Blind Exchange With Mini-Pinning Technique Using the Tron Stent Retriever for Middle Cerebral Artery M2 Occlusion Thrombectomy in Acute Ischemic Stroke

Abstract

Introduction: The usefulness of the blind exchange with mini-pinning (BEMP) technique has recently been reported for mechanical thrombectomy in patients with stroke owing to medium vessel occlusion (MeVO). The Tron stent retriever can be delivered and deployed through a 0.0165-inch microcatheter. This retriever has potential as an effective and safe treatment for acute ischemic stroke (AIS) due to occlusion of the M2 segment of the middle cerebral artery (MCA). Here, we report the outcomes of the BEMP technique using Tron stent retrievers for M2 occlusion thrombectomy.Methods: Consecutive patients with AIS owing to M2 occlusion who underwent the BEMP technique using 2 × 15-mm or 4 × 20-mm Tron stent retrievers were included. The technique involves deploying a Tron stent retriever through a 0.0165-inch microcatheter, followed by microcatheter removal and blind navigation of a 3MAX or 4MAX aspiration catheter over the bare Tron delivery wire until the aspiration catheter reaches the clot. A Tron stent retriever is inserted into the aspiration catheter like a cork and subsequently pulled as a unit. We assessed procedural outcomes [first-pass expanded thrombolysis in cerebral infarction (eTICI) score 2c/3 and 2b/2c/3], safety outcomes [symptomatic intracranial hemorrhage (sICH)], and clinical outcomes (good outcome rate defined as modified Rankin Scale score 0–2 at 90 days and mortality at 90 days).Results: Eighteen M2 vessels were treated in 15 patients (six female, median age: 80 years, and median National Institutes of Health Stroke Scale score: 18). The BEMP technique was performed successfully in all cases. Whether to use a 3MAX or 4MAX catheter was determined by considering one of the following target vessels: dominant, non-dominant, or co-dominant M2 (3MAX, n = 9; 4MAX, n = 9). The first-pass eTICI 2c/3 and 2b/2c/3 rates were 47 (7/15) and 60% (9/15), respectively; sICH was not observed. Seven patients (47%) achieved good outcomes, and one patient (7%) died within 90 days.Conclusions: The Tron stent retriever was safely and effectively used in the BEMP technique for acute MCA M2 occlusion and can be combined with a 0.0165-inch microcatheter, which may be useful for treating MeVO, in general.

Delayed Rupture of an Anterior Communicating Artery Pseudoaneurysm Caused by Distal Occlusion Thrombectomy Using a Stent Retriever: A Case Report and Mechanism of Injury

“…In this condition, more force is applied because the force to retrieve the stent retriever is difficult to transmit, which increases the likelihood of damage to the Acom perforators [ 5 ]. We also performed the BEMP technique to remove the microcatheter and exchange the aspiration catheter over the stent retriever’s push wire [ 7 - 9 ]. During this process, it is highly likely that the Acom perforators underwent excessive push and pull ( Fig.…”

“…Recently, MT has been carefully implemented even for medium vessel occlusion (MeVO) [ 7 - 9 ]. Among the various thrombectomy methods for MeVO, the BEMP technique showed a low symptomatic intracranial hemorrhage (ICH) rate.…”

“…This came from an increased first-pass recanalization rate by performing aspiration and stent retriever methods simultaneously [ 8 ]. The BEMP technique has been reported mainly for MCA M2 occlusions [ 7 , 9 ], and 1 study reported it being used for ACA and posterior cerebral artery branch occlusions [ 8 ]. In our case, we attempted it in a distal ACA occlusion and used a heavier device (Solitaire 4×40 mm) than what was used those in previous reports (Trevo 3×20 mm [ 7 ], Aperio 3.5×28 mm [ 8 ], Catch mini 3×15/3×20 mm [ 8 ], Tron 2×15/4×20 mm [ 9 ]).…”

“…The BEMP technique has been reported mainly for MCA M2 occlusions [ 7 , 9 ], and 1 study reported it being used for ACA and posterior cerebral artery branch occlusions [ 8 ]. In our case, we attempted it in a distal ACA occlusion and used a heavier device (Solitaire 4×40 mm) than what was used those in previous reports (Trevo 3×20 mm [ 7 ], Aperio 3.5×28 mm [ 8 ], Catch mini 3×15/3×20 mm [ 8 ], Tron 2×15/4×20 mm [ 9 ]). Since the use of thrombectomy for MeVO is expected to increase in the future, it should be considered that the BEMP technique might increase the incidence of hemorrhagic complications in some circumstances.…”

“…Additionally, the blind exchange mini-pinning (BEMP) technique was utilized for fast recanalization in a single step. [7][8][9] While removing the microcatheter over the push wire of the stent retriever, the angle formed by the push wire suddenly straightened in this case. Immediately after angiography, blood flow in the Acom and ACA was not observed (Fig.…”