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Objective: Abdominal aortic aneurysm (AAA) is a life-threatening disease, and the only curative treatment relies on open or endovascular repair. The decision to treat relies on the evaluation of the risk of AAA growth and rupture, which can be difficult to assess in practice. Artificial intelligence (AI) has revealed new insights into the management of cardiovascular diseases, but its application in AAA has so far been poorly described. The aim of this review was to summarize the current knowledge on the potential applications of AI in patients with AAA., Methods: A comprehensive literature review was performed. The MEDLINE database was searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search strategy used a combination of keywords and included studies using AI in patients with AAA published between May 2019 and January 2000. Two authors independently screened titles and abstracts and performed data extraction. The search of published literature identified 34 studies with distinct methodologies, aims, and study designs., Results: AI was used in patients with AAA to improve image segmentation and for quantitative analysis and characterization of AAA morphology, geometry, and fluid dynamics. AI allowed computation of large data sets to identify patterns that may be predictive of AAA growth and rupture. Several predictive and prognostic programs were also developed to assess patients' postoperative outcomes, including mortality and complications after endovascular aneurysm repair., Conclusions: AI represents a useful tool in the interpretation and analysis of AAA imaging by enabling automatic quantitative measurements and morphologic characterization. It could be used to help surgeons in preoperative planning. AI-driven data management may lead to the development of computational programs for the prediction of AAA evolution and risk of rupture as well as postoperative outcomes. AI could also be used to better evaluate the indications and types of surgical treatment and to plan the postoperative follow-up. AI represents an attractive tool for decision-making and may facilitate development of personalized therapeutic approaches for patients with AAA., (Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Abdominal aortic aneurysm (AAA) is a life-threatening disease and pharmacologic agents to treat the disease remain lacking for clinical practice. Epidemiologic studies have highlighted a negative association between the use of antidiabetic drugs, including metformin, and AAA. Metformin is well-known for its blood glucose-lowering effect, but its action on both metabolism and inflammatory response has led to propose it as a potential therapeutic target in several cardiovascular diseases. In this review, we summarize the current knowledge on the link between metformin and AAA. Based on the known effects of the drug on the aortic wall, translational applications and clinical trials investigating the interest of metformin in the management of patients with AAA are discussed., (Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Macrophages play a critical role in the initiation and progression of abdominal aortic aneurysm (AAA) and are classically distinguished into M1 "proinflammatory" and M2 "anti-inflammatory" macrophages. Topical application of elastase associated with transforming growth factor β (TGF-β) systemic neutralization reproduces the main pathologic features of human AAA, offering a new model to investigate their role. The aim of this study was to investigate whether macrophages contribute to the expression of canonical M1/M2 markers in the aorta in the AAA model induced by elastase and systemic blockade of TGF-β and whether blocking of TGF-β activity affects macrophage phenotype and the expression of the M2 marker arginase 1 (ARG1)., Methods: C57Bl/6J male mice (6-8 weeks old) were randomly assigned to three experimental groups: mice that had local application of heat-inactivated elastase or elastase and mice that had elastase application and received injection of anti-TGF-β (elastase + anti-TGF-β group). Monocyte-macrophage depletion was achieved in the elastase + anti-TGF-β group using liposome clodronate. Macrophage phenotype was characterized by quantitative polymerase chain reaction, flow cytometry, and immunohistochemistry. Human infrarenal AAA tissues (n = 10) were obtained to analyze ARG1 expression., Results: Analysis of gene expression in the infrarenal aortic wall revealed that after 14 days, no significant difference for the expression of CCL2, NOS2, and Ym1/2 was observed in the elastase group compared with the elastase + anti-TGF-β group, whereas the expression of ARG1, interleukin (IL) 1β, and IL-6 was significantly increased. Macrophage depletion in the elastase + anti-TGF-β group led to a significant decrease of IL-1β, IL-6, ARG1, and Ym1/2 gene expression. Immunofluorescent staining confirmed that TGF-β neutralization significantly enhanced ARG1 protein expression in the aneurysmal tissue. Flow cytometry analysis revealed an increase of macrophages expressing ARG1 in the aorta of mice treated with elastase + anti-TGF-β compared with the elastase group, and their proportion increased with aneurysmal dilation. In humans, ARG1 protein expression was increased in aneurysmal tissues compared with controls, and positive cells were mainly found in the adventitia., Conclusions: TGF-β neutralization finely tunes macrophage phenotype in elastase-induced AAA and leads to an increase in ARG1 gene and protein expression in the aortic wall. Even if further studies are required to elucidate its role in AAA development, ARG1 could represent a new prognostic or therapeutic target in aneurysmal disease., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Although the end cephalic vein-to-side radial artery arteriovenous fistula is the "gold standard" procedure for primary hemodialysis access, it is associated with high rates of primary failure because of the development of neointimal hyperplasia and juxta-anastomotic stenosis. We report initial results of a new approach to perform radial-cephalic fistulas, radial artery deviation and reimplantation (RADAR), designed to avoid juxta-anastomotic stenosis., Methods: RADAR patients' data were prospectively maintained and retrospectively reviewed and compared with a historical control group of traditional radial-cephalic fistulas created in the same center. Duplex ultrasound was used to monitor maturation (flow ≥500 mL/min and venous diameter ≥5 mm) and to diagnose juxta-anastomotic stenosis. Study end points were rates of maturation, juxta-anastomotic stenosis, reintervention, and primary and secondary patency., Results: There were 53 RADAR fistulas performed (follow-up, 10.5 ± 2.6 months) and compared with 73 control fistulas (follow-up, 12.0 ± 6.6 months). RADAR fistulas had increased rates of maturation compared with control fistulas (75% vs 45% at 6 weeks, P = .001; 92% vs 71% at 3 months, P = .003) and decreased incidence of juxta-anastomotic venous stenoses (2% vs 41%; P = .001). At 6 months, RADAR fistulas had increased primary patency (93% vs 53%; P < .0001) and secondary patency (100% vs 89%; P = .0003) and decreased incidence of reinterventions (10% vs 74%; P = .001) compared with control fistulas. No RADAR fistulas caused ischemic symptoms., Conclusions: The RADAR technique is associated with less juxta-anastomotic stenosis, increased maturation and patency, and fewer secondary interventions. These improved outcomes suggest that RADAR may be the preferred surgical technique to perform radial-cephalic arteriovenous fistula., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Although radial-cephalic (RC) and brachial-cephalic (BC) fistulas are the recommended primary accesses for hemodialysis, access failure is frequently due to juxta-anastomotic stenosis (JAS). Because increased turbulence at the anastomosis may lead to JAS, we hypothesized that an acute angle at the arteriovenous anastomosis is associated with JAS, reduced fistula patency, and increased reinterventions., Methods: Between February 2013 and September 2014, the anastomotic angle and vessel diameters were prospectively collected for all patients who underwent RC or BC fistula creation. The primary end point was reintervention on the juxta-anastomotic segment. Secondary end points were primary and secondary patency of the fistula., Results: A total of 149 patients (median age, 72 years) received 73 RC and 76 BC fistulas; the median follow-up was 7 months (range, 1-22 months) for RC and 12 months (range, 2-24 months) for BC fistulas. The median anastomotic angle in RC fistulas, was 30°. Anastomotic angles of <30° were associated with reduced primary patency (38% vs 66%, P = .003) and secondary patency (84% vs 97%, P = .02) and increased numbers of reinterventions (67% vs 34%, P = .001). Cox analysis showed that an anastomotic angle of <30° was an independent factor predicting decreased primary patency (P = .009) and secondary patency (P = .03) as well as increased reinterventions (P = .004). In BC fistulas, the median anastomotic angle was 90°. Patients with anastomotic angles <90° and ≥90° had similar rates of primary patency (67% vs 67%, P = .39) and secondary patency (93% vs 94%, P = .89) at 6 months, with a similar reintervention rate at 12 months (31% vs 32%, P = .56). Vein diameter was the only factor that predicted reintervention (P < .0001)., Conclusions: RC fistulas with anastomotic angles of <30° have reduced primary and secondary patency and increased numbers of reinterventions, suggesting that, if possible, surgeons should avoid an anastomotic angle of <30° when creating RC fistulas. Anastomotic angles of <90° or ≥90° may not play a role in outcome of BC fistulas., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to analyze the pelvic ischemic complications and their impact on quality of life after interventional occlusion of the hypogastric artery (IOHA) in patients undergoing endovascular aortic aneurysm repair (EVAR)., Methods: Between January 2004 and April 2012, 638 consecutive patients with aortoiliac aneurysm treated by EVAR were prospectively registered in two teaching hospitals. We identified all EVAR patients who underwent IOHA. Demographic, clinical, and radiologic data were extracted from electronic databases and patient records as requested. All patients who survived the postoperative period took part in a quality of life survey, the Walking Impairment Questionnaire (WIQ), which included four items: pain, distance, walking speed, and stair climbing. Outcome measures included the 30-day rate of pelvic ischemic complications, the buttock claudication (BC) rate at 30 days and during follow-up, and the comparative WIQ scores between patients with persistent BC, those with regressive BC, and those who never had BC after the IOHA procedure., Results: A total of 71 patients (97% men; mean age, 76 years ± 7.69) required 75 IOHA procedures. These were deemed proximal in 44 cases and distal in 31, with use of coil embolization in 64%, Amplatzer plug in 24%, or a combination of coils and plugs in 12%. The technical success rate was 100%. Two patients (2.8%) experienced fatal acute pelvic ischemic complications in the postoperative period after EVAR. Another patient died of iliac rupture during EVAR, leading to an operative mortality rate of 4.3%. Eighteen patients (25.3%) suffered BC, among whom 11 cases resolved at a median follow-up of 42 months. Young age (odds ratio, 0.92; 95% confidence interval, 0.85-0.99; P = .03) and distal IOHA (odds ratio, 3.5; 95% confidence interval, 1.01-11.51; P = .04) were independent predictors of BC occurrence. The actuarial rate of persistent BC was 85% at 18 months. The WIQ scores were lower for patients with persistent BC (median score, 35.04; interquartile range, 16.36; P = .001) compared with patients with regressive BC (median score, 76.5; interquartile range, 36.66; P = .02) or those who never experienced BC after the IOHA procedure (median score, 65.34; interquartile range, 10.94; P < .0003)., Conclusions: Pelvic ischemia associated with IOHA may be severe and lead to fatality after EVAR. Our data show that BC may lead to severe quality of life impairment when it does not regress during follow-up., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: The timing and urgency of salvage attempts for acutely thrombosed hemodialysis vascular accesses remain poorly defined. We examined the outcome of early surgical thrombectomy after acute access thrombosis to assess the influence of expedited timing on access salvage., Methods: Between January 2007 and October 2012, 114 surgical thrombectomy attempts were performed on 82 patients to salvage 89 accesses. The time between the diagnosis of thrombosis and admission to the operative suite (T1), the time between diagnosis and the following dialysis session (T2), and clinical and biologic parameters were collected prospectively. Data were retrospectively compared between the early (T1 <6 hours) and later (T1 >6 hours) treatment groups. The main outcome measure was technical success. Kaplan-Meier survival analysis was used to estimate functional patency rates., Results: Mean patient follow-up was 22 ± 18 months. The mean time from referral to procedure (T1) was 5.7 ± 4.5 hours. The mean time T1 was 3.6 ± 1.2 hours in the early group and 10.3 ± 5.4 hours in the later group. The mean time to dialysis (T2) was 14.3 ± 6.5 hours in the early group and 23.9 ± 9.4 hours in the later group. Thrombectomy performed ≤ 6 hours after diagnosis (T1 <6 hours) had significantly higher technical success of 86% compared with 69% for thrombectomy performed later (T1 >6 hours; P = .04). The two groups did not differ significantly in patient comorbidities, type of access, or adjunctive procedures performed (P ≥ .1). At 12 months, the primary patency rate for all index cases, including technical failures, was 55% ± 7.1% in the early group and 33% ± 9.7% in the later group (P = .13). The secondary patency rate was 67% ± 6.8% in the early group and 50% ± 9.9% in the later group (P = .05)., Conclusions: After acute access thrombosis, early surgical thrombectomy was associated with higher technical success and potentially improved midterm patency., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: To investigate the mode of presentation, diagnosis, association with other aneurysms, operative management, and outcomes of superficial femoral artery (SFA) aneurysms., Methods: Records of all patients who underwent surgery for isolated, true SFA aneurysms (not due to infection, vasculitis, or tissue disorders) from 2002 to 2012 in two European centers were retrospectively analyzed. Demographic (sex, age), clinical (cardiovascular risk factors, location of the aneurysm, symptoms, presentation, emergency setting), surgical and radiological data (diameter, surgical technique, runoff vessels patency, presence of aneurysms elsewhere) were obtained for analysis. Follow-up was undertaken with clinical and ultrasound examinations at 1 month, 3 months, 6 months, 12 months, and yearly thereafter. The patency of the graft and the status of the anastomoses and inflow and outflow vessels were assessed. Main end points were represented by 30 days and long-term mortality and amputation-free survival., Results: A total of 27 cases of SFA aneurysm were analyzed. Mean age at operation was 78 years ± 8.5. At presentation, SFA aneurysms were often symptomatic (rupture was present in 7/27 cases and acute distal ischemia in 6/27 cases), large (mean diameter, 54 mm ± 33.1 mm), bilateral (38% of the cases), and associated with aneurysms elsewhere (84%). Sixteen patients underwent resection of the aneurysm and polytetrafluoroethylene interposition graft, seven patients exclusion of the aneurysm with a femoropopliteal bypass (autogenous bypass in five cases, prosthetic in two), three patients simple ligation, and one patient underwent primary amputation. Mean follow-up was 41.47 months (range, 0.43-128.67 months). Early (<30 days) mortality and amputation rate were 4% and 7%, respectively. Estimated 5-year survival, limb salvage, and graft patency rates were 62%, 88%, and 85%, respectively., Conclusions: Degenerative aneurysms of the SFA display peculiar characteristics (in terms of clinical onset, diagnostic timing, and clinical behavior) so that they differ from other peripheral aneurysms. In fact, they often grow to reach a considerable diameter before medical attention is sought, presenting with rupture or ischemia at diagnosis. SFA aneurysms preferentially affect elderly men and are often associated with aneurysms elsewhere. However, despite their rarity, the treatment is usually feasible, and long-term outcomes are good., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

The authors report three cases of transient and recurrent paraplegia due to compression of the second right lumbar artery by the diaphragmatic crus. Circumstances of appearance are suggestive when paraplegia occurs in dorsolumbar hyperlordosis and low cardiac output is an associated hemodynamic risk factor. Selective medullary arteriography is indispensable for diagnosis and can demonstrate three signs: an anterior spinal dorsolumbar artery (artery of Adamkiewicz) that does not descend to the conus medullaris; posterior spinal arteries arising from the second lumbar arteries that vascularize the conus medullaris; existence of a tight stenosis on the second right lumbar artery that is aggravated during dynamic maneuvers. Section of the right diaphragmatic crus and release of the second right lumbar artery from the aorta to the fibrous arcade of the psoas permits definitive cure of symptoms.

Purpose: This study reports our midterm results with arteriovenous axillary loop grafts (AVALG) and evaluates their role in construction of vascular access for patients on chronic hemodialysis., Methods: The clinical data of 27 patients who underwent construction of an AVALG for hemodialysis access at our institution between July 2002 and December 2006 were analyzed retrospectively. Outcome measures included graft patency, the complication rate, and the frequency and morbidity of secondary procedures after AVALG creation. The Kaplan-Meier method was used to calculate the primary and secondary patency curves., Results: AVALG was constructed as the first access procedure in eight patients: five patients with no suitable vein to construct an adequate angioaccess on the upper limbs, and three patients with elbow and forearm arteritis. The 19 other patients had all had two to five failed prior vascular accesses leading to exhaustion of venous access sites on the upper extremities (18 cases), or a steal syndrome (one case). No postoperative death occurred, but four patients died of causes unrelated to the intervention between the second and the tenth postoperative months. The mean follow-up was 15 months (range, 2-48 months). The primary patency rate at 12 months and the secondary patency rate at 18 months were 51% and 80%, respectively. Infection (three cases), thrombosis (seven cases), and stenosis of the outflow vein (two cases) were the main complications, occurring in 10 of the 27 patients (41%). Twelve secondary procedures were performed in these 10 patients with little additional morbidity. Five of the 27 patients developed irreversible AVALG occlusion leading to access loss: two patients with concomitant graft infection and three patients with a history of subclavian vein catheterization., Conclusion: AVALG may represent a supplementary option for chronic hemodialysis patients with vascular steal or inadequate upper extremity venous access sites.