Impact of an Ultrasound Demonstration on Vascular Surgery Interest in Preclinical Medical Students.

BACKGROUND: One strategy to address the impending shortage of vascular surgeons is to augment interest in the trainee pipeline. Endovascular procedures are unique to vascular surgery (VS) and endovascular simulations have proven effective at generating VS interest in the past. Like endovascular techniques, the use of ultrasound (US) testing in VS is unique among medical specialties. We hypothesized that an interactive US demonstration would increase VS interest in preclinical medical students. METHODS: We created a 5-point Likert scale survey assessing interest in VS, understanding of VS, likelihood to further investigate VS, choosing VS as a rotational elective, and pursuing VS shadowing and research opportunities. This survey was administered 1 day before and 1 day after the demonstration. Results were compared via paired t-test. A VS attending assisted by a senior registered vascular technologist covered physics, B-mode, continuous, pulsed wave, and color Doppler in an interactive, hands-on experience. Our dedicated US simulation laboratory enabled simultaneous interactive virtual broadcast and in-person learning. All first-year and second-year students at our medical school were invited via e-mail. RESULTS: Five hundred twelve students were invited, 39 attended, and 19 students who completed surveys were included. Sixty eight percent were female. Attendance at the US demonstration resulted in a significant increase in students' interest in vascular surgery (P = 0.012), understanding of vascular surgery (P < 0.001), likelihood to further investigate vascular surgery (P < 0.001), likelihood to choose a vascular surgery rotation (P < 0.001), and likelihood to pursue vascular surgery shadowing and research opportunities (P < 0.001). Although only 2 of 6 in-person attendees returned surveys, their increase in average response to all questions was higher than virtual attendees (+1.80 vs. +0.91, P = 0.043). CONCLUSIONS: Attending an interactive US demonstration significantly increased preclinical medical students' interest in understanding of VS. In-person and virtual attendance both had a positive impact. Such a demonstration may be an effective tool to recruit students. It is imperative that we continue innovating to address the future shortage of vascular surgeons.

Extra-Anatomic Bypass and Excision is Superior to Graft Salvage Attempts with Antibiotic Beads to Treat Vascular Graft Infections in the Groin.

BACKGROUND: This study aimed to determine if conventional extra-anatomic bypass and graft removal versus aggressive attempts at graft preservation have better survival and limb salvage in patients with localized groin wound infections of vascular grafts. METHODS: We conducted a retrospective review of 53 consecutive patients with vascular graft infections presenting in the groin. Treatment groups consisted of group 1 (extra-anatomic bypass and graft excision, n = 22) and group 2 (initial graft preservation attempts with utilization of antibiotic beads, n = 31). In group 2, patients underwent serial debridement and placement of antibiotic beads until culture-negative wounds were achieved. Significantly more patients underwent muscle flap coverage in group 2 (27/31) compared with group 1 (7/22; P < 0.001). Data collected included demographics, comorbidities, intraoperative details, and outcomes, including patency, limb salvage, mortality, and number of procedures. Continuous variables were examined with Student's t-test, and dichotomous variables were examined with chi-squared test. Linear and logistic regressions were used to analyze factors associated with outcomes, in addition to Kaplan-Meier analysis with log rank for actuarial analysis. RESULTS: Both groups were similar with respect to demographics. The overall Kaplan-Meier 1- and 3-year survival rates were 66.2% and 34.1%, with no statistically significant difference between groups. The Kaplan-Meier 1- and 3-year limb salvage rates were 68.8% and 36.6% for group 1 vs. 58.5% and 38.7% for group 2 (P = not significant [NS]). The 1- and 3-year primary patency rates were 71% and 71% in traditional group 1 vs. 72% and 56% in group 2 (P = NS). One-year and 3-year secondary patency rates in traditional group 1 were 83% and 71% vs. 85% and 61% in group 2 (P = NS). Patients in group 1 underwent fewer total procedures when compared with group 2 (2.3 ± 0.2 vs. 5.1 ± 0.7, P = 0.03). The late reinfection rate was significantly less in group 1 (4.5%) compared with group 2 (26%; P = 0.04). Freedom from reinfection at 1 and 3 years were 94% and 94% in traditional group 1 vs. 74% and 62% in group 2 (P = 0.03). Multivariable analysis showed a higher incidence of amputation in patients who suffered reinfection (n = 13, P = 0.049). There was a higher mortality in patients with septic shock (n = 10, P = 0.007) and reinfection (n = 13, P = 0.036). Reinfection was associated with the highest mortality (P = 0.03). CONCLUSIONS: Conventional graft excision with extra-anatomic bypass resulted in similar mortality when compared with aggressive attempts at graft preservation and trended toward improved limb salvage and patency. However, attempts at graft preservation with antibiotic beads resulted in a significantly higher reinfection rate and greater number of procedures, and therefore, this approach should be used very selectively.

A prebifurcated axillobifemoral polytetrafluoroethylene graft simplifies carotid to carotid to subclavian bypass.

The use of thoracic endovascular aortic repair for thoracic aortic disease will necessitate cervical debranching in cases involving the proximal arch. We have presented the case of a 57-year-old athletic woman who had developed a type A dissection that extended to the bilateral iliac arteries. After hemiarch repair, she underwent staged cervical debranching with carotid-carotid-subclavian bypass using a prebifurcated axillobifemoral graft and subsequent thoracic endovascular aortic repair. We have detailed her successful clinical course and described the benefits of using a prebifurcated graft for cervical debranching in hybrid repairs of aortic arch pathology.

Multivalent Ligand Binding to Cell Membrane Antigens: Defining the Interplay of Affinity, Valency, and Expression Density.

Nature uses multivalency to govern many biological processes. The development of macromolecular and cellular therapies has largely been dependent on engineering similar polyvalent interactions to enable effective targeting. Such therapeutics typically utilize high-affinity binding domains that have the propensity to recognize both antigen-overexpressing tumors and normal-expressing tissues, leading to "on-target, off-tumor" toxicities. One strategy to improve these agents' selectivity is to reduce the binding affinity, such that biologically relevant interactions between the therapeutic and target cell will only exist under conditions of high avidity. Preclinical studies have validated this principle of avidity optimization in the context of chimeric antigen receptor (CAR) T cells; however, a rigorous analysis of this approach in the context of soluble multivalent targeting scaffolds has yet to be undertaken. Using a modular protein nanoring capable of displaying ≤8 fibronectin domains with engineered specificity for a model antigen, epithelial cell adhesion molecule (EpCAM), this study demonstrates that binding affinity and ligand valency can be optimized to afford discrimination between EpCAMHigh (2.8-3.8 × 106 antigens/cell) and EpCAMLow (5.2 × 104 to 2.2 × 105 antigens/cell) tissues both in vitro and in vivo.