Kevin O’Connor, MD
Although mechanical thrombectomy (MT) is routinely performed for patients with acute stroke due to large vessel occlusions, interventions for those with medium vessel occlusions (MeVO) are increasing. Techniques for MT for MeVOs include the use stent retrievers and distal aspiration catheters (DACs). A recently developed approach is the blind exchange/mini-pinning (BEMP) technique, which combines a mini stent retriever with a DAC (see Figure 1 below).
Pérez-García et al. retrospectively compared mini stent retrievers alone (initial standard institutional MeVO procedure, n=50) versus the BEMP technique (later standard institutional MeVO procedure, n=56) for effectiveness and safety using a prospective database of MT patients. Aside from the DACs, the devices used for the two groups were comparable. The BEMP technique group had a higher rate of expanded Thrombolysis in Cerebral Ischemia (eTICI) 2c/3 recanalization scores after first pass (n=32, 57% versus n=17, 34%; P=0.017) and at procedure conclusion (n=37, 66% versus n=23, 46%; P=0.037). The rate of eTICI ≥ 2b recanalization scores was comparable between the groups after first pass (n=36, 64% versus n=25, 50%; P=0.137) and at procedure end (n=44, 78.5% versus n=39, 78%; P=0.856). A rescue therapy (other than the initial technique) was used less often in the BEMP group (n=4, 7.1% versus n=11, 22%; P=0.028). The BEMP technique was an independent predictor of eTICI 2c/3 recanalization (OR 2.72 [95% CI, 1.19-6.22]; P=0.018).
Most of the safety outcomes were similar between the groups. There was no difference in rate of proximal or distal emboli in the same territory, subarachnoid hemorrhage, or intraparenchymal hematoma. The incidence of emboli to a new territory was lower for the BEMP group (n=1, 1.8% versus n=6, 12%; P=0.035), and BEMP was associated with a lower rate of symptomatic intracerebral hemorrhage (n=1, 1.9% versus n=5, 12.8%; P=0.038). There was no difference in either mortality at 3-months (BEMP 20.8% versus mini 22.4%; P=0.835) or functional independence (i.e., modified Rankin Scale score 0-2) at 3 months (BEMP 50.9% versus mini 53.1%; P=0.831).
Although the study suggests better effectiveness and safety advantages with the BEMP technique over mini stent retrievers alone, there was no comparison to DACs alone. Additionally, there was no randomization, and functional outcome assessments were not masked. Whether the results are reproducible in other settings also requires further study.
