Incidence, reintervention, and survival associated with type II endoleak at hospital discharge after elective endovascular aneurysm repair in the Vascular Quality Initiative.

BACKGROUND: The longitudinal clinical significance of type II endoleaks (T2ELs) remains controversial. Specifically, the real-world incidence, need for reintervention, and associated mortality referable to T2ELs remain unknown. Moreover, current professional society clinical practice guidelines recommend differing aneurysm sac growth thresholds to prompt intervention. Therefore, the purpose of this analysis was to better quantify the prevalence of early T2ELs after infrarenal endovascular aortic aneurysm repair (EVAR) and determine its association with reintervention and survival. METHODS: All elective EVARs from the Vascular Quality Initiative (2010-2020) were examined to identify patients with isolated T2ELs vs no endoleak (NONE) at discharge. Procedures with a type I or III endoleak were excluded. A subgroup analysis was performed on patients surviving beyond the first postoperative year with follow-up data available on endoleaks. The primary outcome was overall survival. Secondary outcomes included perioperative mortality and reinterventions. Outcomes were assessed by multivariable logistic and Cox proportional hazards regression to adjust for covariates. RESULTS: We identified 53,697 patients who underwent EVAR. The overall incidence of isolated T2ELs at discharge was 16%. In-hospital mortality was lower for those with isolated T2ELs vs NONE (0.8% vs 1.9%, odds ratio: 0.6, 95% confidence interval: 0.5-0.8, P < .0001). Unadjusted overall survival was marginally higher at 5 years for patients with T2ELs vs NONE (84% vs 82%); however, after risk adjustment, survival was similar (hazard ratio: 0.95, 95% confidence interval: 0.9-1.0). Among 44,345 patients with 1-year follow-up, 66% had data on endoleak status for assessment. Survival was similar regardless of endoleak status (NONE, at discharge only, at follow-up only, or at both time points). Among patients with documented T2ELs during follow-up, 6.1% and 2.5% had abdominal aortic aneurysm sac diameter growth ≥5 mm and ≥10 mm, respectively. Reinterventions occurred in 12%. Rupture (1%) and any open reintervention (4%) were rare among patients with 1-year follow-up. For patients with T2ELs, 5-year survival was similar between those with and without reintervention by 1 year (89% vs 91%, log-rank P = .06). CONCLUSIONS: T2ELs remain common after EVAR within the Vascular Quality Initiative and are not associated with long-term mortality. Reinterventions for T2ELs were not associated with improved overall survival among patients with T2ELs. Although additional data surrounding the appropriate role of reintervention for T2ELs remain necessary, it appears that the natural history of T2ELs is benign.

Practice Patterns of Vascular Surgery's "1%".

BACKGROUND: Public focus on health care spending has increased attention on variation in practice patterns and overutilization of high-cost services. Mainstream news reports have revealed that a small number of providers account for a disproportionate amount of total Medicare payments. Here, we explore variation in Medicare payments among vascular surgeons and compare practice patterns of the most highly reimbursed surgeons to the rest of the workforce. METHODS: 2016 Medicare Provider Utilization Data were queried to identify procedure, charge, and payment data to vascular surgeons, identified by National Provider Identification taxonomy. Commonly performed services (>10/year) were stratified into categories (endovascular, open surgery, varicose vein, evaluation and management, etc.). Practice patterns of vascular surgeons comprising the top 1% Medicare payments (n = 31) were compared with the remainder of the workforce (n = 3,104). RESULTS: In 2016, Medicare payments to vascular surgeons totaled $589 M. 31 vascular surgeons-1% of the workforce-received $91 million (15% of total payments). Practice patterns of the 1% differed significantly from the remainder of vascular surgeons (P < 0.05), with endovascular procedures accounting for 85% of their reimbursement. Specifically, the 1% received 49% of total Medicare payments for atherectomy ($121 M), 98% of which were performed in the office setting. CONCLUSIONS: One percentage of vascular surgeons receive an inordinate amount of total Medicare payments to the specialty. This discrepancy is due to variations in volume, utilization, and site of service. Disproportionate use of outpatient atherectomy in a small number of providers, for example, raises concerns regarding appropriateness and overutilization. Given current scrutiny over health care spending, these findings should prompt serious discussion regarding the utility of personal and societal self-regulation.

Renal transplantation in the setting of aortic atresia: Utilizing hepatic artery inflow with donor vessel jump graft.

Both congenital and acquired recipient anatomy can present a significant challenge to renal transplantation. A patient with congenital aortic atresia and limited dialysis access options presented to our institution for consideration of transplant. Through multidisciplinary planning, a strategy to accommodate the patient's variant anatomy was devised and successfully performed. A deceased donor vessel graft was used as conduit in combination with the recipient hepatic artery for renal graft inflow.

Hybrid repair of tandem high-grade innominate and carotid artery stenosis in an asymptomatic male.

Tandem atherosclerotic lesions of the innominate artery (IA) and internal carotid artery (ICA) are challenging and represent an inherent risk of cerebrovascular accident. Treating asymptomatic patients is controversial; therefore, it is critical to minimize the risk of a cerebrovascular accident if repair is undertaken. An asymptomatic 78-year-old man with a chronically occluded left ICA and tandem stenoses of the IA and right ICA underwent a hybrid intervention with stenting of the IA lesion and right ICA endarterectomy. The intra- and postoperative course was successful, without any signs of neurological sequelae. Sixteen months later, the patient remained asymptomatic, with patent reconstructions.

Carotid endarterectomy surgeon volumes in contemporary practice: A comparison to randomized trial inclusion criteria.

BACKGROUND: Clinical decisions regarding the utility of carotid revascularization are informed by randomized controlled trial (RCT) results. However, RCTs generally require participating surgeons to meet strict inclusion criteria with respect to procedure volume. The purpose of this study was to compare annual surgeon volume for carotid endarterectomy (CEA) in contemporary practice to RCT inclusion thresholds. METHODS: Surgeon volume thresholds were identified in 17 RCTs evaluating the efficacy of CEA (1986-present, n = 17). Contemporary annual surgeon volumes (2012-2017) were identified by aggregating data from the Medicare Provider Utilization Database and Healthcare Cost and Utilization Project Network (HCUP), and compared to RCT inclusion thresholds. Further comparisons were performed over time, and across specialties (i.e., vascular surgeon vs. other, based on board certification associated with provider NPI). RESULTS: Minimal surgeon volume in 17 RCTs ranged from 10 to 25 CEA annually when specific case volumes were required. From 2012 to 2017, CEA incidence in Medicare beneficiaries declined from 68,608 to 56,004 and became increasingly consolidated in fewer providers (7,331 vs. 6,626). However, in 2016 only 26.2% of surgeons performing CEA in Medicare beneficiaries would have met the least stringent volume requirement (10 CEA/year). Only 6.5% of surgeons performing CEA met the most stringent RCT volume threshold (25 cases/year) during the same time period. In 2017, 819 vascular surgeons (25.5% of those certified in the specialty) performed >10 CEA in Medicare beneficiaries. CONCLUSIONS: The majority of surgeons performing CEA do not meet the annual volume thresholds required for participation in the RCTs that have evaluated the efficacy of carotid revascularization. Given the established volume-outcome relationship in CEA, the disparity between surgeon experience in the context of RCTs versus contemporary practice is concerning. These findings have potential implications for informed decision-making, hospital privileging, and regionalization of care.

Energetics of intercavity diffusion in a simple model of a low-density p-tert-butylcalix[4]arene crystal.

Potentials of mean force calculated for the diffusion of small guest molecules (CO(2) and CH(4)) between adjacent host cavities in the beta(0) p-tert-butylcalix[4]arene polymorph reveal sufficiently high barriers to diffusion to justify characterizing the lattice voids in this crystal as independent host cavities rather than as extended volumes. In addition, the calculated barrier heights are consistent with a "relay" model for gas diffusion in this ostensibly nonporous organic solid involving the lateral sliding of the host bilayers.

Inadequacy of Algorithmic Ventilator-Associated Pneumonia Diagnosis in Acute Care Surgery.

Clinical utility of algorithms to diagnose ventilator-associated pneumonia (VAP) in surgical patients has not been established. We aimed to test the diagnostic accuracy of two established methods to reliably diagnose VAP in acutely ill and injured surgical patients. After institutional review board approval, we prospectively collected data on 508 mechanically ventilated acute care surgery patients. Microbiologic samples were taken daily from all patients. Demographics, clinical, laboratory, and radiographic data were collected. The Johanson Criteria (JC) and Clinical Pulmonary Infection Score (CPIS) were calculated and analyzed. Sensitivity, specificity, and positive predictive values (PPV) and negative predictive value (NPV) were calculated in comparison to positive respiratory cultures. Of the 508 patients, 312 (61.4%) were acutely injured; emergent general surgery was performed in 141 (27.8%) patients, and 54 (10.6%) underwent elective operation. Positive respiratory cultures were identified in 198 (39%) of the 508 patients. JC diagnosed VAP in 291 (57.3%) patients (sensitivity 82.8%, specificity 59%, PPV 56.4%, NPV 84.3%, accuracy 68.3%). The CPIS resulted in 189 (37.2%) VAP diagnoses (sensitivity 61.1%, specificity 78.1%, PPV 64%, NPV 75.9%, and accuracy 71.5%). To address the inaccuracy of the algorithms, concordance testing was performed on the data to evaluate correlation between the algorithmic VAP diagnosis criteria and respiratory culture data. Nonconcordance with culture data diagnosis was identified with both JC (rho 0.41) and CPIS (rho 0.41). Sensitivity, specificity, PPV and NPV, and accuracy of both established clinical formulas was unacceptably low in acute care surgery patients.

Pulmonary Contusion in Mechanically Ventilated Subjects After Severe Trauma.

BACKGROUND: Pulmonary contusions are thought to worsen outcomes. We aimed to evaluate the effects of pulmonary contusion on mechanically ventilated trauma subjects with severe thoracic injuries and hypothesized that contusion would not increase morbidity. METHODS: We conducted a single-center, retrospective review of 163 severely injured trauma subjects (injury severity score ≥ 15) with severe thoracic injury (chest abbreviated injury score ≥ 3), who required mechanical ventilation for >24 h at a verified Level 1 trauma center. Subject data were analyzed for those with radiographic documentation of pulmonary contusion and those without. Statistical analysis was performed to determine the effects of coexisting pulmonary contusion in severe thoracic trauma. RESULTS: Pulmonary contusion was present in 91 subjects (55.8%), whereas 72 (44.2%) did not have pulmonary contusions. Mean chest abbreviated injury score (3.54 vs 3.47, P = .53) and mean injury severity score (32.6 vs 30.2, P = .12) were similar. There was no difference in mortality (11 [12.1%] vs 9 [12.5%], P > .99) or length of stay (16.29 d vs 17.29 d, P = .60). Frequency of ventilator-associated pneumonia was comparable (43 [47.3%] vs 32 [44.4%], P = .75). Subjects with contusions were more likely to grow methicillin-sensitive Staphylococcus aureus in culture (33 vs 10, P = .004) as opposed to Pseudomonas aeruginosa in culture (6 vs 13, P = .003). CONCLUSIONS: Overall, no significant differences were noted in mortality, length of stay, or pneumonia rates between severely injured trauma subjects with and without pulmonary contusions.