in the group with normal anatomy (0.7%) versus none in the group with multiple arteries. Left kidney procurement using robotic-assisted laparoscopic technique is safe and effective, even in the presence of vascular anomalies.

Correlation of preoperative three-dimensional magnetic resonance angiography with intraoperative findings in laparoscopic renal surgery

BACKGROUND AND PURPOSE

Contrast-enhanced three-dimensional magnetic resonance angiography (3D-MRA) with image reconstruction has important applications in laparoscopic urologic surgery. We now use 3D-MRA as part of our preoperative evaluation in selected patients undergoing laparoscopic donor nephrectomy, pyeloplasty, radical nephrectomy, and partial nephrectomy.

PATIENTS AND METHODS

From June 2001 to December 2002, 50 patients underwent preoperative 3D-MRA at 1.5 T prior to laparoscopic renal surgery. In general, preoperative 3D-MRA was obtained for donor nephrectomies and pyeloplasties and for cases where prior imaging suggested a possible vascular anomaly. Patients who underwent preoperative imaging included those having donor nephrectomy (N = 28), pyeloplasty (N = 12), radical nephrectomy (N = 5), partial nephrectomy (N = 3), and other laparoscopic renal procedures (N = 2). The 3D-MRA studies were interpreted by one radiologist, and all laparoscopic cases were performed by one of two surgeons. The findings of 3D-MRA were correlated with the intraoperative findings with special attention to aberrant vasculature, including duplicated renal arteries or veins, accessory vessels, or crossing vessels.

RESULTS

Among patients undergoing laparoscopic donor nephrectomy, 3D-MRA correctly predicted the number of renal vessels in 27 of 28 cases (96%), including all 3 cases of left retroaortic renal vein. Also, 3DMRA correctly predicted the presence or absence of a crossing vessel in 10 of 12 cases (83%) of laparoscopic pyeloplasty. The imaging study also correctly predicted the number of hilar vessels in all five cases of radical nephrectomy, all three cases of partial nephrectomy, and both cases of other renal operations. Overall, 3D-MRA correctly defined the renal hilar anatomy in 48 of 50 patients, for an overall accuracy of 96%.

CONCLUSIONS

Three-dimensional MRA findings correlate well (96%) with intraoperative findings in laparoscopic renal surgery. The imaging study provides exquisite vascular detail and is highly accurate, making it sufficient imaging prior to laparoscopic donor nephrectomy and useful for pyeloplasty and other complex renal operations.

Multi-detector row CT in evaluation of 94 living renal donors by readers with varied experience

PURPOSE

To retrospectively assess the accuracy of four-section multi-detector row computed tomography (CT) in the evaluation of renal transplant donors when scans are read by one of multiple readers with varied levels of expertise, by using surgery as the reference standard.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board and complied with the Health Insurance Portability and Accountability Act. Informed consent was waived. Between October 1999 and March 2003, 94 renal donors (42 men, 52 women; mean age, 44 years) underwent four-section multi-detector row CT. Unenhanced scanning of the abdomen was performed with 5-mm section thickness and table speed of 15 mm per rotation. Next, 135-150 mL of nonionic iodinated (300 mg/mL) contrast material was injected intravenously at a rate of 4-5 mL/sec. Contrast material-enhanced CT was initiated 20-25 seconds, 65-70 seconds, and 10 minutes after start of injection. Arterial phase scanning was performed with 1.25-mm section thickness and 7.5-mm table speed. Venous and excretory phase scanning was performed with 2.5-mm section thickness and 15-mm table speed. Each scan was evaluated independently by one of 11 readers for renal vascular and ureteral anatomic variants. Findings at CT were compared with those at surgery. Sensitivity and specificity (with 95% confidence intervals) and accuracy of CT were calculated on the basis of presence or absence of variant anatomy at surgery.

RESULTS

CT depicted 107 of 114 renal arteries confirmed at surgery; seven accessory arteries were missed in six donor kidneys. CT depicted 95 of 98 renal veins confirmed at surgery. Sensitivity and specificity of CT were 66% and 100%, 75% and 100%, and 50% and 100%, and overall accuracy was 94%, 97%, and 99%, for identification of variant anatomy of renal arteries, veins, and ureters, respectively.

CONCLUSION

Multi-detector row CT as the sole imaging technique in the preoperative evaluation of living renal donors is accurate even when images are read by multiple readers with varied levels of expertise.

Contrast-enhanced magnetic resonance angiography: evaluation of renal arteries in living renal transplant donors

One of the most important steps before living-donor nephrectomy is assessment of renal vascular anatomy. The number, origins and lengths of the renal arteries and variations of renal veins must be determined in order to identify the kidney that is most suitable for transplantation. Digital subtraction angiography was long considered the standard procedure for this purpose, but this method has been replaced by non-invasive techniques. Contrast-enhanced magnetic resonance angiography is an accurate, safe and reliable method for imaging vasculature. This article reviews the technique and the clinical features of this method in the evaluation of living renal transplant donors.

Laparoscopic Live Donor Nephrectomy in the Presence Of Circumaortic or Retroaortic Left Renal Vein

PURPOSE

Laparoscopic live donor nephrectomy is now an accepted alternative to open surgery in donors with normal renal vasculature. However, the suitability of laparoscopy for donors with anomalous vasculature is less well known. We compared the donor and recipient outcome data of 16 patients with circumaortic or retroaortic left renal vein to 20 recent patients with normal left renal venous anatomy undergoing laparoscopic donor left nephrectomy.

MATERIALS AND METHODS

Of 170 patients undergoing laparoscopic donor nephrectomy at our institution from October 1997 to October 2002, 18 (10.6%) had either a circumaortic or retroaortic left renal vein (group 1). Demographic and perioperative parameters of these donors and their recipients were retrospectively compared to a contemporary cohort of 20 recent patients with a normal single left renal vein (group 2).

RESULTS

All laparoscopic procedures were completed successfully without open conversion. Groups 1 and 2 were similar in regard to operative time (199 vs 226 minutes, p = 0.90), blood loss (125 vs 100 cc, p = 0.45), warm ischemia time (3.4 vs 3.9 minutes, p = 0.14) and hospital stay (2.9 vs 3.2 days, p = 0.45). Length of allograft renal artery and vein was similar between groups. Cold ischemia and revascularization times were also comparable between groups. Recipient serum creatinine was comparable at 5 days (1.7 vs 1.6 mg/dl), 3 months (1.5 vs 1.4 mg/dl) and 1 year (1.5 vs 1.5 mg/dl).

CONCLUSIONS

Presence of a circumaortic or retroaortic renal vein is not a contraindication to laparoscopic live donor left nephrectomy. A left kidney with vasculature anatomically adequate for transplantation can be achieved with excellent donor and recipient outcomes.

Multidetector CT angiography for preoperative evaluation of living laparoscopic kidney donors

OBJECTIVE

The purpose of this study was to determine the accuracy of multidetector CT (MDCT) angiography as the primary imaging technique in the evaluation of living kidney donors.

SUBJECTS AND METHODS

Seventy-four consecutive living kidney donors (30 men, 44 women; mean age, 41.7 years) who underwent MDCT were evaluated. CT examination was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec and a pitch of 6. In every case, arterial and venous phase volumetric data sets were acquired at 25 and 55 sec, respectively. Scans were reconstructed at 1-mm intervals for three-dimensional (3D) imaging using a volume-rendering technique. Axial CT images and 3D CT angiography were evaluated prospectively by one reviewer and retrospectively by two reviewers who had no knowledge of surgical results. Surgical correlation for the location of primary and accessory renal arteries, early branching of the renal arteries, and renal vein anomalies was made.

RESULTS

Seventy-two subjects underwent left nephrectomy, and two subjects underwent right nephrectomy because supernumerary left renal arteries were detected on preoperative CT angiography. Eighteen supernumerary renal arteries (two arteries to 16 kidneys and three arteries to one kidney) to 74 kidneys underwent nephrectomy. CT and surgical findings agreed in 93% of subjects (the average of three reviewers; range, 89-97%). Two small accessory renal arteries were missed by all three reviewers. Those arteries were diminutive and were thought to be insignificant by the surgeons. Early branching of the renal arteries was shown in 14 arteries, and CT and surgical findings agreed in 96% (the average of three reviewers; range, 93-97%). Renal vein anomalies were present in eight subjects, and CT and surgical findings agreed in 99% of the cases (range, 96-100%).

CONCLUSION

MDCT angiography is highly accurate for detecting vascular anomalies and providing anatomic information for laparoscopic living donor nephrectomy.

Living renal donors: optimizing the imaging strategy--decision- and cost-effectiveness analysis

PURPOSE

To determine the most cost-effective strategy for preoperative imaging performed in potential living renal donors.

MATERIALS AND METHODS

In a decision-analytic model, the societal cost-effectiveness of digital subtraction angiography (DSA), gadolinium-enhanced magnetic resonance (MR) angiography, contrast material-enhanced spiral computed tomographic (CT) angiography, and combinations of these imaging techniques was evaluated. Outcome measures included lifetime cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. A base-case analysis was performed with a 40-year-old female donor and a 40-year-old female recipient.

RESULTS

For the donor, MR angiography (24.05 QALYs and 9,000 dollars) dominated all strategies except for MR angiography with CT angiography, which had an incremental ratio of 245,000 dollars per QALY. For the recipient, DSA and DSA with MR angiography yielded similar results (10.46 QALYs and 179,000 dollars) and dominated all other strategies. When results for donor and recipient were combined, DSA dominated all other strategies (34.51 QALYs and 188,000 dollars). If DSA was associated with a 99% specificity or less for detection of renal disease, MR angiography with CT angiography was superior (34.47 QALYs and 190,000 dollars).

CONCLUSION

For preoperative imaging in a potential renal donor, DSA is the most cost-effective strategy if it has a specificity greater than 99% for detection of renal disease; otherwise, MR angiography with CT angiography is the most cost-effective strategy.

Should the indications for laparascopic live donor nephrectomy of the right kidney be the same as for the open procedure? Anomalous left renal vasculature is not a contraindiction to laparoscopic left donor nephrectomy

BACKGROUND

The left kidney is preferred for live donation. In open live donor nephrectomy, the right kidney is selected if the left kidney has multiple renal arteries or anomalous venous drainage. With laparoscopic live donor nephrectomy (LLDN), there is reluctance to procure the right kidney because of the more difficult exposure and further shortening of the right renal vein (RRV) after a stapled transection. An experience with LLDN is reviewed to determine whether the right kidney should be procured laparoscopically.

METHODS

From February 1995 to November 1999, 227 patients underwent live donor renal transplants with allografts procured by LLDN. The results of these transplants were analyzed.

RESULTS

Of the 227 kidneys transplanted, 17 (7.5%) were right kidneys. In the early experience, three (37.5%) of the eight right renal allografts developed venous thrombosis, two of which had duplicated RRV. Based on these initially unacceptable results, donor evaluation and LLDN techniques were modified. Spiral computerized tomography (CT) replaced conventional angiography to define better the venous anatomy. LLDN was modified in one of three ways: (1) changing the stapler port placement such that the RRV was transected in a plane parallel to the inferior vena cava, (2) relocation of the incision for open division of RRV, or (3) lengthening of the donor RRV with a panel graft constructed of recipient greater saphenous vein. Finally, the recipient operation enjoined complete mobilization of the left iliac vein with transposition lateral to the iliac artery. With these modifications, there were no vascular complications with the subsequent nine right renal allografts (P<0.05). Of the left kidneys transplanted, 31 had multiple renal arteries, 14 had retroaortic or circumaortic veins, 4 had both multiple arteries and venous anomalies, and 1 had a duplicated IVC draining the left renal vein. There were no vascular complications with left renal allografts that had multiple arteries or venous anomalies.

CONCLUSIONS

LLDN of the left kidney is technically easier. Left kidneys with multiple arteries or anomalous venous drainage are not problematic. The right kidney can be procured with LLDN; however, a rational approach to preoperative angiographic imaging, donor operation, and recipient operation is crucial.

Arteriographic detection of renovascular disease in potential renal donors: incidence and effect on donor surgery

PURPOSE

To determine the arteriographic incidence and severity of renal arterial disease in potential renal donors and to evaluate the effect of identifying vascular abnormalities on subsequent donor surgery.

MATERIALS AND METHODS

The records of 716 potential living renal donors who underwent conventional arteriography were reviewed. Abnormal arteriograms were reexamined to characterize vascular disease, and the effect of identifying renovascular disease on subsequent donor surgery was ascertained with chart review.

RESULTS

Renovascular abnormalities were noted in the dictated reports in 78 patients (10.9%). The most common causes were fibromuscular dysplasia and atherosclerosis. The arteriograms of 64 patients were available for retrospective review. Abnormalities were characterized as minimal stenosis (<30% narrowing) in 42 patients and mild stenosis (30%-50% narrowing) in 19 of 61 patients with arteriographic abnormalities at retrospective review. In three patients, no significant abnormality was seen at retrospective review. The effect of detecting renovascular disease on donor selection was determined in 74 of the 78 patients. In 73 of these 74 patients (99%), detection of an abnormality directly affected donor surgery.

CONCLUSION

In this population of potential renal donors, the arteriographic incidence of renovascular disease (10.9%) was higher than previously reported. Although renovascular abnormalities were mild, their detection influenced the plan for donor surgery in almost all patients.

Helical computerized tomography arteriography for evaluation of live renal donors undergoing laparoscopic nephrectomy

PURPOSE

Traditionally, live renal donors are evaluated with excretory urography and renal arteriography. Helical computerized tomography (CT) arteriography offers a less invasive alternative for demonstrating necessary anatomical information before laparoscopic allograft harvest. We evaluate the accuracy of helical CT arteriography in depicting renal vascular anatomy with an emphasis on the detection of arterial and venous anomalies.

MATERIALS AND METHODS

Imaging studies were done on 175 patients according to a standard CT arteriography protocol with early arterial phase scanning (14 to 20-second delay), and 1 mm. axial and 3-dimensional maximum intensity projection reconstructions. Renal vascular anatomy was mapped with attention to aberrant arterial and venous anatomy. Intraoperative findings were correlated at laparoscopic donor nephrectomy.

RESULTS

There was overall agreement between CT arteriography and laparoscopic findings in 163 cases (93%). Supernumerary renal arteries were identified in 40 cases (23%). Sensitivity, specificity and accuracy of CT arteriography for arterial anatomy were 91, 98 and 96%, respectively. Cases with less than 2 mm. accessory arteries or early branching single vessels simulating dual arteries were misdiagnosed. Venous anomalies occurred in 11 patients (6.3%). Sensitivity, specificity and accuracy of CT arteriography for venous anatomy were 65, 100, and 97%, respectively. Misdiagnoses included early venous bifurcations and supernumerary tributary veins, which were poorly opacified.

CONCLUSIONS

Helical CT is highly accurate and specific for the demonstration of renal arterial anatomy. Poor opacification resulted in a lower sensitivity for venous anatomy. Overall, helical CT provides essential anatomical information, and is an alternative to standard urography and arteriography.

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.

Helical CT examination of potential kidney donors

OBJECTIVE

The purpose of our study was to evaluate helical CT using axial, coronal, and three-dimensional (3D) reconstruction in the examination of potential kidney donors and to compare the results with angiography and surgery when possible. We also reviewed previously published reports.

SUBJECTS AND METHODS

Thirty-six patients underwent unenhanced and enhanced helical CT (3-mm collimation, 150-170 ml of i.v. contrast material injected at 4 ml/sec; pitch 1.5; 17-sec scan delay) with coronal and 3D shaded-surface-display reconstructions made from 1.5-mm overlapping reconstructions. All CT scans were interpreted independently of each other by two observers unaware of other findings. A third observer, who was aware of other findings, also interpreted the images. Results were compared with angiography (24 cases) and surgery (24 cases). Our results are compared with those of other investigators.

RESULTS

Axial CT was the best method for detecting accessory arteries (24%) and early branching (10%); it also detected relevant venous and ureteral anatomy and incidental findings. The coronal and 3D images rarely added information that resulted in changed patient treatment. CT findings were concordant with those of digital angiography in 89% of kidneys and were 98% concordant with surgery.

CONCLUSION

Helical CT can show arterial, venous, and ureteral anatomy and can also show important incidental findings. If only helical CT is used, a few small accessory vessels and an occasional renal artery stenosis may be missed. Axial images are generally diagnostic and may be supplemented by multiplanar and 3D images read concurrently.

Renal arteries: anatomic study for surgical and radiological practice

The renal arterial supply was analyzed in 266 kidneys dissected from 133 fixed adults subjects. The anatomical findings are presented: 1 hilar artery in 53.3% of the cases, 1 hilar artery with 1 superior pole extra-hilar branch in 14.3%, 2 hilar arteries in 7.9%, 3 hilar arteries in 1.9%, superior polar artery in 6.8%, inferior polar artery in 5.3% and other variations in 8.5%. The urological and radiological implications of these findings in kidney transplantation, renovascular hypertension, renal trauma, interventional radiology, conservative surgery and oncologic surgery are discussed.

Donating a kidney to a family member. How primary care physicians can help prepare potential donors

When a relative needs a kidney to survive, family members often impulsively offer to donate one without stopping to consider the physical, emotional, and financial ramifications, which can be considerable. The family's primary care physician can be very helpful in guiding and educating potential donors and, by arranging for screening to be done in the community, can ease the financial strain. The authors discuss the things a potential kidney donor should consider.