Effectiveness of Recombinant Human Growth Hormone for Pharyngocutaneous Fistula Closure

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

OBJECTIVE

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).

STUDY DESIGN

Prospective controlled animal study.

SETTING

Animal laboratory.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Effect of Stromal Vascular Fraction in the Rat Model of Pharyngocutaneous Fistulas

OBJECTIVE

A pharyngocutaneous fistula is one of the complications after laryngeal and pharyngeal surgery. It may also contribute to wound healing due to adipose tissue-derived stem cells and the growth factors in the stromal vascular fraction. The aim of this study was to investigate the effects of the adipose tissue-derived stromal vascular fraction on wound healing in the pharyngocutaneous fistula model induced in rats.

MATERIAL AND METHODS

Approval was received from the Animal Experiments Local Ethics Committee before starting the study (29.01.2016-2016/09). Eleven male Sprague-Dawley rats weighing approximately 300 g were included in the study. The animals were randomly divided into the study and control groups so that each group would include five animals. An animal was assigned as a donor for the removal of omental adipose tissue. Among the animals in which the pharyngocutaneous fistula model was created under general anesthesia, 1 ml of the stromal vascular fraction was injected into the study group on postoperative day 1. In postoperative week 2, all the animals were sacrificed and examined histologically (epithelialization-cell infiltration - mucosal injury). IBM SPSS Statistics for Windows, version 15, was used in the analyses. A p-value <0.05 was considered significant.

RESULTS

Epithelialization was higher in the study group compared to the control group. However, no statistically significant difference was found between the two groups (p = 0.08). The cell infiltration was found to be statistically higher in the control group compared to the study group (p = 0.03). The mucosal injury was found to be significantly higher in the control group compared to the study group (p = 0.03). According to the Pearson correlation test, a negative correlation was found between epithelialization and cell infiltration and mucosal injury (p = 0.019 and p = 0.001). A positive correlation was found between cell infiltration and mucosal injury (p = 0.009).

CONCLUSION

It was shown that stromal vascular fraction had a positive effect on wound healing in the pharyngocutaneous fistula model. According to the data we have obtained, we think that it can be effective in the treatment of pharyngocutaneous fistulas after more extensive preclinical and clinical studies are carried out.

Effects of insulin-like growth factor-1 on random pattern skin flap survival in rats

PURPOSE

To investigate the effects of pharmacological delay with insulin-like growth factor-1 (IGF-1) on skin flap survival.

METHODS

Thirty Sprague-Dawley rats were submitted to dorsal skin flap (3x9 cm). Seven days before the surgery, the animals were subdivided into three groups of 10 rats. In group 1 (controls), no injection was done. Seven days before the elevation, saline had been injected to the marked skin flap area in group 2 (sham group), and group 3 (experimental group) underwent a pharmacological delay with subcutaneous IGF-1 injections. On the seventh postoperative day, flap area was analyzed for survival. Tissue samples were obtained for histological and biochemical evaluations.

RESULTS

Survival rates were 43.55 ± 16%, 21.40 ± 8%, and 43.12 ± 14% in groups 1, 2, and 3, respectively. Differences between group 2 and other groups were statistically significant. No significant difference was detected between all three groups for tissue or plasma vascular endothelial growth factor (VEGF) levels. There was no significant histological difference between groups.

CONCLUSION

Although a single injection of insulin-like growth factor-1 (IGF-1) did not significantly increase flap survival, its wound healing features are still encouraging and further meticulously planned studies, especially with repeated applications or controlled-release methods, and combinations with binding protein are required.