Perforator Preservation Technologies (PPT) Based on a New Neuro-interventional Classification in Endovascular Treatment of Perforator Involving Aneurysms (piAN)

Background: and Purpose Treatment of perforator involving aneurysm (piAN) remains a challenge to open and endovascular neurosurgeons. Our aim is to demonstrate a primary outcome of endovascular therapy for piANs with the use of perforator preservation technologies (PPT) based on a new neuro-interventional classification. Methods: The piANs were classified into Type I: aneurysm really arises from perforating artery; Type II: saccular aneurysm involves perforating arteries arising from its neck (IIa) or dome (IIb); Type III: fusiform aneurysm involves perforating artery. Stent protection technology of PPT was applied in Type I and III aneurysms, and coil-basket protection technology in Type II aneurysms. Immediate outcome of aneurysmal obliteration after treatment was evaluated (Satisfactory Obliteration: The saccular aneurysm body is densely embolized (I), leaving a gap in the neck (IIa) or dome (IIb) where the perforating artery arising; fusiform aneurysm is repaired and has a smooth inner wall), and successful perforating artery preservation was defined as keeping good antegrade flow of those perforators on postoperative angiography. Periprocedural complication was closely monitored, and clinical and angiographic follow-up were performed. Results: Six consecutive piANs (2 ruptured and 4 unruptured; 1 Type I, 2 Type IIa, 2 Type IIb and 1 Type III) in 6 patients (aged from 43 to 66 years; 3 males) underwent endovascular therapy between November 2017 and July 2019. The immediately angiography after treatment showed 6 aneurysms obtained satisfactory obliteration; and all of their perforating arteries were successfully preserved. During clinical follow-up of 13–50 months), no ischemic or hemorrhagic event of brain occurred in the 6 patients, but one who developed ischemic event in the territory of involving perforators 4 h after operation, and completely resolved within 24 h. Follow-up angiography at 3M to 10M showed patency of the parent artery and perforating arteries of treated aneurysms, with no aneurysmal recurrence. Conclusions: Our perforator preservation technologies on basis of the new neuro-interventional classification seems feasible, safe and effective in protecting involved perforators while occluding aneurysm.