Wiebke Kurre
Mechanical thrombectomy for the treatment of acute stroke is gaining importance in the portfolio of neuro-endovascular procedures. With proper patient selection, optimized workflow, and advanced technique, angiographic and—even more importantly, clinical—success is convincing. Triggered by the rapid evolution of endovascular stroke treatment, randomized trials comparing standard therapy and mechanical thrombectomy were initiated and are actively recruiting patients. Still, there are some not yet properly solved hazards of mechanical thrombectomy. Intensive research leading to methodologic refinement of endovascular stroke treatment should accompany the ongoing trials to increase the chance of positive trial results.
Spread of thrombus material to previously unaffected vessel territories can be observed in mechanical recanalization procedures. Though this spread may increase ischemic damage and hamper clinical outcome, it was not thoroughly investigated in the past. For this reason we chose it as a target for our investigation. From our institutional database we selected 105 consecutive patients treated for isolated middle cerebral artery occlusion by mechanical thrombectomy between 2008 and 2012. In the latter subjects we assessed the frequency of treatment-induced anterior cerebral artery emboli. Meticulous reading of postprocedural angiographic images revealed new embolic occlusions of anterior cerebral artery branches in 11.4% (12 of 105). Thus, spread of thrombus material was identified as a relatively frequent procedural side effect. Six major anterior cerebral artery branch occlusions were treated by mechanical recanalization and 5 of 6 targets were successfully recanalized with no side effects. Postprocedural imaging revealed ischemic infarcts in the anterior cerebral artery territory in 5.5% (6 of 105) of patients, and in 3.8% (4 of 104), motor or supplementary motor areas were affected, suggesting a relevant impact on motor function recovery. Three patients receiving additional anterior cerebral artery recanalization procedures developed new infarcts.