Mechanical Thrombectomy for M2 Occlusions: A Single-Centre Experience

Abstract

Background: The recent success of several mechanical thrombectomy trials has resulted in a significant change in the management of patients presenting with stroke. However, questions still remain as to whether certain groups will benefit from mechanical thrombectomy. In particular, it is still uncertain whether mechanical thrombectomy should be performed in the M2 branches and, more generally, in the distal vasculature. Methods: We retrospectively analysed our prospectively maintained database of all patients undergoing mechanical thrombectomy between January 2008 and August 2016. We collected demographic, radiological, procedural and outcome data. Results: We identified 106 patients that met our inclusion criteria. The mean age of the patients was 68 ± 13.8 years, and there were 58 (54.7%) male patients. Associated medical conditions were common with hypertension seen in 71% of the patients. The average Alberta Stroke Program Early CT (ASPECT) score on admission was 8.5 ± 1.7. The mean National Institutes of Health Stroke Scale score was 11.8 ± 7.02. The mean duration of the procedure was 103 ± 3.4 min, and the average number of thrombectomy attempts required was 1.8 (range 1-8). Angiographically, Thrombolysis in Cerebral Infarction Scale (TICI) ≥2b was obtained in 90.5% of the patients. Five patients (4.7%) had symptomatic intracranial haemorrhage on follow-up. At 90-day follow-up, 54.6% of the patients had a modified Rankin Scale (mRS) score 0-2, and 71.5% had an mRS score ≤3. There were 15 deaths at 90 days (14.1%). Conclusion: Mechanical thrombectomy in patients with solitary M2 clots is technically possible and carries a high degree of success with a good safety profile. Patients with confirmed M2 occlusion should be considered for mechanical thrombectomy.

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.…”

Endovascular treatment for acute ischaemic stroke due to medium vessel occlusion: data from ANGEL-ACT registry

“…The efficacy and safety of EVT for MeVO have been studied extensively, with most publications being retrospective and single-centre studies. [5][6][7][8][9][10][11][12][13] Thus, their findings might not be sufficiently applicable to real-world practice. As a result, a multicentre study is required to explore whether MeVO could benefit from EVT.…”

Endovascular Device Choice and Tools for Recanalization of Medium Vessel Occlusions: Insights From the MeVO FRONTIERS International Survey

“…The optimal strategy for recanalizing MeVOs is currently not known, and the data on the efficacy of first-line aspiration vs. stent-retriever techniques are heterogenous and exclusively from non-randomized studies (12)(13)(14)(15). Use of stent-retrievers, either alone (16)(17)(18)(19) or combined with aspiration (10, 11), seems to be a widespread approach for MeVO EVT. Stent-retrievers alone or combined stent-retrievers and aspiration were the most commonly chosen first-line approaches, with the combined approach being preferred less often in more distal occlusions and stent-retriever alone more often in A3 occlusions.…”