Peter A. Blume

Comparison of Negative Pressure Wound Therapy Using Vacuum-Assisted Closure With Advanced Moist Wound Therapy in the Treatment of Diabetic Foot Ulcers A multicenter randomized controlled trial

OBJECTIVE—The purpose of this study was to evaluate safety and clinical efficacy of negative pressure wound therapy (NPWT) compared with advanced moist wound therapy (AMWT) to treat foot ulcers in diabetic patients. RESEARCH DESIGN AND METHODS—This multicenter randomized controlled trial enrolled 342 patients with a mean age of 58 years; 79% were male. Complete ulcer closure was defined as skin closure (100% reepithelization) without drainage or dressing requirements. Patients were randomly assigned to either NPWT (vacuum-assisted closure) or AMWT (predominately hydrogels and alginates) and received standard off-loading therapy as needed. The trial evaluated treatment until day 112 or ulcer closure by any means. Patients whose wounds achieved ulcer closure were followed at 3 and 9 months. Each study visit included closure assessment by wound examination and tracings. RESULTS—A greater proportion of foot ulcers achieved complete ulcer closure with NPWT (73 of 169, 43.2%) than with AMWT (48 of 166, 28.9%) within the 112-day active treatment phase (P = 0.007). The Kaplan-Meier median estimate for 100% ulcer closure was 96 days (95% CI 75.0–114.0) for NPWT and not determinable for AMWT (P = 0.001). NPWT patients experienced significantly (P = 0.035) fewer secondary amputations. The proportion of home care therapy days to total therapy days for NPWT was 9,471 of 10,579 (89.5%) and 12,210 of 12,810 (95.3%) for AMWT. In assessing safety, no significant difference between the groups was observed in treatment-related complications such as infection, cellulitis, and osteomyelitis at 6 months. CONCLUSIONS—NPWT appears to be as safe as and more efficacious than AMWT for the treatment of diabetic foot ulcers.

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.

Vascular evaluation and arterial reconstruction of the diabetic foot.

Findings of diminished or absent pulses, pallor on elevation, redness of the foot on lowering of the leg, sluggish refilling of the toe capillaries, and thickened nails or absence of toe hair are consistent with impaired arterial perfusion to the foot. When ischemia is recognized as contributing to pedal ulceration and infection in the diabetic foot, quantitation of its severity may be difficult. Standard clinical evaluation of trophic changes is limited in an infected foot with its accompanying swelling, edema, and erythema. A palpable pedal pulse does not preclude the possibility of the presence of limb-threatening ischemia. Additional non-invasive vascular studies should be undertaken for these patients. Management of the diabetic foot is often a complex clinical problem. However, the principles of care are simple, including correction of systemic factors, such as blood glucose control, cardiovascular risk factor management, and smoking, as well as local factor correction, such as debridement, pressure relief, infection control, and revascularization when indicated. When a patient presents with evidence of infection, adequate drainage and antibiotic therapy are mandatory. The next step should be performed to differentiate the more common neuropathic ulcerations from the truly ischemic ulceration. Symptoms of rest pain or claudication are not often helpful because many of these patients are asymptomatic as a result of the presence of their neuropathy and inactivity. If an infected foot requires debridement or open partial forefoot amputation, observing the wound on a daily base is also important. Once infection is eradicated, there should be prompt signs of healing, including the development of wound granulation within several days. If wounds are not showing signs of prompt healing, arteriography is necessary. Early aggressive drainage, debridement, and local foot amputations combined with liberal use of revascularization results in cumulative limb salvage of 74% at 5 years in high-risk groups. Others report that pedal bypass to the ischemic infected foot is effective and safe as long as infection adequately controlled. These studies strongly suggest that early recognition and aggressive surgical drainage of pedal sepsis followed by surgical revascularization is critical to achieving maximal limb salvage in the high-risk population. Patients who have diabetes present a unique challenge in lower extremity revascularization because of the distal origination of many bypasses, distal distribution of the occlusive disease, and the frequently calcified arterial wall. An aggressive multidisciplinary approach to foot disease associated with diabetes involving the primary care provider, medical specialists, interventional radiology, and podiatric, plastic, and vascular surgeons will provide optimal medical and surgical care. Peripheral vascular disease is highly treatable if intervention is instituted in a timely and collegial fashion.

Diagnosis of Pedal Osteomyelitis with Tc-99m HMPAO Labeled Leukocytes

The diagnosis of pedal osteomyelitis is often complicated by the presence of pre-existing bony abnormalities. In this study, the utility of radiolabeled white blood cell imaging for the detection of complicated pedal osteomyelitis was evaluated. Twenty-seven men and women were prospectively enrolled and underwent plain film radiography, three-phase bone scan, and Tc-99m hexamethylpropylamine oxine white blood cell scintigraphy of their feet. The presence or absence of osteomyelitis was confirmed in all subjects by microbiologic and histopatholigic analysis of resected bone tissue. The results indicated that white blood cell imaging was more sensitive (90%) and specific (86%) for infection than either bone scan (75% sensitive, 29% specific) or plain film radiography (55% sensitive, 57% specific). This preliminary study suggests that Tc-99m hexamethylpropylamine oxine-labeled white blood cell scintigraphy is a simple, accurate test for the detection of pedal osteomyelitis.

Retrospective evaluation of clinical outcomes in subjects with split-thickness skin graft: comparing V.A.C.® therapy and conventional therapy in foot and ankle reconstructive surgeries

This retrospective study compared the clinical outcomes of negative pressure wound therapy with reticulated open cell foam (NPWT/ROCF) as delivered by Vacuum‐Assisted Therapy® (V.A.C.® Therapy, KCI Licensing Inc., San Antonio, TX) to non‐NPWT/ROCF conventional therapy (CT) in split‐thickness skin graft (STSG) survival in all patients to determine whether NPWT/ROCF affects the outcome of the graft survival, in terms of overall graft take, duration of graft take, repeated grafts and complications.

Single-stage surgical treatment of noninfected diabetic foot ulcers.

&NA; A retrospective study was undertaken to evaluate a singlestage approach in the treatment of noninfected, chronic, well‐perfused diabetic foot wounds. This single‐stage approach consisted of total excision of the ulcer with broad exposure, correction of the underlying osseous deformity, and immediate primary closure using a local random flap. Four hundred cases of pedal ulcers were analyzed by chart review. Of those, 67 cases underwent a single‐stage surgical treatment and were analyzed for length of hospital stay, postoperative complications, time to heal, recurrence of the ulcer, and postprocedure ambulatory status. The age of the ulcers before surgery was 12 ± 12 months (mean ± SD), with a range of 1 to 60. The median perioperative hospital stay was 5 ± 7.6 days. All patients were followed until the wounds were healed or to amputation. The median total time to heal was 30.8 ± 40 days. Ninety‐seven percent of the wounds healed. The recurrence rate of ulceration was 10.4 percent (seven of 67), over a time span of up to 6 years. All but one patient returned to previous levels of ambulation, and many patients had improved levels of ambulation. The single‐stage approach eliminated the need for additional surgical procedures, with their associated costs and risks. In addition, healing times were significantly reduced, resulting in decreased hospital stays and subsequent costs and providing the patient with an expedient return to footwear so that bipedal function could be restored. Most importantly, by addressing the underlying bony pathologic findings, the recurrence rates were also drastically reduced. (Plast. Reconstr. Surg. 109: 601, 2002.)

Entrapment neuropathy: The etiology of intractable chronic heel pain syndrome

Chronic heel pain syndrome (CHPS) is a common clinical entity. The etiology of CHPS has never been completely defined and there are no clear treatment regimens in the literature. Most authors agree that nonoperative treatment is effective in most patients. However, in 5%-10% of patients, operative intervention is required. Outcomes for these patients have been inconsistent. A series of 51 patients with intractable CHPS who were diagnosed with an entrapment of the posterior tibial nerve and its terminal branches is presented. Descriptive statistics were obtained for the demographic data and pre and postsurgical start-up and standing pain visual analog scale (VAS) scoring. Statistical testing of the VAS mean scores was performed using a paired t-test at the 0.01 level of significance. Pre- and postsurgical start-up and pre- and postsurgical standing pain VAS means were significantly different from each other (t = 19.6, p = .001 and t = 19.4, p = .001, respectively). Based on subjective and objective criteria, 96% of the patients experienced significant improvement and 90% reported completed resolution of heel pain. The presence of tarsal tunnel syndrome in all 51 patients strongly suggests entrapment neuropathy as the etiology of intractable CHPS.

Diabetic foot disease

The authors review the impact, areas of influence, and treatment protocols for diabetic foot disease.

Formulated collagen gel accelerates healing rate immediately after application in patients with diabetic neuropathic foot ulcers

We assessed the safety and efficacy of Formulated Collagen Gel (FCG) alone and with Ad5PDGF‐B (GAM501) compared with Standard of Care (SOC) in patients with 1.5–10.0 cm2 chronic diabetic neuropathic foot ulcers that healed <30% during Run‐in. Wound size was assessed by planimetry of acetate tracings and photographs in 124 patients. Comparison of data sets revealed that acetate tracings frequently overestimated areas at some sites. For per‐protocol analysis, 113 patients qualified using acetate tracings but only 82 qualified using photographs. Prior animal studies suggested that collagen alone would have little effect on healing and would serve as a negative control. Surprisingly trends for increased incidence of complete closure were observed for both GAM501 (41%) and FCG (45%) vs. Standard of Care (31%). By photographic data, Standard of Care had no significant effect on change in wound radius (mm/week) from during Run‐in to Week 1 (−0.06±0.32 to 0.78±1.53, p=ns) but both FCG (−0.08±0.61 to 1.97±1.77, p<0.002) and GAM501 (−0.02±0.58 to 1.46±1.37, p<0.002) significantly increased healing rates that gradually declined over subsequent weeks. Both GAM501 and FCG appeared to be safe and well tolerated, and alternate dosing schedules hold promise to improve overall complete wound closure in adequately powered trials.

Effect of different frequencies of tensile strain on human dermal fibroblast proliferation and survival

The aim of this study is to compare the effect of a high‐frequency repetitive (HF) stretch or an intermittent (I) stretch on the cell proliferation and survival of human dermal fibroblasts and to determine the activation of any relevant signal pathways. Cultured human dermal fibroblasts were exposed to either HF or I stretch. Cell number was measured by counting, while DNA synthesis was assessed by 5‐bromo‐2′‐deoxyuridine (BrdU) staining and apoptosis by terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling staining. To investigate the potential mechanisms of repetitive strain on the proliferation and survival of fibroblasts, the activation of relevant transduction pathways, such as p38 mitogen‐activated protein kinase (MAPK), extracellular signal‐regulated kinase (ERK)1/2, AKT, and BAD, was assessed by Western blot. In addition, the effect of inhibition of these pathways on the fibroblast response was also studied. After either HF or I stretch for 7 days, fibroblast number was significantly decreased and there were less BrdU‐positive cells. The numbers of apoptotic and/or necrotic fibroblasts were not affected. p38 MAPK and ERK1/2 were significantly activated after HF stretch, but AKT and BAD were significantly activated after I stretch. The inhibitors of p38 MAPK and MAPK/ERK kinase as well as dominant‐negative AKT reduced cell number after both HF and I stretch but these pathways were not critical for the stretch‐induced decrease in cell number.