Spontaneous Type Ia Endoleak Sealing in Patients Undergoing Endovascular Aneurysm Repair With the Ovation Stent Graft

Type Ia endoleak may lead to continuous sac pressurization and late rupture after endovascular aneurysm repair (EVAR). Nevertheless, there have been scarce reports suggesting that these endoleaks may occasionally present spontaneous sealing. Taking into account the original sealing mechanism of the Ovation endograft that exploits 2 polymer-filled O-rings, we hypothesize that spontaneous type Ia endoleak sealing may sometimes incur following implantation of this device. We aim to report our experience with spontaneous type Ia endoleak sealing in patients treated with the Ovation endograft. This is a retrospective observational study which included all patients undergoing EVAR with the Ovation endograft in a single institution during a 6-year period. Patients with an intraoperative type Ia endoleak were identified. The primary endpoint was rate of spontaneous sealing. Secondary endpoints were migration, sac expansion, need for reinterventions, secondary type Ia endoleaks, and aneurysm-related and overall mortality. Adherence to the instructions for use (IFU) was evaluated to examine relation with occurrence of endoleak and rates of spontaneous sealing. Among 147 patients treated, 8 (5%) left the operation theater with a type Ia endoleak. In 6 patients, the endoleak spontaneously resolved during a maximum of 3 months of follow-up. Among those, 5 cases were treated outside the IFU (2 short necks and 3 with severe angulation), while the sixth was a patient treated inside the IFU but was anticoagulated. In 2 patients, the endoleak did not spontaneously resolve. One presented a conical neck of marginal length and the other circumferential calcifications. Type Ia endoleak was significantly more common among patients treated in an off-label fashion. Spontaneous sealing of type Ia endoleak is common after EVAR with the Ovation endograft. Nonadherence to the IFU results in more endoleaks, but it does not seem to reduce possibilities for spontaneous sealing.