LOS ANGELES — The latest clinical trial of thrombectomy for acute ischemic stroke has reinforced concerns about performing the endovascular procedure under general anesthesia.
The DEFUSE 3 trial, reported at last month's International Stroke Conference (ISC) 2018 and simultaneously published in the New England Journal of Medicine, showed a large benefit of removing the clot by thrombectomy in patients presenting with a large-vessel occlusion 6 to 16 hours after stroke onset and still having salvageable brain tissue identified on perfusion imaging.
However, results of subgroup analysis suggest that this benefit is greatly curtailed in patients receiving the procedure under general anesthesia.
"I would recommend from these results that general anesthesia should be avoided if possible in patients having endovascular therapy for stroke," said Maarten Lansberg, MD, Stanford University Stroke Center, California, during his presentation here, also at ISC 2018.
"Quite a few trials have looked at the comparison of thrombectomy performed under general anesthesia vs conscious sedation and some of these have shown a worse outcome with general anesthesia, so we wanted to look at this too," he explained.
"We tried to discourage general anesthesia in this trial because of prior data suggesting worse outcomes with this approach, but some sites prefer to use general anesthesia. So we still had 28% of our patients treated that way, and the other 72% received conscious sedation," Dr Lansberg noted.
When the patients treated with thrombectomy under conscious sedation were compared with the control group, there was a larger benefit and it was significant.
But when patients in the thrombectomy group who received the procedure under general anesthesia were compared with the control group, the benefit was much smaller and not significant, Dr Lansberg reported. However, he cautioned that the sample size was small, so it would be difficult to show statistical significance.
Table. Good Outcome With Endovascular Therapy or Control Under General Anesthetic vs Conscious Sedationa
|Type of Anesthesia||Endovascular Therapy (%)||Control (%)||Relative Risk (95% Confidence Interval)|
|General anesthesia (n = 26)||23||17||1.4 (0.6 - 3.2)|
|Conscious sedation (n = 66)||53||17||3.2 (1.9 - 5.3)|
|aGood outcome was defined as a modified Rankin Scale score of 0 to 2.|
The relative risk for a good outcome with endovascular therapy under general anesthesia vs conscious sedation was 0.44 (95% confidence interval, 0.2 - 0.9).
"There was a statistical difference towards worse outcomes under general anesthesia that was not explained by imbalances in the patients' baseline characteristics," Dr Lansberg added. "However, this comparison was not randomized and we can't eliminate all biases."
He told Medscape Medical News that there are some patients for whom general anesthesia is necessary, such as those in respiratory distress who need to be intubated. "But I don't think we want to use it just to supposedly make the procedure easier. Our results suggest that that is not a good idea."
"It really comes down to operator preference," he added. "Some operators prefer general anesthesia because the patient obviously remains much more still, which is an advantage when performing such a delicate procedure on brain vasculature in terms of complications. But we found patients receiving general anesthesia actually had the same rate of symptomatic hemorrhage and vasculature perforation as those receiving conscious sedation in this study."
Commenting on the results, Bruce Ovbiagele, MD, Medical University of South Carolina, Charleston, and ISC 2018 program chair, said general anesthesia for this procedure "is a concern."
"This negative effect on outcomes after endovascular therapy has been shown previously, and now it has been shown again in this broader time window," he said.
Ralph Sacco, MD, Miller School of Medicine, Miami, Florida, suggested the effect may vary in different hospitals. "I think some of this difference may depend on individual circumstances," he told Medscape Medical News. "Some centers are more used to dealing with general anesthesia than others. It's not just selecting the best device and the right patient for endovascular therapy. We also need the right circumstances around how we do the procedure, and that will be refined over time."
International Stroke Conference (ISC) 2018. Abstract LB 6. Presented January 25, 2018.
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Cite this: More Caution on General Anesthesia in Stroke Thrombectomy - Medscape - Feb 08, 2018.