Enhanced Secondary Intention Healing vs. Standard Secondary Intention Healing in Mohs Surgical Defects on the Head and Distal Lower Extremities

Secondary intention healing (SIH) is often underutilized and has several advantages compared to primary surgical repair. Wound care is minimal, bleeding and infection are rare, and risks associated with primary closure (e.g. hematoma, suture granuloma, graft or flap failure) are non-existent. Importantly, SIH facilitates surveillance of tumor recurrence, whereas flaps and grafts may bury residual tumor. When used in appropriate anatomical locations, SIH leads to high patient satisfaction. However, SIH requires regular wound care that can be cumbersome to patients.

Prior studies utilizing biologic dressings have shown patients report better quality of life during the post-operative period related to less pain, decreased dressing changes, and faster healing times. Biologic dressings provide an alternative to surgical autografts and eliminate the risks associated with graft harvesting (e.g. pain, infection, and scarring). For many patients, the cosmetic outcome following healing is important. However, cosmetic outcome with SIH is variable and depends on many factors, namely location (e.g. concavities favorable), skin laxity, and underlying musculature. Exuberant granulation tissue, hypopigmented and telangiectatic scars are the most frequent adverse cosmetic outcomes with SIH.

The novel biomaterial APIS® (SweetBio, Inc. Memphis, TN) is an advanced synthesis of gelatin, manuka honey, and hydroxyapatite bioengineered to protect wounds, manage exudate, and maintain a moist environment. It is FDA cleared (FDA number K1827250) for wound management across 9 indications including surgical wounds. It has been used successfully in a small case series of 8 patients for post-operative Mohs surgical wounds on the head and distal lower extremities. Time to complete re-epithelialization was 6 weeks (42 days), suggesting a reduction in healing time compared to standard SIH times for the leg and head of 127 and 57 days, respectively. Use of this novel biomaterial to enhance SIH is hypothesized to reduce healing times when compared to standard SIH wound care. This provides a useful option to aid SIH in sites like the lower legs, where healing can be prolonged due to intrinsic factors (e.g., cardiovascular disease, peripheral vascular disease, diabetes) or extrinsic factors (e.g., increased risk of surgical site infection following dermatologic surgery at sites below the knee).

Randomized, comparative studies evaluating augmented SIH compared to conventional SIH in dermatologic surgery are limited. This study aims to evaluate whether use of a novel biomaterial enhances SIH, particularly in shortening time to complete re-epithelialization. Patients undergoing Mohs micrographic surgery amenable to SIH on the head and distal lower extremities will be randomized into one of four groups (standard SIH or biomaterial APIS® enhanced SIH on the head or distal lower extremities). Patients will have regularly scheduled follow-up with questionnaires at each visit. The investigators aim to evaluate whether use of this novel biomaterial decreases complete re-epithelialization times, reduces infection rates, and improves cosmetic outcomes.

Inclusion criteria

• 18 years of age or older
• Post-operative wounds following Mohs surgery on the head or distal lower extremities
• Single Mohs post-operative defect
• Post-operative wounds greater than 1cm in width
• Depth of defect at least to subcutaneous tissue
• Patients have the ability to provide their own wound care
• Agreeable to regularly scheduled follow-up visits and transmission of photos via HIPAA compliant Vanderbilt University Medical Center Box
• Patients are able to provide informed consent

Exclusion criteria

• Under 18 years of age
• Unable to provide informed consent
• Unable to understand oral and written English
• Post-operative wounds not appropriate for secondary intention healing
• Sensitivity or allergy to APIS® biomaterial including collagen and its derivatives, porcine-derived materials or honey
• Immunosuppressed and organ transplant patients
• Post-operative wounds superficial to subcutaneous tissue