Mechanical thrombectomy in anterior vs. posterior circulation stroke: A systematic review and meta-analysis.

Background: High-quality evidence exists for mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). The evidence for MT treatment of posterior circulation large vessel occlusion (PC-LVO) is weaker, largely drawn from lower quality studies specific to PC-LVO and extrapolated from findings in AC-LVO, and ambiguous with regards to technical success. We performed a systematic review and meta-analysis to compare the technical success and functional outcomes of MT in PC-LVO versus AC-LVO patients.
Methods: We identified comparative studies reporting on patients treated with MT in AC-LVO versus PC-LVO. The primary outcome of interest was thrombolysis in cerebral infarction (TICI) ≥ 2b. Secondary outcomes included rates of TICI 3, 90-day functional independence, first-pass-effect, average number of passes, and 90-day mortality. A separate random effects model was fit for each outcome measure.
Results: Twenty studies with 12,911 patients, 11,299 (87.5%) in the AC-LVO arm and 1612 (12.5%) in the PC-LVO arm, were included. AC-LVO and PC-LVO patients had comparable rates of successful recanalization [OR = 1.02 [95% CI: 0.79-1.33], p  = 0.848). However, the AC-LVO group had greater odds of 90-day functional independence (OR = 1.26 [95% CI: 1.00; 1.59], p  = 0.050) and lower odds of 90-day mortality (OR = 0.58 [95% CI: 0.43; 0.79], p  = 0.002).
Conclusions: MT achieves similar rates of recanalization with a similar safety profile in PC-LVO and AC-LVO patients. Patients with PC-LVO are less likely to achieve functional independence after MT. Future studies should identify PC-LVO patients who are likely to achieve favourable functional outcomes.
Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: JMP works for and holds equity in Nested Knowledge, Inc., and Superior Medical Experts, Inc. KH works for Nested Knowledge, Inc. KMK works for and holds equity in Nested Knowledge, Inc., works for Conway Medical LLC, and holds equity in Superior Medical Experts, Inc. NH works for and holds equity in Nested Knowledge, Inc. JJH is a consultant for Medtronic and MicroVention and is a member of the scientific and medical advisory board for iSchemaView.