Outcomes following aneurysmal coil embolization with intentionally shortened low-profile visible intraluminal support stent deployment

Abstract

Purpose Among all stents available for neuroendovascular therapy, the low-profile visible intraluminal support stent bears the highest metal coverage ratio. We deployed a low-profile visible intraluminal support stent with a delivery wire or/and microcatheter system push action to shorten the low-profile visible intraluminal support stent and thus achieve a flow diversion effect. We report our single-institution experience with the use of low-profile visible intraluminal support stents for intentionally shortened deployment (shortening group) and non-shortened deployment (non-shortening group) for unruptured intracranial aneurysms. Methods We retrospectively reviewed the medical records of 130 patients with 131 intracranial aneurysms who were treated with low-profile visible intraluminal support stent-assisted coil embolization from February 2016–January 2019. All perioperative complications were noted. Every 6 months, we re-examined the patients with cerebral angiography or magnetic resonance angiography. The outcomes of aneurysm occlusion were evaluated by the modified Raymond–Roy occlusion classification. We used the finite element method and computational fluid dynamics to investigate the hemodynamics after shortened low-profile visible intraluminal support stent deployment. Results Immediately after treatment, the modified Raymond-Roy occlusion classification was significantly better in the shortening group than in the non-shortening group ( p<0.05). The latest angiographic outcomes showed the same tendency. Hemodynamic analysis by computational fluid dynamics suggested an adequate flow diversion effect with the use of our intentional shortening method. Conclusions Stent-assisted coil embolization using this technique showed good results of a high complete occlusion rate and low complication rate. These findings suggest that shortened low-profile visible intraluminal support stent deployment yields a flow diversion effect and may lead to early intra-aneurysmal thrombus formation.

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

“…This is an unexpected finding given the abundance of clinical and simulation studies that have suggested that there is a possible relationship between the aneurysm obliteration rate and a decreased porosity/increased pore density at the aneurysm neck. 12,17,[22][23][24] One reason for the lack of such an association in our study may be that bifurcation aneurysms do not respond to flow diversion as well as sidewall aneurysms. All of the aneurysms in our study were bifurcation aneurysms.…”

“…The SBT has been described using various terms in the literature, such as the "shelf technique," "barrel technique," "stent bulging," "compressed stent," "intentional stent herniation," "intentional shortening," "compaction," or "wrapped-candy" techniques. 8,11,12,[15][16][17][18][19] Although some authors prefer to use the term "compression/compaction" for all types of aneurysms, on the basis of our review of the relevant literature, we think that the terms "compression," "compaction," "shortening," and "wrapped-candy" should be reserved for sidewall aneurysms, whereas "shelf," "herniation," or "bulging" should be used for bifurcation aneurysms. Technically, the maneuvers performed to achieve a compacted stent are similar in both scenarios; however, the intent (the ability to preserve a side branch versus the desire to achieve a better flow diversion) and the immediate angiographic results (bulged stent versus shortened stent) are different.…”

“…27 Although the flow diversion properties of braided stents have not been definitively proved clinically, the data in the literature have suggested that the recurrence or persistence of aneurysms are further lowered if braided stents are used, which diminishes the rate of an inadequate obliteration (RR III) to approximately 5%-10% of the aneurysms on follow-up. 17,[28][29][30][31] Very large cohorts of patients may be required to demonstrate an additional flow diversion by compaction/bulging beyond the diversion that is provided by the coils 32 and the braided stents themselves. In addition, the clinical implications of a significantyet-small difference in the residual or recurrent aneurysm filling, if it exists, may not be profound.…”