Chronic Subdural Hematoma Embolization With Detachable Coils (SEED)

Safety and Efficacy of Chronic Subdural Hematoma Embolization With Detachable Coils

This is a prospective, multi-center, post market registry study designed to evaluate the safety and efficacy of treatment with Balt coils in patients with chronic subdural hematoma (cSDH).

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Subdural Hemorrhage (cSDH)
• Intervention / Treatment: Device: Balt coils: (Balt USA, LLC); Procedure: MMA embolization

Detailed Description

The primary objective of this observational registry study is to assess the safety and efficacy of Balt Coils as an adjunct to middle meningeal artery (MMA) embolization in a real-world setting among patients undergoing treatment for chronic subdural hematoma (cSDH), and explore correlations between patient characteristics, clinical characteristics, and outcomes. By collecting comprehensive, real-world data, the registry will characterize procedural inputs, document clinical and radiographic outcomes, and explore variation in technique and practice setting. The overarching goal is to generate a more complete understanding of Middle Meningeal Artery Embolization (MMAE) in diverse clinical environments, inform future prospective studies, and guide evidence-based adoption of this evolving therapy. Patients may be treated with Balt coils regardless of enrollment in the study as the decision to place the coils should be made independently as per standard of care and prior to enrollment in the study.

• Study Type: Observational
• Enrollment (Estimated): 150

Contacts and Locations

• Study Contact: Name: Sukaina Davdani; Phone Number: (212) 241-2524; Email: sukaina.davdani@mountsinai.org
• Study Contact Backup: Name: Sydney Edwards; Phone Number: (212) 241-2524; Email: Sydney.Edwards@mountsinai.org

Study Locations

• United States
  • New York
    • New York, New York, United States, 10029
      • Mount Sinai Hospital
      • Contact: Sukaina Davdani; Email: sukaina.davdani@mountsinai.org
      • Principal Investigator: Christopher Kellner
      • Contact: Sydney Edwards; Email: Sydney.Edwards@mountsinai.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients with symptomatic chronic subdural hematoma (cSDH), with or without previous surgical evacuation that need additional treatment

Description

Inclusion criteria:

• Age ≥ 18
• Patients experiencing unilateral or bilateral non-acute subdural hematoma confirmed by CT imaging. Acute on Chronic or mixed density hematoma allowed.
• A clinical decision has been made to use coiling and/or embolics as treatment, with or without surgical debridement, independently as per standard of care and prior to enrollment in the study.
• Signed informed consent obtained by patient or Legal Authorized Representative (LAR)

Exclusion criteria:

• Primary acute SDH
• Prior MMAE in target territory
• Premorbid mRS > 3
• Common carotid stenosis >70% or prior carotid stent placement
• Significant medical contraindication to angiography (kidney failure/disease)
• Anatomical variations that would make MMA embolization difficult or unsafe
• Currently participating in an investigational (drug, device, etc.) clinical trial that may confound study endpoints
• Pregnancy
• Life expectancy ≤ 1 year

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Participants with cSDH; All participants enrolled will be treated with the Balt coils.; MMA embolization: Utilize Balt Coils as stand-alone with or without other embolics treatment.; MMA embolization: Utilize Balt Coils in combination with or without embolics in surgical or bedside evacuation, such as:MMA embolization in combination with Balt coils post-surgical debridement, orMMA embolization using Balt coils alone, pre- or post-surgical debridement.

Device: Balt coils: (Balt USA, LLC); MMA embolization utilizing Balt Coils; Other Names: Optima; OptiMax; OptiBlock; Optima series line extensions; Procedure: MMA embolization; surgical or bedside evacuation pre or post-surgical debridement

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in hematoma volume	Change in hematoma volume based on CT imaging	180 days
Change in maximal thickness	Change in maximal thickness based on CT imaging	180 days
Change in midline shift	Change in midline shift (mm) based on CT imaging	180 days
Number of periprocedural major disabling stroke or any death	Number of periprocedural major disabling stroke or any death	30 days
Number of participants with symptomatic recurrence progression requiring retreatment	Number of participants with symptomatic recurrence progression of the SDH requiring retreatment	180 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Device-related adverse events (AE), serious adverse events (SAE), and procedural-related SAE	Number of Adverse events and serious adverse events related to the device as assessed by an independent medical monitor	180 days
Number of Acute successful embolization of the target vessel	Determination of successful embolization based on angiographic imaging	Immediately post-procedure
Change in EuroQoL 5 dimensions 5 levels (EQ-5D-5L)	The EQ-5D is a generic instrument for describing and valuing health. The new version includes the 5 levels of severity in each of the existing five EQ-5D dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, and now called the EQ-5D-5L, each assessed on a 5-point scale (1=no problem, 2=slight problems, 3=moderate problems, 4=severe problems, 5=extreme problems). Participants score each dimension based on their health that day and their responses are used to generate a health index score. Index scores could range from <0 (a health state equivalent to dead with negative values representing a state worse than dead) to 1 (full health). Lower scores indicate a higher QoL.	180 days

Collaborators and Investigators

• Sponsor: Icahn School of Medicine at Mount Sinai
• Collaborators: John Muir Health; Carondelet Neurological Institute
• Investigators: Principal Investigator: Christopher Kellner, ICAHN School of Medicine at Mount Sinai; Principal Investigator: Benjamin Yim, John Muir Health; Principal Investigator: Alexander Coon, Carondelet Neurological Institute

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: December 5, 2025
• First Submitted That Met QC Criteria: December 5, 2025
• First Posted (Actual): December 18, 2025

Study Record Updates

• Last Update Posted (Actual): March 10, 2026
• Last Update Submitted That Met QC Criteria: March 6, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Middle meningeal artery; Coils; Subdural hemorrhage
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Wounds and Injuries; Pathologic Processes; Chronic Disease; Disease Attributes; Hemorrhage; Craniocerebral Trauma; Trauma, Nervous System; Intracranial Hemorrhages; Intracranial Hemorrhage, Traumatic; Pathological Conditions, Signs and Symptoms; Hematoma; Hematoma, Subdural; Hematoma, Subdural, Chronic
• Other Study ID Numbers: STUDY-25-01365

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Upon the completion of the study, Mount Sinai's data management team will clean and analyze all data in preparation of manuscript writing and publication. Data that will be shared and published will be that of all participants combined to protect individual patient privacy and confidentiality.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes