Hydrogels composed of crosslinked, chemically modified hyaluronic acid (HA), gelatin (Gtn) and heparin (Hp) were preloaded with vascular endothelial growth factor (VEGF), angiopoietin-1

Recurrent hemarthrosis (RH) is a rare complication (∼1%) after total knee arthroplasty (TKA). It is a complex and particularly frustrating problem for both patient and surgeon. Typically, patients present several months to years after their index TKA surgery with a painful and swollen joint. Although conservative management may provide temporary relief, the rate of recurrence is high. Despite extensive case series in the literature, no consensus was made on the criteria needed to establish this diagnosis, or how to best provide treatment. Several management strategies have been described for RH, including immobilization, arthroscopic versus open synovectomy, angiographic embolization, and revision arthroplasty. All of these have demonstrated variable effectiveness, with limited evidence for their use in specific situations. This review synthesizes the available literature and suggests an algorithm for the diagnosis and treatment of RH after TKA.

Background Tissue distribution after local delivery has been quantified over a period of 5 hours on 7-T MRI in a rabbit model using gadolinium-labeled diethylenetriamine pentaacetic acid (Gd-DTPA) as an antimicrobial surrogate; however, it is unknown how the Gd-DTPA load in a local depot will affect the duration of high-concentration Gd-DTPA in local tissues after surgical débridement. Questions/purposes We determined whether the Gd-DTPA load in bone cement affected its local tissue distribution over a period of 1 month after local delivery.

This description of gene therapy in gastrointestinal surgery using VEGF(165) transfection demonstrates increased angiogenesis with subsequently improved anastomotic healing in a clinically relevant model.

Laparoscopic hepatic resection produces decreased VEGF mRNA expression in residual hepatoma cells compared with open resection. Decreased stimulation of angiogenesis promoters in the tumor microenvironment after minimally invasive liver resection may contribute to a lower residual disease burden and ultimately lead to a lower recurrence rate.

Proper anastomotic healing is dependent upon many factors including adequate blood flow to healing tissue. The aim of this study was to investigate the impact of vascular endothelial growth factor (VEGF(165)) transfection on anastomotic healing in an ischemic gastrointestinal anastomosis model. Utilizing an established opossum model of esophagogastrectomy followed by esophageal-gastric anastomosis, the gastric fundus was transfected with recombinant human vascular endothelial growth factor via direct injection of a plasmid-based nonviral delivery system. Twenty-nine animals were divided into three groups: two concentrations of VEGF and a control group. Outcomes included VEGF mRNA transcript levels, neovascularization, tissue blood flow, and anastomotic bursting pressure. To determine whether local injection resulted in a systemic effect, distant tissues were evaluated for VEGF transcript levels. Successful gene transfection was demonstrated by quantitative polymerase chain reaction analysis of anastomotic tissue, with significantly higher VEGF mRNA expression in treated animals compared to controls. At the gastric side of the anastomosis, there was significantly increased neovascularization, blood flow, and bursting pressure in experimental animals compared to controls. There were no differences in outcome measures between low- and high-dose VEGF groups; however, the high-dose group demonstrated increased VEGF mRNA expression across the anastomosis. VEGF production was not increased at distant sites in treated animals. In this animal model, VEGF gene therapy increased VEGF transcription at a healing gastrointestinal anastomosis without systemic VEGF upregulation. This treatment led to improved healing and strength of the acutely ischemic anastomosis. These findings suggest that VEGF gene therapy has the potential to reduce anastomotic morbidity and improve surgical outcomes in a wide array of patients.

BackgroundThere is convincing evidence supporting the prophylactic use of intrawound vancomycin powder in spinal fusion surgery and mounting evidence in the arthroplasty literature suggesting that it can reduce surgical site infections. As a result, a number of shoulder arthroplasty surgeons have adopted this practice, despite a paucity of evidence and the presence of a pathogen that is, for the most part, unique to this area of the body—Propionibacterium acnes. The purpose of this study was to evaluate the efficacy of vancomycin against planktonic P. acnes in vitro, using time-dependent concentrations one would expect in vivo after intra-articular application.MethodsIntrawound vancomycin concentrations were interpolated and extrapolated from existing in vivo data. Planktonic P. acnes was then subjected to a time-kill analysis during 96 hours. At each time point, the inoculum was centrifuged into pellet form and then reconstituted for serial drop counts onto blood agar plates. After anaerobic incubation, colony-forming units were counted, and log10 colony-forming units per milliliter were determined.ResultsEarly time points grew to confluence, and thus colony-forming units per milliliter were not calculated. However, at 12 hours of vancomycin treatment, distinct colonies were appreciated. Notably, there was a 3 × log10 reduction in colony-forming units per milliliter between 12 and 48 hours, denoting bactericidal activity. In addition, P. acnes was completely eradicated after 3 days of treatment.ConclusionWhen administered in a fashion meant to simulate time-dependent in vivo intrawound concentrations, vancomycin exhibited bactericidal activity against P. acnes. This may lend credence to the prophylactic use of vancomycin in shoulder surgery.

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