Christopher E. Attinger

The Basic Science of Wound Healing

Summary: Understanding wound healing today involves much more than simply stating that there are three phases: “inflammation, proliferation, and maturation.” Wound healing is a complex series of reactions and interactions among cells and “mediators.” Each year, new mediators are discovered and our understanding of inflammatory mediators and cellular interactions grows. This article will attempt to provide a concise report of the current literature on wound healing by first reviewing the phases of wound healing followed by “the players” of wound healing: inflammatory mediators (cytokines, growth factors, proteases, eicosanoids, kinins, and more), nitric oxide, and the cellular elements. The discussion will end with a pictorial essay summarizing the wound-healing process.

Mechanisms and clinical applications of the vacuum-assisted closure (VAC) device: A review

The use of sub-atmospheric pressure dressings, available commercially as the vacuum-assisted closure (VAC) device, has been shown to be an effective way to accelerate healing of various wounds. The optimal sub-atmospheric pressure for wound healing appears to be approximately 125mm Hg utilizing an alternating pressure cycle of 5 minutes of suction followed by 2 minutes off suction. Animal studies have demonstrated that this technique optimizes blood flow, decreases local tissue edema, and removes excessive fluid from the wound bed. These physiologic changes facilitate the removal of bacteria from the wound. Additionally, the cyclical application of sub-atmospheric pressure alters the cytoskeleton of the cells in the wound bed, triggering a cascade of intracellular signals that increases the rate of cell division and subsequent formation of granulation tissue. The combination of these mechanisms makes the VAC device an extremely versatile tool in the armamentarium of wound healing. This is evident in the VAC device’s wide range of clinical applications, including treatment of infected surgical wounds, traumatic wounds, pressure ulcers, wounds with exposed bone and hardware, diabetic foot ulcers, and venous stasis ulcers. VAC has also proven useful in reconstruction of wounds by allowing elective planning of the definitive reconstructive surgery without jeopardizing the wound or outcome. Furthermore, VAC has significantly increased the skin graft success rate when used as a bolster over the freshly skin-grafted wound. VAC is generally well tolerated and, with few contraindications or complications, is fast becoming a mainstay of current wound care.

Angiosomes of the foot and ankle and clinical implications for limb salvage : Reconstruction, incisions, and revascularization

Background: Ian Taylor introduced the angiosome concept, separating the body into distinct three-dimensional blocks of tissue fed by source arteries. Understanding the angiosomes of the foot and ankle and the interaction among their source arteries is clinically useful in surgery of the foot and ankle, especially in the presence of peripheral vascular disease. Methods: In 50 cadaver dissections of the lower extremity, arteries were injected with methyl methacrylate in different colors and dissected. Preoperatively, each reconstructive patients vascular anatomy was routinely analyzed using a Doppler instrument and the results were evaluated. Results: There are six angiosomes of the foot and ankle originating from the three main arteries and their branches to the foot and ankle. The three branches of the posterior tibial artery each supply distinct portions of the plantar foot. The two branches of the peroneal artery supply the anterolateral portion of the ankle and rear foot. The anterior tibial artery supplies the anterior ankle, and its continuation, the dorsalis pedis artery, supplies the dorsum of the foot. Blood flow to the foot and ankle is redundant, because the three major arteries feeding the foot have multiple arterial-arterial connections. By selectively performing a Doppler examination of these connections, it is possible to quickly map the existing vascular tree and the direction of flow. Conclusions: Detailed knowledge of the vascular anatomy of the foot and ankle allows the plastic surgeon to plan vascularly sound reconstructions, the foot and ankle surgeon to design safe exposures of the underlying skeleton, and the vascular surgeon to choose the most effective revascularization for a given wound.

Guidelines for the treatment of diabetic ulcers

1. Chaired this panel2. University of Pittsburgh/UPMC, Pittsburgh, PA3. Georgetown University Hospital, Washington, DC4. Colaizzi Pedorthic Center, Pittsburgh, PA5. HCA Richmond Retreat Hospital, Richmond, VA6. University of Michigan Hospital, Ann Arbor, MI7. University of Texas Health Science Center, San Antonio, TX8. Covance, Princeton, NJ9. St Joseph’s Hospital, Belleville, IL10. University of South Florida, Tampa, FL11. Penn North Centers for Advanced Wound Care, Warren, PA12. Cabrini Medical Center, NY, NY13. Beth Israel Deaconess Medical Center, Boston, MA, and14. Barnes-Jewish Hospital at Washington University Medical Center, St Louis, MO

Clinical approach to wounds: Débridement and wound bed preparation including the use of dressings and wound-healing adjuvants

Summary: This is a clinical review of current techniques in wound bed preparation found to be effective in assisting the wound-healing process. The process begins with the identification of a correct diagnosis of the wound’s etiology and continues with optimizing the patient’s medical condition, including blood flow to the wound site. Débridement as the basis of most wound-healing strategies is then emphasized. Various débridement techniques, including surgery, topical agents, and biosurgery, are thoroughly discussed and illustrated. Wound dressings, including the use of negative pressure wound therapy, are then reviewed. To properly determine the timing of advance therapeutic intervention, the wound-healing progress needs to be monitored carefully with weekly measurements. A reduction in wound area of 10 to 15 percent per week represents normal healing and does not mandate a change in the current wound-healing strategy. However, if this level of wound area reduction is not met consistently on a weekly basis, then alternative healing interventions should be considered. There is a growing body of evidence that can provide guidance on the appropriate use of such adjuvants in the problem wound. Several adjuvants are discussed, including growth factor, bioengineered tissues, and hyperbaric medicine.

Revascularization of a Specific Angiosome for Limb Salvage: Does the Target Artery Matter?

Ischemic wounds of the lower extremity can fail to heal despite successful revascularization. The foot can be divided into six anatomic regions (angiosomes) fed by distinct source arteries arising from the posterior tibial (three), anterior tibial (one), and peroneal (two) arteries. This study investigated whether bypass to the artery directly feeding the ischemic angiosome had an impact on wound healing and limb salvage. Retrospective analysis was performed for 52 nonhealing lower extremity wounds (48 patients) requiring tibial bypass over a 2-year period. Preoperative arteriograms were reviewed to determine arterial anatomy relative to each wounds specific angiosome and bypass anatomy. Patients were divided into two groups; direct revascularization (DR, bypass to the artery directly feeding the ischemic angiosome) or indirect revascularization (IR, bypass unrelated to the ischemic angiosome). Wound outcome was analyzed with regard to the endpoints of complete healing, amputation, or death unrelated to the wound. Time to healing was also noted for healed wounds. Based on preoperative arteriography, 51% (n = 27) of the wounds received DR to the ischemic angiosome, while 49% (n = 25) underwent IR. There were no statistically significant differences in the comorbidities of the two groups. Revascularization was via tibial bypass using the saphenous vein (n = 34, 65%) or polytetrafluoroethylene with a distal vein patch (n = 18, 35%). Bypasses were performed to the anterior tibial (n = 22, 42%), posterior tibial (n = 17, 33%), or peroneal (n = 13, 25%) arteries based on the surgeons judgment. One bypass failed in the perioperative period and was excluded from the analysis. The remaining bypasses were patent at the time of wound analysis. Due to a 17% mortality rate during follow-up, 43 wounds were available for endpoint analysis. This analysis demonstrated that 77% of wounds (n = 33) progressed to complete healing and 23% of wounds (n = 10) failed to heal with resultant amputation. In the DR group, there was 91% healing with a 9% amputation rate. In the IR group, there was 62% healing with a 38% amputation rate (p = 0.03). In those wounds that did heal, total time to healing was not significantly different--DR 162.4 days versus IR 159.8 days (p = 0.95). Revascularization plays a crucial role in the treatment of ischemic lower extremity wounds. We believe that direct revascularization of the angiosome specific to the anatomy of the wound leads to a higher rate of healing and limb salvage. Although many factors must be considered in choosing the target artery for revascularization, consideration should be given to revascularization of the artery directly feeding the ischemic angiosome.

The mechanisms of action of vacuum assisted closure: More to learn

Division of Plastic and Reconstructive Surgery, Brigham and Women’s Hospital , Boston, MA; Division of Plastic and Reconstructive Surgery, University of Pittsburg School of Medicine , Pittsburg, PA; Department of Surgery, Yale University School of Medicine , New Haven, CT; Department of Surgery, University of Chicago Hospitals , Chicago, IL; Limb Center, Georgetown University Medical Center, Washington, DC; Department of Surgery, Stanford University Medical Center, Stanford, CA; Division of Plastic Surgery, Department of Surgery, Penn State University Milton S. Hershey Medical Center, Hershey, PA

Prevention of venous thromboembolism in the plastic surgery patient.

The term venous thromboembolism refers to a spectrum of disease that includes deep venous thrombosis and pulmonary embolism. Both deep venous thrombosis and pulmonary embolism are often clinically silent and thus difficult to diagnose, which leads to a substantial delay in treatment that results in high rates of morbidity and mortality. The purposes of this article are to help physicians determine the proper venous thromboembolism prophylaxis and to simplify the complex problem of treating venous thromboembolism. The tools provided in this article will help expedite and clarify the decision-making process.

A review of mechanical adjuncts in wound healing: Hydrotherapy, ultrasound, negative pressure therapy, hyperbaric oxygen, and electrostimulation

Chronic or non-healing wounds may develop in the setting of many diseases and are the source of considerable morbidity as well as health costs. These wounds demand an aggressive, multifactorial approach including surgical debridement, revascularization, antibiotics and dressings. In addition serveral adjuvant treatment methods have been developed to further stimulate healing. Whirlpool, although used frequently, has not been proven to be of benefit. However, pulsed lavage does show a promising future. Ultrasound has demonstrated beneficial effects but further controlled studies are needed. Subatmospheric pressure therapy is associated with few complications and is fast becoming a mainstay of adjuvant therapy. Hyperbaric oxygen therapy has been shown to be effective for many types of wounds. Unfortunately, cost and access to chambers may prohibit its use on a routine basis. Finally, electrostimulation may be one of the up and coming therapies for the future. Though, more studies are needed to determine the mode of delivery for various types of wounds.

Serial surgical debridement: A retrospective study on clinical outcomes in chronic lower extremity wounds

This investigation was conducted to determine if a correlation exists between wound healing outcomes and serial debridement in chronic venous leg ulcers (VLUs) and diabetic foot ulcers (DFUs). We retrospectively analyzed the results from two controlled, prospective, randomized pivotal trials of topical wound treatments on 366 VLUs and 310 DFUs over 12 weeks. Weekly wound surface area changes following debridement and 12‐week wound closure rates between centers and patients were evaluated. VLUs had a significantly higher median wound surface area reduction following clinical visits with surgical debridement as compared with clinical visits with no surgical debridement (34%, p=0.019). Centers where patients were debrided more frequently were associated with higher rates of wound closure in both clinical studies (p=0.007 VLU, p=0.015 DFU). Debridement frequency per patient was not statistically correlated to higher rates of wound closure; however, there was some minor evidence of a positive benefit of serial debridement in DFUs (odds ratio—2.35, p=0.069). Our results suggest that frequent debridement of DFUs and VLUs may increase wound healing rates and rates of closure, though there is not enough evidence to definitively conclude a significant effect. Future clinical research in wound care should focus on the relationship between serial surgical wound debridement and improved wound healing outcomes as demonstrated in this study.