タンデム内頚動脈-M1閉塞に対する連続展開型ステントリトリーバー2基を用いた機械的血栓除去術：鉄道テクニック

Tandem occlusions in acute ischemic stroke are usually atherothrombotic; however, in rare cases, they may result from simultaneous emboli at both proximal and distal sites. Embolic tandem occlusions pose challenges for endovascular therapy because single-stent retrievers (SRs) or aspiration approaches often require multiple passes. This report describes a novel technique that uses serially aligned SRs for en bloc retrieval.

A 90-year-old woman with atrial fibrillation presented with a National Institutes of Health Stroke Scale (NIHSS) score of 22. Imaging revealed an embolic tandem occlusion of the intracranial internal carotid artery (ICA) and the M1 segment of the middle cerebral artery (MCA), with a large penumbra and no ischemic core. A mechanical thrombectomy was performed. Using a 0.074-inch inner diameter distal access catheter, a microcatheter was guided into the M2 inferior trunk. An SR (4 × 40 mm) was deployed across the M2 trunk from the M1 thrombus, followed by the deployment of another SR (6 × 37 mm) across the ICA thrombus. This "Railroad Technique," in which 2 SRs are deployed in a straight, serial alignment, enabled simultaneous capture and en bloc retrieval of both thrombi in a single pass, resulting in recanalization of the ICA and M1. A 2nd pass with an SR and aspiration catheter resulted in modified thrombolysis in cerebral infarction (mTICI) 2b reperfusion. The patient recovered rapidly.

The Railroad Technique may be a feasible option for embolic tandem occlusions with large thrombus volumes and anatomically distant lesions.