Cannabis use in Parkinson's disease: Patient access to medical cannabis and physician perspective on product safety.

The rate of medical cannabis use has increased in parallel with the number of states legalizing its use. Parkinson's disease (PD) patients are of particular concern due to their higher cannabis use rate than in the general US population (25-40 % PD patient cannabis users vs. ∼18 % in the general population), as well as their susceptibility to environmental contaminants in cannabis, including pesticides, toxic elements, solvents, microbes, and mycotoxins. In order to address the complex nature of this industry, we examined the changes in PD-related qualifying conditions in the U.S. from 2019 to 2023. We also conducted an online survey to gain insight into the knowledge, risk perceptions, and opinions regarding medical cannabis and contamination issues from physicians who treated PD patients. The number of states including PD-related qualifying conditions increased over the past 5 years from 28 to 36 states. These conditions included PD (increasing from 14 to 16 states), muscle spasms (14 to 24), anxiety (1 to 5), and pain (17 to 35). State-by-state comparisons revealed high variability in the language used to describe the different qualifying conditions. Online surveys were sent out to 45 neurologists and movement disorder specialists who primarily treated PD patients. The response rate was 44 % from nine states (AZ, CA, FL, MA, MN, WI, PA, IL, and NM). When asked if they were aware of any contaminants in cannabis products, we found that 65 % of the physicians were unaware of any contaminants commonly found in cannabis and only 25 %, 15 %, and 15 % of them were aware of pesticide, toxic element, and solvent contaminants, respectively. In their free-text opinion response on the health impact of cannabis-borne contaminants, "long-term effect" (35 %) and "comorbidities and PD prognosis" (40 %) were identified as the two most common themes. These results point to the need for further regulatory deliberation regarding risks and susceptibility to cannabis contaminants. Additionally, education is needed to inform physicians on cannabis safety issues. Further research will identify the implementation strategies to reduce contaminant exposure and protect patient health.

How multidisciplinary clinics may mitigate socioeconomic barriers to care for chronic limb-threatening ischemia.

OBJECTIVE: Although multidisciplinary clinics improve outcomes in chronic limb-threatening ischemia (CLTI), their role in addressing socioeconomic disparities is unknown. Our institution treats patients with CLTI at both traditional general vascular clinics and a multidisciplinary Limb Preservation Program (LPP). The LPP is in a minority community, providing expedited care at a single facility by a consistent team. We compared outcomes within the LPP with our institution's traditional clinics and explored patients' perspectives on barriers to care to evaluate if the LPP might address them. METHODS: All patients undergoing index revascularization for CLTI from 2014 to 2023 at our institution were stratified by clinic type (LPP or traditional). We collected clinical and socioeconomic variables, including Area Deprivation Index (ADI). Patient characteristics were compared using χ2, Student t, or Mood median tests. Outcomes were compared using log-rank and multivariable Cox analysis. We also conducted semi-structured interviews to understand patient-perceived barriers. RESULTS: From 2014 to 2023, 983 limbs from 871 patients were revascularized; 19.5% of limbs were treated within the LPP. Compared with traditional clinic patients, more LPP patients were non-White (43.75% vs 27.43%; P < .0001), diabetic (82.29% vs 61.19%; P < .0001), dialysis-dependent (29.17% vs 13.40%; P < .0001), had ADI in the most deprived decile (29.38% vs 19.54%; P = .0061), resided closer to clinic (median 6.73 vs 28.84 miles; P = .0120), and had worse Wound, Ischemia, and foot Infection (WIfI) stage (P < .001). There were no differences in freedom from death, major adverse limb event (MALE), or patency loss. Within the most deprived subgroup (ADI >90), traditional clinic patients had earlier patency loss (P = .0108) compared with LPP patients. Multivariable analysis of the entire cohort demonstrated that increasing age, heart failure, dialysis, chronic obstructive pulmonary disease, and increasing WIfI stage were independently associated with earlier death, and male sex was associated with earlier MALE. Ten traditional clinic patients were interviewed via convenience sampling. Emerging themes included difficulty understanding their disease, high visit frequency, transportation barriers, distrust of the health care system, and patient-physician racial discordance. CONCLUSIONS: LPP patients had worse comorbidities and socioeconomic deprivation yet had similar outcomes to healthier, less deprived non-LPP patients. The multidisciplinary clinic's structure addresses several patient-perceived barriers. Its proximity to disadvantaged patients and ability to conduct multiple appointments at a single visit may address transportation and visit frequency barriers, and the consistent team may facilitate patient education and improve trust. Including these elements in a multidisciplinary clinic and locating it in an area of need may mitigate some negative impacts of socioeconomic deprivation on CLTI outcomes.

Gluteal and thigh compartment syndrome after open abdominal aortic aneurysm repair.

Although compartment syndrome (CS) can occur in any myofascial compartment, the thigh and buttock are among the least common. CS is characterized by an increase in pressure of a myofascial compartment that results in a reduction of capillary blood flow and myonecrosis. Although >75% of cases of CS occur after long bone fractures, acute CS can also occur from nontraumatic and vascular etiologies. We report a case of gluteal and thigh CS resulting from ischemia-reperfusion injury after abdominal aortic aneurysm repair and left common iliac artery bypass.

Measuring Chief Resident Skill and Entrustment Progression in An Operative Coaching Program: Four Years' Experience.

OBJECTIVE: Operative coaching (OC) may facilitate improvement of surgery residents' competencies by optimizing learning and teaching. We investigated how residents' operative skills and prospective entrustment (PE) progress throughout the chief year in our OC program, how OC is perceived by participants, and how OC may facilitate learning and teaching. DESIGN, SETTING, AND PARTICIPANTS: This is a mixed-methods study conducted within the Ohio State University Wexner Medical Center General Surgery residency. Validated performance evaluations with procedural-specific skill, general skill (GS), step-specific guidance required (SSG) (an autonomy measure), and PE measures completed by chiefs, faculty coaches, and attending surgeons from 7/2018 to 6/2022 were reviewed. We also interviewed OC participants to understand their experience. Descriptive statistical and qualitative content analysis were applied. RESULTS: 441 evaluations from 147 OC cases completed by 22 chiefs, 5 faculty coaches, and 24 attendings were included. Overall, resident GS (p = 0.036), SSG (p = 0.023), and PE (p = 0.002) significantly improved throughout the year. PE significantly correlated (all p < 0.0001) with SSG (r = 0.73), followed by procedural-specific skill (r = 0.59), then GS (r = 0.57). On average, chiefs underestimated their surgical skills while attendings overestimated autonomy they permitted to residents. Chiefs, coaches, and attendings reached consensus on chiefs' PE upon graduation. Five graduated chiefs and 5 attendings were interviewed. Chiefs described OC as effective in improving their self-regulated learning and particularly valued 3 OC elements: neutral authentic feedback, third-party real-time observation, and actionable feedback. Attendings noted OC promoted their engagement in skills assessment and teaching. CONCLUSIONS: Our findings suggest chief residents' skills, autonomy, and PE progress steadily along their OC journey. Despite differences in residents', coaches', and attendings' perceptions of skill, measures of autonomy reliably correlate with entrustment. OC promotes resident learning, faculty teaching, and assessment of resident skills, autonomy, and PE in the OR.

Quantification of Skeletal Muscle Perfusion in Peripheral Artery Disease Using 18F-Sodium Fluoride Positron Emission Tomography Imaging.

BACKGROUND: Perfusion deficits contribute to symptom severity, morbidity, and death in peripheral artery disease (PAD); however, no standard method for quantifying absolute measures of skeletal muscle perfusion exists. This study sought to preclinically test and clinically translate a positron emission tomography (PET) imaging approach using an atherosclerosis-targeted radionuclide, fluorine-18-sodium fluoride (18F-NaF), to quantify absolute perfusion in PAD. METHODS AND RESULTS: Eight Yorkshire pigs underwent unilateral femoral artery ligation and dynamic 18F-NaF PET/computed tomography imaging on the day of and 2 weeks after occlusion. Following 2-week imaging, calf muscles were harvested to quantify microvascular density. PET methodology was validated with microspheres in 4 additional pig studies and translated to patients with PAD (n=39) to quantify differences in calf perfusion across clinical symptoms/stages and perfusion responses in a case of revascularization. Associations between PET perfusion, ankle-brachial index, toe-brachial index, and toe pressure were assessed in relation to symptoms. 18F-NaF PET/computed tomography quantified significant deficits in calf perfusion in pigs following arterial occlusion and perfusion recovery 2 weeks after occlusion that coincided with increased muscle microvascular density. Additional studies confirmed that PET-derived perfusion measures agreed with microsphere-derived perfusion measures. Translation of imaging methods demonstrated significant decreases in calf perfusion with increasing severity of PAD and quantified perfusion responses to revascularization. Perfusion measures were also significantly associated with symptom severity, whereas traditional hemodynamic measures were not. CONCLUSIONS: 18F-NaF PET imaging quantifies perfusion deficits that correspond to clinical stages of PAD and represents a novel perfusion imaging strategy that could be partnered with atherosclerosis-targeted 18F-NaF PET imaging using a single radioisotope injection. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03622359.

The Nanoplasmonic Purcell Effect in Ultrafast and High-Light-Yield Perovskite Scintillators.

The development of X-ray scintillators with ultrahigh light yields and ultrafast response times is a long sought-after goal. In this work, a fundamental mechanism that pushes the frontiers of ultrafast X-ray scintillator performance is theoretically predicted and experimentally demonstrated: the use of nanoscale-confined surface plasmon polariton modes to tailor the scintillator response time via the Purcell effect. By incorporating nanoplasmonic materials in scintillator devices, this work predicts over tenfold enhancement in decay rate and 38% reduction in time resolution even with only a simple planar design. The nanoplasmonic Purcell effect is experimentally demonstrated using perovskite scintillators, enhancing the light yield by over 120% to 88 ± 11 ph/keV, and the decay rate by over 60% to 2.0 ± 0.2 ns for the average decay time, and 0.7 ± 0.1 ns for the ultrafast decay component, in good agreement with the predictions of our theoretical framework. Proof-of-concept X-ray imaging experiments are performed using nanoplasmonic scintillators, demonstrating 182% enhancement in the modulation transfer function at four line pairs per millimeter spatial frequency. This work highlights the enormous potential of nanoplasmonics in optimizing ultrafast scintillator devices for applications including time-of-flight X-ray imaging and photon-counting computed tomography.

Revascularization Outcomes Stratified by Glycemic Control in Patients with Diabetes Mellitus and Chronic Limb-Threatening Ischemia.

BACKGROUND: The prevalence of chronic limb-threatening ischemia (CLTI) has increased alongside rising rates of diabetes mellitus (DM). While diabetic patients with CLTI have worse outcomes compared to patients without diabetes, conflicting data exist on the relationship between the severity of DM and CLTI outcomes. Close inspection of the relationship between DM severity and outcomes in CLTI may benefit surgical decision-making and patient education. METHODS: We retrospectively reviewed patients who received endovascular intervention or surgical bypass for CLTI at our multidisciplinary Limb Preservation Program from 2013 to 2019 to collect patient characteristics using Society for Vascular Surgery (SVS) reporting standards, arterial lesion characteristics from recorded angiograms, and outcomes, including survival, amputation, wound healing, and revascularization patency. Controlled DM was defined as SVS Grade 1 (controlled, not requiring insulin) and Grade 2 (controlled, requiring insulin), while uncontrolled DM was defined as SVS Grade 3 (uncontrolled), and DM severity was assessed using preoperative hemoglobin A1c (HgbA1c) values. Product-limit Kaplan-Meier was used to estimate survival functions. Univariable Cox proportional hazards analyses guided variable selection for multivariable analyses. RESULTS: Our Limb Preservation Program treated 177 limbs from 141 patients with DM. Patients with uncontrolled DM were younger (60.44 ± 10.67 vs. 65.93 ± 10.89 years old, P = 0.0009) and had higher HgbA1c values (8.97 ± 1.85% vs. 6.79 ± 1.10%, P < 0.0001). Fewer patients with uncontrolled DM were on dialysis compared to patients with controlled DM (15.6% vs. 30.9%, P = 0.0278). By Kaplan-Meier analysis, DM control did not affect time to mortality, limb salvage, wound healing, or loss of patency. However, multivariable proportional hazards analysis demonstrated increased risk of limb loss in patients with increasing HgbA1C (hazard ratio (HR) = 1.96 [1.42-2.80], P < 0.0001) or dialysis dependence (HR = 15.37 [3.44-68.73], P = 0.0003), increased risk of death in patients with worsening pulmonary status (HR = 1.70 [1.20-2.39], P = 0.0026), and increased risk of delayed wound healing in patients who are male (HR = 0.48 [0.29-0.79], P = 0.0495). No independent association existed between loss of patency with any of the variables we collected. CONCLUSIONS: Patients with uncontrolled DM, as defined by SVS reporting standards, do not have worse outcomes following revascularization for CLTI compared to patients with controlled DM. However, increasing HgbA1c is associated with a greater risk for early amputation. Before revascularization, specific attention to the level of glycemic control in patients with DM is important, even if DM is "controlled." In addition to aggressive attempts at improved glycemic control, those with elevated HgbA1c should receive careful education regarding their increased risk of amputation despite revascularization. Future work is necessary to incorporate the severity of DM into risk models of revascularization for the CLTI population.

Multicolor x-rays from free electron-driven van der Waals heterostructures.

The emergence of van der Waals (vdW) heterostructures has led to precise and versatile methods of fabricating devices with atomic-scale accuracies. Hence, vdW heterostructures have shown much promise for technologies including photodetectors, photocatalysis, photovoltaic devices, ultrafast photonic devices, and field-effect transistors. These applications, however, remain confined to optical and suboptical regimes. Here, we theoretically show and experimentally demonstrate the use of vdW heterostructures as platforms for multicolor x-ray generation. By driving the vdW heterostructures with free electrons in a table-top setup, we generate x-ray photons whose output spectral profile can be user-customized via the heterostructure design and even controlled in real time. We show that the multicolor photon energies and their corresponding intensities can be tailored by varying the electron energy, the electron beam position, as well as the geometry and composition of the vdW heterostructure. Our results reveal the promise of vdW heterostructures in realizing highly versatile x-ray sources for emerging applications in advanced x-ray imaging and spectroscopy.

Cumulative Sum Chart as Complement to Objective Assessment of Graduating Surgical Resident Competency: An Exploratory Study.

BACKGROUND: Rater-based assessment and objective assessment play an important role in evaluating residents' clinical competencies. We hypothesize that a cumulative sum (CUSUM) chart of operative time is a complement to the assessment of chief general surgery residents' competencies with ACGME Milestones, aiding residency programs' determination of graduating residents' practice readiness. STUDY DESIGN: We extracted ACGME Milestone evaluations of performance of operations and procedures (POP) and 3 objective metrics (operative time, case type, and case complexity) from 3 procedures (cholecystectomy, colectomy, and inguinal hernia) performed by 3 cohorts of residents (N = 15) during their PGY4-5. CUSUM charts were computed for each resident on each procedure type. A learning plateau was defined as at least 4 cases consistently locating around the centerline (target performance) at the end of a CUSUM chart with minimal deviations (range 0 to 1). RESULTS: All residents reached the ACGME graduation targets for the overall POP by the end of chief year. A total of 2,446 cases were included (cholecystectomy N = 1234, colectomy N = 507, and inguinal hernia N = 705), and 3 CUSUM chart patterns emerged: skewed distribution, bimodal distribution, and peaks and valleys distribution. Analysis of CUSUM charts revealed surgery residents' development processes in the operating room towards a learning plateau vary, and only 46.7% residents reach a learning plateau in all 3 procedures upon graduation. CONCLUSIONS: CUSUM charts of operative time complement the ACGME Milestones evaluations. The use of both may enable residency programs to holistically determine graduating residents' practice readiness and provide recommendations for their upcoming career/practice transition.

Detection of multivessel calcific disease progression in a patient with chronic limb-threatening ischemia using fluorine-18 sodium fluoride positron emission tomography imaging.

Vascular calcification contributes to morbidity and poor clinical outcomes for patients with peripheral artery disease; however, the traditional assessment of the calcium burden using computed tomography (CT) imaging or angiography represents already established disease. In the present report, we describe a 69-year-old man with chronic limb-threatening ischemia who had undergone positron emission tomography/CT imaging with fluorine-18 sodium fluoride to evaluate the relationship between baseline levels of positron emission tomography-detectable active vascular microcalcification and CT-detectable calcium progression 1.5 years later. CT imaging at follow-up identified progression of existing lesions and the formation of new calcium in multiple arteries that had demonstrated elevated fluorine-18 sodium fluoride uptake 1.5 years earlier.

The natural history of chronic limb-threatening ischemia after technical failure of endovascular intervention.

OBJECTIVES: The treatment for chronic limb-threatening ischemia (CLTI) has changed dramatically in the last few decades with a shift toward an endovascular-first approach and aggressive revascularization to achieve limb salvage. As the size of the CLTI population and intervention rates increase, patients will continue to experience technical failure (TF). Here, we describe the natural history of patients after TF of endovascular intervention for CLTI. METHODS: We conducted a retrospective cohort study of patients with CLTI who attempted endovascular intervention or bypass at our multidisciplinary limb salvage center from 2013 to 2019. Patient characteristics were collected according to the Society for Vascular Surgery's reporting standards. Primary outcomes included survival, limb salvage, wound healing, and revascularization patency. Product-limit Kaplan-Meier estimated survival functions for these outcomes, and between-group comparisons were made using Mantel-Cox log-rank nonparametric tests. RESULTS: We identified 242 limbs from 220 unique patients who underwent primary bypass (n = 30) or attempted endovascular intervention (n = 212) at our limb salvage center. Endovascular intervention was a TF in 31 (14.6%) limbs. After TF, 13 limbs underwent secondary bypass and 18 limbs were managed medically. Patients who experienced TF tended to be older (P < .001), male (P = .003), current tobacco users (P = .014), have longer lesions (P = .001), and have chronic total occlusions of target arteries (P < .001) as compared with those who experienced technical success. Furthermore, the TF group had worse limb salvage (P = .047) and slower wound healing (P = .028), but their survival was not different. Survival, limb salvage, and wound healing were not different in patients who received secondary bypass or medical management after TF. The secondary bypass group was older (P = .012) and had a lower prevalence of tibial disease (P = .049) than the primary bypass group and trended toward decreased survival, limb salvage, and wound healing (P = .059, P = .083, and P = .051, respectively). CONCLUSIONS: Increased age, male sex, current tobacco use, longer arterial lesions, and occluded target arteries are associated with TF of endovascular intervention. Limb salvage and wound healing are relatively poor after TF of endovascular intervention, but survival appears comparable with patients who experience technical success. Secondary bypass may not always rescue patients after TF, though our sample size limits statistical power. Interestingly, patients who received a secondary bypass after TF trended toward decreased survival, limb salvage, and wound healing compared with primary bypass.

Vessel-by-Vessel Computed Tomography Calcium Scoring of the Foot in Peripheral Artery Disease: Association with Patient-Level Factors.

Objective: Peripheral artery disease (PAD) is associated with increased risk of nonhealing ulcers, amputation, and mortality due to occlusive atherosclerotic plaques. Computed tomography (CT) imaging detects vascular calcification in PAD; however, quantitative vessel-by-vessel analysis of calcium burden in the feet of PAD patients has not been assessed. This study sought to perform quantitative analysis of vessel-specific calcium burden and examine the patient-level determinants of foot calcium burden in PAD patients. Approach: PAD patients (n = 41) were prospectively enrolled and underwent CT imaging of the lower extremities. Manual segmentation of the medial plantar, lateral plantar, and dorsalis pedis arteries was performed. CT image Hounsfield units (HUs) were obtained for each artery to quantify vessel-by-vessel calcium mass using a cutoff value of ≥130 HU. Univariate analyses were performed to evaluate patient-level determinants of calcium burden for each foot artery. STROBE guidelines were used for reporting of data. Results: Univariate analyses revealed that body mass index, diabetes mellitus (DM), and chronic kidney disease (CKD) were significant determinants of foot calcium burden in PAD patients. Image analysis demonstrated that PAD patients with DM had significantly higher calcium mass for the medial plantar (p = 0.005), lateral plantar (p = 0.039), and dorsalis pedis (p = 0.001) arteries compared with PAD patients without DM. Innovation: This is the first study to use CT imaging to quantify vessel-specific calcium burden in the feet of patients with PAD and evaluate the patient-level determinants of foot calcium burden in the setting of PAD. Conclusion: CT imaging quantifies vessel-specific calcification in the feet of PAD patients, which is exacerbated with concomitant DM, CKD, and/or obesity.

Vessel-by-vessel analysis of lower extremity 18F-NaF PET/CT imaging quantifies diabetes- and chronic kidney disease-induced active microcalcification in patients with peripheral arterial disease.

BACKGROUND: Positron emission tomography (PET)/computed tomography (CT) imaging with fluorine-18 (18F)-sodium fluoride (NaF) provides assessment of active vascular microcalcification, but its utility for evaluating diabetes mellitus (DM)- and chronic kidney disease (CKD)-induced atherosclerosis in peripheral arterial disease (PAD) has not been comprehensively evaluated. This study sought to use 18F-NaF PET/CT to quantify and compare active microcalcification on an artery-by-artery basis in healthy subjects, PAD patients with or without DM, and PAD patients with or without CKD. Additionally, we evaluated the contributions of DM, CKD, statin use and established CT-detectable calcium to 18F-NaF uptake for each lower extremity artery. METHODS: PAD patients (n = 48) and healthy controls (n = 8) underwent lower extremity 18F-NaF PET/CT imaging. Fused PET/CT images guided segmentation of arteries of interest (i.e., femoral-popliteal, anterior tibial, tibioperoneal trunk, posterior tibial, and peroneal) and quantification of 18F-NaF uptake. 18F-NaF uptake was assessed for each artery and compared between subject groups. Additionally, established calcium burden was quantified for each artery using CT calcium mass score. Univariate and multivariate analyses were performed to evaluate DM, CKD, statin use, and CT calcium mass as predictors of 18F-NaF uptake in PAD. RESULTS: PAD patients with DM or CKD demonstrated significantly higher active microcalcification (i.e., 18F-NaF uptake) for all arteries when compared to PAD patients without DM or CKD. Univariate and multivariate analyses revealed that concomitant DM or CKD was associated with increased microcalcification for all arteries of interest and this increased disease risk remained significant after adjusting for patient age, sex, and body mass index. Statin use was only associated with decreased microcalcification for the femoral-popliteal artery in multivariate analyses. Established CT-detectable calcium was not significantly associated with 18F-NaF uptake for 4 out of 5 arteries of interest. CONCLUSIONS: 18F-NaF PET/CT imaging quantifies vessel-specific active microcalcification in PAD that is increased in multiple lower extremity arteries by DM and CKD and decreased in the femoral-popliteal artery by statin use. 18F-NaF PET imaging is complementary to and largely independent of established CT-detectable arterial calcification. 18F-NaF PET/CT imaging may provide an approach for non-invasively quantifying vessel-specific responses to emerging anti-atherogenic therapies or CKD treatment in patients with PAD.

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.

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.

Operative Coaching for General Surgery Residents: Review of Implementation Requirements.

Operative coaching offers a unique opportunity to strengthen surgery residents' skill sets and practice readiness. However, institutional organizational capacity may influence the ability to successfully implement and sustain a coaching program. This review concentrates on the implementation requirements as they relate to institutional organizational capacity to help evaluate and determine if adopting such a coaching model is feasible. We searched English-language, peer-reviewed articles concerning operative coaching of general surgery residents between 2000 and 2020 with the MEDLINE database. The abstracts of 267 identified articles were further screened based on the presence of 2 inclusion criteria: general surgery residents and operative coaching. Then we summarized the reported implementation requirements. Findings revealed the implementation requirements (ie people, processes, technology/support resources, physical resources, and organizational systems) of 3 major types of resident operative coaching models were different. Video-assisted coaching faces the most barriers to implementation followed by video-based coaching; in-person coaching encounters the least barriers. Six questions are generated helping residency education leaders assess their readiness for an operative coaching program. Evaluation of the implementation requirements of a desired coaching program using the 5 organizational capacity elements is recommended to ensure the residency's ability to achieve a successful and sustainable program.

MR Elastography of Abdominal Aortic Aneurysms: Relationship to Aneurysm Events.

Background Abdominal aortic aneurysm (AAA) diameter remains the standard clinical parameter to predict growth and rupture. Studies suggest that using solely AAA diameter for risk stratification is insufficient. Purpose To evaluate the use of aortic MR elastography (MRE)-derived AAA stiffness and stiffness ratio at baseline to identify the potential for future aneurysm rupture or need for surgical repair. Materials and Methods Between August 2013 and March 2019, 72 participants with AAA and 56 healthy participants were enrolled in this prospective study. MRE examinations were performed to estimate AAA stiffness and the stiffness ratio between AAA and its adjacent remote normal aorta. Two Cox proportional hazards models were used to assess AAA stiffness and stiffness ratio for predicting aneurysmal events (subsequent repair, rupture, or diameter >5.0 cm). Log-rank tests were performed to determine a critical stiffness ratio suggesting high-risk AAAs. Baseline AAA stiffness and stiffness ratio were studied using Wilcoxon rank-sum tests between participants with and without aneurysmal events. Spearman correlation was used to investigate the relationship between stiffness and other potential imaging markers. Results Seventy-two participants with AAA (mean age, 71 years ± 9 [SD]; 56 men and 16 women) and 56 healthy participants (mean age, 42 years ± 16; 27 men and 29 women) were evaluated. In healthy participants, aortic stiffness positively correlated with age (ρ = 0.44; P < .001). AAA stiffness (event group [n = 21], 50.3 kPa ± 26.5 [SD]; no-event group [n = 21], 86.9 kPa ± 52.6; P = .01) and the stiffness ratio (event group, 0.7 ± 0.4; no-event group, 2.0 ± 1.4; P < .001) were lower in the event group than the no-event group at a mean follow-up of 449 days. AAA stiffness did not correlate with diameter in the event group (ρ = -0.06; P = .68) or the no-event group (ρ = -0.13; P = .32). AAA stiffness was inversely correlated with intraluminal thrombus area (ρ = -0.50; P = .01). Conclusion Lower abdominal aortic aneurysm stiffness and stiffness ratio measured with use of MR elastography was associated with aneurysmal events at a 15-month follow-up. © RSNA, 2022 See also the editorial by Sakuma in this issue.

In-situ bypass is associated with superior infection-free survival compared with extra-anatomic bypass for the management of secondary aortic graft infections without enteric involvement.

OBJECTIVE: The optimal revascularization modality following complete resection of aortic graft infection (AGI) without enteric involvement remains unclear. The purpose of this investigation is to determine the revascularization approach associated with the lowest morbidity and mortality using real-world data in patients undergoing complete excision of AGI. METHODS: A retrospective, multi-institutional study of AGI from 2002 to 2014 was performed using a standardized database. Baseline demographics, comorbidities, and perioperative variables were recorded. The primary outcome was infection-free survival. Descriptive statistics, Kaplan-Meier survival analysis, and univariate and multivariable analyses were performed. RESULTS: A total of 241 patients at 34 institutions from seven countries presented with AGI during the study period (median age, 68 years; 75% male). The initial aortic procedures that resulted in AGI were 172 surgical grafts (71%), 66 endografts (27%), and three unknown (2%). Of the patients, 172 (71%) underwent complete excision of infected aortic graft material followed by in situ (in-line) bypass (ISB), including antibiotic-treated prosthetic graft (35%), autogenous femoral vein (neo-aortoiliac surgery) (24%), and cryopreserved allograft (41%). Sixty-nine patients (29%) underwent extra-anatomic bypass (EAB). Overall median Kaplan-Meier estimated survival was 5.8 years. Perioperative mortality was 16%. When stratified by ISB vs EAB, there was a significant difference in Kaplan-Meier estimated infection-free survival (2910 days; interquartile range, 391-3771 days vs 180 days; interquartile range, 27-3750 days; P < .001). There were otherwise no significant differences in presentation, comorbidities, or perioperative variables. Multivariable Cox regression showed lower infection-free survival among patients with EAB (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.6-3.6; P < .001), polymicrobial infection (HR, 2.2; 95% CI, 1.4-3.5; P = .001), methicillin-resistant Staphylococcus aureus infection (HR, 1.7; 95% CI, 1.1-2.7; P = .02), as well as the protective effect of omental/muscle flap coverage (HR, 0.59; 95% CI, 0.37-0.92; P = .02). CONCLUSIONS: After complete resection of AGI, perioperative mortality is 16% and median overall survival is 5.8 years. EAB is associated with nearly a two and one-half-fold higher reinfection/mortality compared with ISB. Omental and/or muscle flap coverage of the repair appear protective.

Novel Application of 18F-NaF PET/CT Imaging for Evaluation of Active Bone Remodeling in Diabetic Patients With Charcot Neuropathy: A Proof-of-Concept Report.

Charcot neuropathic osteoarthropathy (CN) is a serious and potentially limb-threatening complication for patients with diabetes mellitus and peripheral arterial disease. In recent decades, nuclear medicine-based approaches have been used for non-invasive detection of CN; however, to date, a positron emission tomography (PET) radionuclide specifically focused on targeted imaging of active bone remodeling has not been explored or validated for patients with CN. The radionuclide 18F-sodium fluoride (NaF) has historically been used as a bone imaging probe due to its high sensitivity for targeting hydroxyapatite and bone turnover, but has not been applied in the context of CN. Therefore, the present study focused on novel application of 18F-NaF PET/computed tomography (CT) imaging to three clinical cases of CN to evaluate active bone remodeling at various time courses of CN. PET/CT imaging in all 3 cases demonstrated focal uptake of 18F-NaF in the bones of the feet afflicted with CN, with bone retention of 18F-NaF persisting for up to 5 years following surgical reconstruction of the foot in two cases. On a group level, 18F-NaF bone uptake in the CN foot was significantly higher compared to the healthy, non-CN foot (p = 0.039). 18F-NaF PET/CT imaging may provide a non-invasive tool for monitoring active bone remodeling in the setting of CN, thereby offering novel opportunities for tracking disease progression and improving treatment and surgical intervention.

Structurally abnormal collagen fibrils in abdominal aortic aneurysm resist platelet adhesion.

BACKGROUND: Platelet adhesion to the subendothelial collagen fibrils is one of the first steps in hemostasis. Understanding how structural perturbations in the collagen fibril affect platelet adhesion can provide novel insights into disruption of hemostasis in various diseases. We have recently identified the presence of abnormal collagen fibrils with compromised D-periodic banding in the extracellular matrix remodeling present in abdominal aortic aneurysms (AAA). OBJECTIVE: In this study, we employed multimodal microscopy approaches to characterize how collagen fibril structure impacts platelet adhesion in clinical AAA tissues. METHODS: Ultrastructural atomic force microscopy (AFM) analysis was performed on tissue sections after staining with fluorescently labeled collagen hybridizing peptide (CHP) to recognize degraded collagen. Second harmonic generation (SHG) microscopy was used on CHP-stained sections to identify regions of intact versus degraded collagen. Finally, platelet adhesion was identified via SHG and indirect immunofluorescence on the same tissue sections. RESULTS: Our results indicate that ultrastructural features characterizing collagen fibril abnormalities coincide with CHP staining. SHG signal was absent from CHP-positive regions. Additionally, platelet binding was primarily localized to regions with SHG signal. Abnormal collagen fibrils present in AAA (in SHG negative regions) were thus found to inhibit platelet adhesion compared to normal fibrils. CONCLUSIONS: Our investigations reveal how the collagen fibril structure in the vessel wall can serve as another regulator of platelet-collagen adhesion. These results can be broadly applied to understand the role of collagen fibril structure in regulating thrombosis or bleeding disorders.