Outcomes of vascular wall malapposition following Pipeline Flex embolization device implantation for cerebral aneurysms: A retrospective study

Background: Pipeline Flex embolization device (PLED) is a specific management modality for adults with intracranial aneurysms (IAs). The technical characteristics of the PLED aid in safe as well as extremely efficient usage. We present our experience of attempted and non-attempted resolution of wall malapposition in ICAs and vertebral artery aneurysms with associated cavernous ICA (cICA) tortuosity's. Methods: We conducted a retrospective study to identify PLED wall malapposition from April 2018 to July 2019. We assessed various degrees of vascular tortuosity's, aneurysm characteristics, immediate wall apposition, postoperative resolution of wall malapposition, postoperative follow-up of patients with wall malapposition as well as wall malapposition related complications. The patients were put into two category such as attempt resolution and non-attempted resolution (conservative treatments) groups. Results: We treated a total of 118 patients with PLED out of which 22 patients (18.6%) had wall malapposition. All patients were treated with a single PLEDs. Coils were used to obliterate the aneurysms in nine patients. Adequate aneurysm neck coverage was achieved in all cases. Resolution of wall malapposition was attempted in 13 patients while no resolution was attempted in nine patients intraoperatively. Out of the 22 patients with wall malapposition, 14 of them (63.64%) did not resolve in both groups. These 14 patients were put into follow-up sequence category. Conclusion: Attempted resolution may not be suitable for certain aneurysms in very angulated ICAs with associated cICA tortuosity. Interestingly, spontaneous resolution of wall malapposition of PLED didn't occur as we anticipated in most of our conservative treatment category.