gms | German Medical Science

Objective: In 2010, the Woven EndoBridge (WEB) has been introduced for the treatment of unruptured WNBAs. By now, first data on the off-label use of the WEB device for ruptured bifurcation aneurysms have been published. A recent U.S. multicenter study reported a low rate of procedure-related complications; however, complete occlusion was only achieved in half of the patients. Thus, the main hypothesis was that microsurgical clipping of ruptured WNBAs is associated with a similar; low treatment risk but achieves significant higher occlusion rates. Therefore, we compared our institutional results after microsurgical clipping of ruptured WNBAs with a U.S. multicenter cohort by Cortez et al. treated with the WEB device.

Methods: A retrospective study of consecutive adult patients with ruptured WNBAs who underwent microsurgical clipping at our institution between 2010 and 2020 was performed. According to the WEB protocol, ruptured WNBA aneurysm with necks measuring between 2.5 and 8 mm, a size between 2.8 and 17 mm, and a dome-to-neck ratio >1 and were included. Primary outcome measure was the complete occlusion of the aneurysm according to a Raymond Roy Occlusion Classification (RROC) Class I. Secondary outcome measures were procedure-related morbidity and mortality. Subsequently, our institutional results were compared with the data on the endovascular treatment with the WEB device published in a U.S. multicenter study by Cotez et. al.

Results: A total of 87 patients with ruptured WNBAs were included. Mean age at time of ictus was 56.2 ± 13.6 years. The most common aneurysm location was the anterior communicating artery (45/87, 52%), followed by the MCA bifurcation (38/87, 44%), ICA-terminus (2/87, 2%), and basilar apex (2/87, 2%). Mean neck size was 3.8 ± 1.3 mm and mean dome size was 4.9 ± 1.8 mm. The complete occlusion rate after microsurgical clipping was 94% (82/87) and was significantly higher (p<0.001) compared with the endovascular method (48%). The procedure-related morbidity in our cohort was 2.3% (2/87) and 3.3% (3/91) in the comparative group (p=1.00). In both groups around 13% (11/87 and 12/91) of the patients died as a result of the subarachnoid hemorrhage. However, the procedure-related mortality was 0% (0/87 and 0/91) in both cohorts.

Conclusion: The study demonstrates that microsurgical clipping is a safe and effective treatment method for ruptured WNBAs aneurysms and that it is superior to the endovascular treatment with the WEB device in terms of complete occlusion rates.