The Onyx™ Trial For The Embolization Of The Middle Meningeal Artery For Chronic Subdural Hematoma (OTEMACS)

The Onyx™ Trial For The Embolization Of The Middle Meningeal Artery For Chronic Subdural Hematoma (OTEMACS)

Middle meningeal artery (MMA) embolization via a minimally invasive endovascular approach might increase the likelihood of resolution and might prevent reaccumulation of Chronic Subdural Hematoma (CSDH). The purpose of the OTEMACS Trial is to assess the safety and effect on recurrence rate and functional outcome of endovascular treatment in patients with CSDH.

Study Overview

• Status: Terminated
• Conditions: Brain Diseases; Central Nervous System Diseases; Wounds and Injuries; Hematoma, Subdural, Chronic
• Intervention / Treatment: Device: Middle Meningeal Artery Embolization; Procedure: Standard Management

Detailed Description

The OTEMACS study is a prospective, multicenter clinical trial with randomized treatment allocation, open label treatment and blinded endpoint evaluation (PROBE), designed to demonstrate that MMA embolization via a minimally invasive endovascular approach combined with standard (surgical/conservative) management is superior to standard management alone, in reducing the rate of CSDH-related surgical interventions and the recurrence rate in patient with CSDH at 90 days.

Eligible symptomatic CSDH patients will be randomly assigned, in a 1:1 ratio, to receive either surgical treatment plus an adjuvant MMA embolization (ST+MMAE group; the Experimental arm) or surgical treatment alone (ST group; the Control arm).

Eligible symptomatic nonsurgically treated patients with CSDH will be randomized, in a 1:1 ratio, to MMA embolization (MMAE group; the Experimental arm) or conservative management (CM group; the Control arm).

• Study Type: Interventional
• Enrollment (Actual): 247
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Bordeaux, France
    • CHU de Bordeaux Hôpital Pellegrin
  • Bron, France, 69677
    • CHU Lyon
  • Dijon, France, 69003
    • Chu de Dijon
  • Montpellier, France, 34 295
    • CHU de Montpellier - Gui de Chauliac
  • Nîmes, France, 34090
    • CHU de Nîmes
  • Toulouse, France, 31059
    • CHU de Toulouse Hôpital Pierre Paul Riquet

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 115 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient is ≥ 18 years old at inclusion (no upper age limit).
• CSDH confirmed on cranial imaging (e.g. CT/magnetic resonance imaging [MRI]), as documented by a radiologist.
• One or more symptoms attributable to CSDH including headache, cognitive impairment, gait instability, seizure, mild focal neurologic deficit, speech disturbance, or decreased consciousness.
• No significant pre-morbid disability (baseline mRS score ≤3).
• Decision of conventional therapy (neurosurgeon blinded to the randomization group)
• Patient or patient's representative has received information about the study and has signed and dated the appropriate Informed Consent Form, or fulfilling the criteria for emergency consent.

Exclusion Criteria:

• CSDH developing with underlying conditions: vascular lesions, brain tumor, arachnoid cyst, or spontaneous intracranial hypotension.
• CSDH that have a focal location (confined to the frontal or temporal base or the interhemispheric space without cerebral convexity involvement), is 10 mm or less in thickness, or have no mass effect (cortical flattening or midline shifting).
• Known absence of vascular access or any local cause prohibiting femoral catheterization.
• Known contrast or endovascular or anesthetic product allergy or contraindications.
• Any contraindications to the use of the Onyx™.
• Female who is known to be pregnant or lactating at time of admission.
• Patient presenting severe or fatal co-morbidities or Life expectancy under 6 months that will likely interfere with improvement or follow-up or that will render the procedure unlikely to benefit the patient.
• Patient unable to be present or available for follow-up
• Pre-existing neurological or psychiatric disease that would confound the neurological or functional evaluations (e.g. severe dementia).
• Current participation in another investigational drug or device study.
• Major patients under court protection, guardianship or curatorship.
• Not be affiliated to a French social security system or a beneficiary of such a system

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: MMA embolization group; MMA embolization procedure with Onyx™ in addition to standard (surgical/conservative) management	Device: Middle Meningeal Artery Embolization; MMA embolization using the Onyx™ non-adhesive liquid embolic agent within 72 hours after randomization in addition to standard management
Other: Control group; Standard (surgical/conservative) Management alone	Procedure: Standard Management; Procedure : Surgical Management Surgical evacuation of the subdural hematoma Other: Conservative Management Standard medical management: drug treatment and/or observation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recurrence rate in the Experimental group vs. the Control group	The recurrence of CSDH is defined by: radiological remaining of the hematoma with thickness > 10 mm in the ipsilateral subdural space with or without any clinical presentation at 90 days (+/- 14 days) after the randomization OR; revision surgery (in surgical group) / surgical rescue (non-surgical group) for hematoma reaccumulation (as assessed	Within 90 days

Secondary Outcome Measures

Outcome Measure	Time Frame
Mortality rates at discharge	Within 7 days
Major disabling stroke at discharge	Within 7 days
Incidence of procedure-related and device-related serious adverse events (PRSAEs and DRSAEs)	Through 24 hours (-6/+24 hours) post endovascular treatment
Rate of recurrence of CSDH requiring revision surgery (in surgical group) or surgical rescue (in non-surgical group)	Within 90 days
Change in hematoma volume (HV) in the Experimental group vs. the Control group	At 90 days
Shift on the modified Rankin Scale (mRS) score in the Experimental group vs. the Control group	At 90 days
Proportion of patients with good functional outcome, defined as mRS 0-2	At 90 days
Proportion of patients with favorable functional outcome, defined as mRS 0-3	At 90 days
Degree of disability (shift on the mRS combining scores of 5 and 6)	At 90 days
Distribution of utility weighted mRS (UW mRS)	At 90 days
Quality of life assessed by the EuroQol (Quality of life) EQ-5D scale	At 90 days
Quality of life assessed by the Barthel Index	At 90 days
Length of hospital stay for neurosurgery.	within 90 days
Incidence of all-cause mortality	At 90 days

Collaborators and Investigators

• Sponsor: University Hospital, Montpellier
• Investigators: Principal Investigator: Vincent COSTALAT, MD, PhD, University Hospital, Montpellier

Study record dates

Study Major Dates

• Study Start (Actual): October 12, 2021
• Primary Completion (Actual): May 28, 2025
• Study Completion (Actual): May 28, 2025

Study Registration Dates

• First Submitted: February 3, 2021
• First Submitted That Met QC Criteria: February 5, 2021
• First Posted (Actual): February 8, 2021

Study Record Updates

• Last Update Posted (Actual): July 15, 2025
• Last Update Submitted That Met QC Criteria: July 10, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Embolization; Chronic Subdural Hematoma; Middle Meningeal Artery
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Chronic Disease; Disease Attributes; Hemorrhage; Craniocerebral Trauma; Trauma, Nervous System; Intracranial Hemorrhages; Intracranial Hemorrhage, Traumatic; Wounds and Injuries; Brain Diseases; Nervous System Diseases; Central Nervous System Diseases; Hematoma, Subdural; Hematoma, Subdural, Chronic; Hematoma
• Other Study ID Numbers: RECHMPL20_0362

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No