Retrospective real-world comparative effectiveness of ovine forestomach matrix and collagen/ORC in the treatment of diabetic foot ulcers

Clinical Efficacy of Ovine Forestomach Matrix and Collagen/Oxidised Regenerated Cellulose for the Treatment of Venous Leg Ulcers: A Retrospective Comparative Real-World Evidence Study

Venous leg ulcers (VLUs) are traditionally managed with standard-of-care dressings, compression and appropriate adjunctive venous interventions for pathologic venous reflux. Due to pathophysiological complexity and underlying patient comorbidities, conducting randomised controlled trials to evaluate the comparative efficacy of advanced treatment modalities is difficult, as many patients would likely be excluded. This retrospective, pragmatic, real-world evidence (RWE) study compared the healing outcomes of VLUs treated with either ovine forestomach matrix (OFM) (n = 312) or collagen/oxidised regenerated cellulose (ORC) (n = 239) in outpatient wound care centres. Unlike restrictive randomised controlled trials, minimal inclusion and exclusion criteria were applied to create two treatment cohorts that reflected the general VLU population. The incidence (%) of closure was greater in OFM-treated VLUs at 12, 24 and 36 weeks, and this difference was significant at 24 and 36 weeks compared to collagen/ORC. Median time to wound closure was significantly faster (p = 0.045) in the OFM cohort (11.1 ± 0.6 weeks) compared to the collagen/ORC group (12.3 ± 1.0 weeks). Cox proportional hazards analysis demonstrated that OFM-treated VLUs had a significantly greater probability of healing (up to ~40%). This RWE comparative efficacy study further substantiates the clinical benefit of OFM in the treatment of chronic wounds, such as VLU, in a real-world patient cohort.

Innovative treatment of diabetic ulcers: combining chemical debridement and xenograft applications: a case study

Lower extremity diabetic ulcers (LEDUs) are a common, high-morbidity complication of diabetes, frequently leading to infections, hospitalisations and emergency department visits. This case study examines the treatment effectiveness of a novel wound care approach in a 57-year-old female patient with a hard-to-heal LEDU (a diabetic foot ulcer of the left lower extremity) complicated by poorly controlled diabetes (glycated haemoglobin A1c: 13%). Initially, standard of care (SoC) practices, including alginate dressings, hypochlorous acid gel and sharp debridement, were ineffective in promoting significant healing. This case was further challenged by its occurrence in the remote setting of Tongatopu within the Kingdom of Tonga, where advanced wound care materials and even SoC products are not consistently available, underscoring the need for innovative and adaptable treatment strategies. A new regimen was subsequently initiated that involved preparing the wound bed through chemical debridement using a topical desiccating agent (TDA) with methanesulfonic acid (DEBRICHEM, DEBx Medical, the Netherlands), which has the ability to denature proteins and reduce microbial biofilms, necrotic tissue and inflammatory proteins in the wound bed. This was followed by the application of ovine forestomach matrix (OFM) grafts containing hyaluronic acid (Symphony, Aroa Biosurgery, New Zealand), which was applied at approximately 12-day intervals. Over the 110 days following the initial application of the TDA, the LEDU showed significant improvement as it progressed along the healing cascade towards closure. This case report provides insights into the potential of combined desiccating chemical debridement and xenograft-based wound care in treating hard-to-heal LEDUs, highlighting an approach that could inform future clinical practices in diabetic wound care.

Limb Salvage via Surgical Soft-tissue Reconstruction With Ovine Forestomach Matrix Grafts: A Prospective Study

Background

Complex and chronic lower extremity defects present a surgical challenge and can progress to eventual amputation if closure is not achieved. In addition to morbidity and mortality, these defects have a significant impact on patient quality of life and represent a substantial cost burden to the healthcare system. Ovine forestomach matrix (OFM) grafts are an advanced tissue scaffold option to supplement the surgical reconstruction ladder and may augment limb preservation in cases of complex lower extremity defects.

Methods

A prospective observational study enrolled 130 complex lower extremity reconstructions that received OFM as part of surgical management. Granulation tissue formation, defect closure, and postoperative complications were assessed up to 1 year postoperatively to evaluate the outcome of OFM grafts for limb salvage via surgical reconstruction.

Results

Participant demographics and defect characteristics were reflective of a real-world inpatient population with complex and chronic defects. Despite complexity of the defects, no postoperative infections or major amputations were reported. The median time to complete granulation tissue coverage and fill was 30.0 days (95% confidence interval, 26.9-33.1) and the median time to complete defect closure was 127.0 days (95% confidence interval, 110.5-143.5). At 180 days, a 62% incidence of healing was achieved with a median product application of 1.0 (interquartile range, 1.0-1.0).

Conclusions

OFM-based grafts supported successful coverage of lower extremity defects in a real-world cohort with known risk-factors for amputation. Achieving successful closure with minimal complications, and often in a single application, suggests utility of OFM as a cost-effective adjunct in lower extremity reconstruction.

Varying Properties of Extracellular Matrix Grafts Impact Their Durability and Cell Attachment and Proliferation in an In Vitro Chronic Wound Model

While acute wounds typically progress through the phases of wound healing, chronic wounds often stall in the inflammatory phase due to elevated levels of matrix metalloproteinases (MMPs) and proinflammatory cytokines. Dysregulated expression of MMPs can result in the breakdown of extracellular matrix (ECM) formed during the wound healing process, resulting in stalled wounds. Native collagen-based wound dressings offer a potential wound management option to sequester excess MMPs and support cellular interactions that allow wound progression through the natural healing process. Herein, we utilized commercially available ECM matrices, two derived from porcine small intestinal submucosa (PCMP, 2 layers; PCMP-XT, 5 layers) and one derived from propria submucosa (ovine forestomach matrix, OFM, 1 layer), to demonstrate the impact of processing methodologies (e.g., layering and crosslinking) on functional characteristics needed for the management of chronic wounds. Grafts were evaluated for structural composition using scanning electron microscopy and histology, ability to reduce MMPs using fluorometric assays, and durability in an in vitro degradation chronic wound model. Both intact (nondegraded) and partially degraded grafts were assessed for their ability to serve as a functional cell scaffold using primary human fibroblasts. Grafts differed in matrix substructure and composition. While all grafts demonstrated attenuation of MMP activity, PCMP and PCMP-XT showed larger reductions of MMP levels. OFM rapidly degraded in the in vitro degradation model (<3 hours), while PCMP and PCMP-XT were significantly more durable (>7 days). The ability of PCMP and PCMP-XT to serve as scaffolds for cellular attachment was not impacted by degradation in vitro. Three ECM grafts with varying structural and functional characteristics exhibited differential durability when degraded in a simulated chronic wound model. Those that withstood rapid degradation maintained their ability to function as a scaffold to support attachment and proliferation of fibroblasts, a cell type important for wound healing.

Retrospective Data Analysis of the Use of an Autologous Multilayered Leukocyte, Platelet, and Fibrin Patch for Diabetic Foot Ulcers Treatment in Daily Clinical Practice

OBJECTIVE

To describe the healing outcome of chronic, hard-to-heal diabetic foot ulcers (DFUs) treated with an autologous multilayered leukocyte, platelet, and fibrin (MLPF) patch in addition to the best standard of care, in a real-world clinical setting of two US amputation preventive centers.

METHODS

In this retrospective study of patients treated between September 2021 and October 2022, the authors analyzed DFU healing outcomes based on Wound, Ischemia, and foot Infection-derived amputation risk.

RESULTS

All 36 patients had a diagnosis of type 2 diabetes and 29 (81%) were male. Their average age was 61.4 years, body mass index was 29.2 kg/m2, and glycated hemoglobin was 7.9. Twenty-seven patients (78%) were diagnosed with peripheral vascular disease, 20 (56%) underwent a peripheral vascular procedure, 15 (42%) had a prior amputation, and 6 (17%) were on hemodialysis. Average wound size was 4.9 cm2, and wound age was 9.5 months. Twelve patients (32%) were classified as low risk, 15 (39%) as moderate risk, and 11 (29%) as high risk for amputation. Within 12 weeks of the first MLPF patch application, nine wounds (24%) healed. After 20 weeks, 23 wounds (61%) were closed, and by follow-up, 30 wounds (79%) healed. No amputations were noted. Compared with published data, 40% fewer patients underwent readmission within 30 days, with 72% shorter admission duration.

CONCLUSIONS

Real-world clinical experiences using the MLPF patch to treat hard-to-heal DFUs resulted in the majority of wounds healing. Few patients experienced a readmission within 30 days, and the average admission duration was short.

Updates on Recent Clinical Assessment of Commercial Chronic Wound Care Products

Impaired wound healing after trauma, disorders, and surgeries impact millions of people globally every year. Dysregulation in orchestrated healing mechanisms and underlying medical complications make chronic wound management extremely challenging. Besides standard-of-care treatments including broad spectrum antibiotics and wound-debridement, novel adjuvant therapies are clinically tested and commercialized. These include topical agents, skin substitutes, growth factor delivery, and stem cell therapies. With a goal to overcome factors playing pivotal role in delayed wound healing, researchers are exploring novel approaches to elicit desirable healing outcomes in chronic wounds. Although recent innovations in wound care products, therapies, and devices are extensively reviewed in past, a comprehensive review summarizing their clinical outcomes is surprisingly lacking. Herein, this work reviews the commercially available wound care products and their performance in clinical trials to provide a statistically comprehensive understanding of their safety and efficacy. The performance and suitability of various commercial wound care platforms, including xenogeneic and allogenic products, wound care devices, and novel biomaterials, are discussed for chronic wounds. The current clinical evaluation will provide a comprehensive understanding of the benefits and drawbacks of the most-recent approaches and will enable researchers and healthcare providers to develop next-generation technologies for chronic wound management.

Ovine Forestomach Matrix in the Surgical Management of Complex Volumetric Soft Tissue Defects: A Retrospective Pilot Case Series

Background

Volumetric soft tissue loss is an urgent surgical issue and can frequently lead to suboptimal outcomes for patients due to significant soft tissue loss, compromised vital structures, and contamination. Ovine forestomach matrix (OFM) has demonstrated clinical success in the surgical management of soft tissue defects, especially in contaminated fields, and provides an effective option for immediate coverage of exposed vital structures before definitive closure.

Methods

This retrospective pilot case series (n = 13 defects) evaluated the clinical effectiveness of OFM (graft and/or particulate formats) in the surgical management of contaminated volumetric soft tissue defects. Patients presented with significant soft tissue loss, often with exposed viscera, tendon, bone, or muscle, and were treated with OFM as part of their inpatient surgical management. All patients had at least 1 significant comorbidity with the potential to complicate their healing trajectory. The primary study endpoint was time to 100% granulation tissue coverage (days), and the secondary endpoint was any device-related postoperative complications.

Results

A total of 13 volumetric soft tissue defects were evaluated in 10 patients who underwent surgical reconstruction. Mean defect age was 3.5 ± 5.6 weeks, and mean area was 217.3 ± 77.9 cm2. Most defects had exposed structures (85%), and all defects were Centers for Disease Control and Prevention grade 2 or higher. Mean time to 100% granulation tissue formation was 23.4 ± 9.2 days, with a median product application of 1.0. Staged reconstruction was used in 7 of 13 defects, with the remainder (6 of 13) left to heal via secondary intention using standard wound care protocols. There were no major postoperative infections or adverse events (mean follow-up, 7.4 ± 2.4 weeks.).

Conclusions

This retrospective pilot case series builds on a growing body of evidence that OFM can be utilized to facilitate the formation of functional, well-vascularized soft tissue in large contaminated volumetric soft tissue defects.

Influence of advanced wound matrices on observed vacuum pressure during simulated negative pressure wound therapy

Biomaterials and negative pressure wound therapy (NPWT) are treatment modalities regularly used together to accelerate soft-tissue regeneration. This study evaluated the impact of the design and composition of commercially available collagen-based matrices on the observed vacuum pressure delivered under NPWT using a custom test apparatus. Specifically, testing compared the effect of the commercial products; ovine forestomach matrix (OFM), collagen/oxidized regenerated cellulose (collagen/ORC) and a collagen-based dressing (CWD) on the observed vacuum pressure. OFM resulted in an ∼50% reduction in the observed target vacuum pressure at 75 mmHg and 125 mmHg, however, this effect was mitigated to a ∼0% reduction when fenestrations were introduced into the matrix. Both collagen/ORC and CWD reduced the observed vacuum pressure at 125 mmHg (∼15% and ∼50%, respectively), and this was more dramatic when a lower vacuum pressure of 75 mmHg was delivered (∼20% and ∼75%, respectively). The reduced performance of the reconstituted collagen products is thought to result from the gelling properties of these products that may cause occlusion of the delivered vacuum to the wound bed. These findings highlight the importance of in vitro testing to establish the impact of adjunctive therapies on NPWT, where effective delivery of vacuum pressure is paramount to the efficacy of this therapy.

In-Vivo Evaluation of a Reinforced Ovine Biologic for Plastic and Reconstructive Procedures in a Non-human Primate Model of Soft Tissue Repair

BACKGROUND

Biologic matrices are used in plastic and reconstructive surgical procedures to aid in the kinetics of soft tissue repair and promote functional tissue formation. The human acellular dermal matrix AlloDerm is widely used; however, it is offered at a relatively high cost, and its dermal composition may not provide an ideal remodeling scaffold. OviTex Plastic and Reconstructive Surgery (PRS) Resorbable and Permanent are reinforced biologic matrices engineered with layers of ovine forestomach matrix embroidered with small amounts of polymer to optimize biophysical performance. This study compared the healing outcomes of these matrices in a non-human primate model of soft tissue repair.

METHODS

Animals were implanted with test articles in surgically created full-thickness midline abdominal wall defects and evaluated macroscopically and histologically at 2, 4, 12, and 24 weeks.

RESULTS

Both OviTex PRS Permanent and Resorbable matrices exhibited earlier host cell infiltration, neovascularization, and collagen deposition and also fully remodeled into the host tissue by 12 weeks post implantation. AlloDerm had less host cell infiltration and neovascularization at early time points and never fully integrated into the surrounding host tissue. There was no statistical difference in overall inflammation between AlloDerm and either OviTex PRS product at any time point, despite small amounts of polymer reinforcement in OviTex products.

CONCLUSIONS

In a primate soft tissue repair model, OviTex PRS Permanent and Resorbable matrices performed comparably with the leading human acellular dermal matrix. OviTex PRS Permanent and Resorbable are less expensive than alternatives like AlloDerm and may promote faster host cell proliferation and functional remodeling in some soft tissue repair applications.