Refractory thrombectomy strategy

Refractory Stroke Thrombectomy: Etiology and Strategies

Refractory Stroke Thrombectomy is observed in fewer than 10% of cases in North American cohorts, but more prevalent in East Asian populations, which is defined in the literature as failure to achieve reperfusion after three or more thrombectomy passes (eTICI 0-1 grade) or reocclusion of the target vessel within 72 hours after successful reperfusion. From the perspective of cerebral angiography, it can be divided into non-reperfusion or reocclusion shortly after mechanical thrombectomy, or refractory thrombus that is difficult to capture and/or retrieve. Underlying vessel wall diseases including intracranial atherosclerotic disease (ICAD) and/or intracranial arterial dissection (IAD) may be the most common etiologies, especially prevalent in Asian, African, and Hispanic populations with atherosclerotic risk factors such as diabetes; less common causes are refractory/calcified thrombi, such as hard and firm cardiac thrombi associated with cardiac surgery or atrial fibrillation. 

Solutions to these challenging situations lies in the underlying causes, but we should also perfect the technical details of the thrombectomy strategy to avoid unproductive passes. Repetitive futile attempts using the same strategy would prolong reperfusion time and cause more vessel damage, timely strategy conversion, such as switching from contact aspiration/stent retriever thrombectomy to combined techniques or switching between different branches. 

For sheet-like stent retrievers and aspiration catheters, calcified thrombi may be difficult to interact with the devices to form an effective negative pressure for aspiration or retraction force, and diameter differences or angulation of the proximal and distal vessels can also reduce the effectiveness of contact aspiration. Stent retrievers with three-dimensional configurations, such as NeVa and Nimbus, promoting the engagement of the thrombus within the device, combined with double aspiration and microcatheter pinching techniques, appear have advantages in capturing and removing the refractory thrombus.

Considering the double stent thrombectomy techniques, the serial double stent technique involves two stents sequentially covering the thrombus area, works for long-segment occlusion with high thrombus burden; the Y-shaped double stent technique is ideal for thrombi at the bifurcation of the internal carotid terminus, basilar artery apex, and the middle cerebral artery, similar to the shape of a zipper to clamp the saddle thrombus.

For distal vessel occlusion, tortuous paths, and small vessels with diameters of less than 2 mm, local intra-arterial thrombolytic drug infusion through microcatheter, such as urokinase (within 4.5 to 6 hours after onset), P2Y12 receptor antagonist cangrelor, or glycoprotein IIb/IIIa inhibitor tirofiban, as an adjunct to mechanical thrombectomy, may be effective and safe. Rescue intracranial angioplasty and/or stenting for ICAD or IAD is reasonable, but requires further RCTs such as to show its efficacy. Salvage stents can also be considered for thrombi that are difficult to retrieve, but balloon angioplasty alone at the site of the thrombus may not be durable to keep the vessel from reocclusion.

Reference

1. Abdalla RN, Cantrell DR, Shaibani A, Hurley MC, Jahromi BS, Potts MB, Ansari SA. Refractory Stroke Thrombectomy: Prevalence, Etiology, and Adjunctive Treatment in a North American Cohort. AJNR Am J Neuroradiol. 2021Jul;42(7):1258-1263. doi: 10.3174/ajnr.A7124.
2. Baik SH, Jung C, Kim JY, Shin DW, Kim BJ, Kang J, Bae HJ, Kim JH. LocalIntra-arterial Thrombolysis during Mechanical Thrombectomy for Refractory Large-Vessel Occlusion: Adjunctive Chemical Enhancer of Thrombectomy. AJNR Am JNeuroradiol. 2021 Nov;42(11):1986-1992. doi: 10.3174/ajnr.A7264. 
3. Ifergan H, Dargazanli C, Ben Hassen W, Hak JF, Gory B, Ognard J, Premat K,Marnat G, Kerleroux B, Zhu F, Bellanger G, Sporns PB, Charbonnier G, ForestierG, Caroff J, Fauché C, Clarençon F, Janot K, Lapergue B, Boulouis G; ETISregistry collaborators and the JENI research collaborative. Rescue intracranialpermanent stenting for refractory occlusion following thrombectomy: a propensitymatched analysis. J Neurointerv Surg. 2024 Jan 12;16(2):115-123. doi:10.1136/jnis-2022-020012.
4. Marnat G, Delvoye F, Finitsis S, Lapergue B, Gariel F, Consoli A, DesillesJP, Mazighi M, Dargazanli C, Bourcier R, Darcourt J, Chalumeau V, Elhorany M,Clarençon F, Richard S, Gory B, Sibon I; ETIS Investigators. A MulticenterPreliminary Study of Cangrelor following Thrombectomy Failure for RefractoryProximal Intracranial Occlusions. AJNR Am J Neuroradiol. 2021Aug;42(8):1452-1457. doi: 10.3174/ajnr.A7180. 
5. Imahori T, Miura S, Sugihara M, Mizobe T, Aihara H, Kohmura E. Double StentRetriever (SR) Technique: A Novel Mechanical Thrombectomy Technique toFacilitate the Device-Clot Interaction for Refractory Acute Cerebral LargeVessel Occlusions. World Neurosurg. 2020 Sep;141:175-183. doi:10.1016/j.wneu.2020.05.268.
6. Hofmeister J, Brina O, Bernava G, Rosi A, Reymond P, Lovblad KO, Machi P.Double Stent Retriever Technique for Mechanical Thrombectomy: A SystematicReview and Meta-Analysis. AJNR Am J Neuroradiol. 2024 Aug 9;45(8):1031-1037.doi: 10.3174/ajnr.A8253.