Urinary Bladder Matrix-Extracellular Matrix (UBM-ECM) for Management of Complex Upper Extremity Wounds

Introduction: Open degloving injuries of the upper extremity can be devastating injuries that historically have poor outcomes. While initially, there are tissues present which appear viable, they are often destined to progress on to variable degrees of necrosis with standard wound care. Despite advances in flap transfers, patients often struggle with pain, scarring and limited use with the need for multiple revisions. Other non-operative reported treatments included a variety of topical dressing devices, growth factors, and prostaglandin E-1. Common to all of these treatments is the M1-macrophage directed healing and the attendant scarring that ensues at the site of the traumatic injury with those treatments. A Urinary Bladder Matrix-Extracellular Matrix wound device (UBM-ECM) preferentially promotes wound healing via an M2-macrophage constructive remodeling response and offers a new topical treatment modality for these frequently encountered wounds. 

Methods: The authors reviewed 17 wounds in 9 patients treated with serial placement of a UBM-ECM wound device (MicroMatrix^® Powder and Cytal^® Burn Matrix and Surgical Sheets- ACell^®, Columbia, MD.). There were 6 males and 3 females patients with ages ranging from 20 to 82 years. The individual wound sizes ranged from 1cm² to 170cm². The upper extremity wounds were classified as to the type of injury, orientation of the tissue and original size of the wounds. The time to initial UBM-ECM device varied but in all cases was less than 2 days. The UBM-ECM powder and sheets were initially applied to the wounds in a standardized fashion with patients with larger wounds and exposed bone having initial larger volume of powder placed. Serial placement of the wound device was applied to wounds as indicated with the amount decreasing as the wound became smaller. The wound device was held in place with a petroleum impregnated gauze dressing which helped contain and retain the powder as well as moisture on the open wound bed. Serial hydrogel was topically applied. NPWT was used in 3 cases while the wounds drained 30cc or more per day. All wounds were treated to closure.

Results: UBM-ECM wound treatment produced a durable, well healed wound in all patients. Three patients had secondary skin grafting to hasten the time to total healing. The ratio of skin graft to original wound area ranged from .28 (136.5cm²/481cm²) to .92 (44cm²/48cm²). The time to healing was based on the individual’s response to the UBM-ECM and ranged from 41 to 151 days. All patients regained sensation ranging from deeper pressure appreciation to discriminating sensation in the healed wound site. Clinical photographs of the outcomes of various severity stages are presented. 

Conclusion: Complex upper extremity wounds managed with the UBM-ECM wound device reliably produced well healed, cosmetically acceptable healed wounds. Based on our results we strongly advocate all patients with complex and degloving injuries have early placement of UBM-ECM in their wounds to minimize the scarring and promote a constructive remodeling healing response. Further studies of these ECM wound devices are warranted.