Technique for Recanalization of Sheath Introducer Occlusion due to Captured Thrombus during Mechanical Thrombectomy for Acute Ischemic Stroke: A Technical Note.

Objective: Mechanical thrombectomy (MT) is the gold standard treatment for acute ischemic stroke. During these interventions, a thrombus frequently obstructs a guiding catheter. The obstructed guiding catheter should be withdrawn before distal embolism occurs; however, albeit infrequently, the thrombus occludes even a sheath introducer (SI). While conventionally new SI placement is required for continuation of treatment, we propose a viable alternative for recanalization of the occluded SI, termed vacuum-assisted delivery of thrombus (VADT), with a clinical report of our cases. The usefulness of this technique was also evaluated in simulation experiments. Case Presentations: The VADT procedure is as follows: 1) insert a peel-away sheath, originally attached to a balloon-guiding catheter (BGC), into the SI to continuously open the hemostatic valve; 2) advance the BGC into the peel-away sheath while applying mechanical aspiration; and 3) remove the peel-away sheath/BGC assembly slowly. In a simulation environment using an artificial thrombus, we repeated the VADT procedure five times and reproducibly achieved SI reopening within only 10-20 seconds. From March 2013 to September 2022, 204 patients were treated with MT at our stroke center and SI occlusion occurred in three patients (1.5%). These events occurred exclusively in patients with extracranial internal carotid artery occlusion. All three patients with SI occlusion underwent successfully thrombus extraction in the SI using the VADT on the first try. Conclusion: The results of clinical experience and simulation experiments strongly support VADT as a reliable option for recanalization of an occluded SI.