April 26–29, 2009
Gaylord Texan Resort
Dallas, Texas
www.sawc.net

More than 380 abstracts were submitted for presentation at the 2009 SAWC/WHS. Of those, 24 were accepted for oral presentation. The following is a preview of a few abstracts that will be presented during sessions 29–31, and sessions 42–44. The accepted poster presentations may be viewed throughout the entire meeting and during the scheduled poster session, which will be held Monday April 27 from 7:30am–9:30am. The 2nd annual Poster Gala and Awards will be held from 7:00pm–8:30pm on Monday April 27.

To access the entire SAWC/WHS brochure, including session titles, faculty, and abstracts, visit www.sawc.net.

Topographical localization of bacterial biofilms in a porcine skin explant wound model
Priscilla Phillips; Edith Sampson; Gregory Schultz

     The presence of persistent bacterial biofilms is known to contribute to the molecular pathologies of many diseases including periodontitis and cystic fibrosis. Furthermore, evidence continues to accumulate suggesting that a substantial percentage of chronic skin wounds contain bacterial biofilms. The extreme resistance of bacteria in biofilms to killing by antibodies, phagocytic inflammatory cells, antibiotics, and antiseptics leads to chronic inflammation, which results in elevated levels of proteases and reactive oxygen species that degrade proteins in the wound bed that are essential to healing. At present, the only methods to detect bacterial biofilms in wounds involve techniques that are technically complex and time consuming, which prevents the rapid assessment of wounds for biofilms. Thus, there is a need for a rapid, simple, inexpensive, point-of-care indicator that would detect and localize bacterial biofilms in chronic wounds. Detection of biofilm in a region of a chronic wound would enable more specific and appropriate debridement and treatment of the wound bed. Results of initial experiments with a prototype thin membrane sheet that was pressed onto the surface of pig skin explants with mature Pseudomonas aeruginosa biofilms then briefly exposed to a dye followed by washing produced strong staining of regions of the skin with the mature biofilm. In contrast, only faint staining was produced on the membrane when it was pressed on pigskin explants without biofilm. These initial results suggest that it may be possible to generate a “wound biofilm map” that can localize biofilms in regions of a wound bed. Further optimization of the design and performance of the prototype wound biofilm map are underway which will be followed by initial clinical evaluation in patients with chronic wounds.

Objective outcome evaluation of Charcot foot reconstruction by monitoring dynamic behavior of plantar pressure
B Najafi, PhD; R Crews, MS; M Bharara, PhD; J Wrobel, DPM, MS; LC Rogers, DPM; DG Armstrong, DPM, PhD

     Objective. The optimal surgical approach for Charcot foot reconstruction is a hotly debated topic among foot and ankle surgeons. Although many studies have proposed plantar pressure magnitude (PPM) as a surrogate measure of trauma to the plantar foot, the current evaluation methods suffer from various shortcomings. In the other words, following surgery, patients may increase their gait speed in response to greater confidence in stability and a more efficient gait pattern. Although this increase may be practically advantageous, it may also result in increased PPM, historically viewed as a negative outcome. This study aims to develop a novel assessment protocol, which is speed independent and can reliably screen dynamic plantar loading in patients with Charcot reconstruction. Methods. A time-scale normalization scheme was used to moderate the effect of gait speed. To examine whether the plantar pressure distribution (PPD) measured using EMED plantar pressure system, was normal, a customized normal distribution curve was created for each trial. Then the original PPD was fitted to the customized normal distribution curve. This technique yields a regression factor (RF), which represents the similarity of the actual pressure distribution with a normal distribution. RF values may range from negative 1 to positive 1 and as the value increases positively so does the similarity between the actual and normalized pressure distributions. We tested this novel score on plantar pressure pattern of healthy subjects (N = 15), Charcot preoperation (N = 3) and Charcot post foot reconstruction (N = 1). Results. In healthy subjects, the RF was 0.46 ± 0.1. When subjects increased their gait speed by 25%, the PPM was increased by 8% (P < 0.0001, paired t-test), while RF wasn’t changed (P = 0.7). In preoperative Charcot patients, the RF < 0, however, RF increased post surgery (RF = 0.47), indicating a transition to normal plantar distribution after Charcot reconstruction. Conclusion. Our results demonstrate that although peak of plantar pressure may recognize the abnormal dynamic loading in Charcot patients compared to healthy subjects, it is unable to screen improvement post Charcot reconstruction surgery. To overcome this shortcoming, we suggest a reliable and speed-independent score to demonstrate gait improvement. Further testing involving both barefoot, as well as in-shoe conditions, may elicit a clinical measure and may be integrated into a pervasive healthcare regimen involving virtual clinics and telemedicine platforms.

Safety of deep debridement with anesthesia in the operating room
Daniel O’Neill; Pavandeep Bagga; Fay Marie Hall; Lisa Draghi; Diane Stella; Jason Maggi; Harold Brem

     It is our hypothesis that wound management with deep debridement can be done safely and efficiently in the operating room with anesthesia services. In a subset, 57 patients with 82 wounds underwent 200 anesthetics in the main operating room for wound management. Monitored anesthesia care (MAC, local with or without sedation) was used in 47 cases, general anesthesia was used in 37 cases, and regional anesthesia was used in 24 cases (nerve block = 11, spinal = 11, and epidural/spinal = 2). Airway management techniques included facemask, oral airway, nasal airway, laryngeal mask airway, and endotracheal tubes. Common agents used were propofol, midazolam, fentanyl, ketamine, and sevoflurane. Less than 15% of cases required neuromuscular blockade. Intravenous anesthesia was more commonly used than inhalational anesthesia. Regional anesthetic techniques include central neuroaxial blockade (spinal and epidural), brachial plexus block, sciatic block, popliteal block, and ankle block using lidocaine, mepivacaine, and/or bupivacaine. In two patients, inhalational induction with nitrous oxide and sevoflurane was used to sedate prior to securing vascular access. In one patient, an awake, locally anesthetized central venous catheter was placed for vascular access. Approximately 10% of patients had PICC lines in situ, and 90% of the inpatients had heplocks in situ prior to arriving to the OR. Approximately 15% of the patients were phlebotomized in the operating room for the processing of platelet gel. The age of the patients ranged from 8 to 101 years. The anesthesia services were provided by 30 different attending anesthesiologists. Results. In 200 cases, there were no anesthesia- related deaths, myocardial infarctions, strokes, or other major complications. There was a minor case of epistaxis in a patient requiring nasal airway for snoring during deep sedation. There were no reports of postoperative delirium. The average anesthesia time was 1.8 hours, but with two outliers over 4 hours in duration. Gender and patient age do not correlate with duration of anesthesia.

     Linear model: Time = 1.8178 ‚ h (0.0006 [Age]) has r = -0.016 with coefficient of determination = 0.03%. Conclusion. Wound management in the operating room provides excellent operating conditions including illumination, exposure, hemostasis, instrumentation, and support staff. Patient safety is improved with an anesthesia care team dedicated to maintaining homeostasis during surgical stimulation and throughout the perioperative period.

Topical active Leptospermum honey in recalcitrant venous leg wounds: a preliminary case series
Jason R. Hanft, DPM; Tanisha Smith, DPM; Kennedy Legel, DPM

     Purpose. To investigate the use of active Leptospermum honey impregnated calcium alginate dressings (HICADs) in a series of patients with bacterially burdened recalcitrant venous ulcerations which failed to respond to an assortment of therapeutic modalities including 4-layer compression, topical silver, non-adherent dressings, and antibiotic therapy. Methods. The protocol design included application of active Leptospermum HICAD and a multi-layer compression dressing once weekly. The inclusion criteria included non-healing ulcerations with confirmed venous incompetence and insufficiency via ultrasound imaging. Eleven patients were enrolled and treated until the wound closed, or for 3 to 6 weeks, with applications of active Leptospermum HICAD and a multi-layer compression bandage that was changed on a weekly basis. Results. Eleven patients with chronic recalcitrant lower extremity venous wounds demonstrated an increased velocity of healing. Complete wound closure was achieved within 3 to 6 weeks for all patients. Conclusion. The result of this case series confirms existing evidence of the beneficial effect of active Leptospermum HICADs to heal chronic wounds that are unresponsive to traditional therapies. This treatment provides another “tool in your box,” and may prove to be an alternative therapy for difficult to treat wounds that do not respond to first-line therapy.

The effectiveness of bilayered cell therapy* in the treatment of chronic venous ulcers
Caroline Fife, MD; David Walker, CHT; Gordon Otto, PhD; Brett Thomson; Margaret Grasso, MS

     The objective of this study was to evaluate the effectiveness of bilayered cell therapy* (BCT) in chronic venous leg ulcers (VLU) among patients seen at hospital-based outpatient wound centers. Demographics, co-morbidities, ulcer characteristics, treatment, and outcome of patients with VLU presenting to US wound centers were retrospectively analyzed using the Electronic Medical Records of 17,160 patients collected between January 1, 2001 and May 8, 2008 from the Intellicure Research Consortium database. Twenty-six outpatient wound centers in 16 states across the United States were included in the study.

     Patients (N = 2,139) presented with 4,364 venous ulcers. Mean patient age was 68 years (range 18–102 years) with an average of 9.5 co-morbid medical conditions, primarily hypertension (35%) and diabetes (32%, of which 86% had Type 2). BCT was applied to 169 venous ulcers (3.87%) on 110 patients (5.1%). Mean ulcer duration prior to wound center consultation was 122.4 weeks. A mean of 35.6 weeks of care within the wound center occurred prior to application. Mean ulcer surface area was 21.3 cm2 at presentation and 13.5 cm2 at BCT application. An average of 1.7 BCT applications were performed per ulcer with a mean of 31.9 days (range 3–134 days) between applications. BCT were fenestrated 51% of the time, and secured by a soft silicone contact layer** 56.4% of the time. Success was defined as a wound size < 0.2 cm and absence of exudate or a clinician reported the outcome of “healed,” “healing,” “improved,” “improving,” or “epithelialized.” Although outcome information was not available in 30% of cases, when known, BCT was deemed successful in 95% of cases, despite a mean duration at presentation of more than 2.3 years and many serious co-morbid medical conditions. These results depict effectiveness in “real world” clinical conditions.

Evaluation of health care utilization and costs for hospitalizations and surgical procedures in patients with diabetic foot ulcers treated with negative pressure wound therapy* versus advanced moist wound therapy
Vickie R. Driver; Charles Anderson; Gerry Oster; Charu Taneja

     Background. A multi-center, randomized, clinical trial (RCT) assessed efficacy and safety of negative pressure wound therapy using reticulated open cell foam (NPWT/ROCF) as delivered by NPWT* versus advanced moist wound therapy (AMWT) in adult patients with diabetic foot ulcers (DFUs). NPWT/ROCF was reported to be as safe as and more efficacious than AMWT (eg, hydrogels and alginates). The current study evaluated healthcare utilization and costs for hospitalizations and surgical procedures between patients randomized to NPWT (n = 162) versus AMWT (n = 162) in the above RCT. Methods. Randomized study subjects were followed 2 weeks post wound closure or end of active treatment phase (ATP), whichever occurred first. Attention was focused on all acute inpatient services used, including wound-related surgical procedures. Unit costs (expressed in 2007 dollars) were assigned using secondary data sources. Mean estimated total costs were determined by total inpatient costs divided by total number of randomized and treated patients per study arm. Results. Acute care hospital admissions for NPWT/ROCF patients were 34/162 (21%) compared to 53/162 (32%) for AMWT patients. There was a statistically significant difference between average number of admissions per patient: NPWT/ROCF, 0.21; AMWT, 0.33; (P < 0.05). During ATP, there were fewer amputations in the NPWT/ROCF group (6 versus 11 for AMWT). NPWT/ROCF mean estimated total costs of inpatient services were $5,206 (95% CI: $3,172, $7,561) versus $8,570 ($5,922, $11,432) for AMWT, for a difference of $3,364 per studied patient. Conclusion. During the active treatment phase of this RCT, patients with DFUs treated with NPWT had fewer hospital admissions and amputations, resulting in lower costs related to hospitalizations and surgical procedures compared to patients treated with AMWT.
*V.A.C.® Therapy™ (KCI Licensing, Inc., San Antonio, Tex)