Prosthetic bladder: in vivo studies on an active negative-pressure-driven device.

Active alloplastic bladders were implanted into four dogs after cystectomy and were well tolerated. The prosthesis created a vacuum of -90 cm. H2O in the upper tracts, which gradually decreased until the bladder filled. Renal function was maintained as long as the prostheses worked effectively. Hydronephrosis developed and renal function deteriorated if the bladder was not emptied, even though the leak pressure was only 3 to 5 cm. H2O. Both resolved when active bladder function was restored. Pressures in the ureter were measured percutaneously, at flow rates up to 15 ml. per minute (900 ml. per hour). At 15 ml. per minute, the pressure only reached a maximum of 16 cm. H2O. Encrustation did not occur even in the presence of infection. The results achieved with this negative pressure bladder prosthesis, which is emptied actively, are very promising and should provide the impetus for increased research in this field of urology.