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Hello, and welcome to this online PRESENT education program. My name is John S. Steinberg, DPM. I am an assistant professor with the University of Texas Health Science Center in San Antonio in the podiatry division. The title for this discussion is going to be âAdvances in Healing the Diabetic Wound.â Now, it was not too long ago that wound healing was a very boring topic in medicine and something that we really did not have a lot of new technology to discuss. But recent scientific advances have left us with a significant number of tools that we can utilize to our patientâs benefit in healing these complex and challenging wounds. We are going to discuss some of the simplicity of wound healing, and then we are going to look at some of the complexity of what now science has to offer in a nonhealing wound.
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The ultimate goal of advanced wound healing is to prevent or at least to minimize limb loss and amputation. George Bernard Shaw was quoted above as saying, âI marvel that society would pay a surgeon a large sum of money to remove a patientâs leg but nothing to save it.â Now, this is a bit of a social commentary, but it does describe a problem in our medical system, wherein the reimbursement is often times surgically oriented in the diabetic limb rather than paying for the advanced care technologies for wound healing. We are starting to see a significant shift and an increase in reimbursement for these advanced technologies as our system begins to understand what we already know, and that is that if we can prevent these wounds or if we can heal these wounds, then we can ultimately prevent the cost of a limb loss and amputation.
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There are 2 key reasons why someone can lose their limb because of an ulceration in diabetes. The first, as pictured on the left hand side, is that deep wounds are a portal for infection. These deep wounds can lead to bone infection or osteomyelitis, and osteomyelitis in the lower extremity is generally a surgical disease requiring debridement and/or amputation. The other key reason for limb loss in a chronic wound is necrosis and ischemia. Now, this may happen at day 1 or 2 where you have a frankly necrotic wound that does not have sufficient vascular supply, or the wound may progress as pictured on the right hand side as a healthy granulating wound, yet every day that this increased oxygen demand is placed on that compromised lower extremity is another day that the scales may be tipped towards relative ischemia and thus a gangrenous or ischemic wound.
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This is an introductory case study example of just where we are at in wound healing science now versus where we were at perhaps 20 years ago. The photo on the left shows a patient who is 2 days postoperative from an open partial second ray amputation. She has a history of diabetes and presented 2 weeks after a puncture wound with a significant abscess, both dorsal and plantar. The open partial second ray amputation was done, but 2 days after that procedure, as the photo that you see on the left hand side, she had significant ischemia of both the medial and lateral skin edges. The wound was supported with hyperbaric oxygen therapy and negative pressure wound VAC so that we are able to granulate this wound in, support the microvascular structures of the healing wound base, and thus return to the OR, debride those skin edges once they had been supported properly, and continue the antibiotics to granulating the wound where you see centrally at approximately 2 weeks after that original photo. The photo on the right hand side shows the patient outpatient after eventual grafting was placed onto this site with complete salvage of the foot. This clinical example shows a patient who probably would have progressed on to a mid foot or even more proximal amputation, but because of the advanced technologies, and in this case, hyperbaric oxygen therapy and VAC technology, this patient went on to limb salvage and just required prescriptive shoes as her long-term therapy.
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In contrast to the previous case example, this is a chronic nonhealing wound. This is a diabetic patient with a plantar medial heel wound that has been present for greater than 6 months. He has been receiving care that includes weekly debridements, total contact cast, removable cast walkers, and Hydrogel dressings, but with no success. Radiographs show no evidence of osteomyelitis and noninvasive vascular examination shows no evidence of macrovascular disease, so the example here is of a biology failure in the wound base. To assist in this, we used a topically applied growth factor of Regranex or platelet derived growth factor beta, and as you can see in these next several photos, that over a period of 6 weeks, we were able to completely epithelialize and close this wound site. This, again, is an example of wound biology failure where the mechanics were corrected through offloading, the debridement was being performed properly, yet this patient lacked the intrinsic healing ability to progress towards total wound healing until the extrinsic growth factor was applied.
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So, what is needed to heal a diabetic neuropathic foot ulceration? Well, first of all, we have to build an appropriate team around these patients and their problem wounds. We need to control their diabetes and general health through involving their endocrinologist, family practitioner, and internal medicine physicians. They need adequate diet control through a dietitian, nutritionist, or certified diabetes educator. We need to ensure that there is adequate blood supply to the wound base. This can be done through the vascular surgeon or perhaps even hyperbaric oxygen therapy. Finally, we need to make sure that there is absence of infection to the wound base and this can involve podiatry, orthopedics, and infectious disease. Once all of that has been done for these patients, essentially 3 treatments are necessary to heal the majority of foot ulcerations and those are regular debridement, offloading of pressure from the base of the wound, and providing a moist healing environment. These 3 standard of care treatments, when done properly, will heal upwards of 80% of newly presenting plantar diabetic neuropathic foot wounds. The key portions of what we are going to talk about in this lecture are those percentages that do not respond to the standard of care or perhaps have other compromising abilities in their wound healing function.
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Gail Reiber and her research group at the University of Washington published regularly in Diabetes Care and many other journals regarding diabetic foot epidemiology. This particular concern looking at ulceration and their incidence and outcomes was a very interesting study, which was looked at in March 1999. The incidence of diabetic foot ulcerations that was found in this particular study was roughly 6% of their study population over the 3 years that they followed them. They found that 15% of those wounds developed osteomyelitis and 16% overall required amputation. Very importantly, though, they also looked at cost data for these newly presenting diabetic foot ulcerations. They found that it cost roughly $30,000 for 2 yearsâ worth of ulcer care. This is a very important point in my opinion because when you look at the cost for new technologies and we are trying to justify this cost, it is important to point out what the cost would be to not heal the wound, and that is what this figure tells us is that roughly maintaining a wound for 2 years will cost the system approximately $30,000.
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When approaching something as complex as diabetic foot complications, it is important to have a structured and orderly system by which you treat and diagnose these patients. Presenting here in this slide from 1996 Journal of American Medical Podiatric Association is the University of Texasâ Diabetes Foot Risk Classification System. As you can see, this is a system that goes from 0-6, and it is utilized to evaluate and then help link appropriate treatments to the patients as they progress in their risk spectrum. You can see that the category 0 patient is roughly the unaffected diabetic foot, whereas category 1, 2, and 3 are those who are at risk for ulceration and category 4, 5, and 6 are those at risk for amputation.
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Paul Brandon and others who have contributed significantly to understanding the neuropathic foot is quoted above as having said, âItâs not what you put in a wound, itâs what you take off.â This statement is chiefly referring to offloading or pressure removal and debridement. These 2 treatments make up the groundwork for treating diabetic neuropathic ulcerations, and as you can see on the left hand photo here, a patient who previously had a fairly benign sub first metatarsal head callus with his advancing loss of protective sensation, now has a callus that has heme and is destructive and preulcerative to the deep tissues. The photo on the right hand side is a transfer ulceration or transfer lesion from a partial first ray amputation that now has displaced this additional pressure underneath the second metatarsal head remaining.
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So what exactly does offloading mean and how do we define it? I will share with you my clinical interpretation of comprehensive offloading and what it means in the treatment room. First of all, we have to begin with debridement of the wound. This involves the wound periphery including and hyperkeratotic, macerated, or undermined tissue and also very importantly involves debridement of the wound base to stimulate bleeding and growth factor migration. Secondly, offloading involves acute pressure relief. As seen in this photo, it is being accomplished through a total contact cast. Many other technologies and devices can be utilized including removable cast walkers or perhaps a wheelchair and/or crutches. Offloading also encompasses accommodation. This can be through a pair of extra depth or custom molded shoes with the appropriate insoles or may involve some type of exquisite bracing. Finally, if the offloading cannot be achieved through some type of an accommodative device, then it must be achieved through a surgical means. As you can see being illustrated on this photo, a tendo Achilles lengthening or other soft tissue or bone procedure may be necessary to remove the offending pressure and thus surgically offload the extremity.
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This is a clinical example of a patient who has diabetes and lower extremity neuropathy, who has had previous ulceration in the first intermetatarsal space. This ulcer was treated and healed, and she was then managed in appropriate shoes and prescriptive insoles. She was unable, however, for 2 years to replace these shoes or insoles because of financial constraints and presented back to our clinic a few years later, and as you can see upon debridement of this hyperkeratotic tissue, had an ulcer recurrence. This is an example of how comprehensive management for these patients needs to be short-term for the management of the acute problem, but long-term to accommodate those factors, which caused the ulceration in the first place.
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There are a large variety of devices that are available for offloading the diabetic neuropathic wound. These can be custom made or off-the-shelf variety. In this photo, you can see a wheelchair and crutches. These are often times good adjunctive devices, but very rarely do we utilize these as solo therapy for offloading because of the risk of patient noncompliance. We prefer, as you can see in the right hand photo, to place something to the patientâs extremity that they can ambulate with and still reduce the pressure across the wound site. The best devices are those that cross above the ankle, therefore reducing the pressure of the Achilles tendon onto the forefoot, and these include removable cast walkers, posterior splints, total contact casts, and Crowe walking devices. A second choice device would be a simply modified type of a shoe or a wedge shoe with appropriate insole and possible cutout modification.
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So, how do we define the difference between good versus advanced wound care? Well, on the left hand column you see good wound care. This includes appropriate history and physical examination of the patient, debridement, offloading, and maintaining a moist healing environment. This has become the standard of care in wound healing, and is practiced on almost all wounds. On the right hand column is advanced wound care, which is generally reserved for problem or nonhealing wounds in the high-risk patient. This involves many of the topics or treatments that we are going to talk about in the rest of this lecture involving the new technologies in wound healing.
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Part of the challenge in wound care now has become the information or product overload that we are faced with. There is no one right or wrong protocol for wound healing, and it certainly is a science and art at the same time. The gratifying part is that we have many more tools to work with now, but the challenging part is when and how to utilize those tools. We are going to discuss many of the advanced technologies during this program, and we are going to look at some cases where we are going to talk about usage of these various advanced technologies in particular clinical scenarios.
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Before deciding on an appropriate treatment course for your patient with a problem wound, it is important to properly diagnose the etiology of that problem wound. This case example is a patient who is 2 weeks status post an incision and drainage of a medial abscess overlying the first metatarsophalangeal joint. This wound has failed to respond to good wound care, and the surgical cultures eventually were found to have grown methicillin-resistant Staphylococcus aureus; however, this patient was maintained on cephalexin. Once the patient was switched to linezolid to properly cover the MRSA infection, the wound rapidly contracted and did not require and advanced additional advanced healing modalities. There are many reasons for a problem wound or a nonhealing wound. Some of the cofactors that must be evaluated include ischemia, infection, nutritional deficiencies, high pressures, bacterial burden at the base of the wound, and a loss of cellular signaling or biologic failure of the wound. Each of these factors need to be evaluated prior to determining an appropriate advanced technology wound healing agent.
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An emerging area of knowledge within wound healing and vascular medicine surrounds nitric oxide. Nitric oxide is a vascular endothelial mediator and is a very potent regulator of blood flow; more specifically, vasodilatation in the peripheral vascular system. You can see that nitric oxide is a very simple nitrogen and oxygen molecule, but if you look in the above white diagram, you can see that arginine along with oxygen are combined in a synthase reaction to produce the nitric oxide in the vascular endothelium itself. Patients who have diabetes and problem nonhealing wounds are known to have a deficiency of an ability to produce nitric oxide. Nitric oxide is also important in lipoprotein metabolism, capillary transport, and angiogenesis. So, you can see why this is such an interesting and emerging technology as we learn more about how to diagnose and treat this vascular endothelial deficiency in nitric oxide.
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As you can see from this photo, many of the founding reasons for problem wounds and poor nutrition go far beyond what we can do for these patients in a medical environment, and as our society becomes more tied to the desk, less active, and as our nutritional status deteriorates, this problem and phenomenon of diabetes, obesity, and problem wounds will clearly only get worse.
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The concept of wound bed preparation has become a very important subtopic when looking at advanced technologies. We have to have optimized this wound base and this problem wound in order to properly receive and to best benefit from the advanced technology that you are contemplating using. Generally, the advanced technologies will work best in a clean viable wound bed. The wound bed should be free from frank infection, it should have significant control of the surface contamination, and there should be a minimal amount of exudate present. This all can be achieved through appropriate routine surgical debridements, through pretreatment of the wound with systemic and/or topical antimicrobial agents, and the wound should have the bed optimized through decreasing the bacterial load. Cultures do play a role in chronic wounds; however, for most functional results, quantitative cultures rather than qualitative cultures should be utilized, and finally, talking about wound bed preparation, the MMP or matrix metalloproteinase balance is important to understand. MMPs are a normal and functional part of wound healing and they are involved in items such as collagenase and other wound breakdown products. However, it is important to understand that in chronic nonhealing wounds, the MMP balance is thrown off, and therefore, the wound breakdown exceeds the would buildup and thus a chronic nonhealing wound.
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As mentioned in the previous slide, antibacterial topical agents are playing an increasingly important role, particularly in wound bed preparation. Advanced technologies benefit from this wound bed preparation by having a better chance of wound success faced with decreased amounts of contamination. The surface antibacterial agents control bacterial burden. They do this through decontamination of the wound site and also moderation of infection risk. Antibacterial topicals penetrate into the soft tissues by 1-2 mm, they can be combined with systemic antibiotics to address the bio film layer of contamination that is often times present in the surface of these wounds, and often times contain a nanocrystalline form of silver which has active ionic form for wound treatment.
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Hyperbaric oxygen therapy has become a very important adjunct in many wound-healing centers and diabetic foot treatment plans. It is defined as the use of 100% oxygen at pressures greater than one atmosphere. The concept is systemic inhalation of high levels of oxygen such that the plasma becomes supersaturated with oxygen, and therefore delivering greater perfusion of oxygen density to the tissues. This concept is to utilize what vasculature architecture is available to its greatest ability, and is indeed and adjunct to surgical debridement, local wound care, antibiotic therapy, and many other treatments that are utilized in the diabetic foot. Typical hyperbaric oxygen therapy involves 90 minutes daily treatments at 2 to 2.5 ATA or atmosphere absolute, and this is performed for a series of 20-40 dives done 5-6 days per week.
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Bioengineered products as an advanced wound healing technology have been around for quite a while now. This started with Procuren, which is an autogenous blood product that was sent to a processing facility and then reapplied onto the patientâs wound on a regular basis of extrinsic growth factors. Regranex took this concept and made it more usable by an off-the-shelf version of human platelet derived growth factor. For more complex wounds or wounds that require stimulation on a broader biologic level, the single layered and bilayered tissue of Dermagraft and Apligraf incorporate the human fibroblast living cell technology so that growth factors are produced at the wound bed itself by these donor human fibroblasts.
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The increased use of bioengineered living tissues in diabetic foot wounds is certainly well deserved. These products are a significant advance in technology, and it is important to look at the advantages and particularities of each Apligraf and Dermagraft. If we take a look first at Apligraf, this is a bilayered human tissue composed of a human epidermis with human keratinocyte graft cells, as well as human type dermis with human fibroblasts. This is derived from neonatal foreskin tissue and is shipped as a fresh culture with a typical 5-day shelf life. Apligraf was first approved by the FDA in May 1998 for venous leg ulcers, and later in June 2000 for diabetic foot ulceration. Dermagraft is a similar concept product, but does have some distinct differences. We utilize Dermagraft more for the deeper wounds in our practice because it is composed chiefly of a dermis. Dermagraft is composed of human fibroblasts seated in a Vicryl mesh, which composes this matrix. It is also derived from neonatal foreskin tissue and is shipped as a cryopreserved product, so this has a 6-month shelf life when it is contained in its frozen state, but once it is shipped out in the dry ice container, it lasts for a few days before you must utilize it. The Dermagraft was FDA approved first in October 2001 for diabetic foot ulceration, and these products both have found increasing use in our practices and in many advanced wound healing centers.
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It is important to understand what the contents of bioengineered tissue are and how they work. These really are not off-the-shelf versions of skin graft, but rather are sheets of growth factor that can be easily applied to the wound site on an outpatient basis with minimal risk of complication. Some of the contents of bioengineered tissues include growth factors and cytokines. These are responsible for cellular proliferation and migration, and are important for the structure formation and immuno-regulation at the wound level. In addition, bioengineered tissue products supply matrix proteins. These are responsible for properties such as adherence and epithelialization. Finally, bioengineered tissues contain glucosaminoglycans, and these are responsible for items such as normal dermal structure formation and function.
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In discussing Dermagraft in more detail, Dermagraft is a single-layered skin substitute product containing living human fibroblasts that are seated onto a Vicryl-type mesh. This is cut to shape, applied onto the wound site, and covered with a moist nonadherent dressing. You can see here a photo micrograft on the right showing a cross section of Dermagraft with the spindle shaped living human fibroblasts embedded onto that Vicryl mesh.
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In looking at a little more detail into Apligraf itself, this is a bilayered version of a tissue engineered product. Showing on the left photo micrograft slide, the Apligraf itself with the dermis and epidermis layers and on the right a comparison to normal human skin. You can see the significant structural similarities, but again, I will point out the significance that Apligraf as well as Dermagraft are not utilized for their structural integrity in diabetic foot wounds, but typically are utilized for their growth factor activity.
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The logistics of utilizing bioengineered tissues in the clinical setting is very simple. The Dermagraft itself comes in a cryopreserved form, is shipped overnight mail in a dry ice container, removed from that container to be thawed and rinsed which takes approximately 2-3 minutes, and then is cut to shape and applied onto the problem wound site. In contrast, Apligraf comes at room temperature, is elevated from its agar medium, fenestrated, applied onto the wound site, and covered with a moist nonadherent dressing. Each of these applications takes roughly 10 minutes and is done easily in the outpatient environment.
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There certainly are many other biologics and advanced therapy concepts that we are going to discuss. I want to mention also Oasis which is an intestinal submucosa; not a living product, but certainly a biologic type of a dressing; Gamagraft which has become popular in many arenas now is cadaver skin allograft applied in a similar formation, also as a biologic type dressing; Porcine or pig skin graft has been utilized for many, many years, particularly in the plastic surgery specialties as a biologic wound covering; graft jacket, also a cadaver based product; and Promogran being an emerging technology to address the biologic imbalance of the MMPs or matrix metalloproteinases that we discussed earlier. In an attempt to appropriately bind and remove the excessive MMPs from the wound bed, this can help prevent excessive wound breakdown. X-Cell is another emerging advanced therapy concept utilizing a cellular spaced dressing to provide a better wound environment.
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The concept of negative pressure therapy or VAC in problem wound healing has become a significantly emerging field. The principle here is very simple and the device is very simple in that an electrically operated negative pressure vacuum pump is attached to an airtight foam dressing over the wound site. This creates a negative pressure environment, which can stimulate angiogenesis, cellular proliferation, and remove excess exudate from the wound bed.
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We are going to look at our first clinical case example here to try and put some of this together and discuss some of these advanced technologies. This particular patient that you see here had the history of a plantar puncture wound. He is a 62-year-old male with history of diabetes for 20 years. He has had an incision and drainage performed with significant loss of his dorsal tissue, and you can see that this wound is progressing well and mostly granular; however, he is having significant difficulty with the exposed extensor tendons on a long-term problem wound basis.
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Rather than to surgically excise those exposed extensor dorsal tendons, the decision was made to apply bioengineered tissue grafting over that site and preserve the anatomic function of those extensor tendons. The wound site was curetted and debrided, and Dermagraft as you can see in this photo was applied to the site covering the extensor tendons and the majority of the wound bed. After 2 applications of Dermagraft in 4 weeks, the wound site was completely granular, and the exposed extensor tendons were completely covered.
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The wound continued to progress and at this point was fairly superficial, so the decision was made to switch from Dermagraft containing the human fibroblasts to Apligraf which would contain the fibroblasts in addition to human keratinocytes to further promote epithelialization of this now very superficial wound. The wound continued to contract and decrease in size until we reached this point that you can see in the center photo where the patient had a very small superficial wound, but a nonhealing wound for several months. This wound received continued debridements, appropriate local care with Hydrogel, but was not progressing towards healing. The decision was finally made to address the MMP imbalance in this wound, which was suspected because of the yellow film and persistent exudate, which came from the wound base. After 3 weeksâ worth of treatment utilizing Promogran to balance and bind the excessive MMPs, the wound site finished epithelializing and contracted the remainder portion of the nonhealing aspect.
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In Texas, people like to play with guns and, unfortunately, this gentleman was trying to supposedly clean his gun when it accidentally fired and he sustained a gunshot wound to his forefoot. You can see the damage is fairly well contained to the second ray. You can see the entry wound dorsally, exit wound plantarly.
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Radiographs were obtained of this patient, and when you look here at the lateral as well as the AP views, you can see some remaining metallic fragments from the gunshot wound along with a significant amount of bony destruction to the second ray.
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The patient was brought to the operating room and the second toe along with the surrounding nonviable soft tissues were all debrided, and the wound site was lavaged. At this point, as you can see in the right hand photo, we are looking at the second metatarsal head which is exposed but viable, and then we are looking at the remaining wound base with viable soft tissues. As a surgical team at this point, you have a decision to make as to whether you are going to excise or leave the second metatarsal head and a portion of the second metatarsal neck. Certainly, removing the second metatarsal would make later closure a much easier phenomenon for this patient. However, our decision was to leave second metatarsal head so as to better preserve the function of the forefoot.
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Prior to leaving the operating room, the patient was placed into a negative pressure wound VAC dressing, and this therapy began immediately postoperative and the patient was treated with 125 mmHg negative pressure. The wound VAC dressing was changed every 3 days, and you can see that after 2 weeks, the wound had completely granulated in over the second metatarsal head and the wound margins were contracting in nicely, and after another 2 weeks we began advanced therapy including bioengineered tissue grafting and eventually skin grafting to completely close this wound site.
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Another good clinical example of the negative pressure or VAC therapy; in this case, a patient who has just sustained an abscess to the first ray. This has been debrided and lavaged in the operating room, and prior to leaving the operating room, we applied a negative pressure VAC dressing.
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Just 3 days after the initial VAC was applied and the debridement was performed, this patient was brought back to the operating room in which the VAC dressing was removed, the wound site was lavaged with pulse irrigation and saline, and the wound edges were then primarily closed utilizing sutures. The advantage of utilizing VAC just for this 3-day postoperative period in this patient was to prevent the necessity of 2 or 3 time a day dressing changes which would place the patient at further risk for wound site recontamination postoperatively and would also present a concern for wound hydration and possible maceration of the skin edges.
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This is a clinical example of a patient who had a problem wound several weeks after sustaining a fifth toe amputation. You can see that there was failure of the amputation flap and inability to primarily close this wound secondary to tension. There was also concern that this patient is not ready for advanced therapy because the wound bed has not been properly prepared. Although the majority of the wound is granular, there is significant concern for the proximal gangrenous changes and distal fibrotic tissue present in the wound base. After appropriate debridement and another week or two of local wound care, the wound bed is now appropriately granular and ready to receive advanced technology care such as bioengineered tissue grafting.
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This is the patient after bioengineered tissue grafting was applied. You can see that the wound has contracted significantly and the wound base has filled in with only 2 small remaining open areas. Now again, after this wound is allowed to continue contracting after the single application of bioengineered tissue grafting, the wound is completely closed.
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An example of a patient with a large soft tissue defect at the dorsolateral margin of the fifth ray after having excised a problematic infection of the fifth ray. You can see again exposed extensor tendons and a deep wound with only partial closure with distal sutures. If you look closer at the wound base itself, you can see the exposed extensor tendons and significant depth to this wound margin.
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Split thickness skin grafting is not yet an option for this patient because of the exposed extensor tendons and deep soft tissue margins. However, in an effort to preserve the function and anatomy, we chose not to excise these tendons, but rather to speed the wound base healing through appropriate bioengineered tissues. This shows the wound site pre and post curettage or debridement, and this is again a wound bed preparation principle of appropriately debriding these wounds to a viable bleeding appropriate bed. When you debride away this bio film or this wound surface layer, you are also removing a significant amount of the wound bed contamination.
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Continuing on with the same patient here, illustrating the 3 applications of Dermagraft tissue that were applied as the wound was deep, and then finally as the wound became more superficial we again employed the bilayered tissue of Apligraf for the importance of the keratinocytes combined with the fibroblasts to finalize the epithelialization for this patient. Here, you can see pictorially as that wound advanced and continued to contract, and then finally the wound closure after Apligraf was applied.
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This case example shows a gentleman who sustained a mid foot amputation at the transmetatarsal level, but had failure of the central portion of his flap. This wound site was approximately 1 cm in depth and the concern was that this distal and somewhat plantar wound would be exposed to shoe and insole pressures. We wanted the most sustained and thick tissue that we could provide for appropriate wound healing in this patient. That was achieved by utilizing Dermagraft to build the appropriate wound base, and you can see here how this product as applied to the wound itself.
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The patient received Dermagraft every 2 weeks for a period of 6 weeks, and at this point, you can see how the wound base has significantly filled in. There is a minimal depth at this point and partial epithelialization.
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The patient was then converted to Apligraf for the concern of epithelializing the remaining portion of this wound, and you can see that that occurred rather rapidly over a period of approximately 3 weeks.
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Again, what we are looking at here is a goal of durable full thickness healing. As can be seen in this distal transmetatarsal amputation site dehiscence wound, the wound site must be healed not with just a thin layer of fragile skin which would be likely to have a recurrent wound and ulceration, but rather we need full thickness tissue layers and full thickness skin closure. In this particular case, this was achieved through the use of bioengineered tissue, used in a repetitive manner such that we could augment the patientâs natural healing ability and therefore yield a full thickness skin coverage at this distal pressure area. This can now be properly accommodated in a partial foot orthosis and a proper prescriptive shoe.
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Another important concept to keep in mind is the use of combined advanced technologies. In this particular case, which you see is combination use of the negative pressure wound therapy or the VAC system placed directly over a bioengineered tissue graft. The VAC systems is used in combination often times now with autogenous split thickness skin grafting and many other topical growth factors and other wound healing adjuncts; and in this case, again, we are showing the use of bioengineered tissue simultaneously with the wound VAC.
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In looking at the prevention of recurrence for these patients, the most challenging aspect of wound healing is identifying the actual etiology of the wound, addressing that etiology eventually through accommodative bracing, insoles, or shoes, or if that is unsuccessful, then progressing this patient onto the appropriate surgical procedure to modify their soft tissues or bony architecture and function so that these wounds do not recur. Another yet seldom discussed factor of wound recurrence is patient education, and one way that we have tackled this in San Antonio is through amputee support group, which has been a very highly successful group that meets once a month so that these patients can share some of their successes and some of their concerns with peers rather than depending on their physicians or nursing staff to provide them with that education alone.
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In conclusion, I hope that this introductory lecture has been of help to you, expose you to the advances in technology that are now available in healing the diabetic foot wound. Yet, by no means have we covered all of these technologies, but I hope that the cases have shown you some of the examples and clinical scenarios where you can consider utilizing advanced technologies to not only heal wounds that would have previously not healed, but also to speed the healing course so that these wounds have less exposure to the risk of infection and thus less exposure to the risk of amputation. Please note the University of Texas Health Science Center Podiatry Divisionâs website at www.diabeticfoot.org and them my e-mail address which I will be happy to take questions from if you have them at steinberg@uthscsa.edu. Thank you very much.
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