Surgical Anatomy and Configuration of Sphincter Muscles in Pouch Colon.

Introduction: Anatomy of striated sphincters and its three-dimensional (3-D) visualization in anorectal malformations are well reported but the configuration and 3-D visualization of sphincters in pouch colon is not well documented. This communication reports the configuration of striated muscle complex in cases of pouch colon. Patients and methods: The study was conducted in 2 females and 4 male patients of pouch colon. Preoperative study was conducted by CT imaging of striated muscle complex by obtaining 3 mm slices with 0.5 mm overlap. The selective images of striated sphincters from each slice was transferred to 3-D doctor Software for visualization of entire muscle complex. Intra operative study was conducted by preservation and dissection of bladder bowel fistula under magnification and histology. During PSARP contraction of split-opened striated muscle was recorded and studied in slow motion reproduction. Results: Striated sphincters were well developed in 5 patients of pouch colon and the configuration was similar to the pattern described for anorectal malformations. In one patient sphincter was poorly developed with ribbon thin striated muscle complex. In all patients longitudinal muscle coat was present around the fistula and the thickening of circular muscle was also recorded on histology. Conclusion: Study of anatomy and muscle contraction in pouch colon indicates that parasagittal muscle, vertical muscle complex and levator ani are well developed in most cases and form a single functional unit. Colovesical fistula is surrounded by longitudinal muscle coat and internal sphincter like thickening of circular muscle is present, which may be preserved during PSARP. [ABSTRACT FROM AUTHOR]