MDCT findings of right circumaortic renal vein with ectopic kidney

Multiple renal veins clogging the hilum of the right kidney

Knowledge of variations of renal vessels is of utmost importance in retroperitoneal surgeries and kidney transplant surgeries. We report concurrent variations of the right renal vessels, observed in an adult male cadaver during dissection classes. The right kidney was supplied by three renal arteries, out of which two entered the kidney through the hilum and the other one entered through the lower pole of the kidney. There were five renal veins, emerging independently from the hilum and opening separately through five openings into the inferior vena cava. Among the veins, only one emerged anterior to the renal pelvis and the other four emerged behind it. Four of them terminated into the posterolateral aspect of the inferior vena cava, whereas one terminated into its anterior aspect. Fourth vein from above, received the right testicular vein. The renal hilum was clogged with the presence of seven vessels and renal pelvis.

Circumaortic right renal vein with multiple vascular anomalies

Circumaortic right renal vein is an extremely rare finding and to our knowledge only 1 case has been reported in the literature so far. Its rareness, in contrast to left renal vein anomalies, is thought to be due to a relatively simple embryologic development of right renal vein compared with left renal vein. On the other hand, association of Circumaortic right renal vein with inferior vena cava agenesis and aortic coarctation is an extremely rare occurrence. Our aim is to introduce a case of Circumaortic right renal vein in a 3-month-old child with inferior vena cava agenesis and aortic coarctation. Discussion on the underlying embryology of Circumaortic right renal vein, its clinical importance and the association with other vascular anomalies, will be on our focus as well. Precise understanding of renal vein anomalies is important when planning retroperitoneal surgery or interventional vascular procedures. Awareness of such anomaly implies crucial knowledge for radiologists who should include it in the medical reports to aid future patient's management.

Classification of the renal vein variations: a study with multidetector computed tomography

PURPOSE

To estimate the incidence, anatomical feature as well as type of the renal vein variation with multidetector computed tomography (MDCT) in an adult population.

METHODS

A total of 1,452 patients who underwent MDCT angiography were retrospectively evaluated for the presence (number, length, origination, destination, branching pattern and course) of the renal vein variation. χ² test was used to compare the incidence of variations in left and right renal veins and the incidence of variations in each side renal vein between males and females.

RESULTS

Renal vein variations were observed in 358 patients (24.7 %, 358/1,452), which included 103 patients (7.1 %, 103/1,452) with left renal vein (LRV) variations, 279 patients (19.2 %, 279/1,452) with right renal vein (RRV) variations and 24 patients (1.7 %, 24/1,452) with bilateral renal vein variations. The frequency of RRV variations was significantly higher than that of LRV variations (p < 0.05). No statistically significant correlation was found between variations of renal vein (LRV and RRV) and gender (p > 0.05). According to the morphology of the renal vein, we classified LRV variations into five types: type I, circumaortic LRV (2.1 %, 31/1,452); type II, retroaortic LRV (2.1 %, 30/1,452); type III, abnormal reflux (1.7 %, 24/1,452); type IV, late venous confluence of LRV (0.9 %, 13/1,452); type V, rare type (0.3 %, 5/1,452), and RRV variations into three types: type 1, additional renal vein (18.7 %, 271/1,452); type 2, abnormal reflux (0.4 %, 6/1,452); type 3, rare type (0.1 %, 2/1,452).

CONCLUSION

The renal vein variations are not unusual, particularly in the RRV. Anomalies of the LRV are more complex than those of the RRV. The renal vein anatomy can be well depicted by MDCT angiography. Our new classification of the renal vein variations will improve the recognition of the renal vein morphology preoperatively.