Anatomic characteristics of abdominal aortic aneurysms presenting with delayed rupture after endovascular aneurysm repair.

Objective: Endovascular aneurysm repair (EVAR) has become the mainstay of treatment for abdominal aortic aneurysms (AAAs) requiring repair. Delayed rupture after EVAR represents a rare but potentially fatal complication. The purpose of this study was to review the frequency and characteristics of patients presenting with secondary rupture and to define the relationship between rupture after EVAR and initial compliance with instructions for use (IFU).

Methods: This is a retrospective study of a prospectively maintained database. Patients presenting with delayed rupture after EVAR were identified from January 2002 to December 2014. Medical records and imaging were reviewed to define anatomic characteristics and compliance with IFU criteria. Demographics, comorbidities, preoperative imaging, and long-term outcomes were analyzed. Patients were divided into two groups according to compliance with IFU criteria. Outcomes included type of repair (open vs secondary endovascular) as well as perioperative morbidity and mortality.

Results: A total of 3081 patients underwent EVAR for AAA from 2002 to 2014. Of the 3081 patients, 45 experienced delayed rupture after EVAR. The mean time interval between initial repair and rupture was 38 months. All patients with delayed ruptures had a type Ia endoleak. Mean follow-up after secondary repair was 44.1 months, and overall mortality was 6.7% (n = 3). Patients were divided in two groups according to compliance with IFU criteria: within the IFU and outside the IFU. There was no significant difference in comorbidities between the two groups except smoking, which was more frequent in the outside the IFU group (25% vs 21%; P = .03). Patients repaired outside the IFU had a higher incidence of type Ia endoleak before presenting with a rupture (44% vs 6%; P = .001), more frequently required open repair (44% vs 12%; P = .002), and had higher perioperative mortality (10.3% vs 0%; P = .01). On review of preoperative computed tomography scans, the outside the IFU group had larger aneurysm sac diameters (7.2 vs 5.6 cm; P = .04), larger proximal neck diameters (28 vs 24 mm; P = .01), shorter proximal necks (12 vs 21 mm; P = .007), and a higher degree of neck angulation >40 degrees (56 vs 11%; P < .001).

Conclusions: Delayed rupture after EVAR is a rare but potentially fatal complication. In patients presenting with secondary rupture, EVAR performed outside the IFU was associated with higher perioperative mortality and need for open repair. Careful selection of patients based on AAA anatomy and adherence to the IFU criteria may reduce the incidence of delayed rupture.