A clinical-physiological comparative study in dogs with ileoanal pouch anastomosis with and without single and double myotomy

Resumen

Background. Some of the variability in functional results after reconstructive proctocolectomy (RP) may be explained by the excessive intrinsic motility of the ileum and ileoanal pouches. The effect of performing a single or double myotomy on several functional variables after RP was the aim of this prospective, randomized and single blinded experimental study in beagle dogs . Materials and Methods: 33 beagle dogs were randomized in three groups: Group I (12 dogs), a standard RP with a 10 cm ileal J-pouch-anal anastomosis was performed; Group II (10 dogs), a longitudinal myotomy of 8 cm on the wall of the pouch was added to the RP; Group III (11 dogs), same as group II with a further 10 cm longitudinal myotomy in the afferent pre- pouch ileum loop. Variables studied were daytime and night-time number and characteristics of the stools, as well as their changes over the study period, the intestinal transit time, measured in minutes, and the compliance and capacity of the pou- ches. Results. No difference in morbidity between groups was found. Mean nocturnal stools were statistically significant lower in groups II and III. Although we observed a trend for lower daytime stool frequency, more percentage of soft-hard stools over the study period, longer intestinal transit time and larger reservoirs in group II, none of these variables reached statistical significant differences. Conclusions. Although the myotomies do not increase the morbidity of the RP, there is no clear clinical evidence of their effec- tiveness in providing better functional outcomes. Performing two myotomies is not better than only one. Our study do not sup- port a hypothetic use of myotomies for patients with functional failure after a RP.