Antithrombotic Therapy for Aortic Aneurysms: A Systematic Review and Meta-Analysis.

OBJECTIVES: The role of antithrombotic therapy in the management of aortic and peripheral aneurysms is unclear. This systematic review and meta-analysis aimed to assess the impact of antithrombotics on clinical outcomes for aortic and peripheral aneurysms. METHODS: Medline, Embase, and CENTRAL databases were searched. Randomised controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with any aortic or peripheral artery aneurysm were included. RESULTS: Fifty-nine studies (28 with antiplatelet agents, 12 anticoagulants, two intra-operative heparin, and 16 any antithrombotic agent) involving 122 102 patients were included. Abdominal aortic aneurysm (AAA) growth rate was not significantly associated with the use of antiplatelet therapy (SMD -0.36 mm/year; 95% CI -0.75 - 0.02; p = .060; GRADE certainty: very low). Antithrombotics were associated with increased 30 day mortality for patients with AAAs undergoing intervention (OR 2.30; 95% CI 1.51 - 3.51; p < .001; GRADE certainty: low). Following intervention, antiplatelet therapy was associated with reduced long term all cause mortality (HR 0.84; 95% CI 0.76 - 0.92; p < .001; GRADE certainty: moderate), whilst anticoagulants were associated with increased all cause mortality (HR 1.64; 95% CI 1.14 - 2.37; p = .008; GRADE certainty: very low), endoleak within three years (OR 1.99; 95% CI 1.10 - 3.60; p = .020; I2 = 60%; GRADE certainty: very low), and an increased re-intervention rate at one year (OR 3.25; 95% CI 1.82 - 5.82; p < .001; I2 = 35%; GRADE certainty: moderate). Five studies examined antithrombotic therapy for popliteal aneurysms. Meta-analysis was not possible due to heterogeneity. CONCLUSIONS: There was a lack of high quality data examining antithrombotic therapy for patients with aneurysms. Antiplatelet therapy was associated with a reduction in post-intervention all cause mortality for AAA, whilst anticoagulants were associated with an increased risk of all cause mortality, endoleak, and re-intervention. Large, well designed trials are still required to determine the therapeutic benefits of antithrombotic agents in this setting.

The Triple Wire Technique for Delivery of Endovascular Components in Difficult Anatomy.

We describe a novel endovascular technique in which three 0.014″ guidewires are placed in parallel through a 0.035″ lumen catheter, in order to create a stiff platform to allow for delivery of 0.035″ profile devices through challenging anatomy. Three illustrative cases are presented: a difficult aortic bifurcation during lower extremity intervention, a tortuous internal iliac artery during placement of an iliac branch device, and salvage of a renal artery after inadvertent coverage during proximal cuff deployment for type 1a endoleak. We also quantify the relative stiffness of the triple 0.014″ wire configuration, using several well-known 0.035″ wires for comparison. The "triple wire technique" is an effective method for tracking endovascular devices through difficult tortuous anatomy, and can be used in a variety of clinical settings. The technique is especially useful when a traditional, stiff 0.035″ wire will not track without "kicking out." Each 0.014″ wire is reasonably soft and traverses the tortuous vessel easily, but when the 3 wires are used together as a rail it provides a stiff enough platform for delivery.

Translumbar Infusion of N-Butyl Cyanoacrylate for the Treatment of Type II Endoleaks.

PURPOSE: To evaluate long-term efficacy of translumbar embolization of type II endoleaks exclusively supplied by the lumbar arteries in patients with growing abdominal aortic aneurysm sacs using N-butyl cyanoacrylate (NBCA) instilled via percutaneous needle access. MATERIALS AND METHODS: The study included 25 patients who developed type II endoleak after endovascular aneurysm repair. Inclusion criteria for intervention were defined as sac expansion > 5 mm detected with CT angiography at 6-month follow-up or later. Translumbar infusion of NBCA directly into the patent portion of the aneurysm sac was performed in all cases. Duplex US was performed the day after the intervention, and CT angiography was performed within the first month. Subsequently, duplex US was performed at 3, 6, and 9 months, and CT angiography or CT was performed at 12 months and annually thereafter. RESULTS: Translumbar embolization was achieved in all 25 patients. The endoleak resolved in 22 patients (88%) on duplex US performed 1 day after the embolization procedure. Three patients with persistent endoleak (12%) required repeat embolization. Two complications were detected and were managed conservatively. CONCLUSIONS: This study demonstrates the safety and efficacy of NBCA injection for treatment of type II endoleaks. This technique provides another option for the management of type II endoleaks.

Evidence for Ethylene-Vinyl-Alcohol-Copolymer Liquid Embolic Agent as a Monotherapy in Treatment of Endoleaks.

OBJECTIVE: Endoleak remains the Achilles heel of endovascular aneurysm repair and the exclusion of Type II endoleaks, in particular, remains challenging. This systematic review presents the evidence for ethylene-vinyl-alcohol-copolymer liquid embolic agent as a monotherapy in the treatment of endoleaks. METHODS: A systematic literature search was performed for all studies reporting the use of liquid embolic agent as a sole agent in the treatment of endoleaks. Patient numbers, clinical details (endoleak type, route of delivery) and outcome in terms of survival, technical and clinical success with freedom from endoleak together with follow-up period were examined. RESULTS: Only 12 articles reporting the use of liquid embolic as the sole treatment modality for endoleaks in 174 patients were identified. All but 21 patients had a Type II endoleak. Transarterial embolization was attempted in 73% of patients with 48 patients having direct sac puncture. Technical success was high at 96%, but in patients with adequate imaging, the clinical success rate dropped to 79%. Complications were sparsely reported and follow-up ranged from 0 to 75 months. CONCLUSIONS: This review highlights the lack of data regarding the use of liquid embolic agent as a monotherapy with only 4 studies including more than 10 patients. Data from the largest series suggests a learning curve exists and no study reports on cost effectiveness. Technical success does not always translate into clinical success and with the largest series only reporting median 4-month follow-up no claims regarding durability can be made. In problematic Type II endoleaks, however, liquid embolic agent is a welcome addition to the treatment armamentarium.

The use of an anti-fibrinolytic agent to reduce endoleak following endovascular repair of multiple aortic aneurysms.

This paper reports on the therapeutic use of tranexamic acid in an elderly patient with severe comorbidities that precluded even endovascular reintervention. Orally administered tranexamic acid mitigated and partially reversed two and a half years of progressive aneurysmal expansion and closed a persistent endoleak after thoracic endovascular aneurysm repair and endovascular aneurysm repair for coexisting lesions. Reappearance of the endoleak when tranexamic acid was accidentally stopped and its re-closure after the resumption of tranexamic acid treatment confirmed causality. This singular experience extends prior published observations that administration of prophylactic tranexamic acid before thoracic endovascular aneurysm repair and endovascular aneurysm repair resulted in significantly greater shrinkage, particularly if an endoleak or coagulopathy was present.

A case of hybrid repair of ruptured abdominal aortic aneurysm with use of thrombin for acute treatment of type II endoleak.

Endovascular repair for ruptured abdominal aortic aneurysm has demonstrated superior results when compared with open repair and will likely become the standard of care when the anatomy of the aneurysm is appropriate for endovascular repair.