Blind exchange with mini-pinning technique for distal occlusion thrombectomy

Abstract

IntroductionTechnical improvements to enhance distal occlusion thrombectomy are desirable. We describe the blind catheter exchange technique and report the pinning technique with small devices (‘mini-pinning’) for distal occlusions.MethodsA retrospective review of a prospective database from January 2015 to August 2018 was performed for cases of distal occlusion in which the ‘blind exchange/mini-pinning’ (BEMP) techniques were used. The technique involves the deployment of a 3 mm Trevo retriever followed by microcatheter removal and blind advancement of a 3MAX aspiration catheter over the bare retriever delivery wire (‘blind exchange’) until clot contact under aspiration. The retriever is subsequently partially recaptured in order to ‘cork’ the thrombus (‘mini-pinning’) and the system pulled as a unit. Patients with distal occlusions treated with BEMP and standard techniques (either 3 mm Trevo or 3MAX) were compared.ResultsTwenty-five vessels were treated in 22 patients. The majority of patients had isolated distal occlusions predominantly in the distal middle cerebral artery (MCA) segments, half of which involved the superior division. The comparison between BEMP (n=25 vessels) and standard techniques (n=144 vessels) revealed balanced groups. One of the highlighted differences was the more distal MCA occlusions among those who underwent BEMP (M3 occlusions 52% vs 22%; p=0.001). Otherwise, the vessel, segments, divisions and luminal diameter were comparable. There was a higher rate of first-pass modified Thrombolysis in Cerebral Infarction 2b–3 (80% vs 56%; p=0.03) and a trend towards higher rates of first-pass full reperfusion (60% vs 40%; p=0.07) with BEMP compared with standard techniques. Final reperfusion and clinical outcomes were comparable.ConclusionBEMP appears to be a safe and effective technique for the treatment of distal occlusions. Additional studies are warranted.

A review of endovascular treatment for medium vessel occlusion stroke

“…Crockett et al made an interesting attempt in this regard: in addition to the "regular" TICI, they used a modified TICI, which focused solely on the territory affected by the MeVO, with a scoring system identical to the standard TICI system (1, 2a, 2b, 2c, 3). 36 Figure 1 shows a proposed modified eTICI scoring system for 27 (+DWI if symptom onset unknown) Atchaneeyasakul et al 2020 46 Compagne et al 2019 23 Qureshi et al 2017 48 Sarraj et al 2016 49 Menon et al 2019 24 (CTP/MRI was available in some patients) Coutinho et al 2016 50 Bhogal et al 2017 52 (either NCCT+CTA or MRI) De Castro Afonso et al 2019 26 Grieb et al 2019 30 ► Wide availability ► Inexpensive ► Fast ► Robust against patient motion ► No post-processing needed ► Option to use multiphase CTA, including color-coded time-variant mCTA maps and mCTA-derived CTP-like maps 14 58 ► If single-phase CTA is used MeVOs may be missed 59 ► Little information about collateral status if single-phase CTA is used ► Current ASPECTS thresholds for LVO EVT are probably not optimal for MeVO EVT ► ASPECTS does not capture ischemic changes in ACA and PCA MeVO stroke NCCT+CTA + CTP Haussen et al 2020a 34 Jiang et al 2019 25 Vargas et al 2017 37 Navia et al 2016 29 Menon et al 2019 24 (CTP/MRI was available in some patients) Coutinho et al 2016 50 (CTP/MRI was available in some patients) Grossberg et al 2018 45 Altenbernd et al 2018 28 The key difference to the conventional eTICI score is hereby the "denominator", that is, only the affected territory downstream to the MeVO, rather than the entire middle cerebral artery territory, is used as a comparator.…”

Unfavorable Vascular Anatomy during Endovascular Treatment of Stroke: Challenges and Bailout Strategies

“…A variation of this technique with "blind exchange" has been described for distal occlusions. 66 Distal aspiration catheters (3 MAX™, Penumbra) are longer than microcatheters used during MT (160 cm vs. 157 cm); thus, they cannot be navigated in a coaxial manner. In the blind exchange maneuver, an SR is deployed via a microcatheter; the microcatheter is then pulled out and a 3-or 4-MAX™ (Penumbra) aspiration catheter is gently advanced over the retrieval wire under fluoroscopy until clot contact.…”

“…In the blind exchange maneuver, an SR is deployed via a microcatheter; the microcatheter is then pulled out and a 3-or 4-MAX™ (Penumbra) aspiration catheter is gently advanced over the retrieval wire under fluoroscopy until clot contact. 66 This technique can also be performed with larger aspirations systems in more proximal locations.…”

“…Another way to overcome this situation is an anchoring technique using an SR. First, an SR is deployed over the clot for anchoring, then the aspiration catheter is pulled over the SR wire. A variation of this technique with “blind exchange” has been described for distal occlusions [ 66 ]. Distal aspiration catheters (3 MAX™, Penumbra) are longer than microcatheters used during MT (160 cm vs. 157 cm); thus, they cannot be navigated in a coaxial manner.…”

“…Distal aspiration catheters (3 MAX™, Penumbra) are longer than microcatheters used during MT (160 cm vs. 157 cm); thus, they cannot be navigated in a coaxial manner. In the blind exchange maneuver, an SR is deployed via a microcatheter; the microcatheter is then pulled out and a 3- or 4-MAX™ (Penumbra) aspiration catheter is gently advanced over the retrieval wire under fluoroscopy until clot contact [ 66 ]. This technique can also be performed with larger aspirations systems in more proximal locations.…”