Supernumerary Renal Arteries Research Articles

Prevalence of accessory renal artery and other renal artery variants in south Indian population by CT-Angiography

The most frequent anatomical variations of the renal arterial system are accessory renal arteries (supernumerary renal arteries) and aberrant renal arteries, which occur in varying numbers among various ethnic and racial groups. Prior to surgery, understanding these variations is crucial because it affects the decision to use donor kidneys, the planning of partial nephrectomy, and other urological procedures. Along with the main renal artery on the same side, there is also an accessory renal artery. The aberrant artery supplies the kidney without passing through the hilum, whereas the main renal artery enters the kidney through the hilum to do so.Aim: This tertiary care hospital-based study aims to know the prevalence of variations of the renal arterial system including accessory renal artery, their distribution pattern, and association with gender, age, and side predilection in population of Kancheepuram and West Chennai district of Tamil Nadu.Methodology: One hundred adults (62 males, 38 females; mean age: 45 +/- 25 years) inclusive of prospective live renal donors undergoing pre-operative CT renal angiogram for operative planning and other patients undergoing CECT Abdomen for various abdomino-pelvic pathologies were selected for the study.Research Design: It is a cross-sectional descriptive study conducted in the Department of Radiology, of a tertiary care hospital in Kancheepuram district of Tamil Nadu, India.Results: Renal artery variants (including Accessory renal and aberrant renal arteries) are present in 23% of kidneys. The prevalence of renal artery variants in males – is 30%, and in females – 11%. On the right side the prevalence is 60% and on the left side is 26%. The prevalence of bilateral renal artery variants is 11%.

Comprehensive study of anatomical variations of renal artery on human cadavers with its clinical significance

Introduction: Renal artery is a paired branch of abdominal aorta at level of L1-L2. It divides into anterior and posterior branches. In maximum number of people this division into anterior and posterior branches takes place near the hilum but variation can be seen. Variations of renal artery is common and have different names such as supernumerary, accessory or aberrant. It is important for surgeons to have knowledge about such variations. Materials and methods: In the Department of Anatomy, Subharti Medical College, Meerut, Uttar Pradesh, India 60 human adult cadavers were dissected and 120 kidneys along with their arteries were studied and observed for variations. Results: Out of 120 specimens, supernumerary renal arteries were seen in 25 right kidney and 24 left kidneys. Out of 25 right supernumerary renal arteries 16 are of aortic origin and 9 are of renal origin. While in 24 left supernumerary renal arteries 14 are of aortic origin and 10 are of renal origin. Conclusions: Elaborate knowledge of course along with variations in course of renal artery is of prime importance for any general surgeon, urologists, transplant surgeon or radiologist. Keywords: Renal artery, Supernumerary, Abdominal aorta

Renal artery morphology and anatomical variations among Sudanese subjects

The objectives of this study were to determine the level of origin of the renal artery on both sides of the body, to describe its course and branching pattern on both sides, and to detect the Supernumerary renal arteries (SRA) and their course. Both cadaveric and radiological descriptive studies were conducted from July 2015 to July 2016.The morphology and variations of the renal arteries were documented in 50 formalin fixed cadavers that were dissected in different faculties of medicine in Khartoum state. This was followed by assessment of 150 computerized tomography angiographies of the renal transplant donors who presented to three major transplant centers in Khartoum in the period between 2012 and 2015.The most common vertebral level of origin off the aorta was between the first and second lumbar segments. A supernumerary renal artery was detected in 25.5% and it was the most common anatomical variation. This was followed by early prehilar bifurcation in 6.5%. Supernumerary renal arteries were commonly hilar and lower polar, and they were more frequent in males. Bilateral supernumerary arteries were found in 4% of cases. The most common anatomical variation of the renal artery was supernumerary renal artery.Keywords: Renal artery, supernumerary, anatomical variations

Bilateral supernumerary renal arteries with variant ureteric relation and their embryological and clinical significance

Variations in the renal vasculature always deserve a special attention owing to its higher prevalence and wider range. A thorough knowledge of the normal morphology and the variations in the origin, course, branches and distribution of the renal vasculature are essential for the successful outcome of the surgical interventions in this region without dreadful complications. During routine dissection for the undergraduate medical students following the standard procedures, dissection of the retroperitoneal region in a male cadaver, revealed bilateral variations in the number, origin, course and branches of the renal arteries.The renal arteries with its branches were dissected out meticulously and the variations encountered were documented. Bilateral supernumerary renal arteries with extra-hilar and pre-hilar branches were observed. In addition, it was found that the supernumerary inferior pre- caval right renal artery had a variant course in relation to ureter before entering the hilum of the right kidney. The variant renal arteries documented in the present study with their embryological correlation is clinically important in the urological management, especially during the laparoscopic donor nephrectomy, where the field of vision is limited and also in the endovascular renal artery denervation procedure, which is an useful adjuvant for the patients having drug-resistant primary hypertension.

Bilateral Supernumerary Renal Arteries with variant Ureteric Relation and their Embryological and Clinical Significance

AbstractVariations in the renal vasculature always deserve a special attention owing to its higher prevalence and wider range. A thorough knowledge of the normal morphology and the variations in the origin, course, branches and distribution of the renal vasculature are essential for the successful outcome of the surgical interventions in this region without dreadful complications. During routine dissection for the undergraduate medical students following the standard procedures, dissection of the retroperitoneal region in a male cadaver, revealed bilateral variations in the number, origin, course and branches of the renal arteries.The renal arteries with its branches were dissected out meticulously and the variations encountered were documented. Bilateral supernumerary renal arteries with extra-hilar and pre-hilar branches were observed. In addition, it was found that the supernumerary inferior pre- caval right renal artery had a variant course in relation to ureter before entering the hilum of the right kidney. The variant renal arteries documented in the present study with their embryological correlation is clinically important in the urological management, especially during the laparoscopic donor nephrectomy, where the field of vision is limited and also in the endovascular renal artery denervation procedure, which is an useful adjuvant for the patients having drug-resistant primary hypertension.

Supernumerary renal arteries: A cadaveric study with their embryological and clinical correlations

Supernumerary renal arteries: A cadaveric study with their embryological and clinical correlations

Unusual Pattern of Rt. Renal Artery and Supernumerary Lt. Renal Arteries: A Case Study

Supernumerary renal arteries are more common on left side. Multiple renal arteries have an incidence of 15-30%. Renal vasculature develops from three primitive vascular groups that coalesce to form the mature vascular pattern for all retroperitoneal structures. We are demonstrating an early bifurcation of right renal artery and the branches forming a loop around the inferior vena cava (IVC) which is an unusual pattern and multiple renal arteries (three) arteries supplying the left kidney. Patient is asymptomatic.

A cadaveric study of lower polar supernumerary renal arteries. – Embryological and clinical consideration

Normally aorta gives rise to a single renal artery on each side which supplies respective kidneys. Common variations of renal artery are it's variable number and unusual branching pattern. Supernumerary arteries have been classified into hilar or polar arteries. In a study of 50 kidneys from twenty five formalin fixed cadavers lower polar supernumerary renal arteries were seen in left kidney of two cadavers (4%). The lower polar supernumerary left renal artery was superficially crossed by the left ureter. Such an artery lying superficial to the ureter can cause ureteropelvic obstruction. Variations of renal arteries are of immense importance during planned renal transplants, urological procedures and angiographic interventions as they lead to renal complications. Hence major renal surgeries should be preempted by CT scan and renal

Supernumerary renal arteries and their embryological and clinical correlation: a cadaveric study from north India.

Background. Classically, each kidney is supplied by a single renal artery originating from abdominal aorta. The present study aimed at its variations and their embryological and clinical correlation. Material and Methods. The formalin-fixed thirty-seven cadavers from north India constituted the material for the study. During routine abdominal dissection conducted for medical undergraduates at the department of anatomy, the kidneys along with their arteries were explored and the morphological variations of renal arteries were noted. Results. We observed supernumerary renal arteries in 23/37 (62.2%) cases (48.6% of aortic origin and 13.5% of renal origin) on the right side and 21/37 (56.8%) cases (45.9% of aortic origin and 10.8% of renal origin) on the left side. Supernumerary renal arteries entered the kidney through hilum, superior pole, and inferior pole. Conclusion. Awareness of variations of renal artery is necessary for surgical management during renal transplantation, repair of abdominal aorta aneurysm, and urological procedures and for angiographic interventions.

Anomalies of Major Retroperitoneal Vascular Structure

To identify anomalies of major retroperitoneal vascular structure (AMRVS) during oncological retroperitoneal surgery and to investigate the effects of these anomalies in surgical procedures. Two hundred twenty-nine patients who underwent systematic para-aortic and bilateral pelvic lymph node dissection up to the renal vein between September 2006 and December 2008 were included. Normal architecture and structural anomalies of inferior vena cava, abdominal aorta, renal arteries and veins, and common iliac artery and vein were studied. The mean age of the patients was 54.2 years. Anomalies of major retroperitoneal vascular structure were present in 39 patients (17%). Anomalies of renal vessels were identified in 31 patients. Supernumerary renal arteries and veins observed in 11 patients (17%) were the most common renal vessel anomaly. Great vessel injury was present in 19 patients (8.3%). Vascular complication rate was 20.5% in patients with AMRVS. However, in 4 of 8 patients with vascular complication and AMRVS, the complication was not related with anomalous vascular structures. None of the complications was serious and were corrected surgically. There was no difference between patients with AMRVS and those without AMRVS regarding age, body mass index, the extent of upper abdominal dissemination of malignancy and presence of comorbidity for intraoperative bleeding. There was no difference in intraoperative hemorrhage and amount of transfused red blood cell units between the groups. Great vessel anomalies, discovered in 1 of 6 patients, were together with increased risk of vascular complications. The probability of presence of vascular anomalies should be taken into account during lymph node dissection.

Can Doppler Ultrasonographic Indices of the Renal Artery Predict the Presence of Supernumerary Renal Arteries?

Variations of the renal arteries, including the presence of supernumerary renal arteries, are important to be identified prior to renal transplant. Angiography has been the gold standard test for the pretransplant evaluation of the renal vasculature. However, this modality is expensive and invasive. The aim of this study was to assess whether Doppler ultrasonographic (DU) indices of the renal artery could predict the presence of supernumerary renal arteries. Retrospectively, we analyzed multidetector computed tomography angiography (presence or absence of the supernumerary renal artery), DU (peak systolic velocity, resistive index, pulsatility index, end-diastolic velocity, and acceleration time) findings of 30 healthy potential renal transplant donors. Recipient operator characteristic (ROC) curves were used to examine the predictive values of the available DU indices for supernumerary renal arteries. The mean age of donors was 28.4 +/- 4.1 years. Of 60 kidneys evaluated, a supernumerary renal artery was found in 10%. The ROC curve analysis revealed an area under the curve of noninformative (below 0.5) for all DU parameters, indicating that none of the studied parameters could predict the presence of a supernumerary renal artery. Although the smaller diameter of the main renal artery has previously been found to predict the presence of supernumerary renal arteries, the present study revealed that DU indices of the renal artery may not indicate the presence of supernumerary renal arteries.

Preoperative Evaluation of Living Kidney Donors With Multidetector Computed Tomography Angiography

Objective The purpose of this study was to determinate the accuracy of multidetector computed tomography (MDCT) angiography for imaging evaluation of renal anatomic variants among potential living renal donors for surgical planning. Materials and Methods Two hundred twenty-three living kidney donors underwent MDCT angiography (MDCTA) in our institution over the last 2 years. The examination was performed with a 4-detector scanner, including scanning before and after power injection of nonionic contrast material during the arterial, nephrographic, and excretory phases. Scans were reconstructed for three-dimensional (3D) images using MIP, MPR, VRT, and CPR techniques. Results Arterial variants, including supernumerary renal arteries, were present in 140 subjects: 11 presented luminal stenosis; 10 had calcifications within the vessel wall; 3 had renal artery aneurysms; 2 had obstructions; and 1 had angulation of the renal artery. Calcifications were associated with luminal stenosis (4 subjects) or no pathology (6 subjects). Venous variants were present in 4 subjects, including 3 retroaortic renal veins and 1 left renal vein draining into the retrohepatic portion of the IVC. Incidental findings were 3 renal infarcts. Conclusion MDCTA and urography are a minimally invasive, fast method to detect and classify a variety of anatomic anomalies among potential living renal donors relevant to surgical planning.

Rare origin of supernumerary renal vessels supplying the lower pole of the left kidney

The current observations have documented rare vascular anomalies in the right and left kidneys from a male and female cadaver, respectively. In the female left kidney in addition to being supplied by the normal renal artery and vein it contained a left lower polar renal artery and vein. The polar artery took origin from the inferior mesenteric artery to supply the lower pole and was drained by the left lower polar vein that opened into the left common iliac vein. The right kidney from a male cadaver showed supernumerary renal arteries and veins. The supernumerary upper renal artery took origin from the aorta and after a short course it gave rise into a cranial branch that took a long course to supply the lower pole and a caudal branch that entered the right kidney at the hilum. The supernumerary lower renal artery also took origin from the aorta and passed to supply the lower pole of the right kidney. Therefore, the lower pole of the right kidney received two arteries, but was not associated with a polar vein. The right kidney in addition to the normal right renal vein contained a supernumerary right renal vein. The vein was seen at the hilum and was the most posterior structure; passing behind the supernumerary lower renal artery to open into the posterior surface of the inferior vena cava. The anomalies described in the current observation present a unique pattern of congenital renal vascular abnormalities that may be of surgical importance.

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

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

The inferior supernumerary renal arteries: A classification into three types

Among cases that had multiple renal arteries on one side, an inferior supernumerary renal artery was found in 24/270 cases (ca. 9%) on the right and in 19/270 cases (ca. 7%) on the left, together with the usual renal artery. We have noticed that there are correlations between their levels of origin from the aorta and their positional relation to the ureter and the inferior vena cava (IVC). An inferior supernumerary renal artery (InfRA) of lower origin passes in front of the IVC and behind the ureter. An InfRA of middle origin passes in front of both the IVC and the ureter. An InfRA of upper origin passes behind the IVC and in front of the ureter or renal pelvis. In addition there was a tendency for the lower origin type to have an ureteric branch, while the middle and upper origin types had a gonadal branch. These findings suggest that different derivations lead to the inferior supernumerary renal arteries.

VARIATIONS OF THE ARTERIAL SUPPLY OF THE KIDNEY IN MAN: AN ANATOMICAL AND ANGIOGRAPHIC STUDY

Classically, each kidney is thought to have a single renal artery; however,numerous published studies describe common variations in renal vascularanatomy in which two or more renal arteries supply a kidney(Williams et aI., 1995; Ali~EI-Dein et aI., 2003; Bude et aI., 2003; Bordeiet aI., 2004; Khamanarong et aI., 2004). Although frequently described,there is still controversy regarding the naming of these arteries. There werenamed supplementary by Anderhuber and Weiglein (1992), multiple byChevrel (1994) and Khamanarong et al. (2004), accessory by Williams etal. (1995) and Goscicka et al. (1996), additional by Satyapal et al. (2001)and aberrant by Vilhova et al (2002). Bordei et al. (2004) named the supplementaryarteries entering the renal hilum as proper supplementary arterieswhile those entering the kidney at the upper and lower polar levels werenamed superior and inferior polar arteries, respectively. On the other hand,Debatin et al. (1993) named them supernumerary renal arteries and thehilar supernumerary arteries were classified as co-dominant if they weresimilar in size to the epsilateral main renal artery.

Ligation of an anatomic variant of renal vasculature during laparoscopic periaortic lymph node dissection: a cause of postoperative renal infarction

Background Minimally invasive surgical techniques are becoming more sophisticated as complex procedures are being incorporated into gynecologic oncology in routine and investigative settings. Case We present a case of an aberrant supernumerary right renal artery ligation during periaortic laparoscopic lymph node dissection for endometrial cancer. This injury resulted in infarction of the lower pole of the right kidney, with no late sequela. Conclusion The gynecologic oncologist should be aware of the possibility of aberrant renal vasculature, and special care should be taken to avoid accidental ligation of supernumerary renal arteries during dissection of the periaortic lymph nodes.

Multidetector CT angiography for preoperative evaluation of living laparoscopic kidney donors.

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

Enhanced sonography of the urinary tract

In the evaluation of the urinary tract, ultrasound contrast agents (USCAs) have been shown to be useful. USCAs do not have any renal toxicity. In the screening of renovascular hypertension, contrast-enhanced Doppler sonography improves the detection of main and supernumerary renal arteries, and reduces the frequency of technical failures. Using first-generation USCAs, the detection of renal cortical perfusion was achieved through the destruction of the bubbles to maximize the backscattered signals, requiring intermittent imaging to allow refilling of capillaries. Now, continuous non-destructive imaging has become possible with more recent agents using low and very low mechanical index values. The diagnosis of perfusion defects (i.e., renal infarct, pyelonephritis) is facilitated when the baseline Doppler signal is insufficient. USCAs improve detection of intratumoral blood flow and may be useful for characterization and/or detection of small, cystic, or nondetermined lesions at baseline US. As microbubbles remain strictly inside vessels, they can be viewed as blood pool markers, enabling functional imaging of the kidney. Bolus and infusion techniques are the two modalities of administration of the USCAs. Resulting time-intensity curves allow to approach renal blood flow and regional blood volume, and to provide additional information on perfusion disorders. Cystosonography has proven to be highly sensitive in the detection and grading of vesico-ureteral reflux in children.

Renovascular disease in patients with hypertension: detection with duplex ultrasound.

The aim of this study was to evaluate the accuracy of duplex ultrasound for the diagnosis of renovascular disease in a cohort of hypertensive patients. In 78 patients suspected of renovascular hypertension on clinical grounds duplex ultrasound examination of the renal arteries was performed. Renal angiography was used as the standard of reference. Duplex ultrasound was inconclusive in 11 kidneys (7%). None of the supernumerary renal arteries was detected with duplex ultrasound. The overall prevalence of significant renovascular disease (> or =50% stenosis) was 20%. Based on the combination of parameters at thresholds commonly applied in current literature: ie PSV(max) >180 cm/sec and RAR >3.5 the overall sensitivity of duplex ultrasound for detection of haemodynamically significant renovascular disease was 50.0% with a specificity of 91.3% (PPV: 87.9%; NPV: 59.1). Lowering the thresholds for both parameters improved the test results at the cost of a significant increase of false positive examinations. In a population of hypertensive patients clinically suspected of renovascular hypertension, only limited results for duplex ultrasound could be acquired in the detection of renovascular disease. This result, in combination with the wide range of sensitivities and specificities published in international literature and the relatively large number of incomplete examinations does not support the general application of duplex ultrasound as a screening procedure for detection and assessment of renovascular disease.