Impact of perioperative hyperglycemia in patients undergoing microvascular reconstruction.

BACKGROUND: The effects of perioperative hyperglycemia on complications and outcomes in microvascular reconstruction have not been reported in the literature. METHODS: A retrospective cohort of 203 patients undergoing microvascular reconstruction was generated. Perioperative glucose levels and clinical factors were tested for associations with complications using simple and multivariate analyses. RESULTS: Hyperglycemia (blood glucose ≥ 180 mg/dL) occurred in 91 patients (44.8%) perioperatively, and was associated with increased rates of surgical complications, medical complications, surgical site infections, fistulas, and wound dehiscence. On univariate analysis, a more strict definition of hyperglycemia (blood glucose ≥ 165 mg/dL) was significantly associated with greater rates of venous thrombosis, although this lost statistical significance on multivariate analysis. CONCLUSION: Perioperative hyperglycemia occurs commonly in patients undergoing microvascular reconstruction and is associated with higher rates of complications, independent of a preexisting diagnosis of diabetes mellitus. Further research is needed to define the ideal glycemic target in this population.

Assessment of the biocompatibility and stability of a gold nanoparticle collagen bioscaffold.

Collagen has been utilized as a scaffold for tissue engineering applications due to its many advantageous properties. However, collagen in its purified state is mechanically weak and prone to rapid degradation. To mitigate these effects, collagen can be crosslinked. Although enhanced mechanical properties and stability can be achieved by crosslinking, collagen can be rendered less biocompatible either due to changes in the overall microstructure or due to the cytotoxicity of the crosslinkers. We have investigated crosslinking collagen using gold nanoparticles (AuNPs) to enhance mechanical properties and resistance to degradation while also maintaining its natural microstructure and biocompatibility. Rat tail type I collagen was crosslinked with AuNPs using a zero-length crosslinker, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Several characterization studies were performed including electron microscopy, collagenase assays, ROS assays, and biocompatibility assays. The results demonstrated that AuNP-collagen scaffolds had increased resistance to degradation as compared to non-AuNP-collagen while still maintaining an open microstructure. Although the biocompatibility assays showed that the collagen and AuNP-collagen scaffolds are biocompatible, the AuNP-collagen demonstrated enhanced cellularity and glycoaminoglycans (GAG) production over the collagen scaffolds. Additionally, the Reactive Oxygen Species (ROS) assays indicated the ability of the AuNP-collagen to reduce oxidation. Overall, the AuNP-collagen scaffolds demonstrated enhanced biocompatibility and stability over non-AuNP scaffolds.