Comparison of Pipeline Embolization and Coil Embolization for the Treatment of Large Unruptured Paraclinoid Aneurysms

The efficacy of flow diversion (FD) in the treatment of paraclinoid aneurysms has been established. The pipeline embolization device (PED) is one of the most commonly used FD devices. Coil embolization is also useful for treating paraclinoid aneurysms. This study aimed to compare the efficacy and safety of PED treatment and coil embolization for large unruptured paraclinoid aneurysms. This was a single-center, retrospective study of large unruptured paraclinoid aneurysms treated endovascularly between 2009 and 2019 (coil embolization between 2009 and 2015, and PED between 2015 and 2019). Cases with a follow-up period of less than 1 year and recurrence after coil embolization were excluded. The treatment outcomes between coil embolization and PED were compared. We investigated 45 patients with 45 large unruptured paraclinoid aneurysms treated by endovascular surgery in our institution. Twenty-four patients were treated with coil embolization and 21 with PED. In the PED group, the device cost was significantly lower (2,770.4 ± 699.5 vs. 1941.2 ± 552.8 [1000 yen], P = 0.03), procedure duration was significantly shorter (155.4 ± 66.7 vs. 95.1 ± 35.4 min, P <0.01), and the numbers of re-treatments were lower than those in the coil embolization group (41.7 vs. 14.3%, P = 0.05). Both PED and coil embolization were effective and safe for large unruptured paraclinoid aneurysms, and their treatment results were similar. The PED is more beneficial because of its lower cost, shorter procedure duration, and fewer retreatments, and is therefore more useful for the treatment of large unruptured paraclinoid aneurysms.