BOB in Ped Surg 2023 - CAPS Winner - Christina Theodorou, MD

Synthetic patches such as PTFE or Gore-Tex used for large diaphragmatic defects are associated with significant morbidity, including hernia recurrence, bowel obstructions, and chest wall deformities as the child grows.

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

In the rat model study, 4mm diaphragmatic defects were created followed by immediate patch repair, with six animals in each cohort plus a sham cohort of six rats.

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

At one week, 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 patches, with no significant difference in the size of that inflammatory capsule between the cohorts.

The study had small numbers of animals in each cohort, likely underpowering detection of significant differences.

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

The biodegradation rate of the polyurethane patch cannot be too fast because then there will be another hernia.

Understanding the intrinsic strength of the polyurethane patch at different time periods will be really important for its use as a diaphragm patch.

There is some evidence that absorbable patches are not as good and the recurrence rate is higher for diaphragmatic hernias compared to non-absorbable patches.

Tony personally uses a Gore-Tex patch that stays there forever and gets embedded into the tissues because of the high incidence of recurrent hernias with biodegradable patches.

A short-term study showing that the polyurethane patch works is not adequate evidence to translate it to patient care.