Intentional Stent Herniation Technique Using Neuroform Atlas Stent System for Embolization of a Wide-Necked Basilar Tip Aneurysm

Endovascular Treatment of Wide-Neck Bifurcation Aneurysm: Recent Trends in Coil Embolization with Adjunctive Technique

Wide-neck bifurcation aneurysms (WNBAs) are sometimes challenging to treat. During endovascular treatment, it is important to prevent coil deviation and preserve normal vessels. Adjunctive balloon- and stent-assisted techniques have been developed. A meta-analysis of endovascular treatments of WNBAs revealed that only 40% of patients had complete occlusion. Recently, novel devices have been developed to expand the range of treatment options. Flow-diverter stents and intra-aneurysmal flow disruption devices do not require coils; however, coil embolization remains the standard procedure used by many neurointerventionists. This review describes the recent trends in adjunctive techniques for supporting coil embolization for WNBAs. We referred to literature on balloon-assisted techniques, stent-assisted techniques, Y-stenting, PulseRider, Barrel stents, Comaneci temporary stents, pCONUS, and eCLIPs. These reports showed that adequate embolization rates were generally greater than 80%, and the complete occlusion rate was as high as 94.6%. All devices had a relatively high occlusion rate; however, it may be inaccurate to simply compare each device because of the heterogeneity of the studies. It is important to select the best treatment for each individual case by considering not only literature-based efficacy and safety but also patient background, aneurysm characteristics, and operator experience.

Effect of the Shelving Technique on the Outcome of Embolization in Intracranial Bifurcation Aneurysms

BACKGROUND AND PURPOSE

Stent bulging technique has been introduced as a technique that improves the outcome of aneurysm coiling. Our aim was to evaluate the utility of this technique, which involves the intentional herniation of stents into the bifurcation aneurysms during coiling.

MATERIALS AND METHODS

Unruptured bifurcation aneurysms treated by stent-assisted coiling using a single type of low-profile braided (LEO Baby) stent between November 2012 and October 2018 were retrospectively evaluated. The clinical (age and sex) and morphologic characteristics (aneurysm size, neck size, proximal/distal diameters of the stented artery, incorporation of the origins of the side branches to the aneurysm neck, and bifurcation angle) and response to antiplatelet therapy were evaluated.

RESULTS

Sixty-one patients (29 men, 47.5%; mean age, 55.95 [SD, 12.33] years) with 66 aneurysms were included. There were 36 aneurysms in group A (treated with the stent bulging technique) and 30 aneurysms in group B (treated by classic stent-assisted coiling). There was no significant difference in the patient and aneurysm characteristics in the groups except for the larger size and wider neck of the aneurysms in group A (P = .02 and P = .04, respectively). At the mean follow-up of 27.30 (SD, 17.45) months, there was no significant difference in the complication rate, the occlusion status, and the early and long-term occlusion rates between the groups. The stent bulging technique did not predict total occlusion (Raymond-Roy I) at the final imaging follow-up.

CONCLUSIONS

The stent bulging technique enables the coiling of larger, wide-neck aneurysms; however, we did not observe an added flow-diversion effect with the stent bulging technique compared with conventional stent-assisted coiling. We, therefore, suggest that bifurcation aneurysms should be coiled as densely and as safely as possible using this technique.

Stent-Assisted Embolization for Acutely Ruptured Aneurysm

Objective

The purpose of this study was to report the results of stent-assisted embolization performed at our hospital for acutely ruptured aneurysms.

Methods

This study consisted of 19 patients (4 men and 15 women) with acutely ruptured wide neck aneurysm who underwent stent-assisted coil embolization in acute stage between December 2016 and October 2020. Stent-assisted embolization in the acute stage was performed for very wide neck ruptured aneurysm only when balloon-assisted embolization was failed or was thought to be impossible. Factors related to poor clinical outcome were examined.

Results

There were nine internal carotid artery (ICA) aneurysms, four anterior communicating artery (AcomA) aneurysms, three basilar artery (BA) aneurysms, two vertebral artery (VA) aneurysms and one anterior cerebral artery (ACA) aneurysm. The stents used were one Neuroform EZ and 18 Neuroform Atlas (Stryker). The contrast of the bleb disappeared in all cases with obvious bleb. Complete obliteration was achieved in two cases, neck remnant was in ten, and body filling was in seven. Both of the complete obliteration cases developed thrombotic complications. Modified Rankin score of 0-2 was observed in eight patients (good clinical outcome), whereas that of 4-6 was observed in 11 patients (poor clinical outcome). Several factors possibly affected to poor clinical outcome were examined and only age over 80 years was statically different. Complications related to procedure occurred in five patients; two cases of in-stent thrombosis, one case each of MCA perforation, stent occlusion, and coil fracture.

Conclusion

Stent-assisted coil embolization using Neuroform EZ and Neuroform Atlas could be considered as an emergency treatment for acutely ruptured cerebral aneurysms with very wide neck. It is rarely indicated in patients with age over 80 years.