Influence of vessel morphology and variations on technical and clinical success in mechanical thrombectomy: -In vivo and in vitro analyses.

PURPOSE: To determine the impact of vessel variation and anatomical features on technical and clinical success.

MATERIALS AND

METHODS

In vitro blood clots (n=100) were introduced into a silicon carotid-T flow model of 2, 3 or 4mm. The ICA/M1angle varied at 45°, 90°, 135° and 180°. Peripheral embolism was measured. In vivo 50 pat. (73.5 yrs.,±15) with MCA occlusion were examined for siphon variation, ICA morphology, vessel diameter and angles. The patients were divided according to the clinical success (mRS): group A: mRS≤2 after 90 day and group B: mRS≥3. Furthermore the technical success (TICI) and number of retrieval (n) were analysed.

RESULTS

In vitro with larger vessel diameter the migrated thrombus load decreased (P=.001). The steeper the M1/ICA angles, the higher thrombus weighs (180°: 2.94mg; 135°: 6.32mg; 90°: 8.65mg, 45°: 10.69mg; P<.001). In vivo patients with mRS≤2 had significantly lower NIHSS (16.5 vs 20, P=.009) and higher ASPECTS (9 vs 6, P<.05). TICI≥2b was more often achieved (86.6 vs 40% P=.002). The procedure time was lower (45 vs. 80min, P<.05) with smaller number of retrieval (1.5 vs 4, P<05). Proximal ICA stenosis offers a trend to unfavourable outcome (P=.073). Siphon variation "D" is associated with less retrieval manoeuvre.

CONCLUSION

While in vitro there is a close correlation between embolism and vascular anatomy, in vivo carotid artery stenosis and siphon variation influence clinical and technical success.