Purpose/Background
Flap procedures following excision of recurrent or complex pilonidal sinus disease (PSD) are associated with relatively high wound complication rate.

Hypothesis/Aim
Given the inflammation and contamination associated with PSD, we hypothesized that the addition of an ovine forestomach matrix graft to our existing bilateral gluteal fasciocutaneous advancement flap may help reduce wound complications.

Methods/Interventions
This is an interim analysis of a single site in an ongoing prospective registry study evaluating the safety and efficacy of an ovine forestomach matrix (OFM) graft across a range of surgical procedures (ClinicalTrials.gov Identifier: NCT05243966). The OFM graft (Myriad Matrix™) is an FDA-cleared biologic implant, which provides a scaffold for cell re-population and rapidly forms well vascularized tissue and is remodeled over time.
Following elliptical excision of pilonidal disease, gluteal fasciocutaneous advancement flaps were elevated circumferentially. Prior to closure, a hydrated OFM graft was placed in the surgical dead space above the pre-coccygeal fascia. The flaps were approximated with interrupted sutures incorporating the OFM graft. A surgical drain was then placed in the subcutaneous space followed by midline closure of the dermal layer with interrupted absorbable sutures. Two full thickness retention sutures tied over a rolled-up gauze were placed at the inferior portion of the midline incision. The primary outcome for the study were device related adverse events, wound complications, and time (weeks) to complete healing.

Results/Outcomes
A total of 9 (8 males) patients with a mean age of 26 (range: 21-35) years and mean BMI of 28.2 (range: 23.2-35.9) were included. Mean follow up was 13 weeks (range:4-27). Seven (77.8%) patients had complete healing at their 1 month follow up. The mean time to complete healing was 6.5 weeks (range:4-16). There were two superficial wound dehiscences that occurred before the 1-month post op visit and one superficial wound dehiscence that occurred after the 1-month follow. All three healed without any need for subsequent surgery. There were no post-procedural infections, hematoma/seroma formation or device related adverse events. Four (44.4%) patients achieved a 3 month follow up with an average patient scar satisfaction score of 4.8 on a 1-5 scale.
Limitations
This study is an interim analysis of an ongoing long term registry study with a limited sample size.

Conclusion
The addition of the OFM graft to reconstruction of PSD wound was safe and had low rate of wound complications and high satisfaction with scar cosmesis. A larger analysis will be completed at the conclusion of the study.