Hypertrophic scar (HTS) formation is a common challenge for patients after burn injury. Dermal microvascular endothelial cells (DMVECs) are an understudied cell type in HTS. An increase in angiogenesis and microvessel density can be observed in HTS. Endothelial dysfunction may play a role in scar development. This study aims to generate a functional and expression profile of HTS DMVECs. We hypothesize that transcript and protein-level responses in HTS DMVECs differ from those in normal skin (NS). HTSs were created in red Duroc pigs. DMVECs were isolated using magnetic-activated cell sorting with ulex europaeus agglutinin 1 (UEA-1) lectin. Separate transwell inserts were used to form monolayers of HTS DMVECs and NS DMVECs. Cell injury was induced and permeability was assessed. Gene expression in HTS DMVECS versus NS DMVECs was measured. Select differentially expressed genes were further investigated. HTS had an increased area density of dermal microvasculature compared to NS. HTS DMVECs were 17.59% less permeable than normal DMVECs (p < 0.05). After injury, NS DMVECs were 28.4% and HTS DMVECs were 18.8% more permeable than uninjured controls (28.4 ± 4.8 vs 18.8 ± 2.8; p = 0.11). PCR array identified 31 differentially expressed genes between HTS and NS DMVECs, of which 10 were upregulated and 21 were downregulated. qRT-PCR and ELISA studies were in accordance with the array. DMVECs expressed a mixed profile of factors that can contribute to and inhibit scar formation. HTS DMVECs have both a discordant response to cellular insults and baseline differences in function, supporting their proposed role in scar pathology. Further investigation of DMVECs is warranted to elucidate their contribution to HTS pathogenesis.

Introduction The obesity epidemic is an important public health problem in the United States. Previous studies have revealed the association between obesity and various surgical complications. Tracheostomy which is an important lifesaving procedure may prove technically challenging in an obese patient. This study sought to evaluate the association between obesity and early complications following standard tracheostomy using a national registry. Methods Adult patients who underwent tracheostomy from 2007 to 2017 were analyzed using the Nationwide Inpatient Sample (NIS). The population was stratified into obese and non-obese groups. Early complications following standard tracheostomy were identified and compared between the two groups. Multivariable logistic regression analyses were performed to assess the association between obesity and early complications following tracheostomy. Results Data pertaining to 205 032 adult patients were evaluated. Obese patients accounted for 12.1% (n = 21 816) of the entire cohort. The most common complication in the cohort was perioperative bleeding (4316 [2.1%]). A total of 1382 (0.67%), 949 (0.46%), and 134 (0.07%) patients developed pneumothorax/pneumomediastinum, stoma/surgical site infection, and tracheal injury following standard tracheostomy, respectively. There was no difference in the odds of tracheal injury, perioperative bleeding, and pneumomediastinum/pneumothorax following standard tracheostomy in the obese and non-obese group in multivariable analysis. However, obesity was associated with 60% increased odds of developing stoma/surgical site infection following standard tracheostomy (OR 1.60 [1.33-1.92], P < 0.01). Conclusion Obesity is associated with an increased risk of developing stoma/surgical site infection following standard tracheostomy. This adds to the growing need for measures to help curb the obesity epidemic in a bid to improve surgical outcomes.