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Tests bypass surgery plus medication against medication alone for a blocked brain artery

Tests bypass surgery plus medicine against medicine alone in adults with a blocked brain artery.

Key facts

Who runs it
Xuanwu Hospital, Beijing
Where
Beijing, ChinaSee the site
Trial code
Registry title
Extracranial-intracranial Bypass Surgery for Symptomatic Chronic Middle Cerebral Artery Occlusion: the CMOSS-2 Trial
Status
Recruiting
People taking part
420 people, planned
Started
15 Sept 2023
Expected to end
Sept 2027
Type of study
Interventional, 2 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • Extracranial-Intracranial Bypass Surgery
  • Medical treatment alone
Record updated
28 March 2025

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults aged 18-65 with a blocked middle cerebral artery on one side, poor blood flow in that part of the brain, and recent stroke-like events. It compares bypass surgery plus medicine with medicine alone.

Age
18-65 years
Sex
All sexes
Disease stage
Chronic blockage (occlusion) of one middle cerebral artery, confirmed by DSA or CTA. Other brain arteries narrowed by less than 50%. CT perfusion shows severe poor blood flow (MTT ≥ 6s or rCBF ≤ 0.8). mRS score 0-2. Large cerebral infarction (more than 1/2 of the artery's territory) must be ruled out.
Earlier treatment
No previous EC-IC bypass surgery. No clinical trial drug or device within 30 days before screening.
Biomarker or test result
CT perfusion result: MTT (symptomatic side) ≥ 6s or rCBF (symptomatic side/contralateral side) ≤ 0.8.

Main reasons for not taking part

  • Brain, subarachnoid, subdural or extradural bleeding within 6 weeks
  • Unstable angina, heart attack or congestive heart failure within 6 months
  • Pregnant or breastfeeding women
  • Bleeding tendency or clotting problems, or heart conditions that can cause emboli (such as atrial fibrillation or prosthetic valves)
  • Uncontrolled diabetes or high blood pressure, or severe liver problems

The registry criteria, word for word

Show all 24 criteriaShow less

Who can take part

  • Age of 18-65 years
  • Confirmed as chronic occlusion of unilateral middle cerebral artery (MCA) by digital subtraction angiography (DSA) or computed tomography angiography (CTA). Other cerebral artery stenosis should be less than 50%
  • CT perfusion demonstrates severe hemodynamic insufficiency in the territory of the qualifying MCA with MTT (symptomatic side) ≥ 6s or rCBF (symptomatic side/contralateral side) ≤ 0.8
  • mRS score is 0-2 points
  • A history of ischemic events (including<1/2 cerebral infarction in the middle cerebral artery supply area, or transient ischemic attack [TIA]) related to the qualifying artery within 12 months
  • The onset of acute stroke should be more than 1 month
  • CT or MRI excludes large cerebral infarction (infarction>1/2 of the territory of the qualifying middle cerebral artery)
  • Patients or their guardians voluntarily participate of the study and sign the consent form

Who cannot take part

  • Previous treatment with EC-IC bypass surgery
  • Having received a clinical trial drug or device within 30 days prior to screening, or being enrolled in another clinical trial
  • History of intracranial hemorrhage, subarachnoid hemorrhage, subdural hemorrhage, or extradural hemorrhage within 6 weeks
  • Unstable angina pectoris or myocardial infarction, congestive heart failure within 6 months
  • Other diseases with a life expectancy of less than 2 years
  • Known allergy or contraindication to aspirin or clopidogrel or other antiplatelet drugs
  • Uncontrolled hypertension with a sitting systolic blood pressure >180 mmHg or a sitting diastolic blood pressure >110 mmHg
  • Active peptic ulcer disease
  • Other diseases or medical history that, in the judgment of the investigator, may affect the efficacy or safety evaluation of this study
  • Coagulation dysfunction or hemorrhagic tendency (e.g. INR > 1.5 and/or platelet count < 100,000 mcL)
  • Known cardiac conditions that may lead to cardiogenic embolism: including prosthetic valves, infective endocarditis, left atrial or left ventricular thrombosis, atrial fibrillation, sick sinus node syndrome, atrial mucinous tumor or cardiomyopathy, ejection fraction <25%
  • Allergy to iodine or x-ray contrast, blood creatinine > 3.0 mg/dl or other contraindications to arteriography
  • Uncontrolled diabetes mellitus with fasting blood sugar (FBS) >16.7 mmol/L
  • Severe liver dysfunction, defined as serum alanine transaminase (ALT) and/or glutamic oxalacetic transaminase (AST) > 3 times the upper limit of normal range
  • Women who are pregnant or lactating
  • Persistent worsening of neurological symptoms within 72 hours

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 18 and 65 years old?

Where in China

  • Xuanwu Hospital, Capital Medical UniversityBeijing, ChinaContact: Liqun Jiao, MDTaking people

About the trial

What the trial wants to find out

The CMOSS-2 trial is a government-funded, prospective, multicenter, randomized controlled trial. It will recruit symptomatic chronic occlusion of the middle cerebral artery in patients with severe hemodynamic insufficiency. Only high-volume center with a proven track record will be included. Patients will be randomized (1:1) to best medical treatment alone or medical treatment plus bypass surgery. Primary outcome is ischemic stroke in the territory of the target artery within 24 months after randomization.

The 2 groups in the trial

  • SurgeryTreatment being tested

    The patients in the surgical group will be treated with direct extracranial to intracranial bypass surgery plus best medical treatment.

    Treatment: Extracranial-Intracranial Bypass Surgery

  • Medical treatmentExisting treatment, for comparison

    The patients will receive medical treatment alone according to the AHA/ASA Stroke and Transient Ischemic Attack (TIA) Stroke Prevention Guidelines (2021 edition).

    Treatment: Medical treatment alone

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
Extracranial-intracranial Bypass Surgery Versus Medical Treatment Alone for Symptomatic Chronic Middle Cerebral Artery Occlusion: the CMOSS-2 Trial
Plain-language title
Tests bypass surgery plus medication against medication alone for a blocked brain arteryGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Fit questions
Built from NCT05899582, who can take part
Record updated
28 March 2025