Management of colovesical and colovaginal diverticular fistulas Our experience and literature reviewed.

AIM: This study aims evaluate the effectiveness of various surgical techniques in treating diverticular fistulas, and the safety and efficacy of the laparoscopic procedure comparing our results with those of the literature. MATERIAL OF STUDY: This was a prospective and uncontrolled study performed at a general surgery units. Between 2005 and 2011, 16 patients (11 men, 5 women) underwent surgery for diverticular fistulas. The mean age was 70.2 (range, 35-87) years. The medical evaluation of these patients was based on symptoms and diagnostic procedures confirming the diagnosis of diverticular fistulas. Our surgical options included one-stage, two-stage, and defunctioning procedures. RESULTS: Out of 16 cases of diverticular fistula 14 were colovesical and 2 colovaginal. One-stage procedure was performed in 12 patients, two-stage procedure in 3 and defunctioning colostomy in 1. The overall complication rate was 31.2%. We recorded 1 colovesical recurrent fistula. The laparoscopic surgery was performed in 4 patients, nobody was converted to open and there were no post-operative complications and recurrence. DISCUSSION AND CONCLUSIONS: The data show that one-stage procedure is effective in the majority of cases of diverticular fistulas. However, the surgery of colovesical and colovaginal fistulas is often associated to high complication rates. This is often due to the shoddy clinical conditions and long-term diverticular illness of this group of patients. At present, the laparoscopy in an elective setting is not considered any more a contraindication in the treatment of diverticular fistulas. KEY WORDS: Diverticular fistulas, Laparoscopic surgery.

Characterization of ibodutant at NK(2) receptor in human colon.

We have characterized the pharmacological profile of the nonpeptide tachykinin NK2 receptor antagonist ibodutant (MEN15596) through radioligand binding and contractility assays in the human colon smooth muscle. The antagonist affinity of ibodutant was evaluated through concentration-dependent inhibition curves at the [(125)I]NKA specific binding by using membranes prepared from human colon smooth muscle. In this assay the affinity of ibodutant (pKi 9.9) was compared to that of other two selective NK2 receptor antagonists, nepadutant (pKi 8.4) and saredutant (pKi 9.2). The antagonist potency of ibodutant was evaluated towards the [ßAla(8)]NKA(4-10)-mediated contractions of human colon smooth muscle strips. In this assay ibodutant (3, 10, 30 and 100 nM) induced a concentration-dependent rightward shift of the [ßAla(8)]NKA(4-10) concentration-response curves without depressing the maximal contractile effect. The analysis of the curves yielded a Schild-plot linear regression with a slope not different from unity (1.02), thus indicating a surmountable antagonist behavior. The calculated apparent antagonist potency as pKB value was 9.1. No sex related differences were observed in NK2 receptor pharmacology for [ßAla(8)]NKA(4-10) or ibodutant in colonic strips obtained from male or female patients. Reversibility experiments of tachykinin NK2 receptor blockade indicated that the inhibition of the agonist-induced contractions in preparations pre-exposed to ibodutant, and afterwards subjected to repeated washing cycles remained almost constant showing no sign of recovery during the 3h observation period. Overall, the present study indicates ibodutant as a potent tachykinin NK2 receptor antagonist in the human colon tissue, also endowed with a persistent duration of action.