Thromboembolic Complications After Neuroform Stent-Assisted Treatment of Cerebral Aneurysms: The Duke Cerebrovascular Center Experience in 235 Patients With 274 Stents

Neurosurgery 69:369–375, 2011 DOI: 10.1227/NEU.0b013e31821bc49c

The Neuroform Stent has facilitated the endovascular treatment of wide-necked cerebral aneurysms. It is unknown which factors pose risks of thromboembolic events after stent placement.

OBJECTIVE: This series is the largest single-center study reporting on the incidence of and factors influencing thromboembolic complications after Neuroform stent placement.

METHODS: A total of 235 patients were treated with 274 Neuroform stents. The thromboembolic event rate was determined by imaging or clinical evidence of cerebrovascular accident within 90 days of stent placement; for patients with incomplete follow-up through chart review, telephone interviews were conducted. Analyses were performed to investigate patient factors that may be associated with stroke.

RESULTS: Most aneurysms were unruptured; 30 patients (12.8%) presented with acute subarachnoid hemorrhage. Twelve patients of the 224 with follow-up (5.4%, 95% confidence interval: 2.4%-8.3%) demonstrated imaging or clinical evidence of a new thromboembolic event within 90 days of stent placement. There was a 3.1% thromboembolic rate for unruptured aneurysms and a 20% rate in patients with subarachnoid bleed. Hemorrhage was significantly associated with having a thromboembolic event (P = .002). There was a trend toward an increased thromboembolic event rate for patients with hypertension (P = .07). Larger stent caliber was significantly associated with a decreased thromboembolic event rate (P = .032).

CONCLUSION: Our results suggest that the thromboembolic event rate associated with Neuroform stent use is low in unruptured aneurysms. In ruptured aneurysms, the complication rate is high, possibly partly related to restricted use of antiplatelet therapy. Stent size and hypertension may be associated with the risk of stroke, but additional studies are needed to confirm their significance.

KEY WORDS: Cerebral aneurysms, Neuroform stent, Stent-assisted aneurysm coiling, Stent thrombosis, Thromboembolic complications