As the incidence of cardiovascular disease continues to climb worldwide, there is a corresponding increase in demand for surgical interventions involving vascular grafts. The current gold standard for vascular grafts is autologous vessels, an option often excluded due to disease circumstances. As a result, many patients must resort to prosthetic options. While widely available, prosthetic grafts have been demonstrated to have inferior patency rates compared with autologous grafts due to inflammation and thrombosis. In an attempt to overcome these limitations, many different materials for constructing vascular grafts, from modified synthetic nondegradable polymers to biodegradable polymers, have been explored, many of which have entered the translational stage of research. This article reviews these materials in the context of large animal models, providing an outlook on the preclinical potential of novel biomaterials as well as the future direction of vascular graft research.

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IMPORTANCE Hypocalcemia is a common complication of total thyroidectomy.OBJECTIVES To identify factors associated with hypocalcemia after total thyroidectomy and to explore the association between hypocalcemia, magnesium disorders, and costs of care. DESIGN, SETTING, AND PARTICIPANTSA retrospective cross-sectional analysis was performed using data from the MarketScan Commercial Claim and Encounters database on 126 766 commercially insured patients younger than 65 years undergoing total thyroidectomy

There remains a need for large animal models to evaluate tissue-engineered vascular grafts (TEVGs) under arterial pressure to provide preclinical data for future potential human clinical trials. We present a comprehensive method for the interrogation of TEVGs, using an ovine bilateral arteriovenous (AV) shunt implantation model. Our results demonstrate that this method can be performed safely without complications, specifically acute heart failure, steal syndrome, and hypoxic brain injury, and it is a viable experimental paradigm. Our method allows for a non-invasive evaluation of TEVGs in terms of graft flow, graft diameter, and graft patency, while also allowing for graft needle puncture under ultrasound guidance. In addition, traditional pathological analysis, histology, and immunohistochemistry may be performed with the contralateral side providing paired control data to eliminate inter-subject variability while reducing the total number of animals. Further, we present a review of existing literature of preclinical evaluation of TEVGs in large animal models as AV conduits.

Objective: Infected arteriovenous grafts necessitate intervention to obtain source control. However, excising the graft material can be challenging and can lead to complications. Leaving a cuff of graft at the sites of anastomosis allows for the avoidance of potential risks. However, it is unclear whether doing so places patients at risk of recurrent graft infection. The purpose of the present study was to investigate the effect of complete vs partial excision of infected arteriovenous prosthetic dialysis access grafts. Methods:The data from all patients who had undergone surgical intervention for infected arteriovenous grafts at a single institution were retrospectively reviewed. The patients were grouped according to intervention type: complete excision and partial excision of arteriovenous prosthetic grafts. Partial excisions were further substratified based on whether flow had been restored through the arteriovenous access. The primary outcome was freedom from subsequent intervention for infection, defined as the number of days from excision to subsequent reoperation for reinfection. Freedom from infection was analyzed using the Kaplan-Meier method.Results: A total of 117 patients had undergone surgical intervention for 122 infected arteriovenous grafts from 2003 to 2016. Of these 117 patients, 79 (64.8%) had undergone partial excision of infected arteriovenous grafts, and 43 (35.2%) had undergone complete excision with vascular repair. Within the partial excision cohort, 71 infected arteriovenous grafts (58.2%) were not flow restored and 8 (6.6%) were flow restored using either prosthetic or autogenous interpositions. The median follow-up time was 2.4 years (interquartile range, 0.6-4.5 years). The most common causative organisms included methicillin-resistant Staphylococcus aureus (n ¼ 34; 27.9%), methicillin-sensitive S. aureus (n ¼ 17; 13.9%), and S. epidermidis (n ¼ 15; 12.3%). The recurrent infection rate in the partial excision group was 16.5% (n ¼ 13) compared with 2.3% (n ¼ 1) in the complete excision group. In the flow-restored subcohorts, those with restoration using prosthetic interposition grafts had the greatest reinfection rate at 57.1% (n ¼ 4), and those with restoration using autogenous conduits did not experience reinfection (P ¼ .033).Conclusions: Incomplete excision of infected arteriovenous prosthetic grafts was associated with a higher rate of reinfection compared with complete graft excision. Complete excision presents technical challenges but could provide superior source control in managing infected dialysis access. Complete excision with vascular reconstruction should be performed when possible to avoid leaving remnant prosthetic material. (J Vasc Surg 2020;71:174-9.)