Neuroform Atlas stent in treatment of iatrogenic dissections of extracranial internal carotid and vertebral arteries: a single-centre experience

Abstract

Aim of the study: To present our experience in the treatment of iatrogenic dissections of extracranial internal carotid and vertebral arteries with the Neuroform Atlas stent.

Materials and methods: Between January 2017 and February 2018 we treated iatrogenic dissections of three internal carotid arteries and three vertebral arteries. These iatrogenic dissections occurred during the endovascular treatment of ruptured and unruptured intracranial aneurysms. The indication for stenting was haemodynamically significant, flow-limiting dissection with threatening flow arrest. In all six cases, the dissections were treated by placement of Neuroform Atlas stents in the dissected segments of internal carotid or vertebral arteries. Deployment of the stent was followed by the usual dual antiplatelet regimen.

Results: Single or multiple Neuroform Atlas stents were deployed without any technical difficulties, and blood flow was restored immediately after placement of the stents in all six cases. Midterm follow-up (6-8 months) showed complete reconstruction of the shape and lumen of all treated arteries, with negligible intimal hyperplasia.

Conclusion: Our results indicate that a favourable outcome can be achieved by treating iatrogenic dissections of extracranial internal carotid and vertebral arteries with the Neuroform Atlas stent.

Keywords: Atlas; iatrogenic dissection; treatment.

Figure 1.

Patient 1 (a) Subtracted angiography, right carotid artery, lateral projection shows tip of the guiding catheter proximal to the tonsillar loop of the internal carotid artery (arrow) and middle cerebral artery aneurysm (arrowhead). (b) Subtracted angiography, right carotid artery, antero-posterior projection shows occluded aneurysm (arrow). (c) Subtracted angiography, cervical right carotid artery, antero-posterior projection shows dissection involving tonsillar loop of the artery. (d) Non-subtracted angiography, cervical right carotid artery, antero-posterior projection: two Atlas stents (4.5 × 21 and 4.5 × 30) are deployed in telescopic fashion covering an entire tonsillar loop. Arrowhead indicates distal markers and double arrowheads indicate proximal markers. (e) Subtracted angiography, cervical right carotid artery, antero-posterior projection shows reconstructed lumen of the artery and minimal residual dissection (arrow). (f) Follow-up at 6 months. Subtracted angiography, cervical right carotid artery, antero-posterior projection shows reconstructed lumen of the artery, unchanged gross morphology of the tonsillar loop and minimal, haemodynamically insignificant intimal hyperplasia.

Figure 2.

Patient 5 (a) Non-subtracted angiography, vertebrobasilar system, antero-posterior projection, status after coiling of a basilar tip aneurysms and stenting of basilar artery and both P1 segments with two Atlas stents deployed in ‘Y’ fashion; two flow-diverting stents deployed in left internal carotid artery in previous treatment. (b) Subtracted angiography, vertebral artery, antero-posterior projection: dissection of V2 segment of right vertebral artery with significant stenosis of the lumen and unstable intimal flap (arrow). (c) Non-subtracted angiography, vertebral artery, antero-posterior projection: status after deployment of a 4 × 20 Atlas stent; arrowhead indicates distal markers and double arrowheads indicate proximal markers. (d) Subtracted angiography, vertebral artery, antero-posterior projection: residual dissection, but significantly widened true lumen of the artery. (e) Follow-up at 6 months: Subtracted angiography, vertebral artery, antero-posterior projection: completely reconstructed lumen without dissection remnants.

Figure 3.

Low-profile braided (a, b), laser-cut, closed-cell (c, d) and laser-cut, open-cell (e) intracranial, single-structured stents. Note the same structure of the mesh along the working segment of all stents (between vertical black lines) and symmetrical design of ends of working segments. (f) Atlas stent. Dual structured. Working length corresponds to the total length. The ends of the stent are asymmetrically designed. The mesh is composed of alternately arranged eight-cell and 12-cell structural elements.

Figure 4.

The results of the measurement of radial force of different types of stents show that the radial force of the Neuroform Atlas stent is higher than the radial force of several other low-profile intracranial stents. Note negative correlation between radial force and the degree of constraint of all stents.