Background: The success of kidney transplant surgery and ureteral reco
nstruction requires the preservation of the ureteral blood supply, Bec
ause of its potential vulnerability to surgical trauma during transpla
nt and reconstructive surgery, the ureteral vasculature merits a full
anatomical description. Methods: The microvascular anatomy of the uret
er was studied in male New Zealand white rabbits by light microscopy a
nd transmission electron microscopy and scanning electron microscopy o
f vascular corrosion casts and alkali digested tissue. Results: The ra
bbit 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 n
o external vascular connections to the middle ureter with the exceptio
n 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 ve
ssels pass tangentially through the muscularis to supply a vascular co
mplex within the lamina propria. This complex in turn supports a rich,
mucosal capillary plexus located at the junction between the transiti
onal epithelium and the lamina propria, In the fixed ureter the capill
ary plexus lies in grooves formed by displacement of the basal layers
of the overlying transitional epithelium, The capillaries are continuo
us or fenestrated, are often invested with pericytes, and are distribu
ted uniformly around the entire circumference of the ureter. Conclusio
ns: The ureteral vasculature exhibits several unique features related
to its function in urine conduction and its ability to accommodate exp
ansion and contraction. The combination of techniques used provides a
clear three-dimensional view of this vasculature, Our findings also co
nfirm that, because of its limited blood supply, the meter may be very
susceptible to injury during renal transplantation or other abdominal
surgery. (C) 1995 Wiley-Liss, Inc.