Large-Diameter Fenestrated Endograft Repair of Abdominal Aortic Aneurysms Is Not Associated With Medium-Term Outcomes.

INTRODUCTION: Recent data suggests that infrarenal abdominal aortic aneurysm (AAA) endovascular repair (EVAR) with large diameter grafts (LGs) may have a higher risk of endoleak and reintervention. However, this has not been studied extensively for fenestrated endovascular aneurysm repair (fEVAR). We, therefore, sought to evaluate the outcomes of patients undergoing fEVAR with large-diameter endografts. METHODS: Patients from the national Vascular Quality Initiative registry who underwent fEVAR for intact juxtarenal AAA were identified. Patients with genetic causes for aneurysms, those with prior aortic surgery, and those undergoing repair for symptomatic or ruptured aneurysms were excluded. Rates of endoleaks and reintervention at periprocedural and long-term follow-up timepoints (9-22 mo) were analyzed in grafts 32 mm or larger (LG) and were compared to those smaller than 32 mm (small diameter graft). RESULTS: A total of 693 patients (22.8% LG) were identified. Overall, demographic variables were comparable except LG exhibited a more frequent history of coronary artery disease (32.9% versus 25.4%, P = 0.037). There were no significant differences in the rates of endoleak at procedural completion. Overall survival at 5 y was no different. The rate of reintervention at 1 y was also no different (log-rank P = 0.86). CONCLUSIONS: While graft size appears to have an association with outcomes in infrarenal aneurysm repair, the same does not appear to be true for fEVAR. Further studies should evaluate the long-term outcomes associated with LG which could alter the approach to repair of AAA with large neck diameters traditionally treated with standard infrarenal EVAR.

Identification and characterization of new candidates for abdominal aortic aneurysm screening in patients outside of current accepted guidelines.

BACKGROUND: Previous studies have identified groups of patients with abdominal aortic aneurysm (AAA) that fall outside of currently accepted screening guidelines. Population-based studies have found AAA screening would be cost-effective at a prevalence of 0.5% to 1.0%. The goal of this study was to determine the prevalence of AAA in patients that fall outside of the current screening guidelines. In addition, we analyzed outcomes of the groups with a prevalence of greater than 1%. METHODS: Using the TriNetX Analytics Network, several patient cohorts were abstracted with a diagnosis of ruptured or unruptured AAA based on previously identified groups with a potentially high risk for AAA that fall outside of currently accepted screening guidelines. Groups were also stratified by sex. For groups found to have a prevalence of greater than 1%, the unruptured patients were further analyzed for long-term rates of rupture and included male ever-smokers aged 45 to 65, male never-smokers aged 65 to 75, male never-smokers aged greater than 75, and female ever-smokers aged 65 or greater. Long-term mortality, stroke, and myocardial infarction rates were compared in patients with treated and untreated AAA after propensity score matching. RESULTS: We identified 148,279 patients across the four groups with a prevalence of AAA of greater than 1% with female ever-smokers aged 65 or older being the most prevalent (2.73%). In each of the four groups, the rate of AAA rupture increased every 5 years and all had rupture rates of greater than 1% at 10 years. Meanwhile, controls for each of these four subgroups without a previous AAA diagnosis had rupture rates between 0.090% and 0.013% at 10 years. Those who underwent repair of their AAA had decreased incidence of mortality, stroke, and myocardial infarction. Specifically, male ever-smokers aged 45 to 64 had a significant difference in incidence of mortality and myocardial infarction at 5 years and stroke at 1 and 5 years. CONCLUSIONS: Our analysis suggests male ever-smokers aged 45 to 65, male never-smokers aged 65 to 75, male never-smokers aged greater than 75, and female ever-smokers aged 65 or greater have a more than 1% prevalence of AAA and, therefore, may benefit from screening. Outcomes were significantly worse compared with well-matched controls in these groups.

Initiation of hemodialysis at one month following fistulogram in patients with advanced kidney disease.

OBJECTIVE: Previous studies have demonstrated that low contrast volume used in access-related interventions had limited effects on the progression of chronic kidney disease (CKD) after fistulography, but studies are limited and heterogeneous. We sought to evaluate the rate of and factors associated with progression to dialysis (HD) within 1 month after fistulography for patients with advanced CKD. METHODS: A single-institution retrospective cohort analysis of patients with CKD stage IV and V, not yet on HD, undergoing fistulography from 1 January 2014 to 31 December 2018 was performed. The primary outcome was progression to HD within 1 month. Additional variables and the association with the primary outcome such as medical comorbidities, contrast type or volume were assessed. RESULTS: A total of 34 patients underwent 41 fistulograms prior to HD initiation. Progression to HD within 1 month of fistulogram occurred in seven patients (all CKD V). The mean time between fistulogram and HD was 271 days for 31 of 34 patients who ultimately progressed to HD. Those with CKD IV began HD in 549 days on average, while those with CKD V began HD in 190 days on average. Three patients had not initiated HD at a mean of 539 days of follow-up. The only factors associated with progression to HD within 1 month included use of isovue (p = .005) and elevated contrast volume, with a mean of 40 mL (p = .027). CONCLUSION: Although none of the patients with CKD IV required HD within 1 month after fistulogram, the use of larger iodinated contrast volume was associated with progression to HD within 1 month of fistulography for patients with CKD V. Further studies should investigate the safety of iodinated and alternative (e.g., carbon dioxide) contrast media in fistulography or duplex-based HD access procedures for CKD patients, especially CKD V, not yet on HD.

Impact of tibial bypass conduit on long-term amputation-free survival and primary patency in the Vascular Quality Initiative.

OBJECTIVE: Much research remains focused on tibial bypass conduit selection. We sought to describe long-term amputation-free survival (AFS) and primary patency (PP) of patients undergoing tibial bypass by conduit type and configuration across several permutations in the Society for Vascular Surgery Vascular Quality Initiative. METHODS: Patients in the Vascular Quality Initiative registry undergoing elective first-time femoral- or popliteal-to-tibial bypass for occlusive disease involving rest pain or tissue loss were identified. Prior ipsilateral infrainguinal bypass or concomitant procedures were excluded. Outcomes of interest included patient AFS at 22 months and PP at 1 year (defined as freedom from revision, thrombectomy, or graft occlusion). RESULTS: A total of 4192 bypasses were identified. The majority utilized great saphenous vein (GSV) (76.2%), followed by polytetrafluoroethylene (10.6%), nonautologous biologic (6.5%), composite (3.3%), arm vein (2.8%), and small saphenous vein (0.6%). Compared with all prosthetic and composite bypasses, vein grafts had the best AFS (76.4%; P < .0001) and PP (68.1%; P = .041). Of the single segment vein conduits, GSV bypasses had the best PP (69.1%) and arm vein the worst (60.2%). AFS and PP were similar between single-segment GSV orientations. Single-segment GSV bypasses exhibited better PP than multiple segment bypasses (69.1% vs 54.6%; P = .0016). PP was significantly better for polytetrafluoroethylene compared with nonautologous biologic (68.4% vs 51.2%; P = .0039). PP did not significantly differ between vein cuff for prosthetic bypass compared with no vein cuff (69.1% vs 59.7%; P = .091). PP was not significantly different between single-segment GSV and prosthetic grafts with vein cuff (69.1% vs 69.1%; P = .51). There were no significant differences in AFS comparing arm vein, prosthetic bypass with vein cuff, or composite grafts (67.2% vs 63.8% vs 59.3%; P = .092), as well as in PP (60.2% vs 69.1% vs 54.8%; P = .14). CONCLUSIONS: Single-segment vein bypass was only marginally the most optimal conduit. Surprisingly, there may be more equipoise among conduit types, particularly in the absence of adequate GSV. Prosthetic grafts overall may not be as disadvantaged in the long term as initially thought, especially when compared with arm vein, as prosthetic bypass with vein cuff did not significantly differ in PP. Similarly, a composite conduit may not impact long-term outcomes. These data suggest that conduit choice may not impact outcomes to the degree previously thought and that other factors may have a greater impact than presumed, especially in conduit limited situations.

The current state of vascular surgery presence and educational content in Google and YouTube internet search results.

BACKGROUND: Information on the internet regarding vascular disease has not been extensively assessed. Our goal was to compile and appraise the information available via Google and YouTube searches regarding various topics of interest for vascular surgeons (VS) and related procedures with a focus on the role of the VS. METHODS: The Google and YouTube platforms were independently queried for 25 keywords/phrases relating to common vascular diagnoses and procedures by two separate researchers from March to July 2019. Paid advertisements or a Society for Vascular Surgery (SVS) webpage or affiliated video in the first 25 results was documented. Results were reviewed for information regarding the responsible medical specialty and the target audience, and disease-related information (screening, risk factors, risk reduction, diagnostic testing, operative treatment, alternative treatment, follow-up, complications, and recovery). RESULTS: From the Google search, 357 unique domains of 1241 total webpages were identified with 75% directed toward the public. An SVS page was present in 56% of the first-page results and least likely to be present in searches for claudication, gangrene, carotid stent, rib resection, and thrombolysis. VS were mentioned as referral physicians in 56% of the 68% of websites that mentioned a specialty, endovascular specialists/interventional radiology in 20%, and cardiothoracic surgeons in 19%. Only 4% of the websites contained information from all categories, with the greatest number for aortic dissection. Advertisements were present in 18% of all searches (most commonly for "varicose vein," "varicose vein surgery," and "inferior vena cava filter"). From YouTube, 1247 search results (613 unique videos) were evaluated with 64% directed toward the public. An SVS affiliated video was present in 36% of searches. In the 47% of videos where a specialty was mentioned, 56% mentioned VS, interventional radiology in 10%, and cardiothoracic surgeons in 7%. Only 0.24% of the videos contained information from all categories. The greatest number of content categories was in videos related to peripheral arterial disease. Across both platforms, dialysis access searches yielded results with the least number of content categories. CONCLUSIONS: Patient-related information regarding vascular surgical topics is readily available on the internet, but the content is highly variable and not comprehensive. Only half of the searches mention VS as the referral physician of choice or authority for these medical conditions. Further efforts should focus on developing the online presence of vascular surgery, improving the quality of education of vascular disease on the internet, and directing patients to the vascular specialists to treat these conditions.

Exported Epoxide Hydrolases Modulate Erythrocyte Vasoactive Lipids during Plasmodium falciparum Infection.

Erythrocytes are reservoirs of important epoxide-containing lipid signaling molecules, including epoxyeicosatrienoic acids (EETs). EETs function as vasodilators and anti-inflammatory modulators in the bloodstream. Bioactive EETs are hydrolyzed to less active diols (dihydroxyeicosatrienoic acids) by epoxide hydrolases (EHs). The malaria parasite Plasmodium falciparum infects host red blood cells (RBCs) and exports hundreds of proteins into the RBC compartment. In this study, we show that two parasite epoxide hydrolases, P falciparum epoxide hydrolases 1 (PfEH1) and 2 (PfEH2), both with noncanonical serine nucleophiles, are exported to the periphery of infected RBCs. PfEH1 and PfEH2 were successfully expressed in Escherichia coli, and they hydrolyzed physiologically relevant erythrocyte EETs. Mutations in active site residues of PfEH1 ablated the ability of the enzyme to hydrolyze an epoxide substrate. Overexpression of PfEH1 or PfEH2 in parasite-infected RBCs resulted in a significant alteration in the epoxide fatty acids stored in RBC phospholipids. We hypothesize that the parasite disruption of epoxide-containing signaling lipids leads to perturbed vascular function, creating favorable conditions for binding and sequestration of infected RBCs to the microvascular endothelium. IMPORTANCE: The malaria parasite exports hundreds of proteins into the erythrocyte compartment. However, for most of these proteins, their physiological function is unknown. In this study, we investigate two "hypothetical" proteins of the α/ß-hydrolase fold family that share sequence similarity with epoxide hydrolases (EHs)-enzymes that destroy bioactive epoxides. Altering EH expression in parasite-infected erythrocytes resulted in a significant change in the epoxide fatty acids stored in the host cell. We propose that these EH enzymes may help the parasite to manipulate host blood vessel opening and inflame the vessel walls as they pass through the circulation system. Understanding how the malaria parasite interacts with its host RBCs will aid in our ability to combat this deadly disease.