In a cadaveric model, the endoscopic LTO approach affords a direct route to access MC. Its main advantage is that it is minimally disruptive in nature, less brain retraction is required, and it reaches the middle fossa in an anterolateral perspective. It also requires no manipulation of the temporalis muscle, limited cosmetic incision, and rapid recovery. It seems a viable alternative to traditional approaches for lesions lateral to the cranial nerves at the cavernous sinus and MC, that is, schwannomas. Clinical utilization of this approach will challenge its efficacy and identify limitations.

OBJECTIVEThe utilization of the Pipeline embolization device (PED) has increased significantly since its inception and original approval for use in large, broad-necked aneurysms of the internal carotid artery. While microsurgical clipping and advances in endovascular techniques have improved overall efficacy in achieving complete occlusion, recurrences still occur, and the best modality for retreatment remains controversial. Despite its efficacy in this setting, the role of PED utilization in the setting of recurrent aneurysms has not yet been well defined. This study was designed to assess the safety and efficacy of PED in the recurrence of previously treated aneurysms.METHODSThe authors reviewed a total of 13 cases in which patients underwent secondary placement of a PED for aneurysm recurrence following prior treatment with another modality. The PEDs were used to treat aneurysm recurrence or residual following endovascular coiling in 7 cases, flow diversion in 2, and microsurgical clipping in 4. The mean time between initial treatment and retreatment with a PED was 28.1 months, 12 months, and 88.7 months, respectively. Clinical outcomes, including complications and modified Rankin Scale (mRS) scores, and angiographic evidence of complete occlusion were tabulated for each treatment group.RESULTSAll PEDs were successfully placed without periprocedural complications. The rate of complete occlusion was 80% at 6 months after PED placement and 100% at 12 months in these patients who underwent PED placement following failed endovascular coiling; there were no adverse clinical sequelae at a mean follow-up of 26.1 months. In the 2 cases in which PEDs were placed for treatment of residual aneurysms following prior flow diversion, 1 patient demonstrated asymptomatic vessel occlusion at 6 months, and the other exhibited complete aneurysm occlusion at 12 months. In patients with aneurysm recurrence following prior microsurgical clipping, the rate of complete occlusion was 100% at 6 and 12 months, with no adverse sequelae noted at a mean clinical follow-up of 27.7 months.CONCLUSIONSThe treatment of recurrent aneurysms with the PED following previous endovascular coiling, flow diversion, or microsurgical clipping is associated with a high rate of complete occlusion and minimal morbidity.