AT THE EUROPEAN STROKE CONFERENCE
VIENNA (FRONTLINE MEDICAL NEWS) – Sonothrombolysis proved to be an effective alternative to endovascular treatment in patients with large intracranial occlusions, but clot removal via a retrievable stent appeared to have the edge when it came to achieving a good functional outcome, according to data presented at the annual European Stroke Conference.
In the first head-to-head comparison of the two strategies, there was no difference in the primary end point of the final modified Rankin Scale (mRS) score at the end of neurorehabilitation or death within 90 days. The mean final mRS was 3.78 with endovascular treatment and 3.95 with sonothrombolysis, with a nonsignificant (P = .12) odds ratio of 1.70 favoring the noninvasive procedure.
However, patients who underwent endovascular therapy were 3.89 times more likely than were those who had sonothrombolysis to achieve the secondary end point of a good functional outcome defined as a final mRS of 0-2 (24.7% vs. 13.6%; P = .02). Early recanalization was also possible in more patients with endovascular therapy than with sonothrombolysis (82.2% vs. 32.2%; OR, 15.77; P < .001).
“At the moment, everything veers toward using stent retrieval with thrombectomy, which requires very high costs at present and cannot be performed in every center,” noted study investigator Matthias Reinhard of the University Medical Center Freiburg (Germany) in an interview. On the other hand, Dr. Reinhard said, “sonothrombolysis is much less invasive and does not need specific interventionists, and it can be done with normal ultrasound devices, which are already available in every stroke unit.”
Sonothrombolysis enhances the thrombolytic activity of recombinant tissue plasminogen activator (rTPA) near to the clot, he explained, and has been shown in a Cochrane reviewto double the odds for functional independence, as well as upping the chances for recanalization around threefold ( Cochrane Database Syst. Rev. 2012;10:CD008348 ). This is on a par with the results obtained with endovascular treatment in recent trials.
Since the two methods for enhancing thrombolysis with rTPA had not been directly compared before, Dr. Reinhard and his associates decided to look back at the medical records of patients with acute anterior circulation stroke with M1 or carotid T occlusion who were treated at two adjacent medical centers that used one or other of the methods as a standard treatment. After thrombolysis with rTPA, patients at one center underwent endovascular treatment with stent retrieval while patients at the other center had sonothrombolysis.
A total of 132 patients were assessed: 73 underwent endovascular treatment and 59 had sonothrombolysis. The median age in each group was 71 and 75 years, respectively, with around half the participants in each group being male. The groups had similar mean National Institutes of Health Stroke Scale scores (15 and 13). The majority of patients in each group had M1 vessel occlusions (60% and 69%) with the remainder (40% and 31%) having carotid T vessel occlusions. The mean onset to rTPA was 117 minutes and 105 minutes, respectively.
Subgroup analysis showed a significant benefit for endovascular treatment over sonothrombolysis in patients with carotid T occlusions, with an adjusted OR of 5.61 (P = .008). However, the two methods were comparable (OR, 1.07; P = .880) in patients with M1 occlusions.
“The main finding was that sonothrombolysis might perhaps be as equally effective as endovascular treatment in moderate-size occlusions such as middle cerebral artery occlusions but not in the very proximal occlusions of the carotid T,” Dr. Reinhard said. “So, one strategy might be to first apply sonothrombolysis and if this does not work, then to move the patient to the endovascular treatment,” he suggested, noting that this might be a better strategy to test in a future clinical trial than directly comparing the methods in a larger number of patients.
In terms of safety, there was no significant advantage of using one procedure over the other, despite three (4.1%) patients in the endovascular group and none in the sonothrombolysis group experiencing symptomatic intracranial hemorrhage (P = .25). Type 1 parenchymal hematomas were more common in patients who had sonothrombolysis than in those who had endovascular therapy (15.3% vs. 5.5%, P = .09). Mortality at 90 days was around 20% in both groups.
Dr. Reinhard had no disclosures.