A Novel Technique to Retrieve a Snagged Stent Retriever: Technical Note.

Abstract

Currently, there are no established approaches for removal of devices, such as stents, which sometimes become difficult to recover during endovascular treatment. We report a new method to successfully remove a stent that has become snagged during thrombus removal. An 82-year-old female who had undergone a mitral valve annuloplasty developed sudden aphasia, right hemiplegia, and right unilateral spatial neglect on postoperative day 10. Cranial MRI indicated occlusion of the horizontal segment of the left middle cerebral artery. During mechanical thrombectomy, a vasospasm snagged the stent, and re-sheathing attempts failed repeatedly. We wedged the microcatheter into the spasm site and slowly injected a solution containing 1 cc of nicardipine, 2 cc of contrast medium, and 2 cc of heparin in normal saline intra-arterially. After several minutes, we retracted the Trevo wire slightly and easily removed the stent. The thrombus adhered to the retrieved stent. Post-retrieval imaging showed that the branch was completely recanalized. In cases wherein a microwire or stent retriever becomes difficult to remove, we propose switching to a microcatheter with a sufficient diameter to allow vasodilator injection. If the microcatheter is difficult to remove, our method can be utilized by severing the hub, inserting a larger-bore catheter, and injecting vasodilators. Adding contrast medium to the intra-arterial injectate allows visualization of whether the solution has reached the spasm site. Furthermore, by injecting the solution through the wedged catheter, pooling of the solution at the spasm site can be confirmed.