Microsurgical replantation following digital amputation has variable success rates. Sociodemographic factors and surgery-related variables have been shown to influence survival rates; however, few studies have evaluated these data systematically across a combined dataset. Therefore, the objective of this study was to analyze the current literature to identify the predictors of replant survival. A literature review was performed using the PubMed/Medline database focused on complete digit amputation/replantation studies. Studies were evaluated for patient and surgery-related variables and their respective effects on survival. Statistical analysis was conducted to identify predictors of survival and derive pooled estimates from the combined dataset. Thirty-two studies representing more than 6,000 digit amputation/replantation cases met inclusion/exclusion criteria. Statistical analysis revealed the number of venous anastomosis (0 vs. 1 vs. 2), the number of arterial anastomosis (0 vs. 1 vs. 2), and the mechanism of injury (sharp cut versus blunt cut versus avulsion versus crush) to influence replant survival ( < 0.05). The authors failed to find a significant association between survival and the following variables: age, sex, zone of injury, digit number, tobacco use, ischemia time, method of preservation, and use of vein graft. Patient- and surgery-related variables affect digit survival following replantation. The etiology of injury can help risk-stratify patients and assist in an informed decision making process, whereas surgery-related factors can guide surgeon practice to improve clinical outcomes following replantation.

SummaryMalignant brain tumors, such as glioblastoma, are characterized by extensive angiogenesis and permeability of the blood-brain barrier (BBB). The infiltration of glioma cells away from the primary tumor mass is a pathological characteristic of glial tumors. The infiltrating tumor cells represent a significant factor in tumor recurrence following surgical debulking, radiation, and chemotherapy treatments. Vascular endothelial growth factor (VEGF)-mediated vascular permeability (VP) has been associated with the progression of glioma tumor growth and infiltration into surrounding normal brain parenchyma. While VEGF induces a robust VP response in control mice (src +/+ or src +/− ), the VP response is blocked in src −/− mice that demonstrate a 'leakage-resistant phenotype' in the brain. We used the Src-deficient mouse model to determine the role of Src in the maintenance of the BBB following orthotopic implantation and growth of glioma cells in the brain. Although solid tumor growth was the same in control and src −/− mice, the infiltrating component of glioma growth was reduced in src −/− mice. Characterization of the expression and localization of the extracellular matrix (ECM) protein fibrinogen was evaluated to determine the effect of a Src-mediated VP defect in the host compartment. These studies indicate that the reduced VP of host brain blood vessels of src −/− mice mediates a reduction in glioma cell invasion in a mouse brain tumor xenograft model.

The use of engineered tissue for the treatment of a variety of acute to chronic wounds has become a clinical standard, and a better understanding of the cellular mechanisms of re-vascularization and barrier integrity could enhance clinical outcomes. Here, we focus on the characterization of the revascularization of acellular grafts such as Integra ™ in an animal model to better understand the physiological properties of blood vessels growing in the collagen-glycosaminoglycan matrix vs. wound margins. While Integra ™ has been extensively studied in pre-clinical models, the re-modeling mechanisms of the capillary bed under these matrices are not well understood. Therefore, our first objective was to quantify the kinetics of revascularization. The second objective was to assess changes in vascular permeability (VP) of the wound bed compared to normal adjacent skin. The third objective was to establish a non-invasive and quantitative assay for the measurement of VP to facilitate the rapid and reproducible characterization of vascular integrity. Using an excisional wound model in mice, we characterize the appearance, growth, and maturation of blood vessels in an Integra ™ graft over 28 days post-surgery. Initial appearance of blood vessels in the graft was observed at 7 days, with angiogenesis peaking between at 7-14 days. The onset of VP coincided with the increase in re-vascularization of the wound bed and there was a sustained elevation of VP that declined to baseline by 28 days. We propose that a non-invasive strategy to assess VP of the wound capillary bed to facilitate a better understanding of the cell and molecular basis of angiogenesis in wound healing.