Renal Vascular Variations Research Articles

Correlation between CT Renal Angiography of Live Kidney Donors and Intraoperative Findings: A Cross-Sectional Study

Introduction: A comprehensive understanding of the renal vascular anatomy variations is paramount to a successful kidney transplant. This reduces vascular injury risks and minimizes ischemia duration, optimizing surgical outcomes. The current study aims to assess the accuracy of renal computed tomography angiography (CTA) findings of live renal donors by comparing them with intraoperative findings. Methods: This prospective cross-sectional study was conducted between October 2018 and February 2020. It included all healthy donors with two kidneys of normal size, shape, and position who were deemed suitable for nephrectomy. The CTA examinations were performed with the same protocol, which combined the vascular-excretory phase. Anatomical findings were recorded by a specialized radiologist. The CTA results were compared with intraoperative findings, which were documented by the transplantation team. Results: The study included 220 patients. The preoperative CTA was highly sensitive and accurate, reaching 99.5% and 98.6%, respectively, for single vessels and 100% sensitivity and accuracy for triple vessels, pelvicalyceal system, and ureter duplication. The sensitivity of CTA for double vessels (vein and artery) was 90% and 92.6%, respectively, while accuracy was 98.6% for both. Conclusion: CTA can be used to assess renal arteries and veins for potential renal donors with high accuracy. Although the CTA’s minor, statistically nonsignificant discordance with the surgical findings regarding double arteries and veins, no artery or vein was missed on the CTA. Therefore, the sensitivity of CTA can reach 100%.

Renal vascular disparities among kidney donors presented at renal transplant unit- A single centre study

Renal vasculature has been reported to show anatomical variations, which may lead to surgical complications. The pattern of renal vascular variations in Pakistani population is not well reported. Thus, this study was designed to assess the renal vascularity among kidney donors and correlate with age, gender and site of vessels. A total of 223 healthy volunteers underwent evaluation for kidney donation at the Radiology Department, DOW University Hospital, Karachi, Pakistan from January 2020 to July 2022 were included. The assessment of renal vasculature was done on computed (CT) angiogram. Renal vascular variations were found in 112 (50.2%), 59.8% were seen in males and 40.2% in females. On right side 50% vascular anomalies were found followed by left side with 27% and 22% on both sides. The arterial variants included accessory renal artery seen in 76 (67.8%) individuals, out of which 13.2% had in upper polar, 26.3% in hilum, 36.8% in lower polar, while 23.7% of early branching was observed. Ten retro-aortic, fourteen accessory renal veins and six bifurcation renal veins, along with six early branching renal veins, were present. Patient who received donor nephrectomy, the outcomes of the operation were completely consistent with the results of the CTA. According to this study, Pakistani population have differences in their renal venous and arterial anatomy, which can significantly influence surgical procedures.

Vascular Variations and Incidental Pathologies in Potential Living Renal Donors Using 160-Slice Multidetector Computed Tomography Angiography.

The aim of the study is to evaluate the vascular variations and incidental pathologies in potential living renal donors using 160-slice multidetector computed tomography (MDCT) angiography. This is an observational study conducted at the Department of Radiology from January 2017 to May 2022. In this study, we performed retrospective data analysis of 61 CT renal angiograms, totaling 122 kidneys of potential renal donors, using a Toshiba 160 slice MDCT scanner with a four-phase CT image acquisition protocol, performed for pre-transplant workup. All patients had normal renal functions. Of our 61 patients, 34 (55.7%) were male and 27 (44.3%) were female, and their mean age was 31.2 ± 9.4 years. We have found 31 (50.8%) variations in the right renal arteries and 21 (34.4%) in the left renal arteries. Of these patients, 13 had bilateral renal arterial variations. The late confluence of the renal vein was found in 3.3% of males, multiple right renal veins in 7 (11.5%), and left renal veins in 2 (3.3%). By distributing the data according to gender, we noticed more diversity in the renal vessels of male patients. Left renal artery variations were more frequent in males (16, 76.2%) than in females (5, 23.8%), and they were statistically significant (p=0.02). Likewise, variations in the right renal arteries were also more frequently found in males (19, 61.3%) as compared to females (12, 38.7%). Right renal vein variations were more common in males (9, 81.8%) as compared to females (2, 18.2%) (p=0.05). Frequent renal vascular variations and incidental pathologies in potential living donors were found by MDCT examination, and these vascular variations should be analyzed before renal transplant.

Evaluation of renal vascular variations with computed tomography

BackgroundIt is important to know the renal vascular variations before renal surgeries and invasive procedures. The aim of this study is to evaluate the prevalence and types of variation of renal arteries and veins.MethodsThe abdominal CT images of 460 patients, taken between 2019 and 2021, were retrospectively analyzed in axial and coronal planes. The presence and number of accessory renal arteries and early branching in the main renal artery were evaluated. Then, bilateral renal vein variations were investigated. Finally, the compression of the left renal vein by different anatomical structures was evaluated.ResultsOf the 450 patients included in the study, the mean age was 53 years. No variations were detected in 378 renal arteries on the right side (84%) and 392 renal arteries on the left side (87.1%). The most common variation in renal arteries was an accessory inferior hilar artery in 7.5% and 6% rates on the right and left, respectively. An accessory inferior renal polar artery was observed at an overall rate of 1.3%. An accessory superior renal hilar artery was found at 3.3% and 2% rates on the left and the right, respectively. An accessory superior renal polar artery was found at an overall rate of 3.5%. Multiple variations in the renal arteries were observed at a rate of 6.4%. Early branching was observed at a rate of 4.9% on the right and 2.2% on the left. The presence of two and three right renal veins was observed at rates of 13.1% and 0.6%, respectively. Retroaortic and circumaortic left renal veins were found at 3.5% and 4.4% rates, respectively. The compression on the anterior and posterior left renal veins was observed at 4.6% and 0.9% rates, respectively.ConclusionConsidering that variations in renal arteries and veins are too many and of different types to underestimate, a CT examination for the renal vascular anatomy before and at the planning phase of renal surgery or interventional procedures will be of great benefit to avoid potential complications.

Does a Renal Vascular Variation in the Renal Allograft Determine the Outcome of Renal Transplantation? Experience from the National Kidney Transplantation Center, Ethiopia

Does a Renal Vascular Variation in the Renal Allograft Determine the Outcome of Renal Transplantation? Experience from the National Kidney Transplantation Center, Ethiopia

Evaluation of Renal Artery Anatomical Variations Using Multi-Detector Computerized Tomographic Scan in Sudan

Evaluation of Renal vascular anatomical variations Using Multi-Detector Computerized Tomographic scan in Sudan, the total number of patients studied is 400, 202 (50.5%) male and 98 (49.5%) females, and their ages ranged between (3 - 94) years. The types of Accessory renal arteries were 1.8% (7/24) upper pole, 1.8% (7/24) lower pole and 2.5% (10/24) hilus. In males, 4 upper pole, 4 lower pole and 7 hilus. In females, 3 upper pole, 3 lower pole and 3 hilus. The percentage of right accessory renal arteries is almost twice that of the left and more than twice the bilateral accessory arteries. Accessory renal artery is a common but a significant anatomical variant of the renal vascular system, due to their clinical importance. In our sample, the accessory renal artery presence was detected in 6% and displayed a greater variation on the right than the left side. Because this abnormality plays an important role in kidney transplantations, in radiological, vascular and urological interventions, a detailed presentation of accessory renal artery incidence was conducted, gathering from the literature a large number of relevant studies in order to create a classification according to population, gender, side and specimen. The study concluded that the renal arteries present a broad spectrum of variability in their morphological expression regarding their length, diameter and entrance to the kidney parenchyma, additional arteries’ morphological expression was higher in men than women. This is statistically not significant and variation in the right side was found greater frequency than the left side.

Renal Vascular and Ureteral Anatomic Variations in 1859 Potential Living Renal Donors

Renal vascular and ureteral anomalies detected by preoperative computed tomography angiography (CTA) are important for determining the side of the donor nephrectomy and the optimal surgical technique. In the present study, we aimed to examine the renal vascular and ureteral variations in living kidney donor candidates. A retrospective analysis was made of 1859 patients who were examined in our clinic as donor nephrectomy candidates between November 2008 and December 2019. Renal CTA images were acquired using a 64-channel multidetector computed tomography scanner, and renal vascular and ureteral variations were evaluated. The prevalence rates of multiple renal arteries on the right and left sides were 18.3% and 22.6%, respectively. The prevalence rates of early branching of the renal arteries, in turn, were 6.3% on the right side and 6.5% on the left side. The overall rate of renal artery variations on both the right and left sides was significantly higher in male individuals than in female individuals (P < .001). Multiple renal veins rates were 28.2% and 2.3% on the right and left sides, respectively, and the short renal veins rates on the right and left sides were 10.1% and 4.35%, respectively. Among the 941 cases undergoing donor nephrectomy, the procedure was completed by laparoscopy in 815 and by conversion from laparoscopic to open surgery in 36. The rate of vascular variations was higher in the conversion to open surgery group than in the laparoscopy group (P=.015). Careful preoperative assessments of donor renal vascular and ureteral anatomy and variations in CTA are essential for successful and safe renal transplant.

Renal vascular variations among kidney donors presented at the national kidney transplantation center, Addis Ababa, Ethiopia

BackgroundRenal vascular anatomy is known for presenting a wide range of variations as illustrated by previous cadaveric and imaging studies. However, the pattern of renal vascular variations is not well known in Ethiopian population. Hence, the present study is aimed at evaluating the renal vascular variations among kidney donors presented at the national kidney transplantation center, Addis Ababa, Ethiopia. MethodsInstitution based cross-sectional study was performed through a retrospective review of the charts of kidney donors underwent donor nephrectomy at the transplantation center from 2015 to 2020. We studied 120 donors, 61 (50.8 %) males and 59 (49.2 %) females. Age range is 20–62 years (mean = 34.88 ± 11.4). Descriptive statistical analysis was done by using SPSS version 25. ResultThere were 240 kidneys from 120 donors. Renal vascular variations of any kind were found in 59 kidneys (25 right and 34 left) among 46 (38.8 %) donors (29 male, 17 female). Variations were significantly more common in males, P = 0.035. Arterial variations identified in this study were accessory renal artery, which is the most common variation (23.3 %), early branching (prehilar) renal artery (10.8 %) and unusual branching pattern of renal artery (4.1 %). The identified renal venous variations were accessory renal vein (9.1 %), late confluence of renal vein (0.8 %) and retroaortic left renal vein (0.8 %). Vascular variants showed no statistically significant association with laterality. ConclusionThis study has shown that variations of the renal arterial and venous anatomy are a frequent finding among Ethiopians. All of the described variants have significant implications for treatment planning for a variety of surgical procedures. Radiologists and surgeons must be aware of all possible variants to avoid diagnostic pitfalls and for optimization of surgical techniques to prevent avoidable postsurgical morbidities.

Evaluation of Renal Vascular Variations with Multi-Section Computerized Tomography Angiography

Evaluation of Renal Vascular Variations with Multi-Section Computerized Tomography Angiography

Normal Anatomy and Variants of Renal Vasculature with Multidetector Computed Tomography in a Tertiary Care Hospital: A Descriptive Cross-sectional Study.

Preoperative multisection computed tomography evaluation can provide necessary anatomic information in minimally invasive surgeries. This study was done to estimate the preva-lence and pattern of variations of renal vasculature through contrast-enhanced computed tomogra-phy in patients referred to the radiology department of a tertiary care hospital. A descriptive cross-sectional study was conducted from 6th April 2016 to 6th April 2017. Ethical approval was taken. The triple-phase contrast-enhanced computed tomography was per-formed on 188 patients enrolled through convenient sampling. The images were evaluated in un-enhanced, arterial, and venous phases for the vascular variants. Data were analyzed based on the anatomical types of variations and descriptive statistics such as frequency and percentage using the Statistical Package for the Social Sciences. Out of the 188 patients, 60 (31.9%) had accessory renal arteries. The most common variant was hilar arteries which comprised 38 cases (20.2%) whereas polar arteries were present in 21 (11.1%)cases and the capsular artery was present in one (0.5%) case. Early bifurcation of the renal artery was noted in 15 (8%) cases with 10 (5.3%) on the right and 5 (2.7%) on the left side. Twelve (6.3%) cases of the double right renal vein were noted whereas retroaortic left renal vein was noted in only 4(2.1%) cases. Based on our study, almost one in three patients had accessory renal arteries and eighty-five out of a thousand patients had variants of renal veins.

Three-dimensional nephrometry scoring system: a precise scoring system to evaluate complexity of renal tumors suitable for partial nephrectomy.

PurposeSeveral nephrometry scoring systems have been developed based on two-dimensional computerized tomography images to quantify anatomical features of renal tumors. We have developed an accurate three-dimensional nephrometry scoring system to respond to the urgent need for advanced systems based on three-dimensional images.Materials and MethodsWe retrospectively reviewed 135 patients who underwent partial nephrectomy in our institution. Stereoscopic models were reconstructed from preoperative computerized tomography images and three-dimensional scores were assigned directly on stereoscopic models. All tumors were analyzed for following features: tumor volume; endophytic tumor proportion; renal vascular variations; tumor’s relationships with urinary collecting system or renal sinus; longitudinal distance from tumor to equatorial plane. Correlation between three-dimensional score and warm ischemic time was calculated compared with existing classical nephrometry scoring systems. The value of nephrometry scoring systems predicting longer warm ischemic time was explored by receiver operating characteristic curves.ResultsMean tumor volume was 31.25 ml; endophytic volume was less than 50% in 42 cases, more than 50% in 79 cases, and 100% in 14 cases; mean longitudinal distance from tumor to equatorial plane was 1.41 cm; 30 patients (22.2%) presented renal vascular variations; 18 cases (13.3%) involved both urinary collecting system and sinus. Mean three-dimensional score was 8.3. Variance analysis and covariance analysis revealed warm ischemic time a significant association with all evaluated tumor features. Furthermore, three-dimensional scores most highly correlated with warm ischemic time (rs = 0.64, p < 0.001), followed by R.E.N.A.L. scores (rs = 0.21, p = 0.012), centrality index (rs = − 0.20, p = 0.019) and Preoperative Aspects and Dimensions Used for Anatomy score (rs = 0.20, p = 0.019). Area under curve of above nephrometry scoring systems was 0.91, 0.67, 0.68 and 0.67 respectively (p < 0.05).ConclusionsThe three-dimensional scoring system developed in this study was a highly-accurate system to quantify the anatomical features of renal tumors. It was identified to have a value in predicting duration of warm ischemic time.

Prevalence of Renal Vascular Variations in Patients Subjected to Contrast CT Abdomen

Prevalence of Renal Vascular Variations in Patients Subjected to Contrast CT Abdomen

Variations of renal vascular anatomy in a nigerian population: A computerized tomography studys.

A broad spectrum of renal vascular variations has been reported by anatomists and radiologists. The prevalence of these variations is extremely divergent in different populations. Therefore, radiologists and surgeons in different climes must be knowledgeable about the type and prevalence of the variants in their area of practice to avoid diagnostic pitfalls and for optimization of surgical techniques. The objective of this study is to describe the types and prevalence of renal vascular variations among patients undergoing contrast-enhanced computerized tomography (CECT) of the abdomen in a Nigerian population, as well as provide a concise review of literature on the embryological basis and clinical significance of the identified variations. This study was a retrospective review of 200 CECT of the abdomen to identify variations of arterial (accessory, early branching, and precaval) and venous (multiple, retroaortic, and circumaortic) anatomy of the kidneys. We studied 200 patients, 102 (51%) females and 98 (49%) males. Age range is 18-90 years (mean = 53.08 ± 17.01). Prevalence of any renal vascular variations was 50%, arterial variations were 37%, and venous variations were 13%. Variations were significantly more common in males, P = 0.000075. The most common arterial variant was the accessory renal artery (23%) seen in 10% (right) and 13.0% (left); early branching was seen in 4.0% (right) and 0.5% (left) as well as precaval right renal artery seen in 4.5%. Venous variants were late confluence 3.0% (right) and 2.5% (left); multiple veins was seen in 2.5% (right) and 2.5% (left) as well as retroaortic left renal vein seen in 2.0%. The inferior polar accessory artery was the most prevalent accessory artery. Early arterial bifurcation was significantly more common on the right (P = 0.016) while other vascular variants showed no statistically significant association with laterality. Variation of renal vascular anatomy is a frequent finding among Nigerians. Radiologists and surgeons must be aware of these variants for optimization of surgical techniques.

Multiple renal vascular variations with double ureter

We describe a case involving globe perforation after phacoemulsification in an eye with high axial myopia. Retinal and vitreous hemorrhages were seen. A retinal break was noted in the inferotemporal quadrant on indirect ophthalmoscopy. Barrage laser photocoagulation of the retinal break was done immediately, and antibiotic steroid eyedrops were started. The patient was followed until the hemorrhages cleared, after which cataract surgery was performed. The final corrected distance visual acuity was 6/9. In this case, the perforation was noted early and appropriate management was performed immediately. Early diagnosis and intervention are warranted in cases of iatrogenic globe perforation.

Oblique Retro-Aortic Left Renal Vein and its Clinical Importance.

Kidneys are the organs that remove the waste products of the metabolic activities. A smooth blood flow to the kidneys is essential to maintain their function. Abnormalities of the renal vasculature may result not only in impairing the renal function but can lead to conditions like varicocele. During an autopsy of an adult male, we observed renal vascular variations. The left renal vein had a retro-aortic course before its termination into the inferior vena cava. It was joined with the inferior vena cava at the level of inferior mesenteric artery with an acute angle. The left testicular vein joined the left renal vein with an acute angle. The right kidney was supplied by two renal arteries. The knowledge about retro-aortic course of the left renal vein may be important during renal transplantation. The oblique course of left renal vein and the termination of left testicular vein into it with an acute angle may increase the chances of left sided varicocele.

The Radiological Scrutiny of the Relation between Renal Vascular Dimensions and Anatomical Variation of Renal Arteries: The Must to Know before Renal Transplantation

Renal transplantation is the preferred treatment of patients suffering from end stage renal disease. Because of challenges in performing surgical vascular anastomosis in variant renal anatomy, knowledge on renal vascular anatomy is very important in the pre surgical workup of potential kidney donors. These anatomical variations differ geographically and ethnically. In Kenya there has been scanty statistics on prevalence of extra-renal branching of arteries but also the clear knowledge in the understanding of the relation between renal sizes, their main arterial diameters in predicting the presence of accessory arteries without invasive diagnostic methods. This study was designed to add into the body of literature more information about the dimensions of renal vascular anatomy of adult African population in Kenya and transmit this knowledge to enrich the renal surgery practice in the region and beyond. Therefore the aim of this study was to determining the relationship between kidney size, main renal arterial caliber and how they relate in the presence or absence of accessory arteries. The study was a three-year crosssectional descriptive study conducted at Kenyatta National Hospital from June 2008 to June 2011. A total of 204 cases including 103 (50.5%) females and 101 (49.5%) males were recruited for CTA. Most normal sized kidneys with accessory arteries had smaller main renal arterial diameters. Extra renal branching occurred in 14.7% of cases. It is concluded that the presence of accessory arteries cannot be determined by the study of kidney sizes alone. The current value of Renal CTA cannot be easily replaced by simplified noninvasive modalities for indirect and accurate study of renal vascular anatomy of potential kidney donors.

Prevalence of renal vascular variations: Evaluation with MDCT angiography.

The purpose of this retrospective study was to investigate the prevalence of renal artery (RA) and renal vein (RV) variations, the distribution of these variations with respect to gender and the types of RA and RV variations on multi-detector computed tomographic (MDCT) angiography. The MDCT angiography examinations of 504 patients (317 men, 187 women) with a mean age of 56.4 years±11.7 (SD) (range: 18-92 years) were retrospectively reviewed to determine the number and branching pattern of the RAs and the number and variations of the RVs (retroaortic or circumaortic left RV, late venous confluence). The prevalence of multiple RAs was 31.3% (22.2% for two RAs, 7.5% for three RAs, 1.4% for four RAs, 0.2% for five RAs) and prehilar branching was 6.5%. The prevalence of multiple right RVs was 21.6% (19.2% for two RVs, 2.2% for three RVs and, 0.2% for four RVs). The prevalence of circumaortic left RV was 5.2%, retroaortic left RV was 4.2% and, late venous confluence was 7.3%. No associations were found between gender and presence of RA or RV variations (P=0.630 and 0.650, respectively). Accessory RAs are frequently observed. Multiple right RVs is the most common RV variation. No associations are found between gender and RA or RV variations.

Evaluation of renal vascular anatomy in live renal donors: Role of multi detector computed tomography.

Background:Evaluation of renal vascular variations is important in renal donors to avoid vascular complications during surgery. Venous variations, mainly resulting from the errors of the embryological development, are frequently observed.Aim:This retrospective cross-sectional study aimed to investigate the renal vascular variants with multidetector computed tomography (MDCT) angiography to provide valuable information for surgery and its correlations with surgical findings.Materials and Methods:A total of 200 patients underwent MDCT angiography as a routine work up for live renal donors. The number, course, and drainage patterns of the renal veins were retrospectively observed from the scans. Anomalies of renal veins and inferior vena cava (IVC) were recorded and classified. Multiplanar reformations (MPRs), maximum intensity projections, and volume rendering were used for analysis. The results obtained were correlated surgically.Results:In the present study, out of 200 healthy donors, the standard pattern of drainage of renal veins was observed in only 67% of donors on the right side and 92% of donors on the left side. Supernumerary renal veins in the form of dual and triple renal veins were seen on the right side in about 32.5% of donors (dual right renal veins in 30.5% cases and triple right renal veins in 2.5% cases). Variations on the left side were classified into four groups: supernumerary, retro-aortic, circumaortic, and plexiform left renal veins in 1%, 2.5%, 4%, 0.5%, cases respectively.Conclusions:Developmental variations in renal veins can be easily detected on computed tomography scan, which can go unnoticed and can pose a fatal threat during major surgeries such as donor nephrectomies in otherwise healthy donors if undiagnosed.

Variation of right renal artery duplication with retroaortic left renal vein: a case report

Variations of renal arteries and veins are of particular importance in the treatment of renal and renovascular conditions. Multiphase upper abdominal computed tomography of a 68-year-old male patient with renal cell carcinoma of right kidney revealed duplication of right renal artery and retroaortic left renal vein variation. Differential diagnosis should be made with great care in patients with renal neoplasms since variations may complicate diagnostic procedures. Here, we present a rare variation. Knowledge of variations accompanied by pathologies as in our case may be important as it can affect diagnostic and treatment procedures. The aim of this case report and literature review is to increase awareness about renal vascular variations among clinicians and oncologists who work in this field. Keywords: retroaortic left renal vein; right renal artery duplication; variation

From Open to Laparoscopic Living-donor Nephrectomy: Changing the Paradigm in a High-volume Transplant Center

In 1995, Ratner et al reported the first laparoscopic living-donor nephrectomy, and since then this approach is gradually replacing traditional open surgery. The learning curve of the procedure is still unclear and lessons taken from initial experience series are of utmost importance. We retrospectively analyzed our initial 50 living-donor laparoscopic nephrectomies, of which 90% were performed on the left side. Renal vascular variation occurred in 28% of donors. The median age and body mass index of the donors were 50 years (IQR 39–55) and 24.65 kg/m2 (IQR 22.5–27.3), respectively. The median operative time and warm ischemia time were 160 minutes (IQR 141–178) and 240 seconds (IQR 210–280), respectively. Estimated blood loss was 60 mL (IQR 60–127.5). The serum creatinine of the receptors was 97.6 μmol/L (IQR 87.5–139.6) 1 month after transplant. Overall, there were 5 complications, including 2 (4%) open conversions, 1 (2%) incisional hernia, 1 (2%) graft loss, and 1 (2%) reintervention. The body mass index and the multiple arteries did not influence the operative time and warm ischemia time or the recipient's serum creatinine level. Along the series, there was a significant reduction in the operative time (Spearman ρ = −5.2; P < .001), but no significant differences were found for warm ischemia time, blood loss, or serum creatinine of the recipients (P > .05). Laparoscopic donor nephrectomy is a safe procedure in centers experienced in laparoscopic surgery; however, the learning curve plateau was not reached after the initial 50 cases.