Frictional force analysis of stent retriever devices using a realistic vascular model: Pilot study

Area of Science:

• Biomedical Engineering
• Medical Device Technology
• Neurointerventional Surgery

Background:

• Assessing frictional forces between stent retrievers and cerebral vessels is crucial for stroke treatment.
• Existing models lack the anatomical and physiological fidelity of human vasculature.

Purpose of the Study:

• To develop a novel in vitro intracranial cerebrovascular model that accurately simulates human vasculature.
• To analyze and compare the frictional forces of three commercially available stent retriever devices (Trevo XP, Solitaire 2, Eric 4) within this realistic model.

Main Methods:

• A patient-specific vascular mold was created using digital subtraction angiography.
• The model was constructed from polydimethylsiloxane (PDMS) with a low-friction inner coating (~0.037) to mimic the intima.
• A pulsatile blood pump simulated physiological blood flow conditions.

Main Results:

• Statistically significant differences in initial and maximal retrieval forces were observed among Trevo XP, Solitaire 2, and Eric 4.
• Trevo XP exhibited the lowest initial (0.09 ± 0.04 N) and maximal (0.36 ± 0.07 N) retrieval forces.
• Total pulling energy also varied, with Trevo XP requiring the least (0.40 ± 0.10 N·cm).

Conclusions:

• The developed realistic vascular model effectively differentiates the frictional forces of various stent retriever devices.
• These findings underscore the need for advanced in vitro models in evaluating neurothrombectomy devices.
• Further research utilizing this model is recommended for comprehensive assessment of stent retriever technology.