Circumaortic Left Renal Vein Research Articles

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

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. 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. 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. 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. 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.

Atnalı böbrekte nutcracker sendromu beklenen bir vasküler anomali midir?

Purpose: Horseshoe kidney is the most common fusion anomaly that congenital systemic and urological anomalies accompany most of the patients. In this study, we aimed to investigate its association with vascular anomalies and especially nutcracker syndrome along with accompanying urological and other systemic anomalies in children with horseshoe kidney. 
 Materials and methods: Twenty-six patients are diagnosed with horseshoe kidney in our clinic and 22 healthy children of the same age and sex were included in the study. All children were prospectively evaluated using Doppler ultrasonography in terms of renal artery and renal vein flow velocities, lumen diameters and vascular anomalies and presence of nutcracker syndrome. 
 Results: Urological anomaly was found in 50% of the children with horseshoe kidneys, and systemic anomaly in 44% of them. In Doppler ultrasonographic evaluations performed on patients to detect vascular pathologies and nutcracker syndrome; findings of nutcracker syndrome were present in 2 patients in the horseshoe kidney group, while they were detected incidentally in 1 patient in the control group. An accessory renal artery originating from the left common iliac artery was found in a case with horseshoe kidney, and a circumaortic left renal vein in one case. 
 Conclusions: In our study in which we investigated nutcracker syndrome based on the presence of vascular anomalies accompanying horseshoe kidneys in children, nutcracker syndrome findings were found in similar numbers in both groups. However, we think that these children should be followed for a long time in terms of vascular pathologies (aneurysm, rupture) and malignancies that may occur in adulthood, as well as congenital vascular anomalies.

Percentages and Gender Distribution of Anatomic Variations of Inferior Vena Cava, Renal Veins, and Posterior Lumbar Tributaries of the Left Renal Vein Left Renal Vein Drainage Variations

Objective: The aim of this study was to investigate percentages and gender distribution of the variations of the inferior vena cava (IVC), renal veins, and posterior lumbar tributaries of the left renal vein (LRV).
 Materials and Methods: For this cross sectional observational study, the computed tomography (CT) images of 1949 patients were evaluated retrospectively.
 Results: In the present study, percentages of double IVC, left IVC, and IVC interruption with azygos continuation were 0.5%, 0.2%, and 0.1%, respectively; circumaortic left renal vein (CLRV) was 6% and retroaortic left renal vein (RLRV) was 4.2%. Multiple renal vein variations were 24.1% on the right, but none on the left. Posterior lumbar tributaries of the renal veins were 0.15% on the right and 48% on the left. There was no difference between genders in terms of LRV and IVC variations. While the incidence of multiple right renal veins was statistically significantly higher in male patients compared to female patients (p = 0.045), the opposite was true for the posterior lumbar tributaries of the LRV (p = 0.035).
 Conclusion: The venous system has a wide variety of variations, and the renal venous circulation is supported by number variations on the right in men and collaterals on the left in women.

Evaluation of left renal vein and IVC variations in MDCT examinations performed in patients with a preliminary diagnosis of renal calculi

Background/Aim: Left renal vein (LRV) and inferior vena cava (IVC) variations are not rare, an observation that is extremely important to understanding the presence of these structures before performing surgery. This study aimed to evaluate the type and frequency of IVC and LRV variations with multi-detector computer tomography (MDCT) in patients admitted with a preliminary diagnosis of renal calculi and to evaluate the relationship of these variations with renal calculi, renal cysts, and horseshoe kidneys. Methods: We retrospectively analyzed 1640 patients who underwent abdominal CT for suspicious renal calculi between January 2018 and December 2019. This retrospective cohort study consisted of 1604 patients after the exclusion criteria. Renal surgery and/or renal agenesis examinations without enough diagnostic quality due to motion artifacts were considered the exclusion criteria. Age, gender, presence and types of IVC and renal variations, and presence of renal calculi, renal cysts, and horseshoe kidney were recorded. The relationship between variation types and presence of renal calculi, renal cysts, and horseshoe kidneys was evaluated. Results: IVC and LRV variations were detected in 107 patients (6.7%). The prevalence of circumaortic LRV (CLRV) and retroaortic LRV (RLRV), left IVC, and double IVC in 65 patients was 4.1%, 2.4%, 0.1%, and 0.1%, respectively. Male gender predominance in both total and RLRV were found in the variations (P=0.033 and P=0.033, respectively). Urinary calculi were found in 1016 (63.3%) of the patients, kidney cysts in 247 (15.4%), and horseshoe kidneys in 10 (0.6%). No correlation between the presence of renal calculi, kidney cysts, and horseshoe kidney and the presence of variations in patients with LRV was found (P=0.433, P=0.215, and P=0.500, respectively). Conclusions: LRV and IVC variations are not uncommon. It is necessary to be informed about these variations before performing retroperitoneal surgery to prevent possible complications. LRV and IVC variations can be easily recognized in pre-diagnosed renal calculi on MDCT without the use of an intravenous contrast agent.

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.

Evaluation of the incidence of renal vein anomalies and their relationship with renal stone disease and renal tumors by abdominal multidetector computed tomography

Purpose: This study aimed to evaluate the types and incidence of renal vein anomaly (RVA) and their relationship with renal stone disease and renal tumors with multidetector computed tomography (MDCT). 
 Materials and Methods: We evaluated retrospectively 10124 patients abdominal MDCT images. After the exclusion criteria, the final study population consisted of 9294 patients. The demographic characteristics of the patients, the presence of RVA, the presence of renal stone disease and renal tumor were recorded. RVAs were separated into three subgroups: retroaortic left renal vein (RLRV), circumaortic left renal vein (CLRV), and double right renal vein (DRRV). The presence of renal stone disease and renal tumors were recorded in patients with RVAs.
 Results: 1389 cases had RVA (14.9%). RVA was higher in males than females. The prevalence of DRRV, RLRV, and CLRV were 9.5%, 3.9%, and 1.9%, respectively. Renal tumors was detected in 20, and renal stone disease was detected in 243 of 1389 RVA cases, there was no statistically significant correlation. However, a statistically significant correlation was found between left renal stone disease with RLRV and CRLV.
 Conclusion: Contrary to popular belief, RVAs are not uncommon. It is very important to know the presence of RVA before retroperitoneal surgery to prevent possible complications. In addition, RLRV and CLRV are thought to be factors that predispose to the development of left renal stone disease.

Aneurysm of the left ascending lumbar communicating vein: Its prevalence and possible association with nutcracker phenomenon

PurposeTo evaluate abdominal computed tomography (CT) studies in respect of the prevalence of the left ascending lumbar communicating vein (ALCV) and ALCV aneurysm and to identify possible causes of aneurysm development in the ALCV. MethodsContrast-enhanced abdominal CT examinations were retrospectively investigated for the prevalence of the ALCV in the adult population. In patients with ALCV, the diameters of the following vessels were measured: ALCV, left renal vein (LRV) at two levels, compression ratio of the LRV (CR), left gonadal vein, right and left ascending lumbar veins (ALVs). The aortomesenteric angle was also measured for preaortic LRVs. ALCV aneurysm was noted during the assessment. ResultsEvaluation was made of 500 patients. ALCV was found in 240 patients (48%), more common in patients with retroaortic LRV and circumaortic LRV than in patients with preaortic LRV (p = 0.003). The mean diameter of the ALCV was 3.85 ± 2.06 mm. ALCV and the left gonadal vein merged to form a common vein draining into the LRV in 23 patients with preaortic LRV (9.6%). Of the patients with ALCV, 19 (8%) had aneurysm. The diameter of the left ALV and CR were significantly greater in patients with aneurysm than in patients without (p = 0.001 and 0.032, respectively). Patients with ALCV aneurysm had a significantly narrower aortomesenteric angle (p = 0.004). ConclusionThe results of this study indicated that a narrower aortomesenteric angle and a greater CR might play a role in the development of ALCV aneurysm.

Prevalence of Congenital Anomalies of the Inferior Vena Cava: CT Assessment in Thai Patients

Objective: To determine the prevalence of inferior vena cava (IVC) anomalies in Thai patients who underwent contrast-enhanced computed tomography (CT) of the abdomen. Materials and Methods: Two radiologists retrospectively and independently reviewed the contrast-enhanced abdominal CT examinations in 1,429 Thai patients between August 1, 2018 and January 25, 2019 who met the inclusion criteria. Patients were included, if (a) their CT showed well visualized IVC, renal veins, and right ureter that were not obliterated by tumor, cyst, fluid collection, or intraperitoneal free fluid, (b) they had not undergone previous abdominal surgery that altered anatomical configuration of the IVC, renal veins, and right ureter. The presence of all IVC anomalies were recorded. Results: Among the 1,429 studied patients, 678 were male (47.4%) and 751 were female (52.6%). The prevalence of IVC anomalies was 3.5%. Five types of IVC anomalies were presented. The most common was circumaortic left renal vein in 24 patients or 48.0% of all IVC anomalies and 1.7% of the study population, followed by retroaortic left renal vein in 15 patients or 30.0 % of all IVC anomalies and 1.0% of the study population. Other IVC anomalies included double IVC, left IVC, and retrocaval ureter at 0.5%, 0.2%, and 0.1% of the study population, respectively. Conclusion: The prevalence of IVC anomalies in the present study differed from the previous studies conducted in other countries, which may be attributable to differences in race and ethnicity. Awareness of these anomalies is essential when evaluating routine CT examinations in asymptomatic patients. Their presence should be carefully noted in radiology reports to avoid anomaly-related complications. Keywords: Prevalence; IVC anomalies; Circumaortic left renal vein; Retroaortic left renal vein; Double IVC; Left IVC; Retrocaval ureter

Variations in the Number and Drainage Levels of Retroaortic Left Renal Veins

Abstract Aim: Circumaortic left renal vein (CLRV) and retroaortic left renal vein (RLRV) are the most common variations of the left renal vein and have a retroaortic course. We aimed to detect the anatomical variations of retroaortic left renal veins in terms of their number and entrance levels into the inferior vena cava (IVC). Materials and Methods: The computed tomographic (CT) images of 2804 patients who had undergone abdominal CT examinations in our hospital between May 1, 2017, and June 30, 2017, were evaluated. Results: CLRV variations were detected in 139 (4.96%) patients, while in another 132 (4.71%) RLRV variations were detected. Double branches were present in 15 (10.8%) patients in the RLRV group, and 3 patients (2.3%) in the CLRV group. The most common drainage levels into the IVC for these variations were the L3 vertebra level and the middle 1/3 infrarenal IVC segment. Conclusion: CLRV and RLRV may possess single or double retroaortic branches. The entrance levels into the IVC are various in these variations. Knowing these variations is important for surgical and interventional procedures.

Pelvic Venous Congestion Secondary to a Circumaortic Renal Collar in an Adolescent Female: Report of a Case

We report a 13-year-old girl who presented with a recurrent abdominal pain that started after her menarche. The abdominal palpation revealed tenderness over the left ovarian point. The laboratory study, ultrasonography, and abdominal X-ray were normal. The computed tomography and magnetic resonance imaging showed a double left renal vein with a retroaortic component, an increased left parauterine circulation, and ipsilateral ovarian vein engorgement. A diagnostic and therapeutic phlebography allowed a selective catheterization of a group of pelvic varicose veins draining to the left ovarian and to the internal iliac veins. There were no complications during the procedure and the symptoms disappeared 2 days later. Circumaortic left renal vein may cause hematuria, proteinuria, pelvic congestion syndrome, and massive hemorrhage during surgery. A conservative treatment is recommended for patients without gynecourological/renal symptoms or with mild hematuria. The endovascular treatment by gonadal venous embolization is safe and effective.

Evaluation of the frequency of left renal vein variations in computed tomography and its relationship with cancer development

Left renal vein (LRV) variations occur in 0.8-10.2% of the population. The most common LRV variations are retroaortic left renal vein (RLRV) and circumaortic left renal vein (CLRV). The purpose of this study is to determine the frequency of LRV variations in a large series on computed tomography (CT) and to investigate the association between LRV and malignancy development. Between January 2015 and January 2017, an abdominal CT examination of 12,341 (5505 female, 6836 male) patients was evaluated retrospectively in this study. Patients' clinical and demographic data were recorded using the Hospital Information System. Left renal vein variations were detected in 314 (2.54%) of the 12,341 patients within the study. Of the 314 cases found to have LRV variations, 227 (1.84%) had RLRV, and 87 (0.70%) had CLRV. There was no statistical difference in total LRV variations (p = 0.083) and CLRV variation (p = 0.96) groups in terms of gender. However, the RLRV variation was found to be 1.32 times higher in males than in females (p = 0.039). Of the 314 patients with LRV variations, 73 (23.2%) had any sort of concomitant malignancy. A high incidence of malignancy was detected in patients with LRV variations. Of the LRV variations, RLRV variation is more common than CLRV variation. The presence of total LRV variations and CLRV variations is not associated with gender; whereas the presence of RLRV variation is more common in males.

Evaluating incidence and clinical importance of renal vein anomalies with routine abdominal multidetector computed tomography.

Renal vein anomalies are usually asymptomatic embryological developmental disorders. If unidentified, they can lead to significant morbidity during surgical explorations. This study aims to evaluate the type, frequency, clinical importance of renal vein anomalies in patients scanned with Multidetector Computed Tomography (MDCT). It was also investigated whether renal vein anomalies are associated with malignancies or their types. Abdominal MDCT images of 8517 patients were examined retrospectively. Renal vein anomaly types, gender, age, and symptoms were recorded. Renal vein anomalies were divided into three subgroups as retroaortic left renal vein (RLRV), circumaortic left renal vein (CLRV), and double right renal vein (DRRV). The presence of malignancy and their types in patients with renal vein anomalies were noted. Malignancies were divided into five subgroups as lung, gastrointestinal system (GIS), genitourinary system, breast, and others. 156 patients had renal vein anomaly (1.8%). The prevalence of RLRV, CLRV, and DRRV were 1.1%, 0.3%, and 0.2%, respectively. Renal vein anomalies were more frequent in females. Malignancy was present in 89 (57.1%) out of 156 renal vein anomaly patients. Among these 89 patients, RLRV was found in 52 (58.4%), CLRV in 22 (24.7%), and DRRV in 15 (16.8%) patients. The presence of malignancy was present in more than half of the renal vein anomaly patients but there was no significant correlation (p = 0.1). This high ratio is probably due to the high number of cancer patients undergoing CT scan in our radiology department. Renal vein anomalies are rare conditions, however, coexistence of renal vein anomalies and malignancies is not. An awareness of this entity before retroperitoneal surgeries is very important in order to avoid complications such as hemorrhage, transfusion, death, or conversion to open surgery.

Circumaortic left renal vein: a rare but important anatomical variation to consider prior to a radical nephrectomy.

Circumaortic left renal vein: a rare but important anatomical variation to consider prior to a radical nephrectomy.

Anatomical Variations of the Left Renal Vein During Laparoscopic Donor Nephrectomy

ObjectivesThe aim of this study is to investigate the outcome of laparoscopic donor nephrectomy with vascular anomalies of the left renal vein. Patients and MethodsBetween August 2010 and September 2018, a total of 120 laparoscopic donor nephrectomies were performed at Kagoshima University. Among them, we experienced 7 cases of donors with anomalous left renal vein (circumaortic left renal vein n = 5, retroaortic left renal vein n = 1, left renal vein drainage into hemiazygos vein n = 1). We analyzed the following clinical outcomes: pneumoperitoneum time, estimated blood loss, warm ischemia time, length of hospital stay, and serum creatinine level of 1 month after surgery for evaluating the safety of laparoscopic donor nephrectomy. ResultsAmong the 7 cases, 3 cases underwent transperitoneal approach, and 4 cases underwent retroperitoneal approach. The median pneumoperitoneum time was 168 (108–191) minutes. The median estimated blood loss was 90 (23–170) mL, and no donor required a blood transfusion. Median warm ischemia time was 4 (3–7) minutes. Length of hospital stay was 7 (6–9) days, and no readmission occurred. Median serum creatinine level of 1 month after surgery was 1.19 (0.84–1.74) mg/dL. Kidneys were transplanted successfully, and none of recipients required dialysis. Conclusions. Laparoscopic donor nephrectomy was safe for donors with an anomalous left renal vein. Preoperative recognition of anomalous left renal vein in computed tomography is important for avoiding hemorrhagic complication.

Techniques of adrenal venous sampling in patients with inferior vena cava or renal vein anomalies.

To review the techniques and technical success rate of adrenal venous sampling (AVS) in patients with inferior vena cava (IVC) or renal vein anomalies. The techniques and success rate of AVS in 15 patients with anomalies [8 with double IVC (dIVC), 3 with left IVC (ltIVC), 2 with retroaortic left renal vein (LRV), and 2 with circumaortic LRV] underwent AVS was retrospectively reviewed. Among 11 patients with IVC anomalies, the success rates for sampling the right and left adrenal veins (RAV and LAV) were 81.8 and 90.9%, respectively. In dIVC, the LAV was selected using the following four methods: approaching through the right IVC from the right femoral vein, flipping the LAV catheter tip in the LRV (n = 4) or the interiliac-communicating vein (n = 1), or through the ltIVC from the right (n = 1) or left (n = 2) femoral vein. Among the four patients with LRV anomalies, the success rate was 100% for each adrenal vein. AVS can be successfully performed in patients with anomalies. The key to technical success is understanding the venous anatomy based on pre-procedural CT images and choosing appropriate methods.

Secondary vascular alterations in nutcracker phenomenon and its variants on multidetector CT

Objectives: Nutcracker phenomenon is caused by the compression of left renal vein between the superior mesenteric artery and the aorta. There are also variants namely the ‘posterior nutcracker phenomenon’ where the posteriorly located retroaortic or circumaortic left renal vein is compressed between the aorta and the vertebral body. The aim of this study is to define vascular alterations in veins other than the left renal vein secondary to anterior and posterior nutcracker phenomena and emphasize their contribution to diagnosis. Methods: Computed tomography images of 57 patients with nutcracker phenomenon were retrospectively nvestigated fort he presence of secondary vascular alterations. In addition, 169 patients with a retroaortic and 32 patienys with a circumaortic left renal vein variation were searched for thepresence of a posterior nutcracker phenomenon and associated secondary vascular findings. Results: Dilatation of left gonadal (n: 15, 26%), left lumbar or ascending lumbar (n: 9, 16%), hemiazygos (n: 4, 7%), left suprarenal (n: 4, 7%), and inferior phrenic (n:2, 4%) veins were seenin anterior nutcracker phenomenon. Pelvic varices/varicoceles pseudothrombosis in the left renal vein were present in 7(12%) and 4 ( 7%) patients, respectively.. There was a appearance in 4 patients. 14 % of 169 patients with a retroaortic left renal vein and 16 % of 32 patients with circumaortic left renal vein showed a posterior NC phenomenon and associated vascular alterations. Conclusions: Awareness of the secondary vascular findings in nutcracker phenomenon may aid in the diagnosis and guide management.

Detection of retroaortic left renal vein and circumaortic left renal vein by PET/CT images to avoid misdiagnosis and support possible surgical procedures.

We aimed to identify retroaortic left renal vein (RLRV) and circumaortic left renal vein (CLRV) by using positron emission tomography/computed tomography (PET/CT) images, to obtain their percentages and to evaluate the effect of gender on their frequencies. Plain CT and fluorine-18-2-fluoro-2-deoxy-D-glucose PET/CT images of 222 consecutive patients who underwent oncological PET/CT imaging were used to detect RLRV and CLRV. The numbers and percentages of total left renal vein (LRV) variations, RLRV and CLRV were obtained. Fisher's exact test was used to determine the relation between the LRV variations and gender. In the whole group (n=222), the percentages and the numbers of total LRV variations, RLRV and CLRV were 5.85% (n=13), 2.70% (n=6) and 3.15% (n=7), respectively. In male population (n=116), the percentages and the numbers of total LRV variations, RLRV, and CLRV were 6.03% (n=7), 2.58% (n=3) and 3.45% (n=4), respectively. In female population (n=106), the percentages and the numbers of total LRV variations, RLRV, and CLRV were 5.66% (n=6), 2.83% (n=3) and 2.83% (n=3), respectively. The percentages of RLRV and CLRV were found to be independent of gender (P=1.000). PET/CT is a useful imaging modality in detecting RLRV and CLRV. The relationship of gender with RLRV or CLRV was not statistically significant.

SOL RENAL VENİN NADİR GÖRÜLEN ANOMALİSİ: İKİ VAKANIN SUNUMU

Introduction: Retroperitoneal vascular structure anomalies are not uncommon, with an incidence of 13 to 30 per 100 people. Renal vascular anomalies are responsible for more than half of the cases. Case: We report a circumaortic left renal vein during the staging surgery of a 39 years-old woman with ovarian tumor and a retroaortic left renal vein during the surgery of 43 years-old woman with ovarian tumor. There was no vascular injury associated with these anomalies. Conclusion: While dealing with retroperitoneum, it is important to be aware of possible anomalies of vascular and renal structures for the surgeons because these anomalies can easily mislead the surgeon and there can be serious injury associated with these vessels.

Symptomatic congenital saccular aneurysm of the inferior vena cava associated with a circumaortic left renal vein.

Congenital saccular aneurysms of the inferior vena cava (IVC) are extremely rare, with 23 cases reported so far. We present a case of a 55-year-old woman with an acute episode of back pain that mimicked aortic dissection. Computed tomography ruled out aortic dissection but demonstrated a saccular aneurysm of the infrarenal IVC and a circumaortic left renal vein. The saccular aneurysm was excised, and the postoperative anatomopathologic examination revealed that it was congenital in nature. Surprisingly, preoperative symptoms of recurrent palpitations, dyspnea, and positional abdominal discomfort resolved after resection. This is the first reported case of a symptomatic congenital saccular aneurysm of the IVC with an associated circumaortic left renal vein.

Étude radiologique des variations anatomiques des veines rénales par scanner multidétecteurs en coupes fines

To determine the prevalence of renal vein variants. To investigate the distribution of renal veins. We retrospectively reviewed spiral computed tomography (CT) scans of the abdomen performed during a two-month period. The same protocol was used for all CT scans: same multidetector-row CT scanner (Siemens(®)), 1 to 2-mm section thickness, injection of intravenous iomeprol. The study group included 121 patients, aged 21.7 to 93.4 years (mean age 60.9 ± 15.4 years). The sex ratio was 2/1, with 80 men and 41 women. Seventy-three percent of the study group (88 patients) had no variants of the renal veins. Indeed almost 40% (48 patients) had one artery and one vein on each side, with typical course, and 33% (40 patients) had course and/or number variants of the renal arteries. Variants of the right renal vein consisted in multiple veins in 20.6% (25 cases). We detected no case of multiple left renal veins, but we described variations of its course in 9.1% (11 cases): 5 cases of retroaortic left renal vein (4.1%) and 6 cases of circumaortic left renal vein (5%). Three of these 11 patients had an associated double right renal vein. The probability to have a right renal vein variant was significantly higher than a left one (OR = 2.6, P = 0.01). And we found a significantly higher risk of having a venous variant in women (OR = 2.4, P = 0.04). We detected no case of inferior vena cava variant. In our study, prevalence of a circum- or retroaortic left renal vein appeared higher than previously reported in the literature (9.1%). Knowledge of anatomical variants of renal vasculature is crucial and this study puts the emphasis on variations of course and number of renal vessels. Those variations are not so uncommon and should be known by radiologists and also by surgeons. Their knowledge has major clinical implications in practice and it contributes to the safety of renal and retroperitoneal surgery.