Objective: To evaluate the effect of continuous balloon distension on the treatment of anorectal stenosis.
Methods: Animal experiment on 17 guinea pigs and clinical study on 13 patients with anorectal stenosis were carried out. The procedure of the continuous balloon distension was followed to stimulate the growth of the anus or stenotic segment.
Results: In animal experiment, the procedure induced muscle growth of the external anal sphincter at a rate of 2 mm per day. The grown muscle showed good contractile ability. By histological examination, it was found that the muscle cells were hypertrophic and Schwann's cells of the nerve fibers in the muscle became hyperplastic. Under electron-microscope, the muscle sarcomeres were found splitting both transversely and longitudinally. Twelve of the 13 patients were successfully treated by continuous balloon distension within 5 to 15 days (average: 6.7 days). During 4 to 14 months follow-up, all patients defecated without difficulty.
Conclusions: Continuous balloon distension may induce growth of the external anal sphincter. This procedure is an acceptable therapy for anorectal stenosis.