The Carotid and Middle Cerebral Artery Occlusion Surgery Study "CMOSS"

Recruiting

Phase 3 Results N/A

Trial Description

The recently published Carotid Occlusion Surgery Study (COSS) failed to show a benefit of extracranial-intracranial (EC-IC) bypass surgery over medical therapy in patients with symptomatic hemodynamically significant carotid occlusion. Since then on, different controversies have been raised on several aspects including the study population, qualifications of surgeons and hemodynamic evaluation.
In COSS protocol, the primary inclusion population is the patient demonstrating occlusion of unilateral ICA while the contralateral ICA less than 50% stenosis. Because of the enrollment problems, in the final result report, 18% patients suffered from contralateral ICA stenosis more than 50%. As we known, COSS utilized oxygen extraction fraction (OEF) ratio by PET as the criterion of hemodynamic evaluation. Bilateral ICAs lesion will disturbed the ratio even the identifying the subgroup of patients with hemodynamic insufficiency.
As an interventional trial, the COSS should ensure the certification for the experienced surgeons. While for expanding the number of centers and enhancing recruitment, COSS made some concessions on the surgeons training and certification. The 15% postoperative event rate is not the best that can be achieved according to recent surgical technical development.
The cerebral hemodynamic insufficiency has been considered as the primary pathophysiological factor for patients with ICA or MCA occlusion. For these patients, antiplatelet therapy is not likely to prevent hemodynamic stroke.EC-IC bypass surgery probably will be the possible effective therapy.
These underlying assumptions deserved further exploration and more strict research.So the CMOSS study in China is designed to compare the efficacy and safety of EC-IC bypass surgery with medical therapy in patients with symptomatic hemodynamically significant carotid occlusion.

Detailed Description

Patients with symptoms of cerebral or retinal ischemia associated with ipsilateral internal carotid artery (ICA) occlusion have an annual risk of 5-8% of recurrent ischemic stroke. While in China, the incidence of middle cerebral artery (MCA) occlusion is higher than in western countries. The annual risk of recurrent ischemic stroke in patients with symptomatic ICA or MCA occlusion has not improved over the years. The proportion of recurrence that was minor disabling was rather high.

Conditions

Interventions

  • Clopidogrel (Plavix┬«)Drug
    Other Names: Plavix
    ARM 1: Kind: Experimental
    Label: medical group
    Description: all the participants in this group will be given medical therapy including aspirin 100mg per day or clopidogrel 75mg per day
  • Aspirin Drug
    Other Names: clopidogrel; combination aspirin-dipyridamole
    Intervention Desc: all participants in this group will be given medical therapy including Aspirin 100mg per day or clopidogrel 75mg per day
    ARM 1: Kind: Experimental
    Label: medical group
    Description: all the participants in this group will be given medical therapy including aspirin 100mg per day or clopidogrel 75mg per day
  • Bypass surgery Procedure
    Other Names: EC-IC bypass surgery
    Intervention Desc: all participants in this group will be performed EC-IC bypass surgery
    ARM 1: Kind: Experimental
    Label: bypass group
    Description: all the participants in this group will be performed EC-IC bypass surgery

Trial Design

  • Allocation: Randomized
  • Masking: Single Blind (Outcomes Assessor)
  • Purpose: Treatment
  • Endpoint: Safety/Efficacy Study
  • Intervention: Parallel Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary the number of participants who suffer from stroke or death after EC-IC bypass surgery or medical therapy up to 30 days Yes
Primary the number of participants who suffer from ipsilateral ischemic stroke up to 24 months No
Secondary the number of participants who suffer from severe transit ischemic attack (TIA) up to 24 months of randomization No
Secondary the number of participants who suffer from all stroke or death during 30 days to 24 months during 30 days to 24 months No
Secondary the changes from baseline in mRS, national institutes of health stroke scale (NIHSS) and Barthel Index at 7 days, 30 days, 6 months, 12 months and 24 months No
Secondary the changes from baseline of cerebral blood flow (CBF) ratio in CT perfusion at 24 months No
Secondary the number of participants who suffer from all kinds of adverse events related to surgery up to 30 days Yes

Sponsors