Interventional procedure overview of endoanchoring systems in endovascular aortic aneurysm repair

Technical success

In a systematic review of 628 patients, 455 patients had an endoanchoring system used during the primary EVAR procedure (84% for prophylaxis, 15% for intraoperative endoleak and 1% for graft maldeployment). The weighted mean technical success was 98% (95% CI 96% to 100%; Qamhawi, 2020).

In a systematic review of 968 patients who had endoanchors placed during an initial EVAR, technical success was 97% (95% CI 93% to 100%; I²=67%, p=0.01; Karaolanis, 2020).

In a cohort study of 319 patients, technical success was 96% in the 242 patients who had an endoanchoring system used during the primary EVAR procedure (Jordan, 2014). In a cohort study of 221 patients, including 175 who had an endoanchoring system used during the primary EVAR procedure, initial technical success was 89% (197/221), 30‑day and follow up technical success was 96% (211/221; Valdivia, 2021).

In a single-arm study of 155 patients, successful device delivery was reported in 99% (153/155) of patients. One patient had conversion to open surgical repair before the endoanchors were placed and the second patient had a different endovascular device placed (Mehta, 2014).

In a case series of 86 patients, including 61 who had an endoanchoring system used during a primary procedure, 29% (170/580) of endoanchors were maldeployed (Goudeketting, 2019).

Type 1a endoleak

In the systematic review of 628 patients, the weighted mean proportion of patients with type 1a endoleak after primary fixation during EVAR was 4% (95% CI 2% to 6%) with a mean follow up of 15.4 months (Qamhawi, 2020).

In the systematic review of 968 patients, the incidence of type 1a endoleak was 6% (95% CI 1% to 15%; I²=90%, p=0.00) during a mean follow up of 6 months (Karaolanis, 2020).

In the cohort study of 319 patients, 92% of patients in the primary treatment group did not have type 1a endoleak at completion angiography (Jordan, 2014). In the cohort of 221 patients, 96% in the primary treatment group did not have type 1a endoleak at 24 months (Valdivia, 2021).

In the single-arm study of 155 patients, 1 patient had a type 1 endoleak in the first year of follow up. The primary effectiveness end point (composite of delivery success and absence of type 1 or type 3 endoleaks needing intervention after the index procedure, migration, open surgical conversion, or aneurysm rupture within 1 year of the index procedure) was met by 97% (151/155) of patients (Mehta, 2014).

Graft migration

In the systematic review of 628 patients, the weighted mean proportion of patients with graft migration after primary fixation during EVAR was 2% (95% CI 0.1% to 6%) with a mean follow up of 15.4 months (Qamhawi, 2020).

In the systematic review of 968 patients, the rate of graft migration was 0.3% (95% CI 0.0% to 2%; I²=0%) with a mean follow up of 10 months (Karaolanis, 2020).

In the single-arm study of 155 patients, endograft migration of more than 1 cm was reported in 3% (5/155) of patients (Mehta, 2014).

Change in aneurysm size

In the systematic review of 968 patients, expansion of the aneurysmal sac was reported in 2% of patients (95% CI 1% to 3%, I²=0%). Regression of the aneurysmal sac was reported in 69% of patients (95% CI 51% to 84%, I²=95%; Karaolanis, 2020).

In the non-randomised comparative study, freedom from aneurysm enlargement at 1 year was 97% in the endoanchor group and 96% in the control group (p=0.89). At 2 years it was 97% in the endoanchor group and 94% in the control group (p=0.67). The cumulative incidence of aneurysm sac regression at 1 year was 54% in the endoanchor group and 32% in the control group (p=0.03). At 2 years it was 81% in the endoanchor group and 49% in the control group (p=0.01; Muhs, 2018).

In the cohort study of 221 patients, 180 patients had at least 6 months of imaging follow up. Of these, 41% showed sac regression, 51% remained stable and sac growth was reported in 8% of patients (Valdivia, 2021).

In the single-arm study of 155 patients, aneurysm sac diameter had decreased by more than 5 cm in 44% (62/140) of patients at 6 months, 60% (79/131) at 1 year, 73% (78/107) at 2 years and 82% (67/82) at 3 years. The diameter increased by more than 5 cm in 1% (1/140) of patients at 6 months, 2% (2/131) at 1 year, 3% (3/107) at 2 years and 4% (3/82) at 3 years (Mehta, 2014).

Reintervention

In the systematic review of 628 patients, there were 136 aneurysm related interventions in the 455 patients who had primary fixation; 90% (122) of these were in 74 patients in a single study. There were 3 reinterventions for endoanchor failure (Qamhawi, 2020).

In the systematic review of 968 patients, freedom from aneurysm-related reintervention was 98% (95% CI 95 to 99%), with a mean follow up of 10 months (Karaolanis, 2020).

In the cohort study of 319 patients, 3% (7/242) of patients in the primary treatment group had a secondary intervention during a mean follow up of 9.3 months. Of the 7 secondary interventions, there was 1 repair of a type 1a endoleak and 1 treatment of type 2 endoleak. There were no interventions for migration (Jordan, 2014). In the cohort of 221 patients, freedom from neck related reinterventions was 98% and freedom from any reintervention was 87% at 24 months (Valdivia, 2021).

In the single-arm study of 155 patients, 48% (74/221) of patients had a total of 122 secondary interventions, 92 of which were in patients with thrombus-related events (Mehta, 2014).

Survival

In the systematic review of 968 patients, overall survival was 93% (95% CI 90% to 96%; Karaolanis, 2020).

In the cohort of 221 patients, freedom from all-cause mortality was 89% and freedom from aneurysm-related mortality was 98% at 24 months (Valdivia, 2021).

In the single-arm study of 155 patients, overall survival at 1, 2 and 3 years was 97%, 96% and 92% respectively. Freedom from aneurysm-related mortality was 99% (Mehta, 2014).

Technical success

In a systematic review of 628 patients, 107 patients had an endoanchoring system used during a secondary procedure (56% for type 1a endoleak alone, 11% for graft migration and 33% for type 1 endoleak, graft migration, or both). The weighted mean technical success was 92% (95% CI 86% to 96%; Qamhawi, 2020).

In the cohort study of 319 patients, technical success was 91% in the 77 patients who had an endoanchoring system used during a revision procedure (Jordan, 2014).

Type 1a endoleak

In the systematic review of 628 patients, the weighted mean proportion of patients with type 1a endoleak after secondary fixation was 23% (95% CI 9% to 40%) with a mean follow up of 10.7 months (Qamhawi, 2020).

In a non-randomised comparative study of 198 patients who had EVAR with or without an endoanchoring system, freedom from type 1a endoleak at 1 and 2 years was 97% for the endoanchor group and 94% for the control group (p=0.34; Muhs, 2018).

In the cohort study of 319 patients, 87% of patients in the revision treatment group were free from type 1a endoleak at completion angiography (Jordan, 2014).

Graft migration

In the systematic review of 628 patients, there were no reports of graft migration after secondary fixation with a mean follow up of 10.7 months (Qamhawi, 2020). In the non-randomised comparative study of 198 patients, there was no migration more than 10 mm in either treatment group within 2 years (Muhs, 2018).

Reintervention

In the systematic review of 628 patients, there were 13 aneurysm-related interventions in the 107 patients who had secondary fixation. There were 8 reinterventions for endoanchor failure (Qamhawi, 2020).

In the cohort study of 319 patients, there were 11 secondary interventions in 7 patients (9%) in the revision treatment group. These included 7 repairs of a type 1a endoleak and 4 treatments for type 2 endoleak. There were no secondary interventions for migration (Jordan, 2014).