# Effects of Myroxylon pereirae, Phenytoin, and Clinoptilolite After Pharyngocutaneous Fistula: An Experimental Animal Model

## TL;DR

This study tested how Myroxylon pereirae and phenytoin affect healing of pharyngocutaneous fistulas in rats, finding they promote healing better than clinoptilolite.

## Contribution

The study introduces a novel comparative evaluation of three substances for treating pharyngocutaneous fistulas in an animal model.

## Key findings

- Myroxylon pereirae and phenytoin significantly reduced fistula formation and inflammation in rats.
- Myroxylon pereirae promoted fibroblast proliferation and collagen accumulation more effectively than other treatments.
- Clinoptilolite showed no significant improvement in healing parameters compared to the control group.

## Abstract

The objective of this study was to conduct a comparative evaluation of the effects of Myroxylon pereirae (MP), phenytoin, and clinoptilolite on wound healing in an experimental animal model for the treatment of pharyngocutaneous fistula (PCF).

Prospective controlled animal study.

Animal laboratory.

Forty‐four male Sprague–Dawley rats were randomly assigned to one of four groups: sham control group, MP group, phenytoin group, and clinoptilolite group. A PCF was created in each rat via surgical intervention, followed by a course of topical treatment administered twice daily for a period of 7 days. The healing of the fistula was evaluated both macroscopically and histopathologically.

Macroscopic fistulae developed in 90% of the control group, 18% of the MP group, and 27% of the phenytoin group (P = .005). The phenytoin group had the lowest inflammation scores, which were significantly lower than the clinoptilolite and control groups (P = .006 and P = .001). The MP group had the highest levels of fibroblast proliferation and collagen accumulation (P < .001 and P = .001, respectively). The level of inflammation and amount of fibroblast proliferation, angiogenesis, and collagen accumulation in the clinoptilolite group was lower than in the control group, but none of these differences were significant statistically.

MP and phenytoin improved the healing of PCF, particularly by reducing the inflammation and promoting the of fibroblast proliferation and collagen accumulation. Clinoptilolite did not demonstrate a notable advantage in any of these parameters. These findings suggest that MP and phenytoin may serve as potential agents in the management of PCF.