Predicting Outcomes in Thrombectomy for Isolated M2 Occlusions

Why the fuck are you lazily predicting outcomes rather than creating protocols that deliver recovery?  

Laziness? Incompetence? Or just don't care? No leadership? NO strategy? Not my job? Not my Problem?

I'd fire you for this crapola! And you have the wrong measurement of outcomes! Survivors don't give a flying fuck about recanalization, THEY WANT RECOVERY! Are you that blitheringly stupid? 100% recovery is the only goal in stroke, if you don't measure that you'll never get there!

“What's measured, improves.” So said management legend and author Peter F. Drucker 

Predicting Outcomes in Thrombectomy for Isolated M2 Occlusions

• Shannon Tierney, MD @stierneymd

Originally published November 29, 2023 10.1161/blog.20231128.743740

Kniep H, Meyer L, Broocks G, Bechstein M, Heitkamp C, Winkelmeier L, Faizy T, Brekenfeld C, Flottmann F, Deb-Chatterji M, et al. Thrombectomy for M2 Occlusions: Predictors of Successful and Futile Recanalization. Stroke. 2023;54:2002-2012.

Since the release of randomized control trials in 2015 proving the efficacy of endovascular therapy in large vessel occlusion stroke, ensuing research has focused on advancing the use of thrombectomy in acute ischemic stroke treatment. Subgroup analyses and retrospective studies have suggested efficacy of thrombectomy for medium and distal vessel occlusion stroke, and three randomized control trials on the subject are underway. Predictors of thrombectomy success in these cases have not been well-described. Kniep et al. aimed to describe predictors of successful recanalization of isolated M2 occlusions using data from the German Stroke Registry-Endovascular Treatment (GSR-ET). The GSR-ET is a nationwide registry which enrolled patients from 2015-2021 who were ³18 years old, had a clinical diagnosis of acute ischemic stroke, and received endovascular treatment.¹ In this study, 13082 patients from the registry were screened for eligibility, and 1294 patients with isolated M2 occlusions were included in the analysis.

The primary outcome was successful recanalization defined as TICI 2b or 3. Successful recanalization was achieved in 83.6% of patients, 40.6% of whom received TICI 2b and 59.4% TICI3. When compared to unsuccessful (TICI <2b) recanalization, successful recanalization was significantly associated with lower pre-stroke mRS, lower NIHSS, fewer passes, higher rates of general sedation, and lower rates of conversion from conscious to general sedation. The frequency of comorbidities, ASPECTS score, and rates of IV thrombolysis were similar between groups. Successful recanalization was associated with lower adverse events, including sICH. A good functional outcome, as defined by a 90-day mRS £2, was achieved in 48.6% of patients compared to 20.3% with unsuccessful recanalization (p <0.001).

Secondary outcomes were complete (TICI 3), near-complete (TICI 2b), and futile recanalization (TICI 2b or 3 achieved with a poor 90-day functional outcome). Complete recanalization had higher rates of good outcomes compared to near-complete, but only the proportion of patients with excellent outcomes (90-day mRS £1) and the change in mean mRS were significant. Complete recanalization was associated with younger age, higher rates of hypertension, dyslipidemia, and atrial fibrillation, higher ASPECTS, higher rates of generalized anesthesia, and fewer passes. Patients with futile recanalization tended to be older with poorer pre-stroke functional baselines, higher rates of comorbidities, higher NIHSS, and lower ASPECTS. They received IV thrombolysis significantly less often, had a higher rate of general sedation, higher rate of conversion from conscious to general sedation (3.8% vs 3.0%), more passes (1.5 vs 1.1), and more complications including symptomatic ICH (5.2% vs 0.4%).

In a multivariable logistic regression analysis, general anesthesia was associated with increased odds of successful and complete recanalization whereas conversion from conscious to general sedation was associated with reduced likelihood of both successful and complete recanalization. Significant predictors of futile recanalization included poorer pre-stroke mRS, comorbid diabetes, adverse treatment events, more passes, higher NIHSS, age, lower ASPECTS, and lower rates of IV thrombolysis.

This article reports similarly high rates of successful M2 recanalization as recent meta-analyses.^2,3 It demonstrated higher rates of a good outcome in those with successful recanalization. General sedation was frequently used (71.4%) and was a significant predictor for successful and complete recanalization. This finding might be explained by virtue of M2 occlusions involving a smaller vessel caliber and thereby posing additional technical challenges. Further investigation of the impact of sedation type on thrombectomy functional outcomes, particularly as it may be modified by the site of occlusion, is warranted.⁴ There are clear limitations to this study. By design, the registry was inherently susceptible to selection bias. Data such as time from last known well, prior antithrombotic use, and favored stroke etiology were not captured. The endovascular techniques employed were also not described, and a variety of devices were used across the 23 sites. Still, considering these limitations, this study advances our understanding of factors influencing real-world successful recanalization of isolated M2 occlusions and emphasizes the importance of further investigation of the role of sedation.