Red Breast Syndrome and Acellular Dermal Matrix

Increasingly popular for use in breast reconstruction, acellular dermal matrix (ADM) can provide support and protection to implants. However, use of ADM may be associated with infection and complications, including red breast syndrome (RBS). RBS is an inflammatory event that typically presents with cutaneous erythema over the domain where the ADM is surgically implanted. As ADM use increases, presumably, more cases of RBS will occur. Thus, techniques and tools to mitigate or manage RBS are needed to improve patient outcomes. Here, we describe a case where RBS was diagnosed and interestingly resolved after exchange for a different brand of dermal matrix. This surgical resolution maintained excellent reconstructive results with no recurrent erythema over a follow-up period of 7 months. Although we cannot rule out RBS due to other variables, RBS due to patient hypersensitivity to certain ADMs has been documented in the literature. In this instance, our results suggest that revision with an alternate ADM brand may serve as a potential solution.

Two-stage treatment of ischial pressure ulcers in spinal cord injury patients: Technique and outcomes over 8 years

BACKGROUND

Despite newly introduced techniques, reconstruction of ischial pressure ulcers remains a difficult problem with high-reported failure rates.

METHODS

A retrospective chart review was performed on all spinal cord injury patients who underwent ischial pressure ulcer reconstruction by the senior author (V.L.) between 2004 and 2012. The two-stage procedure consisted of debridement and bone biopsy, followed by bursectomy, partial ischiectomy, fascial release, and gluteus maximus and hamstring advancement flaps. Postoperative care included 2-week supine bed rest on an air-fluidized bed, sitting tolerance rehabilitation, and thorough behavioral training.

RESULTS

Sixty-five patients (74 flaps) were identified. A 45.9% had a previous attempt at reconstruction. The median follow-up period was 622 days. Overall, 67.6% of flaps were intact at the last follow-up. Superficial and deep dehiscence rates were 16.2 and 28.4%, respectively. Seven out of 35 flaps suffered late recurrence after being well healed for more than 1 year. History of previous reconstruction was found to be associated with increased odds of superficial (OR 6.02, 95% CI 1.55-23.3) and deep dehiscence (OR 12.3, 95% CI 1.99-76.9).

CONCLUSIONS

The evolution of the senior author's decades of practice has led to the development of a simpler repair, which relies on plane-by-plane release of scarred tissues to improve the mobility of muscle and skin flaps without large tissue movements, even in the setting of apparent extensive tissue loss. This technique is a reliable option, particularly for the primary ischial pressure ulcer.

Excisional wound healing is delayed in a murine model of chronic kidney disease

Background

Approximately 15% of the United States population suffers from chronic kidney disease (CKD), often demonstrating an associated impairment in wound healing. This study outlines the development of a surgical murine model of CKD in order to investigate the mechanisms underlying this impairment.

Methods

CKD was induced in mice by partial cauterization of one kidney cortex and contralateral nephrectomy, modifying a previously published technique. After a minimum of 6-weeks, splinted, dorsal excisional wounds were created to permit assessment of wound healing parameters. Wounds were harvested on postoperative days (POD) 0, 3, 7, and 14 for histological, immunofluorescent, and quantitative PCR (qPCR).

Results

CKD mice exhibited deranged blood chemistry and hematology profiles, including profound uremia and anemia. Significant decreases in re-epithelialization and granulation tissue deposition rates were found in uremic mice wounds relative to controls. On immunofluorescent analysis, uremic mice demonstrated significant reductions in cellular proliferation (BrdU) and angiogenesis (CD31), with a concurrent increase in inflammation (CD45) as compared to controls. CKD mice also displayed differential expression of wound healing-related genes (VEGF, IL-1β, eNOS, iNOS) on qPCR.

Conclusions

These findings represent the first reported investigation of cutaneous healing in a CKD animal model. Ongoing studies of this significantly delayed wound healing phenotype include the establishment of renal failure model in diabetic strains to study the combined effects of CKD and diabetes.

Limitations of the db/db mouse in translational wound healing research: Is the NONcNZO10 polygenic mouse model superior?

Murine models have provided valuable insights into the pathogenesis of both diabetes and chronic wounds. However, only a few published reports to date have investigated wound healing differences among the differing diabetic mouse models. The goal of the present study was to further define the wound healing deficiency phenotypes of streptozotocin-induced (STZ-induced), Akita, and db/db diabetic mice in comparison with a promising new polygenic strain of Type 2 diabetes (NONcNZO10) by using three specific wound models that targeted different critical processes in the pathogenesis of chronic wounds. Incisional, excisional, and ischemia/reperfusion wound models were established on mice of each strain. Wound healing parameters including tensile strength, epithelial gap, and wound necrosis were evaluated. In contrast to the other diabetic mice, the NONcNZO10 strain was found to have significant wound healing impairments in all wound healing models. Not only do the NONcNZO10 mice appear to better model human Type 2 diabetes, these provocative findings suggest that the mice may show more clinically relevant wound healing deficiencies than previous diabetic mouse models.

Staphylococcal biofilms impair wound healing by delaying reepithelialization in a murine cutaneous wound model

Bacterial biofilms have gained increasing visibility in recent years as a ubiquitous form of survival for microorganisms in myriad environments. A number of in vivo models exist for the study of biofilms in the setting of medically relevant implanted foreign bodies. Growing evidence has demonstrated the presence of bacterial biofilms in the setting of a number of chronic wound states including pressure sores, diabetic foot ulcers, and venous stasis ulcers. Here we present a novel murine cutaneous wound system that directly demonstrates delayed reepithelialization caused by the presence of a bacterial biofilm. We established biofilms using either Staphylococcus aureus or Staphylococcus epidermidis in splinted cutaneous punch wounds created on the backs of normal C57Bl6/J mice. Wound reepithelialization was significantly delayed by bacterial biofilms. This effect was specifically dependent on the ability of the bacteria to form biofilms as demonstrated by exogenous administration of biofilm inhibiting peptides and the use of mutant Staphylococcus spp. deficient in biofilm formation. This represents the first direct evidence for the effect of bacterial biofilms on cutaneous wound healing.