A Comparison of Safety and Effectiveness Between Wingspan and Neuroform Stents in Patients With Middle Cerebral Artery Stenosis

Background: Percutaneous transluminal angioplasty and stenting with the Wingspan stent has proven safe and effective in patients with middle cerebral artery stenosis (MCAS), but the off-label use of the Neuroform stent might be an alternative treatment. This study aimed to compare the safety and effectiveness of the above two intracranial stents in patients with MCAS.Methods: We retrospectively analyzed consecutive patients with symptomatic MCAS who had been treated with the Neuroform EZ or the Wingspan stent. A propensity score was generated to control for differences in baseline characteristics. The endpoints were the rate of peri-procedural complications within 30 days after stenting, the in-stent restenosis rate, and any target-vessel-related stroke or deaths during follow-up.Results: After matching for propensity score, the peri-procedural complication rate in the Wingspan group was 7.4% compared with 5.6% in the Neuroform group (p = 1.00), while the follow-up in-stent restenosis rates were 23.3 vs. 14.3%, respectively (p = 0.41). In the restenosis group, the patients tended to be younger (p < 0.01) and the degree of artery stenosis before stenting was higher (p < 0.01).Conclusion: This study indicated that in patients with symptomatic MCAS, Neuroform EZ stents are an alternative to Wingspan. Moreover, younger age and higher degree of artery stenosis before stenting might be a risk factor of in-stent restenosis.

Double-barrel Y-configuration Stenting for Flow Diversion of a Giant Recurrent Basilar Apex Aneurysm with the Pipeline Flex Embolization Device

ABSTRACTGiant basilar apex aneurysms are extremely challenging to successfully manage. The Pipeline Flex embolization device (PFED) is a new generation flow-diverting stent with a modified delivery system which allows resheathing of the stent after partial deployment. We describe a case of double-barrel Y-configuration stenting of a giant, recurrent basilar apex aneurysm using the PFED. A 73-year-old male was previously treated for an unruptured 11-mm basilar apex aneurysm with stent-assisted coiling using a Neuroform stent. The aneurysm was retreated twice with repeat coiling. After the third recurrence and persistent aneurysm growth into a giant, symptomatic lesion, we decided to proceed with flow diversion. We performed Y-stenting of the basilar bifurcation using three PFEDs, and was recoiled the aneurysm sac. Due to the low porosity of the flow diverters, a side-by-side double-barrel configuration was necessary in the basilar artery. Without the PFED’s resheathable capability, it would not have been possible to perform Y-stenting with flow diverters.

Abstract TP84: Delayed Ipsilateral Intraparenchymal Hemorrhage After Neuroform Stent Assisted Coiling of Intracranial Aneurysms

Background: Delayed ipsilateral intraparenchymal hemorrhage (IPH) has been reported following technically successful treatment of intracranial aneurysms using flow-diverting stents (Pipeline embolization device) in 8.5% of patients and does not appear to be related entirely to dual antiplatelet therapy. We report a similar phenomenon in Neuroform-assisted coiling. Methods: Neuroform-assisted coiling patients were entered into a prospective registry at our institution. Procedural and 30 day complications were recorded. Delayed ipsilateral IPH cases within 30 days were reviewed. Results: Between 11/2002 and 7/2012, 98 patients had Neuroform-assisted coiling of 100 cerebral aneurysms, 8 acutely ruptured. Intra-procedurally, there were 3 thromboembolic events and 4 hemorrhages due to vessel or aneurysm perforation (not necessarily symptomatic). After the procedure but within 30 days follow-up (available for 92 patients), there were 6 TIA’s, 2 minor strokes and 1 SAH. There were 2 cases of ipsilateral IPH (2%). One was a 60-year-old man who had stent-assisted coiling of an ACOM aneurysm (Neuroform from right A1 into left A2). He was on aspirin 81 mg and clopidogrel 75 mg daily with a PRU (P2Y12 reaction units) of 72 on day of procedure. Despite decreasing clopidogrel dosing to every other day, he had a frontal lobe IPH 7 days later (Figure 1) with a PRU of 59. The other IPH (Figure 2) occurred in a 70-year-old man 14 days after Y-stent assisted coiling of an MCA aneurysm. He was on clopidogrel 75 mg and warfarin (INR 2.0) for prior pulmonary embolism and dural venous sinus thrombosis. Both patients recovered without neurological deficit. Conclusion: Recently described in flow diversion, delayed ipsilateral IPH is not limited to flow-diverting stents. Though less frequent, a potential for this may exist following any intracranial stenting procedure, possibly related to hemorrhagic conversion of microembolic phenomenon while on dual antiplatelets or anticoagulation.

Abstract WP85: Risk factors for Stenosis of Stents Utilized for Stent Assisted Coiling of Unruptured Intracranial Aneurysms

Introduction: Stent-assisted coil embolization facilitates the treatment of wide-necked aneurysms. In-stent stenosis, although rare, may lead to stroke by occlusion of the parent artery or by thromboembolism. To our knowledge, the risk factors for in-stent stenosis in this context have not yet been investigated. Hypothesis: We hypothesized that cardiovascular risk factors and vessel size would be associated with in-stent stenosis. Methods: Consecutive patients undergoing stent-assisted coil embolization at our institution using the Neuroform stent (Stryker, Kalamazoo, MI, USA) were identified by billing records. Medical comorbidities were extracted retrospectively from patient charts. In-stent stenosis on last angiogram and vessel size (dichotomized into <2 mm or ≥2 mm) were estimated by direct review of angiography. Patients were grouped into those with and without ≥50% in-stent stenosis and the characteristics of the two groups were compared using a t-test for continuous variables and Fisher’s exact test for categorical variables. Results: A total of 224 unruptured aneurysms were treated with stent assisted-coil embolization between 2003 and 2010 utilizing the Neuroform stent. Follow-up catheter angiography was available in 196/224 (87.5%) at mean of 19 mos in those with in-stent stenosis and 24 mos in those without. In-stent stenosis occurred in 8/196 (4.1%). Mean age was 59 in those with in-stent stenosis and 62 in those without. The prevalence of cardiovascular risk factors in the groups with and without stenosis were as follows: diabetes 25% (2/8) vs. 6.9% (13/188), hypertension 42.6% (80/188) vs. 50% (4/8), hyperlipidemia 13% (1/8) vs. 5.9% (11/188), coronary artery disease 13% (1/8) vs. 3.7% (7), and smoking 38% (3/8) vs. 39% (75/188). Vessel size was <2 mm in 25% (2/8) in those with in-stent stenosis and 9.6% (18/188) in those without. None of these results were statistically significant. Conclusions: The overall risk of in-stent stenosis in patients undergoing stent-assisted coil embolization was relatively low. Although cardiovascular comorbidities were numerically more common in patients with in-stent stenosis, the differences between the two groups were not statistically significant.