Residency Insight -- A PRESENT Podiatry eZine

Guest Editor, Paul Kim, DPM, FACFAS.

Dr. Paul Kim is an Assistant Professor at the Arizona Podiatric Medicine Program at Midwestern University College of Health Sciences in Glendale, Arizona. Certified in Foot Surgery, American Board of Podiatric Surgery Qualified in Rearfoot and Ankle Surgery, American Board of Podiatric Surgery, Dr. Kim received his Bachelor of Arts degree, Magna Cum Laude, in Psychology and Biology from the University of Colorado at Boulder in 1995 and his Doctor of Podiatric Medicine degree from the Ohio College of Podiatric Medicine in 2002. Dr. Kim completed a Podiatric Medicine and Surgery 36 residency program in 2005 from the INOVA Fairfax Hospital Podiatric Residency Program in Falls Church, Virginia. He received advance training in Diabetic limb salvage from Drs. John Steinberg and Christopher Attinger from Georgetown Hospital. Dr. Kim has authored and lectured on various topics in basic science and clinical practice utilizing techniques of Evidence Based Medicine.

In this week's issue of Residency Insight, Dr. Kim clarifies for Bioengineered Tissues.

—John Steinberg, DPM, PRESENT Editor

Terminology for Bioengineered Alternative Tissues?

Paul J Kim, DPM, FACFAS
Associate Professor
Arizona Podiatric Medicine Program at Midwestern University College of Health Sciences in Glendale, Arizona

Approximately 8 years ago I remember sitting in the audience listening to a prominent speaker giving a lecture on products related to woundcare. He was describing a group of woundcare products, allografts and xenografts, which were being utilized to potentiate wound contracture and healing. After the lecture had concluded, I left confused and unclear about how and when to appropriately utilize any of them. This was not a reflection on the speaker, but had more to do with inconsistent terminology that was used. After further exploration it became clear that the source of the confusion was the inconsistent terminology utilized in the literature that described and defined these products.

Appropriate and consistent terminology is absolutely necessary to effectively communicate concepts. The language of medicine is primarily based in Latin roots. Medical terminology can generally be taken apart to its individual components in order to decipher the meaning of the word or phrase. However, with the new age of medical technology that is product driven, it has been increasing difficult to standardized medical language.

This brings us back to my original point regarding allografts and xenografts. We introduced the term “Bioengineered Alternative Tissues” (BAT) in order to clear up some of the confusion and lack of clarity regarding these products. The problem was that this group of products was called a multitude of different names including “Bioengineered Tissue”, “Tissue Grafts”, and “Skin Substitutes”. The use of these terms further added to the confusion because they inaccurately described their function. The most egregious inaccuracy is the use of the term “Skin Substitutes” which implies that these products can be used in lieu of a split thickness skin graft. This is a false assumption and these products should never be used in this way. However, due to this misnomer, these products have been applied incorrectly potentially delaying healing and increasing overall medical costs. BAT effectively describes these products by distinguishing what it is and what it does. “Bioengineered” refers to the fact these products have been processed or manufactured. “Alternative” reflects a sense that these tissues are not substitutes but are different in function and structure. “Tissue” refers to the fact that these can be either allografts or xenografts.

After further consideration, it was clear that a subdivision was needed to further clarify and distinguish BAT products. In order to simplify and properly categorize these products, we modified terms from the orthobiolgics world. Orthopedic and Podiatric surgeons are familiar with the terms “Osteoinductive” and “Osteoconductive” to describe products that contain cells and proteins that potentiate bone healing (Osteoinductive) and/or serve as scaffolds for the osteocyte migration (Osteoconductive). In the same manner the terms “Dermoinductive” and “Dermoconductive” is a more accurate and precise way of classifying BAT products. Obviously “Derm” refers to skin related structures and “inductive” and “conductive” refer to their function. Dermoinductive BATs (e.g. Apligraf™, Dermagraft™) contain living cells that recruit other cells that stimulate healing, hence are “inductive”. Dermoconductive BATs (e.g. Integra™ and Graftjacket™) serve as collagen scaffolds for fibroblast and keratinocyte migration, hence are “conductive”.

Proper and consistent use of appropriate medical terminology facilitates application of these woundcare products in the most efficacious and cost-effective manner. This will ultimately result in better and more predictable patient outcomes. I believe that the use of the terms Bioengineered Alternative Tissues, Dermoinductive, and Dermoconductive is a positive step in this direction.

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