Circumaortic Left Renal Vein Research Articles

Evaluation of left renal vein and inferior vena cava variations through routine abdominal multi-slice computed tomography.

The aim of this study was to evaluate the frequency of left renal vein (LRV) and inferior vena cava (IVC) variations and the effect of gender on this frequency, as well as the presence of associated abdominal pathologies. Multi-slice computed tomography (MSCT) images from 746 patients were evaluated retrospectively. Left renal vein variations were identified in 9.8% of cases, while retroaortic LRV (RLRV) and circumaortic LRV (CLRV) were found in 7.4% and 2.4% of cases, respectively. No significant correlation was found between gender and LRV variations (p = 0.797). Of the cases with LRV and IVC variations, 73% had abdominal pathologies, the most common of which were nephrolithiasis, which appeared in 18 (32%) cases, and renal cysts, which appeared in 14 (25.4%) cases. MSCT is a rapid and reliable method of identifying LRV and IVC variations and associated abdominal pathologies.

Vascular anomalies in patients undergoing retroperitoneal lymph node dissection.

382 Background: Anomalies of the renal vessels usually are clinically silent and might depicted during CT scanning of the abdomen for staging purposes of urological malignancies. Awareness of these rare anomalies is crucial especially in patients undergoing staging for germ cell tumors in order to avoid overstaging and unnecessary therapy. We report on the incidence of renal vessel anomalies in an unselected group of patients undergoing retroperitoneal lymph node dissection (RPLND) for testis cancer. Methods: 245 patients with testicular germ cell tumors underwent primary or secondary RPLND following inductive chemotherapy. Prior to RPLND, all patients underwent abdominal staging by CT scans or by MRI in selected cases. CT scans were reviewed with regard to the detection of vascular anomalies of the vena cava inf., renal veins, renal arteries, and iliac vessels. CT findings were correlated with intraoperative findings. Results: Overall, vascular anomalies were encountered in 39 patients (15.9%): retroaortic left renal vein in 10 (4.1%), circumaortic left renal vein in two (0.8%), reduplication of the common iliac vein in one (0.4%), accessory renal arteries in 14 (5.7%), thrombosis of the inferior vena cava in 12 (4.9%) patients with IIC disease. Anomalies of the renal vein were detected in 10 out of 12 (83%), in two cases venous anomalies were falsely diagnosed as lymph node disease in stage I NSGCT. All arterial anomalies were identified preoperatively. CT scan identified caval thrombosis in only eight cases (68%), four cases were identified by an additional MRI of the abdomen. Conclusions: Vascular anomalies are frequently encountered in patients with RPLND for testis cancer and have to be acknowledged during surgery even with negative imaging studies. Retroaortic renal veins represent a potential pitfall of CT imaging resulting in unnecessary therapy; it should be considered in pts with CT suspicious lymph nodes caudal to the renal hilus. IVC thrombosis is associated with advanced disease and is best diagnosed by MRI of the abdomen.

Precaval Right Renal Arteries with Circum-aortic Left Renal Vein.

Sir, I have read with interest, the article which is entitled, “A Right Ectopic Kidney with Bilateral Multiple Anomalies of the Renal vasculature – A Case Report” by Krishnaveni C and Roopa Kulkarni, which appeared in the year 2013, Volume 7, Issue 1, pages 150-153 of your journal [1]. The authors have described a case of unilateral right renal ectopia with bilateral multiple renal arteries, 5 on the right side and 2 on the left side. The renal veins were 3 on the right side and 2 on the left side, with retroaortic left renal vein in a male cadaver and their observations were supported with good photographs. I wish to draw the attention of readers to the following additional variations which were observed, which have not caught the attention of the authors, probably due to lack of awareness of such variations. The authors have reported the presence of 5 renal arteries which supplied an ectopic right kidney, with the hilum facing anteriorly. Though the authors described the origins of all five right renal arteries, they did not mention the abnormal course of all five arteries which passed anterior to inferior vena cava, to reach the renal hilum. This course is clearly seen in the [Table/Fig-1] which was published. [Table/Fig-1]: Right renal arteries (RRA1 – RRA4) having a precaval course crossing anterior to IVC are marked * Normally, right renal artery passes posterior to inferior vena cava to reach the renal hilum, but right renal arteries which have an anomalous anterior course are referred to as precaval right renal arteries. The incidence of precaval right renal arteries which has been reported in the literature variesfrom 5.0%- 9.17% [2–4]. Rameshbabu et al in a MDCT angiographic study, reported a prevalence of 8.88 % [5]. A majority of precaval right renal arteries are accessory inferior polar or accessory hilar arteries. All right renal arteries, main and accessory, which have a precaval course are very rare. Precaval right renal artery may be one of the causes of obstruction of ureteropelvic junction, which causes hydronephrosis and clinical symptoms and may be injured in endopyelotomy procedures and may be confused with other vessels such as mesenteric or gonadal arteries during laparoscopic and other surgical procedures. Though much attention has been paid to the numerical variations and prehilar branching patterns of the renal arteries, anomalous precaval course of the right renal artery has drawn very little attention and it has been reported only sporadically in the literature. The authors have also reported the presence of two left renal veins, one main (LRV 1) and the other, accessory renal vein (Acc RV) as seen in [Table/Fig-2]. The accessory left renal vein extended behind the aorta as the retro-aortic renal vein and it drained into the inferior vena cava. In discussion, the authors have given the embryological explanation that the persistence of the posteriorm part of the renal collar gave rise to the retro-aortic renal vein. But the authors have failed to emphasize that the main left renal vein had a normal preaortic course which crossed anterior to aorta, just below the level of origin of superior mesenteric artery. Presence of two left renal veins, one passing anterior and another posterior to aorta, is called as circumaortic left renal vein or renal venous collar, whatever the level of crossing is, but the authors have not mentioned it. This developmental anomaly occurs due to the persistence of both ventral and dorsal limbs of intersubcardinal anastomosis around the dorsal aorta. Normally, the ventral limb persists as the left renal vein and the dorsal limb disappears. Persistence of the dorsal limb alone gives rise to retroaortic left renal vein. Approximate prevalence of circumaortic left renal vein is 0.3 – 3.7 % [6]. Aljabri et al., [7], after analyzing 1788 cases reported a prevalence of circumaortic left renal vein in 1.62 %. cases and emphasized the importance of left renal vein anomalies in aortoiliac surgeries. The retroaortic segment may be compressed between aorta and vertebral column, resulting in posterior nutcracker phenomenon. This case report under discussion, actually depicts the presence of circumaortic left renal vein, associated with multiple precaval right renal arteries supplying an ectopic malrotated right kidney. Knowledge on the variations is very important for proper appreciation of them. I have tried to add some observations for the benefit of the readers. The suggested references may enrich the knowledge of readers about the renal vascular anomalies and their clinical importance.Thanks to the authors and the journal for publishing such a rare association of renal anomalies, which was supported by excellent photographs, which clearly depicted the vascular anomalies. [Table/Fig-2]: Circumaortic left renal vein with the Main Left renal vein (LRV) having a normal preaortic course and an accessory LRV having a retroaortic course are marked *

The retroaortic left renal vein abnormalities in cross-sectional imaging.

The normal anatomic course of the left renal vein (LRV) from the kidney to inferior vena cava (IVC) is usually preaortic. It is called retroaortic left renal vein (RLRV) when located between the aorta and vertebra; the circumaortic left renal vein (CLRV) has both a preaortic and retroaortic course. In this study, we aimed to find the incidence and characteristics of LRV abnormalities in routine abdominal CT and MR examinations conducted in our clinic. A total of 2189 abdominal CT and MR examinations, performed between April 2007 and June 2009, were reviewed retrospectively for retroaortic and circumaortic LRV abnormalities. LRV abnormalities were detected in 50 (2.3%) examinations. Forty-four of these (2%) were RLRV and 6 (0.3%) were circumaortic LRV abnormalities. Preoperative knowledge of LRV abnormalities facilitates the safe performance of surgery and reveals the clinical symptoms. It is easy to see LRV and its drainage way on routine CT and MR imagings.

Clinical Outcomes of Inferior Vena Cava Filter Placement in Patients with Renal Vein Anomalies

To investigate the clinical outcomes in patients with renal vein anomalies who undergo inferior vena cava (IVC) filter placement. Contrast-enhanced computed tomography images of 410 patients who underwent IVC filter placement were retrospectively reviewed to detect renal vein anomalies. Clinical outcomes involving de novo pulmonary embolism and worsening of renal function were compared between patients with the location of filters placed in relation to the anomalous renal veins versus not in relation to any renal veins. A total of 97 (23.7%) renal vein anomalies were identified: 62 (15.1%) multiple right renal veins, 23 (5.6%) circumaortic left renal veins, 10 (2.4%) retroaortic left renal veins, and 2 (0.5%) accessory left renal veins. Frequency of de novo pulmonary embolism in patients with circumaortic left renal veins who had filters placed at or in between the 2 left renal veins was not significantly different from patients who underwent infra- or suprarenal filter placement (5.9% [1/17] vs. 3.1% [12/387]; P = 0.433). The frequency of patients who had a >25% decrease in estimated glomerular filtration rate after IVC filter placement was not significantly different whether the filter was placed in an infrarenal location or at or above the level of the anomalous renal veins (11.0% [37/335] vs. 17.6% [6/34]; P = 0.261). Clinical outcomes involving the frequency of de novo pulmonary embolism and worsening of renal function are not dependent on location of IVC filter placement in patients with renal vein anomalies.

The value of 16-slice multidetector computed tomographic angiography in preoperative appraisal of vascular anatomy in potential living renal donors

BackgroundComprehensive preoperative appraisal of potential living renal donors is the key for selecting a proper donor and a suitable kidney. ObjectiveTo prospectively assess the diagnostic value of 16-slice multidetector computed tomography (MDCT) in preoperative appraisal of vascular anatomy in potential living renal donors. Materials and methodsPreoperative angiography using a 16-slice MDCT scanner was performed in 68 consecutive potential living renal donors. The MDCT angiography included unenhanced and contrast-enhanced multiphasic scans. The MDCT images were reviewed for the number and branching pattern of the renal arteries and for the number and presence of major or minor variants of the renal veins. The results were compared with the actual anatomy at the open donor nephrectomy as the diagnostic standard of reference. ResultsThe sensitivity and the specificity of MDCT angiography for the detection of various anatomic variants of renal arteries as well as renal venous anomalies were 100%. The anatomic variants of renal arteries included accessory arteries (n=7) and early arterial branching (n=10). Whereas, the detected venous anomalies were of major category of the circumaortic left renal vein anomaly (n=2). No minor renal venous anomaly was identified in any subject. Conclusion16-Slice MDCT angiography is highly accurate for preoperative assessment of diverse anomalies of the renal vascular anatomy in potential living renal donors; in consequence, it markedly affects the surgical planning.

8:56 AM Abstract No. 182 - Clinical outcomes of IVC filter placement in patients with renal vein anomalies

Purpose To investigate the clinical outcomes in patients with renal vein anomalies who undergo inferior vena cava (IVC) filter placement. Materials and Methods Contrast enhanced computed tomography images of 410 patients who underwent IVC filter placement were retrospectively reviewed to detect renal vein anomalies. Clinical outcomes involving de novo pulmonary embolism and worsening of renal function were compared between patients with the location of filters placed in relation to the anomalous renal veins versus not in relation to any renal veins. Results A total of 97 (23.7%) renal vein anomalies were identified: 62 (15.1%) multiple right renal veins, 23 (5.6%) circumaortic left renal veins, 10 (2.4%) retroaortic left renal veins, and 2 (0.5%) accessory left renal veins. Frequency of de novo pulmonary embolism in patients with circumaortic left renal veins who had filters placed at or in between the two left renal veins was not significantly different from patients who underwent infra- or supra-renal filter placement (5.9% [1 of 17] vs. 3.1% [12 of 387], p = .433). Frequency of patients who demonstrated a greater than 25% decrease in estimated glomerular filtration rate (eGFR) following IVC filter placement was not significantly different whether filter was placed in an infrarenal location, versus at or above the level of the anomalous renal veins (11.0% [37 of 335] vs. 17.6% [6 of 34], p = .261). Conclusion Clinical outcomes involving frequency of de novo pulmonary embolism and worsening of renal function are not dependent on location of IVC filter placement in patients with renal vein anomalies.

Evaluation of left renal vein entrapment using multidetector computed tomography.

Nutcracker syndrome, also called left renal vein entrapment syndrome, is a cause of non-glomerular hematuria with difficulties in diagnosis. Multidetector computed tomography (MDCT) is a powerful tool to prevent unnecessary diagnostic procedures. To retrospectively determine the prevalence of nutcracker phenomenon and nutcracker syndrome seen in MDCT in consecutive patients. The institutional review board approved the study and waived the requirement for informed consent. Abdominal contrast-enhanced MDCT scans were reviewed from 1000 consecutive patients. MDCT scan assessment included renal vein diameter measurements and evaluation for the presence of anterior or posterior left renal vein entrapment. Electronic medical records and urine analysis reports of patients with left renal vein entrapment were reviewed. Student's t test was used to assess differences in renal vein diameter in patients with left renal vein entrapment. Left renal vein entrapment was observed in 10.9% (109), retro-aortic left renal vein in 6.5% (65), entrapment of left renal vein between superior mesenteric artery and aorta in 4.1% (41), and circumaortic left renal vein in 0.3% (3) of patients. Mean diameters of right (8.8 ± 1.9 mm) and unentrapped left (8.9 ± 1.8 mm) renal veins were not significantly different (P = 0.1). The mean diameter of anterior entrapped left renal veins (10.3 ± 2 mm) was significantly greater (P = 0.04) than contralateral renal veins (8.6 ± 2.1 mm) in their widest portion. In 8.8% of patients with the left renal vein entrapment, urine analysis showed isomorphic hematuria or proteinuria with no other known cause. Varicocele and pelvic congestion were seen in 5.5% of patients with the left renal vein entrapment. Left renal vein entrapment is not a rare entity and renal nutcracker phenomenon might be underdiagnosed.

Dual-energy computed tomography angiography for evaluating the renal vascular variants

Background Recognizing renal vascular variants preoperatively is important in order to avoid vascular complications during surgery. This study aimed to investigate the renal vascular variants with dual-energy computed tomography (DECT) angiography to provide valuable information for surgery. Methods A total of 378 patients underwent DECT. The number, size, course and relationships of the renal vessels were retrospectively observed from the scans. Anomalies of renal arteries and veins were recorded and classified. Multiplanar reformations (MPR), maximum intensity projections (MIP), and volume renderings (VR) were used for analysis. Results In 378 patients (756 kidneys), renal artery variations were discovered and recorded in 123 kidneys (16.3%, 123/756) of 106 patients (28.0%, 106/378). Type IB (early branches of the only one main renal artery) and IC (accessory renal artery with only one main renal artery) were found most frequently with an incidence of 11.4% (43/378) and 14.5% (55/378). The incidence of renal artery variations in the left kidney was not statistically different than in the right kidney (12.4% vs. 11.1%). The incidence of renal vein variations was detected in 104 patients (27.5%, 104/378). The incidence of venous variants in the right kidney was higher than in the left kidney (20.1% vs. 7.4%), but left renal vein variations were more complex. Variants of the left renal vein were detected in 28 patients including type 1 (circumaortic left renal vein) in eight cases, type 2 (retroaortic left renal vein) in seven cases, type 3 (abnormal reflux) in six cases, type 4 (late venous confluence of left renal vein) in five cases, and type 5 (rare type) in two cases. The frequency of left renal vein variation associated with the left renal accessory artery was significantly higher than with early branches of the left renal artery (P=0.037). Conclusions The renal vascular variants are rather common and complex. DECT angiography can demonstrate the precise anatomy of the renal vessels, which is a benefit for renal transplantation or other renal operations

The left inferior vena cava: a surgically important variant tributary of left renal vein

In an interesting study based on cadaveric dissection, the three most common variations of the left renal vein (LRV) were investigated recently by Yi et al. [5]. They reported that the median incidences of circumaortic left renal vein (CLRV) were 7.0 %, while the median incidences of retroaortic left renal vein (RLRV) were 1.7 % in cadaveric dissections. Moreover, the incidence of retropelvic tributary of the renal vein (RPTV) ranged from 30.0 to 46.4. However, how about the left inferior vena cava (LIVC) which usually drains into the LRV [1]? Should it be considered a surgically important variant tributary of LRV?

Circumaortic Left Renal Vein Associated with Juxtarenal Abdominal Aortic Aneurysm

The patient was an 82-year-old man who was found to have a juxtarenal abdominal aortic aneurysm accompanied by a circumaortic left renal vein (CLRV). During dissection of the proximal anastomosis site the CLRV was injured, but was successfully repaired. A graft implantation was performed below the renal arteries. The incidence of CLRV is thought to be rare, however it is found in 7% of cadavers donated for anatomy. CLRV may cause unexpected bleeding by inadvertent dissection of the abdominal aorta. To prevent unexpected bleeding, surgeons should always keep in mind this potential risk when performing surgery.

Evaluation of the left renal vein variations and inferior vena cava variations by means of helical computed tomography

PurposeTo evaluate the percentages of the left renal vein (LRV) variations and inferior vena cava (IVC) variations as well as the effect of gender on their frequencies. Materials and MethodsContrast-enhanced abdominal helical computed tomography (CT) examinations of 1204 patients were retrospectively evaluated. ResultsThe correspondent percentages of the total LRV variations, retroaortic left renal vein (RLRV), and circumaortic LRV were 5.2%, 3.1%, and 2.1%, respectively. A statistically significant correlation was found between RLRV variation and gender (P=.036). ConclusionsHelical CT is an efficient, fast, easily applicable, and reliable imaging modality in demonstration of LRV variations and IVC variations.

The three most common variations of the left renal vein: a review and meta-analysis

The authors describe three anatomic variations, circumaortic, retroaortic left renal vein, and retropelvic tributary of the renal vein, in Japanese cadavers. The incidences and the clinical significances of these variations are discussed with a detailed review of the literature. The median incidences of circumaortic left renal vein (CLRV) were 7.0% in cadavers examined and 1.8% in clinical subjects examined. The detection of CLRV in CT/MDCT or angiography was relatively difficult compared with that by cadaver dissection. The median incidences of retroaortic left renal vein (RLRV) were 1.7% in cadavers examined and 2.2% in clinical subjects examined. The detection of RLRV was lower in operations, and relatively easy by ultrasonography. The incidence of retropelvic tributary of the renal vein ranged from 30.0 to 46.4%, which is very frequent. Moreover, the incidences of communicating veins between the left renal vein and retroperitoneal veins ranged from 30.0 to 84.2% in cadaver dissections and from 34.0 to 75.8% in clinical reports.

Study of the left renal variations by means of magnetic resonance imaging

A prospective study was designed to figure out the percentages of the left renal vein variations using routine lumbar spinal magnetic resonance imaging (MRI) in patients with neurological problems. Between March 2010 and October 2010, the study population was recruited from a total of 2,644 consecutive patients who would undergo a routine lumbar spinal MRI examination. In addition to the routine MRI sequences, axial, balanced turbo field echo sequence (BTFE-BH SENSE) was applied after detection of a left renal vein variation. As the left renal vein variations, retroaortic left renal vein (RLRV) and circumaortic left renal vein were detected. The number of cases with the correspondent percentages of the total left renal vein variations, RLRV and circumaortic left renal vein were 71/2,644 (2.68%), 44/2,644 (1.66%) and 27/2,644 (1.02%), respectively. In cases with RLRV, the numbers of males and females with their correspondent percentages were 19/44 (43.2%) and 25/44 (56.8%), respectively. In cases with circumaortic left renal vein, the numbers of males and females with their correspondent percentages were 13/27 (48.1%) and 14/27 (51.9%), respectively. With Chi-square test, no statistically significant gender difference was found between the percentages of left renal vein variations (P = 0.83). MRI is useful in detecting RLRV and circumaortic left renal vein. If a left renal vein variation is detected, an additional BTFE-BH SENSE sequence is suggested to confirm whether it is retroaortic or circumaortic.

64-slice spiral CT appearance of congenital anomalies of the inferior vena cava

Objective To evaluate the imaging findings of congenital anomalies of inferior vena eava (IVC) with 64-slice spiral CT. Methods Between January 2008 and May 2009, 6986 patients who had routine abdominal 64-row multi-detector computed tornography were retrospectively analyzed for congenital anomalies of IVC. Results Among 6986 cases, 25 cases with congenital anomalies of IVC were identified. Six case were left IVC, showing IVC left to the aorta inferior to the renal hilum. Ten cases were double IVC, showing two IVC besides the aorta inferior to the renal hilum. Five cases were abnormal renal vein, showing retroaortic and circumaortic left renal vein. Two cases were IVC interruption with collateral circultion by azygous or hemiazygous vein, contrast-enhanced CT scan showing deficiency of the IVC between hepatic and renal hilums, the enlarged azygos vein communicating with IVC at renal level and the hepatice vein draining into the right atrium. Venography showed that IVC draining into the superior vena cava through azygous or hemiazygous veins. One case was interruption of the IVC with portal vein continuation, contrastenhanced CT scan showing the communication between the IVC and portal vein. One case was hemiazygos continuation of a left IVC, contrast-enhanced CT scan demonstrating dilatation hemiazygos continuation of a left IVC and jointed the azygos vein. Conclusion The 64-slice spiral CT can be a diagnostic standard for congenital anomalies of inferior vena cava. Key words: Inferior vena cava; Abnormalities; Tomography,X-ray computed

Retroaortic and circumaortic left renal veins with their CT findings and review of the literature

Both circumaortic and retroaortic left renal veins are the result of persistence of the dorsal limb of the embryonic left renal vein and of the dorsal arch of the renal collar. However, in retroaortic left renal vein the ventral arch regresses so that a single renal vein passes posterior to the aorta. The approximate prevalence of circumaortic left renal vein is 0.3 to 3.7%, and retroaortic left renal vein is 0.5 to 6.8%. Cross-sectional computerized tomography study was done in both cases. In one of the cases the left renal vein was observed posterior to the abdominal aorta and in the other case the left renal vein was covering the abdominal aorta, one vein superior and posterior and the second vein inferior and anterior to the abdominal aorta. Venous anomalies of the renal veins are clinically important especially in retroperitoneal surgery and intracaval interventions. These anomalies should not be misdiagnosed as dilated gonadal vein, retroperitoneal lymphadenopathies or masses.

Multidetector row CT angiography of living related renal donors: Is there a need for venous phase imaging?

Objective To prospectively evaluate whether renal venous anatomy can be detected from arterial phase images of multidetector row CT (MDCT) of renal donors. Material and methods Institutional review board approved our study protocol with waiver of consent. Forty-eight consecutive renal donors (age range, 21–56 years; M:F, 20:28) referred for MDCT evaluation were included. Two sub-specialty radiologists performed an independent and separate evaluation of renal venous anatomy in arterial and venous phase images. Opacification of renal venous structures was scored on a five-point scale (1-not seen; 3-minimal opacification; 5-excellent opacification). Arterial and venous phase opacification scores were compared by Wilcoxon signed rank test. Results Both readers detected all renal venous anomalies in arterial as well as venous phase images. Each reader detected accessory right renal veins ( n = 14), retroaortic left renal vein ( n = 2), circumaortic left renal vein ( n = 1), and left renal hilar arteriovenous malformation ( n = 1) in arterial phase images. Retroaortic left renal venous branch was difficult to differentiate from lumbar vein (reader-1, n = 1; reader-2, n = 2) in both arterial and venous phase images. Sensitivity of detection of renal veins, left adrenal, gonadal and lumbar veins in arterial phase images was 100, 83–88, 100, and 85–90%, respectively. As expected, venous phase images showed significantly greater opacification of renal veins, left gonadal, adrenal and lumbar veins ( p < .05). However, this did not substantially limit the evaluation of renal venous anatomy in arterial phase images. Both readers had substantial interobserver agreement (kappa coefficient, 0.7; p < 0.05). Conclusions Arterial phase MDCT images alone can be used to detect renal venous anomalies, and to identify small left renal venous branches namely, the left gonadal, adrenal and lumbar veins in renal donors. Venous phase MDCT acquisition is not necessary for evaluation of renal venous anatomy in renal donors.

Assessment of 100 Live Potential Renal Donors for Laparoscopic Nephrectomy with Multi–Detector Row Helical CT

To retrospectively review the authors' experience with multi-detector row helical computed tomography (CT) in assessing 100 consecutive live potential renal donors. Hospital ethical committee approval was obtained; informed patient consent was not required. One hundred potential renal donors underwent multi-detector row CT assessment. Nonenhanced, arterial phase, and nephrographic phase examinations were performed. Delayed topograms were acquired to visualize the collecting system anatomy. A vascular radiologist prospectively interpreted the multi-detector row CT images. A second vascular radiologist, blinded to the initial results, retrospectively reviewed the images. Eighty candidates subsequently underwent donor nephrectomy, including 70 laparoscopic donor nephrectomies (LDNs) and 10 open donor nephrectomies (ODNs). Surgical findings served as the reference standard for 80 kidneys. The imaging findings in all 100 candidates (200 kidneys) were reviewed, although these findings were considered observational data only because there was no reference standard for 120 kidneys. Multi-detector row CT findings predicted uncomplicated LDN in 67 of 70 patients. Small upper-pole capsular arteries arising from the distal main renal artery in two patients were not described in the multi-detector row CT report: In one patient, the arising vessels resulted in conversion to ODN because of bleeding; in the other patient, arterial reconstruction was performed. In another patient, conversion to ODN was necessary because of ongoing bleeding from an avulsed large lumbar venous tributary to the left renal vein. Observational data revealed that multiple renal arteries--most of which were accessory renal arteries--were seen in 52 (26%) kidneys. Early branching of the main renal artery was seen in 24 (12%) kidneys, and main renal arterial abnormalities were identified in six (3%). Capsular arteries were detected in 10 (5%) kidneys. Major variations in the anatomy of the main renal veins--including multiple right renal veins, a retroaortic left renal vein, and a circumaortic left renal vein--were seen in 28 (14%) kidneys. Large (>5 mm in diameter) systemic tributaries to the left renal vein were seen in 25 (25%) kidneys. There was no significant interobserver disagreement between the vascular radiologists. Multi-detector row CT findings can predict successful LDN in live potential renal donors.

Inferior Vena Cava in Urology: Importance of Developmental Abnormalities in Clinical Practice

Anomalies of the inferior vena cava (IVC) have been known since 1793, when Abernethy first described a congenital, mesocaval shunt and azygous continuation of the IVC in a 10-month-old infant with polysplenia and dextrocardia. The IVC is formed by a complex process of embryogenesis during the sixth to tenth week of gestation. It forms from continuous appearance and regression of the three paired veins: posterior cardinal, subcardinal, and supracardinal. Improper completion of the developmental process may result in at least 14 anatomic anomalies, out of which the following four are usually encountered in clinical practice: duplication of the IVC, transposition or left-sided IVC, retroaortic left renal vein, and circumaortic left renal vein. It is suggested that the preoperative diagnosis of the vascular anomalies reduces the complication rate of abdominal vascular procedures. Our vast experience with approximately 400 kidney donors who were evaluated preoperatively with spiral CT scan with three-dimensional reconstruction (3D) reconfirmed this view. Thereafter, it became easier to choose the side and decide between laparoscopic vs. open approach. This prompted us to write the present article focusing on those developmental anomalies of the IVC that may be encountered by the urologist and their implication on the clinical practice.

Prospective Comparison of 3-Dimensional Volume Rendered Computerized Tomography and Conventional Renal Arteriography for Surgical Planning in Patients Undergoing Laparoscopic Donor Nephrectomy

We prospectively assessed the accuracy of 3-dimensional (3-D) volume rendered computerized tomography (CT) and conventional renal arteriography to visualize renovascular anatomy in patients undergoing laparoscopic donor nephrectomy. A total of 60 consecutive patients undergoing laparoscopic donor nephrectomy (left side in 46 and right side in 14) prospectively underwent 3-D CT and renal angiography. A short videotape of 3-D CT was prepared using volume rendering software that demonstrated the anatomical location, number, anomalies and spatial interrelationships of the renal arteries and veins. These 3-D videotapes and arteriogram findings were directly correlated with intraoperative surgical findings at laparoscopy and during ex vivo bench preparation of the harvested kidney. The perceived intraoperative value of 3D-CT to delineate renovascular anatomical detail was scored subjectively by the laparoscopic surgeon for each case on a 10-point scale of 0--completely inaccurate to 10--completely accurate. There were no complications related to the 3-D CT protocol and volume rendering was successful in all patients. Three-D CT accurately identified the number of renal arteries in 59 patients (98%). In 1 patient with 3 renal arteries 3-D CT and arteriogram each identified only 2. In the 46 patients undergoing left donor nephrectomy 3-D CT accurately identified the number of veins and venous anomalies in 45 (98%), including 2 with a circumaortic left renal vein. Another case of circumaortic vein was misdiagnosed as 2 renal veins. On the right side in 14 patients 3-D CT accurately identified the renal veins in 13 (94%) and missed 1 vein in a patient with 2 renal veins. Angiography correctly identified the number of renal veins in only 52 cases (87%). Furthermore, it misdiagnosed all 3 cases of circumaortic left renal vein. The laparoscopic surgeon believed that 3-D CT accurately identified the location and anatomical interrelationship of the renal vessels with precision. Mean subjective score +/- SEM was 8.5 +/- 1 for the arterial system, 8.6 +/- 1.1 for the venous system and 9.2 +/- 0.5 for any vascular anomalies. Three-D CT accurately identifies renal vascular anatomy in a manner that may facilitate renal hilar dissection during laparoscopic donor nephrectomy, especially during the initial surgeon experience. This imaging modality integrates essential information from angiography, venography and excretory urography into a single study, and it can obviate the need for more invasive vascular imaging in most cases.