Anatomical Arrangement of Renal Hilar Structures

The ureter is the most posterior structure at the renal hilum, positioned behind both the renal artery and renal vein. 1

Normal Anatomical Arrangement

The typical arrangement of structures at the renal hilum from anterior to posterior is:

This anatomical relationship is important to understand for various surgical procedures involving the kidney and urinary tract.

While the standard arrangement follows the "VAU" pattern (Vein-Artery-Ureter from anterior to posterior), several variations exist:

Six different patterns of hilar structures have been documented, with the classic arrangement being the most common (30.3% of cases) 1
Variations in renal vasculature can include accessory renal arteries and veins, which may alter the typical relationship 2, 3
In cases of kidney malrotation or ectopia, the relationship between these structures may be altered 2

Understanding the posterior position of the ureter relative to the renal vessels has important clinical implications:

During surgical procedures involving the upper ureter, preservation of its blood supply is essential to prevent ischemic complications 4
In ureteral trauma management, knowledge of the anatomical relationships helps in determining viability of ureteral segments for repair 4
When mobilizing the ureter during repair procedures, care must be taken to preserve its blood supply while recognizing its posterior position 4

The posterior position of the ureter has implications for various urological procedures:

In cases of renal trauma, the posterior position of the ureter makes it less vulnerable to direct injury compared to the more anterior vascular structures 5
During surgical exploration for ureteral injuries, direct visualization is mandatory to identify the ureter in its posterior position 5
When performing procedures involving the renal hilum, careful dissection is required to avoid damaging the ureter, which may be obscured by the more anterior vascular structures 1

The posterior position of the ureter is explained by embryological development:

The ureter develops from the ureteric bud, which grows dorsally into the metanephric blastema 6
The renal vasculature develops later, with the renal artery and vein forming anterior to the already-positioned ureter 7
This developmental sequence explains why the ureter typically maintains its posterior position relative to the renal vessels 6

The consistent posterior position of the ureter has implications for imaging and diagnosis:

On contrast-enhanced CT scans, the ureter can be identified in its posterior position relative to the renal vessels 5
Understanding this relationship helps in the interpretation of imaging studies for suspected ureteral or renal vascular injuries 5
In cases of suspected ureteral injury, the posterior position of the ureter must be considered when evaluating the relationship to surrounding structures 5