The findings indicate a need to objectively measure outcomes and encourage an optimal technique or set of techniques, the researchers say.
Use of stent retriever in combination with aspiration, a technique coined “Solumbra,” has become a popular approach to mechanical thrombectomy for acute ischemic stroke, according to recent survey Variations in the technique are plentiful, however, and it remains unclear how they influence patient outcomes.
Tapan Mehta, MD (University of Minnesota, Minneapolis), and colleagues say the until now, these variations in understanding and implementation of the Solumbra technique have not been reported. The survey results published online in the Journal of NeuroInterventional Surgery are “fairly representative of physicians from different backgrounds and practice settings,” they note.
Back in 2018, Mehta et al posted a link in the members-only forum on the Society of NeuroInterventional Surgery website to an 18-part anonymous survey questionnaire. The survey included multiple questions related to the Solumbra technique.
During a 4-week period, 80 physicians responded. The favored technique reported by the largest proportion of respondents (41.12%) was direct aspiration without a balloon guide catheter (BCG), followed by the Solumbra technique without a BCG (32.4%).
Among those who reported using the Solumbra technique, 77.6% said they wait between 2 and 5 minutes to allow clot engagement, 55.2% always remove the microcatheter before aspiration, and 69.1% initiate aspiration through the intermediate catheter only when retrieving the stent retriever.
Unexpectedly, those who reported that they did not use BGCs, or use them only infrequently, also reported a higher incidence of > 80% TICI 2b/3 annual recanalization rates (OR 8.85, 95% CI 2.03-38.55), compared with those who consistently use BGCs.
“This contradicts the results from a recent thoughtfully analyzed retrospective data set as well as the results of numerous other basic science and clinical studies which show a reduced incidence of distal secondary emboli and increased incidence of TICI 2b/3 recanalization with the use of BGCs,” Mehta and colleagues write.
More in line with expectations, 95.5% of respondents reported performing aspiration after positioning the intermediate catheter at the face of the clot. Those who used this technique also reported higher rates of TICI 2b/3 recanalization compared with those who kept the intermediate catheter between the stent retriever and guide catheter.
The authors noted that there was such wide variation in the approach to the Solumbra technique that it is difficult to even define exactly operators may mean when they report using it.
“[O]ur study reveals that there are wide variations in mechanical thrombectomy techniques, particularly in the Solumbra technique,” they conclude. “The impact of these variations on recanalization rates and eventually patient outcomes are unclear, especially given the self-reported outcomes contained in this study. Therefore, it will be crucial for operators to objectively assess their outcomes and for practitioners in general to continue to evolve towards an optimal [mechanical thrombectomy] technique or set of techniques.”
Mehta T, Male S, Quinn C, et al. . J NeuroInterv Surg. 2019;Epub ahead of print.
Mehta reports no relevant conflicts of interest.