De-serosalized muscle layer covering method for antireflux ureteroileostomy: a new operative technique and pressure study with ureterometry at the ureteroileal anastomotic site in dogs.
In pursuit of a more effective antireflux ureteroileostomy with a lower postoperative complication rate we performed a new operative technique and evaluated intraureteral pressure with ureterometry to examine the mechanism of antireflux function. A total of 11 beagle dogs were used in this study. A 3 x 2 cm. section of the ileal serosa was removed, the severed ureter was directly anastomosed to the de-serosalized area and 1 cm. of terminal ureter and the direct anastomotic site were covered with the de-serosalized ileal wall. The bladder was augmented with the ileum containing the ureter. Postoperative evaluations were performed monthly and ureterometry of the reimplanted ureter was done 6 months postoperatively. Complete reflux prevention and a low stricture rate were achieved with this procedure. Direct ureteroileal anastomosis caused stricture in 1 of the 11 ureters but the covering procedure to prevent ureteral reflux caused no ureteral strictures. When the bladder was empty, ureteral closure pressure at the intramural portion of the ureter was low. At the phase of high intravesical pressure ureteral closure pressure at the intramural ureter was as high as intravesical pressure. The de-serosalized muscle layer covering method prevented ureteral reflux completely with a low stricture rate. The antireflux function of this method seems to depend on the flexibility of the terminal ureter covered with the de-serosalized ileal wall. Reflux prevention in the low intravesical pressure phase seems to be due to extension of the ileal wall.