Successful Use of an Autologous Homologous Skin Construct for the Management of Acute Surgical and Traumatic Wounds: A Clinical Experience in Two Patients

Wound care is a multibillion-dollar industry in developed countries, with wound care costs accounting for as much as 3% of total health care expenditures. In the United States alone, wound care costs are $50 billion annually.^1,2 It is not surprising that new wound care products are developed and marketed to patients and clinicians alike each year. With so much activity in this space, it is important to critically assess the costs and benefits of each new technology before its widespread adoption over conventional reconstructive techniques, including grafts, flaps, and off-the-shelf adjuncts.

Skin grafts represent a relatively easy and reliable solution for the rapid coverage of large wounds. However, potential drawbacks include donor site pain and/or scarring; a lack of suitable donor sites, particularly in patients with large burns or in small children; and total or, more often, partial graft loss in over 50% of cases.³ Commercially available skin substitutes, including acellular dermal matrices, allograft skins, and animal collagen scaffolds, have been developed in an attempt to mitigate some of these downsides. For most large wounds, however, such products cannot provide permanent, bilaminar skin (resulting in the need for additional surgeries and/or skin grafts), lack dermal appendages, and predispose the patient to breakdown or recurrence.⁴

Recently, a surgical solution to the management of acute or chronic wounds was developed (SkinTE; PolarityTE, Inc).⁵ This AHSC uses a sample of the patient’s own full-thickness skin that is processed and expanded at the manufacturer prior to its return to the surgeon for application to the wound in order to regenerate polarized, appendage-bearing autologous skin.^6-8 With so many surgical options available for wound management, data on the value and efficacy of the AHSC will play an important role in determining its indications for use. For the current study, it was hypothesized that the AHSC would be most beneficial in patients who were unable to undergo conventional reconstruction with skin grafts or flaps. The aim of this case series is to demonstrate the efficacy of the AHSC for this indication through highlighting the authors’ experience using the product in the management of 2 surgical patients; the manufacturer donated the treatment free-of-charge to the patient and hospital.

This was a single-center, retrospective case series evaluating 2 patients treated with the AHSC. This study was exempt from institutional review board approval.

Both patients were advised of the risks, benefits, and alternatives to the use of the AHSC and provided written consent to proceed with the treatment. Patients were considered for intervention with this system if they had a relative contraindication to conventional reconstruction, including lack of sufficient donor sites, history of collagen disorders, and failure or refusal to consent to conventional therapies.

The AHSC treatment required 2 stages of intervention. In the first stage, a full-thickness skin sample was harvested and sent to the manufacturer for processing. At the second stage, the returned product was applied to the wound and a negative pressure dressing was applied. The patients were followed up at 1 week and 2 weeks postoperatively and then as needed until the end point of complete wound closure.

Case 1

A 17-year-old male presented with near circumferential degloving of the skin overlying the left lower leg due to being struck by a motor vehicle. The degloving injury extended to the level of the subcutaneous fat, without any exposed bone or periosteum.

The patient revealed a personal and family history of an unspecified collagen disorder affecting primarily the lower leg with extensive bruising and blistering of the pretibial skin and difficulties related to delayed wound healing. At baseline, the bilateral pretibial regions were subject to extensive scarring and hyperpigmentation due to the repeated injuries, and the patient wore shin guards to avoid trauma. Despite the symptoms, the patient had not undergone further workup (ie, skin biopsy, genetic testing). The father was a known carrier of a mutation in the collagen gene (COL7A1).

The patient was taken to the operating room and underwent debridement of the wound, resulting in a final wound dimension of 25 cm × 20 cm, after which a dermal regeneration template (Integra Dermal Regeneration Template, Integra LifeSciences) was applied. Because of concern regarding the patient’s ability to heal a rather large donor site for a split-thickness skin graft, the decision was made to proceed with final reconstruction using the AHSC. The patient returned to the operating room 1 month later, at which time an ellipse of full-thickness skin, measuring 10 cm × 3 cm, was harvested for processing by the AHSC manufacturer (Figure 1). The groin donor site was closed primarily and healed uneventfully. Within 1 week, the patient returned for application of the AHSC to the wound. A silicone membrane was applied over the grafted material and reinforced with a negative pressure dressing (low intensity, continuous pressure at −125 mm Hg). At 1 week postoperatively, the dressing was exchanged, but the silicone membrane was left in place. At 2 weeks postoperatively, the silicone membrane was removed to reveal multiple islands of adherent skin throughout the wound within a bed of surrounding granulation tissue in addition to epithelialization around the wound edges (Figure 1D). By 8 weeks postoperatively, the skin islands coalesced to form nearly complete coverage of the wound except for several areas of dry eschar along the anteromedial aspect of the leg (Figure 1E). At 4 months postoperatively, the wound was fully healed (Figure 1F).

Case 2

A 69-year-old male with a history of multiple nonmelanoma skin cancers presented for evaluation of a 10-cm, recurrent basal cell carcinoma of the upper back. On the day of surgery, excision was carried through the muscle fascia, leaving a wound measuring 16 cm x 16 cm with muscle at its base. Purse string suturing of the defect to a final dimension of 12 cm × 12 cm was performed, and a meshed split-thickness skin graft harvested from the thigh was sutured in place and covered with a negative pressure dressing (low intensity, continuous pressure at −125 mm Hg).

Recovery was complicated by a hematoma on postoperative day 2, with subsequent loss of approximately 85% of the skin graft. The wound was otherwise clean, with granulation tissue at its base (Figure 2A). At that time, to minimize additional donor site morbidity, the decision was made to proceed with the AHSC system for wound coverage. The patient returned to the operating room, and an ellipse of full-thickness skin measuring 7 cm x 3 cm was harvested from the groin, followed by primary closure of the donor site. The tissue was sent for processing, and 5 days later the patient returned for application of the AHSC and overlying silicone membrane with a negative pressure dressing (low intensity, continuous pressure at −125 mm Hg). Two weeks after hospital discharge, the silicone membrane was removed to reveal considerable healing of the wound from its edges along with multiple islands of epithelialization within the remaining bed of granulation tissue (Figure 2B). At 5 weeks, the wound was healed completely, and no issues related to breakdown or recurrence were noted at 7-month follow-up (Figure 2C, 2D).

The AHSC system promises to regenerate bilaminar, appendage-bearing skin with relatively minimal donor site morbidity. The authors’ early experience using the system highlights its utility and potential downsides as well as areas for future research as plastic surgeons aim to understand its role in the reconstructive surgeon’s operative tool kit. At the time of this writing, both patients who underwent this treatment have demonstrated successful wound healing without subsequent wound breakdown or recurrence. Time to healing was 5 weeks for the smaller wound (100 cm²) and between 2 and 4 months for the larger wound (500 cm²). Although formal histologic analysis of the healed wounds is not available, in both cases the epidermis is well adherent to the underlying tissues without any evidence of sloughing with manipulation. Case 2 offers an opportunity to directly compare an area of the wound with surviving skin graft to the remaining area treated with the AHSC system (Figure 2). Although the areas appear distinct from one another, there was no discernable macroscopic difference with regard to durability or the presence of skin appendages at 5-week follow-up (Figure 2C). Future histologic analysis will be necessary to definitively compare wounds treated with this system to other modalities, such as skin grafts.

To the authors’ knowledge, as of the time of this writing, only 3 other published studies have examined the AHSC system with wound healing rates similar to those reported in this case series. The first proof of concept includes a patient who underwent treatment with the AHSC for a wound measuring 200 cm² in size; the wound healed in 8 weeks.⁶ In that patient, static 2-point discrimination was not different between the treated and native skin, and bioimpedance analysis further demonstrated no difference in moisture, oil, or pliability of the tissues. A different case report demonstrated an 8-week healing time for a wound measuring 200 cm² on the chest.⁷ Polarized dermoscopy demonstrated the presence of hair within the regenerated skin as well as melanin and melanocyte populations distributed throughout. A biopsy of the regenerated skin was performed at 5-month follow-up and demonstrated bilaminar skin with architecture that resembled normal skin. A third case report demonstrated nearly complete healing at 7 weeks and 8 weeks, respectively, of 2 wounds measuring 20 cm² each.⁸ To the authors’ knowledge, the wound measuring 500 cm² in the current study is the largest reported in the literature to date; additionally, no published studies to date have provided data on the costs of the AHSC system.

This study has several limitations. Because this is a report of only 2 patients, the authors did not plan and collect formal outcomes data other than time to wound healing and are unable to perform formal statistical analyses. The follow-up time was also limited to 6 to 7 months, so it is not possible to comment on long-term results with the AHSC system.

The AHSC system reported on herein is associated with an added financial cost of purchasing the system as well as a second trip to the operating room to apply it. Formal data on the cost of this system are not publicly available; however, the cost scales with the size of the wound being treated. The only cost data available to date were reported in a filing with the United States Securities and Exchange Commission highlighting interim data from a randomized controlled trial evaluating the system in diabetic foot ulcers, which demonstrated a mean cost of product per treated wound of $1311.20.⁹ It is important to consider, however, that diabetic foot ulcers tend to be much smaller than the wounds treated in this series, and costs for the patients in this case series may have been as much as an order of magnitude greater based on wound size. Furthermore, although the authors of this case series harvested the full-thickness skin samples in the operating room, it is conceivable that some patients may tolerate skin harvest under local anesthesia in the office setting, thus potentially saving cost and operating room block time.

Ultimately, the financial downsides must be formally weighed against any potential benefits in a cost-efficacy analysis. Currently, in the senior author’s practice (H.S.), the AHSC system is reserved for cases in which a traditional split-thickness skin graft or flap is relatively contraindicated or when conventional reconstruction has been unsuccessful.

Additional controlled studies evaluating clinical outcomes, tissue histology, and cost will be necessary to formally establish the role of this treatment option in the surgical management of wounds. Nonetheless, this technique appears to be a promising alternative, particularly in patients in whom conventional options, including skin graft, have been unsuccessful or are relatively contraindicated.