Previously, a human subject clinical trial (NCT01292876, PRO10010500) to evaluate a regenerative medicine approach using ECM for VML treatment was conducted. ECM scaffolds were implanted and combined with aggressive and early physical therapy in 13 subjects, then followed for 24-28 weeks after implantation. Histomorphological assessments collected from core needle biopsies identified formation of new, vascularized, innervated islands of skeletal muscle within the implantation site. Subjects demonstrated increased force production in physical therapy evaluations and improved functional task performance when compared with pre-operative performance. By 6 months after ECM implantation, subjects had a 37.3% improvement in strength and 27.1% improvement in range-of-motion tasks. Additionally, changes in nerve conduction study (NCS) and electromyography (EMG) before and after ECM implantation were measured. 63% of study participants experienced improvements in NCS or EMG within the scaffold remodeling site, indicating clinical improvement in muscle strength. The promising functional and regenerative results from this early study encourages evidence of ECM bioscaffolding as a viable treatment to VML.

This study proposes to use XenMatrix™ AB Surgical Graft which has 510(k) approval \[#K162193\] intended for implantation to reinforce soft tissue where weakness exists and for surgical repair of damaged or ruptured soft tissue, including abdominal plastic and reconstructive surgery; muscle flap reinforcement; hernia repair including abdominal, inguinal, femoral, diaphragmatic, scrotal, umbilical, and incisional hernias. The graft has an antibiotic coating, specifically, Rifampin and Minocycline. This coating has been shown in preclinical in vitro and in vivo testing to reduce or inhibit microbial colonization on the device. The claim of reduction of bacterial colonization of the device has not yet been established with human clinical data, nor has a clinical impact associated with this claim been demonstrated and will need further investigation. This trial proposes to test the applicability and utility of XenMatrix™ AB Surgical Graft in the restoration of function in the setting of volumetric muscle loss after trauma. 10 subjects will be enrolled for participation in the study. Prior to Graft implantation, subjects will receive a pre-operative course of physical therapy for a maximum time period of 16 weeks. A physical therapist will confirm that functional plateau is reached prior to implantation of the Graft. Following Graft implantation, radiographic, functional, and electrophysotherapy outcomes will be measured at various time points up to 24-28 weeks post-operatively. A CT scan or MRI will be collected at screening and pre-operative visits to evaluate tissue volume, then again at post-operative Visit 1 and Visit 6. Physical therapy training will be performed as a research procedure following Graft implantation for a maximum of 30 weeks. Additionally, Physical Therapy evaluations will be conducted at screening, pre-op visit 1, post-op, and at post-op Visits 3, and 4. A small core needle biopsy 1-5 grams will be collected at three time points to conduct histomorphological assessment of the tissue prior to Graft implantation (Operative visit, Visit 2 and at Visit 4).