Porcine Xenograft Versus Second Intention Healing

The purpose of this research study is to test whether it is better to allow patients with post- operative wounds on the legs to heal on their own without a covering or to use a porcine xenograft (skin graft that is made from pig cells) to cover the wound during healing. It is currently not known which option is better in terms of the appearance, complication rate or the impact on the patient's quality of life during the healing process. In this location, it is common receive either treatment.

Porcine xenograft has been used as a barrier to the skin for over 30 years, and due to its wound healing promoting factors, we believe that its use may result in decreased healing time, smaller scar size, better cosmetic outcomes, lower pain levels, and decreased rates of infection and other post-surgical complications.

Upon completion of dermatologic surgery following standard procedures, patients will be randomized into one of two groups (porcine xenograft placement or second intention healing). Weekly follow-up via questionnaires will be conducted as well as a final office visit follow-up at 3 months.

The application of porcine xenograft dressings for wound healing was first studied in 1985, with evidence supporting several benefits when compared to traditional dressings \[1\]. Subsequent studies have substantiated the use of this dressing for a variety of clinical settings \[2,3\].

The EZ-DERM™ porcine xenograft is a biosynthetic dressing made from porcine collagen containing aldehyde crosslinking \[1,3\]. It has been most commonly applied to the management of 2nd degree burns, both partial-thickness and full-thickness defects \[4\]. This dressing can be used for two healing purposes, either for primary healing or as an intermediate in the preparation for a skin graft \[2\].

Compared to other biosynthetic dressings, porcine xenografts afford longer wound adherence and can be stored at room temperature \[1\]. The xenograft triggers rejection by the surgical defect, increasing local vascularization \[5\]. It also allows for rapid granulation, a reduced risk of infection, as well as reduced wound-related fluid and thermal losses \[6-8\]. There is also evidence that the quicker wound healing reduces the frequency of dressings, hospitalization time, pain, and analgesic \[9,10\].

Several clinical case series have extended the use of porcine xenografts to Mohs Micrographic Surgery (MMS) to facilitate post-operative wound care. Porcine xenograft dressings were determined to be safe, well-tolerated, and able to be applied to a wide anatomical range \[3,12\].

In addition to biosynthetic dressings, healing via second intention remains an alternative \[13,14\]. The extremities of elderly patients are a common location for wound granulation. Drawbacks to second intention healing on the extremities include prolonged healing time and extended wound care for the patient \[15\].

Chern et. al. completed a review of biological dressings in dermatologic surgery and concluded that there is a limited number of studies focusing on the conclusive benefits of dressings \[16\]. Although studies have established that EZ-DERM™ was helpful for wound healing following Mohs surgery, there have not been any definitive statistical measures reported in the literature. Additionally, there is a lack of studies assessing the direct comparison to second intention healing.

Our plan is to perform a direct comparison of porcine xenograft placement to second intent healing. Based on the previously studied benefits of the xenograft as a barrier to the skin and one which has wound healing promoting factors, we believe that its use may result in decreased healing time, smaller scar size, better cosmetic outcomes, lower pain levels, and decreased rates of infection and other post-surgical complications.

Our study will allow surgeons to make informed decisions on whether porcine xenograft dressing is superior to that of second intention healing and thus worth considering.

Eligibility Criteria:
Inclusion Criteria:

* Over 18 years of age
* Able to give informed consent themselves
* Willing to return for follow-up visits
* Post-operative defects greater than 8 mm (in greatest diameter or length of circular or oval geometric shape) on the lower extremities (including the feet)
* Single defect

Exclusion Criteria:

* Mentally handicapped
* Unable to understand written and oral English
* Incarceration
* Under 18 years of age
* Unwilling to return for follow-up
* Pregnant women
* Wounds less than 8 mm in length
* Wounds on the head, neck or digits
* Patients in which primary linear closure is recommended