Endovascular Treatment
Authors: Compagne Kars C.J. , van der Sluijs Pieter M. , van den Wijngaard Ido R. , Roozenbeek Bob , Mulder Maxim J.H.L. , van Zwam Wim H. , Emmer Bart J. , Majoie Charles B.L.M. , Yoo Albert J. , Lycklama à Nijeholt Geert J. , Lingsma Hester F. , Dippel Diederik W.J. , van der Lugt Aad , van Es Adriaan C.G.M. , Roos Yvo B.W.E.M. , van Oostenbrugge Robert J. , Boiten Jelis , Vos Jan Albert , Jansen Ivo G.H. , Goldhoorn Robert-Jan B. , Schonewille Wouter J. , Vos Jan Albert , Coutinho Jonathan M. , Wermer Marieke J.H. , van Walderveen Marianne A.A. , Staals Julie , Hofmeijer Jeannette , Martens Jasper M. , Boiten Jelis , de Bruijn Sebastiaan F. , van Dijk Lukas C. , van der Worp H. Bart , Lo Rob H. , van Dijk Ewoud J. , Boogaarts Hieronymus D. , de Kort Paul L.M. , Peluso Jo J.P. , van den Berg Jan S.P. , van Hasselt Boudewijn A.A.M. , Aerden Leo A.M. , Dallinga René J. , Uyttenboogaart Maarten , Eshghi Omid , Schreuder Tobien H.C.M.L. , Heijboer Roel J.J. , Keizer Koos , Yo Lonneke S.F. , den Hertog Heleen M. , Sturm Emiel J.C. , van Walderveen Marianne A.A. , Sprengers Marieke E.S. , Jenniskens Sjoerd F.M. , van den Berg René , Beenen Ludo F.M. , Postma Alida A. , Roosendaal Stefan D. , van der Kallen Bas F.W. , Martens Jasper M. , Yo Lonneke S.F. , Vos Jan Albert , Bot Joost , van Doormaal Pieter-Jan , Roos Yvo B.W.E.M. , van Oostenbrugge Robert J. , Boiten Jelis , Vos Jan Albert , Schonewille Wouter J. , Hofmeijer Jeannette , Martens Jasper M. , van der Worp H. Bart , Lo Rob H. , van Oostenbrugge Robert J. , Hofmeijer Jeannette , Flach H. Zwenneke , el Ghannouti Naziha , Sterrenberg Martin , Puppels Corina , Pellikaan Wilma , Sprengers Rita , Elfrink Marjan , de Meris Joke , Vermeulen Tamara , Geerlings Annet , van Vemde Gina , Simons Tiny , van Rijswijk Cathelijn , Messchendorp Gert , Bongenaar Hester , Bodde Karin , Kleijn Sandra , Lodico Jasmijn , Droste Hanneke , Wollaert M. , Jeurrissen D. , Bos Ernas , Drabbe Yvonne , Elfrink Marjan , Zweedijk Berber , Khalilzada Mostafa , Venema Esmee , Chalos Vicky , Geuskens Ralph R. , van Straaten Tim , Ergezen Saliha , Harmsma Roger R.M. , Muijres Daan , de Jong Anouk , Hinseveld Wouter , Berkhemer Olvert A. , Boers Anna M.M. , Huguet J. , Groot P.F.C. , Mens Marieke A. , van Kranendonk Katinka R. , Treurniet Kilian M. , Kappelhof Manon , Tolhuijsen Manon L. , Alves Heitor 
Published: January 2019

Background and Purpose—
It is unclear whether endovascular treatment (EVT) is beneficial for patients with acute ischemic stroke with occlusion of the M2 segment of the middle cerebral artery. We aimed to compare functional outcomes, technical aspects, and complications of EVT between patients with acute ischemic stroke because of M2 and M1 occlusions in clinical practice. Furthermore, outcome and complications after EVT in dominant and nondominant caliber M2 division occlusions were studied.

Methods—
Data were obtained from the MR CLEAN Registry (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) which is an ongoing observational study in 16 Dutch centers performing EVT in the Netherlands. Functional outcome was measured with the modified Rankin Scale score at 90 days. Neurological recovery (delta National Institutes of Health Stroke Scale), successful reperfusion rates (extended Thrombolysis in Cerebral Infarction ≥2B), and safety outcomes were also investigated. Associations between occlusion location and outcome were analyzed with ordinal logistic regression models, with adjustment for other prognostic factors.

Results—

In total, 244 (24%) patients with an M2 and 759 (76%) patients with an M1 occlusion who underwent EVT were analyzed. Functional outcomes were not significantly different between patients with M2 versus M1 occlusions (adjusted common odds ratio, 1.24; 95% CI, 0.87–1.73). Occurrence of symptomatic intracerebral hemorrhage was also similar for M2 and M1 occlusions (6.6% versus 5.9%;
P
=0.84). Further analysis about dominance of an M2 branch was performed in 175 (72%) patients. Neurological recovery was comparable (mean delta National Institutes of Health Stroke Scale, −2±10 for dominant M2, −5±5 for nondominant M2, and −4±9 [
P
=0.24] for M1 occlusions). Furthermore, the effect of reperfusion status on functional outcome was comparable between occlusion divisions (common odds ratio, 1.27; 95% CI, 1.06–1.53 for dominant M2; common odds ratio, 1.32; 95% CI, 0.93–1.87 for nondominant M2; and common odds ratio, 1.35; 95% CI, 1.24–1.46 for M1 occlusions).

Conclusions—
Outcomes and complication rates after EVT were similar in patients with M2 and M1 occlusions. Although based on observational data and a limited sample size, a similar association of reperfusion status with functional outcome for all subgroups provides no evidence that patients with either a dominant or a nondominant M2 occlusion should be routinely excluded from EVT.