Implications and late outcomes of type II endoleaks after endovascular aneurysm repair.

OBJECTIVE: Type II endoleaks (T2ELs) are the most common cause of reintervention after endovascular aneurysm repair (EVAR). Although most resolve spontaneously, the long-term implications of T2ELs remain elusive. We aim to evaluate the impact of persistent and late T2ELs on clinical outcomes after EVAR. METHODS: This was a single-institution retrospective review of patients who underwent EVAR for degenerative infrarenal abdominal aortic aneurysm between January 2010 and June 2022 with no type I (T1EL) or III (T3EL) endoleak seen at EVAR completion. Patients were categorized based on T2EL status. Group 1 included patients with never detected or transient T2ELs (detected at EVAR completion but not after). Group 2 encompassed persistent T2ELs (seen at EVAR completion and again during follow-up) and late T2ELs (detected for the first time at any point during follow-up). Time-to-event analysis was conducted using a time-dependent approach to T2EL status. Primary outcomes included freedom from sac enlargement (SE), aneurysm-related reinterventions, and overall survival. RESULTS: A total of 803 patients met inclusion criteria. Group 1 included 418 patients (52%), of which 85% had no T2ELs and 15% had transient T2ELs. Group 2 had 385 patients; 23% had persistent T2ELs, and 77% developed a new T2EL. Patients in group 1 had a higher prevalence of smoking (88% vs 83%; P < .001), chronic obstructive pulmonary disease (33% vs 25%; P = .008), chronic kidney disease (13% vs 8%; P = .021), and a higher mean Society for Vascular Surgery score (7 vs 6 points; P = .049). No differences were found in aneurysm diameter or morphology. Mean follow-up was 5 years for the entire cohort. In Group 2, 58 patients (15%) underwent T2EL treatment, most commonly transarterial embolization. At 10 years after EVAR, Group 2 was associated with lower freedom from SE (P < .001) and abdominal aortic aneurysm-related reinterventions (P < .001) and comparable overall survival (P = .42). More T1ELs were detected during follow-up in Group 2 (6 [1%] vs 20 [5%]; P = .004), with 15 (75%) of these detected at a median of 3 years after the T2EL. No difference between groups was observed in explant (0.7% vs 2.1%; P = .130) or aneurysm rupture (0.5% vs 1.3%; P = .269) rates. CONCLUSIONS: One-half of patients treated with infrarenal EVAR developed persistent/late T2ELs, which are associated with a higher risk of SE and reinterventions. No difference in overall survival or aneurysm rupture risk was seen at 10 years, based on T2EL status or T2EL intervention. A conservative approach to T2ELs may be appropriate for most patients with absent T1ELs or T3ELs.

Dynamic, Time-Resolved Computed Tomography Angiography Technique to Characterize Aortic Endoleak Type, Inflow and Provide Guidance for Targeted Treatment.

PURPOSE: To illustrate dynamic, time-resolved CTA (d-CTA) imaging technique in characterizing aortic endoleak type/inflow using quantitative parameters and its value in providing image guidance for targeted treatment approach. TECHNIQUE: Dedicated endoleak protocol involved acquiring multiple time-resolved contrast enhanced scans using third-generation CT scanner (Somatom Force®, Siemens Healthineers). Parameters such as scan field of view (FOV), kV, number/timing of scans were customized based on patient's body-mass-index, timing bolus, and prior imaging findings. D-CTA image datasets were evaluated qualitatively and quantitatively using time-attenuation curves (TAC) analysis after motion correction using a dedicated software (syngo.via®, Siemens). D-CTA findings from 4 illustrative cases demonstrating type I, type II (inferior mesenteric and lumbar artery inflow), and type III endoleak were illustrated. TAC analysis with time to peak parameter enabled better characterization of endoleak type and inflow. During endoleak intervention, target vessels from d-CTA images were electronically annotated and overlaid on fluoroscopy using 2D-3D image fusion to provide image guidance for targeted treatment. CONCLUSION: D-CTA imaging with TAC analysis characterizes aortic endoleak type and inflow, in addition to providing image guidance for targeted endoleak treatment. Such dynamic, time-resolved imaging techniques may provide further insights into understanding aortic endoleak that remains an Achilles heel for endovascular aortic aneurysm repair.

Factors Influencing Clinical Success Following Endovascular Treatment of Type II Endoleaks.

PURPOSE: To compare long-term outcomes of transarterial (TA) and translumbar (TL) embolization of type II endoleaks (T2E) following EVAR, as well as factors that predict clinical success. METHODS: 129 (mean age, 71.4y; range, 53-95) with T2E referred for embolization from August-2003 to December-2017 were retrospectively reviewed. One-hundred-eighty procedures were performed via TA (n = 139) and TL (n = 41) approaches, with 37 patients undergoing 51 reinterventions. Clinical success was defined as absence of endoleak and/or absence of aneurysm sac enlargement on follow-up imaging. Medical comorbidities, procedural data, embolic agents used, presence of successful sac embolization, and 30-day morbidity and mortality data were collected. RESULTS: TL approaches had higher technical success (41/41 vs.122/139, p = .014). Clinical success rates were 52% (N = 58/111) and 62% (N = 23/37) for TA and TL procedures respectively (p = .34). Looking at all procedures, sac embolization using n-butyl cyanoacrylate glue had higher clinical success compared to other embolic agents (p = .017-.037). Successful sac access was a strong predictor of success for TA procedures (46/78 vs.12/33, p = .0379). 30-day complication rates were similar between TA (5.8%) and TL (4.9%) approaches. There was 1 death secondary to graft infection following TA embolization. CONCLUSIONS: Overall clinical success of TA and TL embolization when considering re-interventions is high. n-butyl cyanoacrylate glue had significantly higher success than other embolic agents (p = .017-.037). Successful sac access was associated with success for TA procedures.

Type IIIb Endoleak: The Great "Masquerader" - Risks of Liquid Agent Dislocation During Sac Embolization Techniques.

The diagnosis of late type III endoleaks may be very challenging on non-invasive imaging studies, and it is not unusual for type IIIb endoleaks to be misdiagnosed as type I endoleaks. The present report illustrates a type III endoleak that was misdiagnosed and treated as Type Ia endoleak. Embolization of the endoleak using a liquid embolic agent (Squid) was complicated by intraluminal graft dislodgement of the liquid agent. This unusual complication was recognised and treated successfully. Type IIIb endoleaks should always be considered in patients with persistent aneurysm sac perfusion treated with embolization using liquid embolic agents.

Aortic graft infection with enteric organism after embolization of late type II endoleak.

An 82-year-old man with a history of endovascular repair for ruptured abdominal aortic aneurysm 6 years ago presented with a type II endoleak and enlarging sac. He had successful transabdominal direct sac puncture embolization but developed fever 2 days postoperatively. Contrast-enhanced computed tomography showed a rim-enhancing collection, and sac aspiration was positive for enteric organisms, confirming endograft infection. The patient underwent graft explantation and neoaortic reconstruction using superficial femoral veins. Three months postoperatively, computed tomography showed complete resolution of fluid collection and no signs of graft infection. This report illustrates direct puncture embolization complicated by endograft infection from enteric bacteria.