SUTURELESS RABBIT BLADDER MUCOSA PATCH GRAFT URETHROPLASTY USING DIODE-LASER AND SOLDER

Fistula and strictures at the site of sutured anastomoses are frequent complications of major urethroplasty. We harvested bladder mucosa in 26 rabbits to repair large defects in the proximal urethra using laser -activated solder in the hope that such a repair would be stronger, fa ster to create and avoid common complications seen with conventional r epair. Large oval defects were created in the proximal urethra in all animals undergoing urethroplasty. Twelve animals underwent bladder muc osa graft closure via diode (808 nm.) laser activation of an albumin-b ased solder (50% were suture-free). Fourteen additional animals underw ent closure with 7-zero polydiaxanone suture (controls). Leak pressure and time of repair were recorded for each graft. Additional sections of bladder mucosa were harvested, transected and repaired by laser wel ding to determine tensile strength. In both groups, radiography, ureth roscopy and clinical course were evaluated for as much as 6 weeks post operatively. Urethroplasty time was significantly (p < 0.01) shorter f or the laser group (13.8 +/- 2.5 minutes) than for the sutured repair group (24.0 +/- 5.3 minutes). Initial leak pressures for the lasered g rafts averaged at least 4 times those of sutured grafts (p < 0.01). Th e tensile strength for lasered bladder mucosa was 3.16 +/- 1.12 kg./cm .(2) Early retrograde urethrograms (RUG) performed at 7 days (n = 5) r evealed urinary extravasation and fistula formation in 2 control anima ls compared with a normal urethral appearance in 3 lasered repairs. Ea rly retrograde urethrograms performed at 21 days (n = 21) demonstrated smooth-walled urethras with no evidence of fistula, stricture, or uri nary extravasation in the lasered group; varying degrees of reactive m ucosal proliferation were seen in the controls. Urethroscopy confirmed these observations. At 6 weeks, histologic examination confirmed the presence of viable graft in all animals. We conclude that bladder muco sa patch graft urethroplasty using diode laser welding and albumin-bas ed solder is an attractive alternative to conventional methods.