Introduction: Pipeline Embolization Device twisting or torsion manifests with appearance of a “figure 8” in perpendicular planes on DSA. The prevalence of this intra-procedural complication has not been described.
Methods: Case images were reviewed for instances of twisting from a prospectively-maintained, IRB-approved database of cerebral aneurysm patients undergoing flow diversion.
Results: A total of 628 PED-Flex devices were used in 509 procedures on 438 patients and 19 instances of twisting were observed (prevalence 3.0%, 19/628). Twisting was most common in large, non-saccular aneurysms along the ICA. The average aneurysm size was 17mm (range 4-38 mm), morphology was fusiform or dissecting in 31%, and location was 13 ICA, 1 anterior communicating artery, and 2 mid-basilar artery. Larger diameter and longer devices are predisposed to twisting. Of the twisted devices, 89.5% (17/19) were =4.5mm diameter and 10.5% (2/19) were <4.5mm. The average length was 27.5 mm (range 16-35 mm). Of the 19 twisted devices, 13 were remediated and successfully deployed and six were removed (31.6%). Remediation maneuvers included resheathing and wagging the device. Balloon angioplasty facilitated opening in 3/16 cases and was used for post-processing in 6/19 cases. Procedural success was achieved in 15/16 cases and one procedure was aborted after twisting. One major complication (6%) was observed, a patient with mid-basilar aneurysm treated by PED who experienced perforator stroke that may have been related to incomplete device apposition. Occlusion outcomes were inferior to the overall PED population. Follow-up DSA was available for 62.5% (10/16); complete occlusion was observed in 44.4% (4/9) at 6 months, 50% (4/8) at 12 months, and 50% (5/10) at last follow-up.
Conclusions: The prevalence of device twisting in a large series of PED-Flex deployments was 3.0%. Twisting is more common with large diameter devices. Remediation is challenging but can be accomplished to avoid clinical consequence.
Patient Care: Improved understanding of the clinical ramifications of Pipeline Embolization Device twisting when treating cerebral aneurysms with flow diversion.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the prevalence of and associated risk factors for PED twisting, 2) Describe techniques for remediation, and 3) Describe clinical outcomes associated with PED twisting.