Objective: To study the morphology and function of the upper urinary tract over the long-term in dogs with an enterocystoplasty and a refluxing or anti-refluxing uretero-intestinal anastomosis.
Materials and methods: Subtotal cystectomy and "cup" ileocystoplasty were performed in 13 dogs. The right ureter was implanted into the cystoplasty with a refluxing technique in seven and with an anti-reflux procedure in six dogs. The left renal unit acted as an intact control in 11 dogs, while in two the intramural part of the left ureter was incised to produce reflux. Thus, of the 26 renal units, nine had a refluxing junction (anastomosis), six were anti-refluxing and 11 served as intact controls. Total and separate glomerular filtration rates (GFRs) were measured preoperatively and regularly thereafter, and cystometry, urography and ascending enterocystography were performed. At necropsy, urine was obtained for culture from the cystoplasty and renal pelves, and both kidneys were examined histologically.
Results: The cystometric pressure was low in 12 of the 13 dogs: urography showed no obstruction. The fall in separate GFR did not differ significantly among the groups (with and without reflux protection, and control units). Reflux was detected in three of nine renal units with refluxing anastomosis and in three of 11 control units. Bacteriuria was found in the cystoplasty in all dogs; the incidence in the upper urinary tract was seven of eight renal units with a refluxing anastomosis, one in five of those with an anti-refluxing anastomosis and three of nine control units. Pyelonephritis was found in none of the control kidneys, in six of nine kidneys with a refluxing and in two of six with an anti-refluxing anastomosis: it was less severe in the latter.
Conclusion: Refluxing ureteric implantation in a low-pressure enterocystoplasty was commonly associated with bacteriuria in the upper urinary tract and with pyelonephritis. Thus, anti-reflux implantation was beneficial for renal preservation in this setting.