Study the Possibility of Creating Mucosal Valve Mechanism at Ureteric Orifice without Obstructing the Urine Outflow but Preventing the Urine Backflow into the Ureters

OBJECTIVE

To study the possibility of creating mucosal valve mechanism at ureteric orifice without obstructing the urine outflow but preventing the urine backflow into the ureters.

MATERIALS AND METHODS

Ethical waiver was obtained from the institutional ethical committee. Prospective experimental study was conducted on the post-mortem specimen of intact bladder with urethra and bilateral ureters retrieved from the already slaughtered lamb available in the meat market. Feeding tube inserted via urethral opening into the bladder lumen and bladder inflated with saline demonstrated no reflux of urine via transverse cut opening of ureters. Bladder lumen opened, ureteric orifices incised backwards to eliminate the obliquity. After closing the bladder opening, saline inflation test demonstrated bilateral reflux of saline via cut openings of bilateral ureters. Bladder was re-opened. The upper limb of horizontal U started 10 mm lateral and 8 mm above the refluxing ureteric orifice. Distal most curvature of horizontal U was kept 5 mm medial to ureteric orifice continuing along the lower limb of horizontal U terminating 10 mm lateral and 8 mm below the refluxing ureteric orifice, mucosal flaps from superior and inferior incision mobilized and edges joined to cover the ureteric orifice creating a flap valve mechanism. Influx of saline via cut end of ureters demonstrated no obstruction. Bladder was closed. Saline inflation test and contrast study demonstrated abolition of reflux on flap side and persistence of reflux on another side.

RESULTS

Five such experiments were conducted. On the side where the valve was created, Vesicoureteral reflux was abolished in four but in one minimal reflux still persisted.

CONCLUSION

Creating a mucosal flap valve around the ureteric orifice can prevent reflux in 80% of cases without obstruction and without the necessity of ureteric mobilization or creating submucosal tunnel.

Creation of effective antireflux mechanism without creation of submucosal tunnel in surgical correction of vesicoureteric reflux: Myth or reality?-An experimental study

Objective:

To evaluate the possibility of creating an effective antireflux mechanism without the need to create submucosal tunnel in surgical correction of vesicoureteric reflux.

Materials and Methods:

Ethical clearance was obtained from the institute ethical committee. The prospective experimental study was conducted on fresh postmortem specimens comprising of intact ureter-bladder-urethra of slaughtered lamb. Through perurethral tube, bladder distension revealed intact antireflux mechanism which disappeared following a cephalad slit of ureteric orifice. After intravesical advancement, mobilized ureters were anchored to the hiatus and the exposed detrusor along the proposed submucosal tunnel after stripping the bladder mucosa. Limited nonobstructed narrowing of the advanced ureteric ends was fashioned. After closure, bladder was distended and reflux was observed through proximal transected ureteric orifices with check cystogram. In second part of experiment, in a rectal reservoir, two intestinal segments as dilated ureters were implanted without creating submucosal tunnel, but anchoring the intrarectal segment to exposed submucosa. Intraluminal end of one segment was narrowed, while other left as such. Reservoir distension test was done to notice the status of reflux. In 24 months, 12 experiments were conducted.

Results:

In first part of experiment, successful antireflux mechanism was created in 11 ureters. In second part of experiment, reflux persisted in the ureteral segment implanted with obliquity but without distal nonobstructed narrowing, while there was no reflux in the ureteral segment with both obliquity and narrowing.

Conclusion:

Advancement and anchoring of the ureteral segment to the exposed detrusor with creation of nonobstructive and limited narrowing can create effective antireflux mechanism without the need to create submucosal tunnel.