Vascularized lymph node transfer for treatment of lymphedema: a comprehensive literature review.

OBJECTIVE: A comprehensive literature review of VLNT with updates and comparisons on current application, techniques, results, studies and possible future implications. BACKGROUND: Lymphedema is a debilitating condition that often results secondary to treatment of cancer. Unfortunately there is no cure. However, microsurgical procedures such as VLNT has gained popularity as there have been increasing reports that VLNT may help alleviate the severity of lymphedema. METHODS: A review of literature was conducted over major medical indices (PubMed-MEDLINE, Factiva, Scopus, Sciencedirect, EMBASE). Search terms were focused on vascularized, lymph node transfer (also autologous, lymph node transplant) to cover both human and animal studies. Each study was verified for the nature of the procedure; a free microsurgical flap containing lymph nodes for the purpose of relieving lymphedema. RESULTS: There are human and animal studies that individually report clear benefits, but because of methodological shortcomings comparative studies with uniform patient selection and monitoring are lacking. CONCLUSIONS: Although the results with the use of VLNT for treatment of lymphedema have been largely positive, further exploration into standardized protocols for diagnosis, treatment optimization, and patient outcomes assessment is needed.

Traumatic lower limb injury and microsurgical free flap reconstruction with the use of negative pressure wound therapy: is timing crucial?

BACKGROUND: The timing of microsurgical free flap reconstruction for traumatic lower limb injury has been described as being optimal if conducted within the early period following injury, as higher rates of infection and flap loss were reported in the subsequent time period. However, for various reasons, reconstruction of these defects may be delayed. The aim of this article is to show that adequate debridement, negative pressure wound dressing, and sound reconstructive principles has led to increased free flap success rates regardless of the period between injury and reconstruction. PATIENTS AND METHODS: A 10-year retrospective single-center analysis of 50 traumatic lower limb cases from 2002 to 2012 was conducted. All patients had microsurgical free flap reconstruction after a period of negative pressure wound therapy (NPWT). Patient factors and reconstructive methods were analyzed and outcomes were compared. RESULTS: Mean interval between admission and free flap coverage was 17.5 days, and patients underwent NPWT for an average of 12 days (range, 1-35). Approximately 8% of patients had postoperative infections. Overall free flap success rate was 96%. Approximately 90% of patients were able to return to their premorbid footwear, with 96% able to mobilize independently approaching the end of their follow-up period. CONCLUSION: Our study shows that traumatic lower limb reconstruction in the delayed period is no longer associated with high rates of flap failure. Improvements in microsurgery and the advent of NPWT have made timing no longer crucial in free flap coverage of traumatic lower limb injuries.

Ultrashort peptide nanofibrous hydrogels for the acceleration of healing of burn wounds.

There is an unmet clinical need for wound dressings to treat partial thickness burns that damage the epidermis and dermis. An ideal dressing needs to prevent infection, maintain skin hydration to facilitate debridement of the necrotic tissue, and provide cues to enhance tissue regeneration. We developed a class of 'smart' peptide hydrogels, which fulfill these criteria. Our ultrashort aliphatic peptides have an innate tendency to self-assemble into helical fibers, forming biomimetic hydrogel scaffolds which are non-immunogenic and non-cytotoxic. These nanofibrous hydrogels accelerated wound closure in a rat model for partial thickness burns. Two peptide hydrogel candidates demonstrate earlier onset and completion of autolytic debridement, compared to Mepitel(®), a silicone-coated polyamide net used as standard-of-care. They also promote epithelial and dermal regeneration in the absence of exogenous growth factors, achieving 86.2% and 92.9% wound closure respectively, after 14 days. In comparison, only 62.8% of the burnt area is healed for wounds dressed with Mepitel(®). Since the rate of wound closure is inversely correlated with hypertrophic scar formation and infection risks, our peptide hydrogel technology fills a niche neglected by current treatment options. The regenerative properties can be further enhanced by incorporation of bioactive moieties such as growth factors and cytokines.

Creation of consistent burn wounds: a rat model.

BACKGROUND: Burn infliction techniques are poorly described in rat models. An accurate study can only be achieved with wounds that are uniform in size and depth. We describe a simple reproducible method for creating consistent burn wounds in rats. METHODS: Ten male Sprague-Dawley rats were anesthetized and dorsum shaved. A 100 g cylindrical stainless-steel rod (1 cm diameter) was heated to 100℃ in boiling water. Temperature was monitored using a thermocouple. We performed two consecutive toe-pinch tests on different limbs to assess the depth of sedation. Burn infliction was limited to the loin. The skin was pulled upwards, away from the underlying viscera, creating a flat surface. The rod rested on its own weight for 5, 10, and 20 seconds at three different sites on each rat. Wounds were evaluated for size, morphology and depth. RESULTS: Average wound size was 0.9957 cm(2) (standard deviation [SD] 0.1845) (n=30). Wounds created with duration of 5 seconds were pale, with an indistinct margin of erythema. Wounds of 10 and 20 seconds were well-defined, uniformly brown with a rim of erythema. Average depths of tissue damage were 1.30 mm (SD 0.424), 2.35 mm (SD 0.071), and 2.60 mm (SD 0.283) for duration of 5, 10, 20 seconds respectively. Burn duration of 5 seconds resulted in full-thickness damage. Burn duration of 10 seconds and 20 seconds resulted in full-thickness damage, involving subjacent skeletal muscle. CONCLUSIONS: This is a simple reproducible method for creating burn wounds consistent in size and depth in a rat burn model.

Reliability of ultrasound duplex for detection of hemodynamically significant stenosis in hemodialysis access.

OBJECTIVE: This study aims to evaluate the accuracy of AVF and AVG duplex ultrasound (US) compared to angiographic findings in patients with suspected failing dialysis access. MATERIALS AND METHODS: From July 2008 to December 2010, US was performed on 35 hemodialysis patients with 51 vascular accesses having clinical feature or dialysis parameter suspicious of access problem. Peak systolic velocity ratio of ≥2 was the criteria for diagnosing stenosis ≥50%. Fistulogram was performed in all these patients. Results of US and fistulogram were compared using Kappa and Receiver Operator Characteristic (ROC) analyses. RESULTS: In 51 accesses (35 AVF, 16 AVG), US diagnosed significant stenosis in 45 accesses according to the criteria and angiogram confirmed 44 significant stenoses. In AVF lesions, Kappa was 0.533 with 93.3% sensitivity and 60% specificity for US whereas in AVG lesions, Kappa was 0.636 with 100% sensitivity and 50% specificity. Overall Kappa value of 0.56 meant fair to good agreement. ROC demonstrated area under the curve being 0.79 for all cases and was significant (p = 0.016). Using the ≥50% criteria for stenosis diagnosed by US yielded the best sensitivity (95.5%) and specificity (57.1%). CONCLUSION: Duplex ultrasound study, using ≥50% criteria, is a sensitive tool for stenosis detection in patients with suspected failing AVF and AVG.