Objective: A method for retrieving hard thrombi that prevent sufficient expansion of stent thrombus retrievers was evaluated in vitro and in vivo.

Case Presentation: Using a silicone vascular model, a method effective for retrieving hard thrombi that prevent sufficient expansion of stent thrombus retrievers was evaluated. The tip of the guidewire was shaped into a J-shape, and the stent was deployed by guiding the microcatheter to spirally penetrate the space between the thrombus and the vascular wall. The safety and reproducibility of this technique (corkscrew penetrating method) was examined. A 77-year-old woman was found lying in a street and ambulanced to our hospital. Right complete hemiplegia and aphasia were noted. A diagnosis of occlusion of the proximal left middle cerebral artery was made, and endovascular mechanical thrombectomy was carried out. Although clot retrieval was attempted using a stent retriever, the thrombus was considered hard and recanalization could not be achieved by the first pass. Therefore, the second pass was performed by the corkscrew penetrating method. When the stent was recovered, a hard and long thrombus was caught winding around the stent. Complete recanalization was achieved, and right hemiplegia was radically mitigated.

Conclusion: This method was suggested to be effective for the retrieval of hard thrombi that would prevent the expansion of the stent clot retriever and resist capture.