Bilayered Extracellular Matrix Technology & Wound Healing

Discussion

The morbidity and economic burden associated with venous ulcers have led to a growing interest in the development of new approaches to accelerate healing. In this retrospective study, the authors have shown that ECM does not significantly improve venous ulcer healing compared to standard compression dressing. Although ECM leaves an adequate layer of granulation tissue, is easy to apply, and is well tolerated by patients, the physicians at the CMC Wound Care Center believe that the foundation of venous ulcer treatment includes the control of lower-extremity edema and the maintenance of a more stable compression pressure. Given the data collected by this project and the present body of evidence collected to date, it is recommended that further considerations be made to augment clinicians' armament to treat venous leg ulcers.

The standard of care for patients with venous disease implies following a "minimum" set of parameters and treatment regimens. These standards focus on accurate diagnosis, local wound care, infection control, and the application of compression therapy. The mainstay of therapy has been the relief of venous hypertension by external compression.[10,12,13] The traditional Unna boot is a popular and effective form of compression therapy. It is a moist zinc-impregnated bandage and provides both compression and topical treatment.[8] Additionally, compression may be applied by re-enforcement of web-role elastic bandage in multiple layers. However, this decision remains with the clinician. Available data has not proved nor disproved the effectiveness of this theory. Fletcher and Sheldon[14] reviewed 24 randomized trials and found that compression alone is superior to other treatment modalities without compression. This significant difference was partly explained by the maintenance of a more stable compression pressure. Conversely, the Unna boot does not accommodate changes in the volume of the leg. Another disadvantage is the operator-dependent nature of the compression achieved. In many studies, no clear difference in the effectiveness of different types of compression systems has been shown.[9] However, compression therapy has remained the standard therapy.[10,12]

Extracellular matrix is a new biomaterial taken from porcine small intestine. The sub-mucosa provides strength to the intestine through a complex organization of collagen that forms a fibrous matrix. Extracellular matrix is extracted from the intestine in a manner that removes all cells but leaves the complex matrix intact. It retains the natural composition of matrix molecules, such as collagen (types I, III, IV), glycosaminoglycans (hyaluronic acid, chondroitin sulfate A and B), proteoglycans, and glycoproteins (fibronectin), which are known to have important roles in host tissue repair and remodeling. Benbow[11] reported that ECM stimulates healing in noninfected wounds.

Prospects to augment compressive therapy could include spray application of living keratinocytes and fibroblasts as biological dressings. For surgical management of venous hypertension to resolve venous reflux, the patient's vein reflux is treated with endoluminal radiofrequency thermal occlusion, which obliterates the vein. Hydroxyrutosides restore endothelial barrier function. Electrical stimulation has been recently shown in a meta-analysis to provide significant benefit for healing chronic wounds of many etiologies, including venous ulcers, and at this point has the most literature-based support.[15-18]  Printer- Friendly Email ThisReprint Address

Ira Lown, MD, Cabrini Medical Center, Department of Surgery 227 E. 19th St., New York, NY 10003 Phone: 212-995-6000; Email: iralown@yahoo.com .

Wounds.  2005;17(2):27-31.  ©2005 Health Management Publications, Inc.
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