Mechanical thrombectomy injury to the arterial wall: A comparison between catheter aspiration and stent retriever

To compare the extent of arterial wall damage when SR and CA were used for treatment of AIS models to evaluate their efficacy and safety.

A thrombin-induced thrombus was pre-injected into the right distal external carotid-maxillary artery (ECMA) in 12 dogs to create an acute thrombus occlusion model and were randomly divided into the SR group (n = 6; received SR treatment) and CA group (n = 6; received CA treatment). Device safety was also assessed by five passages through the normal left ECMA using each device. Device manipulation-related damage to arterial walls, final flow restoration, recanalization time and complications were recorded.

Sixteen retriever and 10 aspiration attempts were performed in the SR and CA groups. Reperfusion time was significantly reduced in the CA group (17.83 ± 1.96 vs. 28.33 ± 3.26 in the SR group; P = 0.02). Stent retriever thrombectomy resulted in an increased risk of endothelium denudation (1.17 ± 0.24 in SR group vs. 0.42 ± 0.15 in CA group; P = 0.01) and reduced frequency of vessel vasospasm (0.67 ± 0.14 in SR group vs. 0.25 ± 0.13 in CA group; P = 0.04). Injury score and thrombus deposition were similar between the two groups (P > 0.05). TICI 2b/3 flow restoration values of the right ECMA were 100 % in both groups. Device-related complications, including dissection (P = 0.21), side branch influence (P = 0.24), and distal thromboembolism (P = 1.00), did not differ between the two groups.

Both devices had similar efficacy and caused minimal arterial wall damage in our dog models. SR was more likely to cause endothelium denudation, while CA had a greater risk of vasospasm.