BOB Ped Surg 2023 - Christina Theodorou, CAPS - Presentation

In cases of large congenital diaphragmatic hernia defects, diaphragmatic replacements are used, most commonly synthetic patches such as PTFE or Gore-Tex.

Synthetic patches for diaphragmatic hernia repair are associated with significant morbidity including hernia recurrence, bowel obstructions, and chest wall deformities as the child grows.

The ideal diaphragm replacement would integrate with native tissue, mechanically match the function of the diaphragm and allow for growth with the child.

Biodegradable forms of polyurethane have been used in tissue repair recently such as vascular and muscular tissue replacement and have high mechanical strength.

The study created 4 mm diaphragmatic defects in rats followed by immediate patch repair, with cohorts of six animals each plus a sham cohort of six rats.

Animals were survived for four weeks with fluoroscopic evaluation of diaphragmatic excursion at one and four weeks post-op.

No recurrences were seen in either the polyurethane or Gore-Tex cohort at four weeks.

At one week post-op, there was no difference in diaphragmatic excursion between sham, Gore-Tex, and polyurethane animals.

At four weeks, Gore-Tex had limited diaphragm rise compared to sham, but no difference was found between polyurethane and sham.

There were no differences in diaphragmatic excursion between polyurethane and Gore-Tex at any time point.

An inflammatory capsule was formed surrounding both polyurethane and Gore-Tex patches.

There was no significant difference in the size of the inflammatory capsule between the polyurethane and Gore-Tex cohorts.

The study had small numbers of animals in each cohort (six per group), likely under powering detection of significant differences.

Most diaphragmatic hernia recurrences occur at least a few months out from surgery, most commonly within the first two years.

The biodegradation rate of the polyurethane patch can be altered to match the rate of tissue in-growth with the goal of complete replacement over time with native diaphragm tissue.