Vascular anatomy of the rabbit ureter

The success of kidney transplant surgery and ureteral reconstruction requires the preservation of the ureteral blood supply. Because of its potential vulnerability to surgical trauma during transplant and reconstructive surgery, the ureteral vasculature merits a full anatomical description.

The microvascular anatomy of the ureter was studied in male New Zealand white rabbits by light microscopy and transmission electron microscopy and scanning electron microscopy of vascular corrosion casts and alkali digested tissue.

The rabbit ureter is supplied predominantly by a branch of the renal artery proximally (cranial ureteral artery) and by a branch of the vesicular artery distally (caudal ureteral artery). Minor vascular continuities are also present between the capillary beds of the ureter and those of the renal pelvis cranially and the bladder wall caudally. There are no external vascular connections to the middle ureter with the exception of a single, small vein which drains into the inferior vena cava. A single group of longitudinal arteries and veins runs the full length of the ureter within the adventitia. Branches of these longitudinal vessels pass tangentially through the muscularis to supply a vascular complex within the lamina propria. This complex in turn supports a rich, mucosal capillary plexus located at the junction between the transitional epithelium and the lamina propria. In the fixed ureter the capillary plexus lies in grooves formed by displacement of the basal layers of the overlying transitional epithelium. The capillaries are continuous or fenestrated, are often invested with pericytes, and are distributed uniformly around the entire circumference of the ureter.

The ureteral vasculature exhibits several unique features related to its function in urine conduction and its ability to accommodate expansion and contraction. The combination of techniques used provides a clear three-dimensional view of this vasculature. Our findings also confirm that, because of its limited blood supply, the ureter may be very susceptible to injury during renal transplantation or other abdominal surgery.