Experimental model of continent colostomy using rectus abdominis neosphincteroplasty

Background: Use of dynamic myoplasty to create a continent stoma has produced promising results, but long-term stoma continence has not been achieved. The aim of the study was to establish and test a new model.

Methods: Three types of dynamic rectus abdominis sphincteroplasty around a colostomy and two conditioning protocols were tested in ten domestic pigs. Continence was assessed by means of conventional defaecography and neosphincter manometry after 8 and 12 weeks. The neosphincter muscle was studied histologically to assess the transformation of muscle type.

Results: Use of a distal rectus muscle sling surrounding the stoma by 270 degrees with a low-frequency conditioning protocol achieved a continent colostomy for more than 12 h on each of 5 consecutive days. The neosphincter had a 40-mm high-pressure segment with mean pressure of 74 (range 67-82) mmHg. The proportion of type I muscle fibres increased from 38 (range 32-42) to 74 (range 66-78) per cent after 12 weeks of conditioning.

Conclusion: This pilot study demonstrated the feasibility of a continent stoma in an animal model with a dynamic rectus neosphincter. Long-term results should be confirmed in a larger series before use in humans can be considered.