Middle Meningeal Artery Coagulation During Burr-Hole Drainage for Chronic Subdural Haematoma (BURR-MMA) (BURR-MMA)

BURR-MMA: A Prospective Pilot Feasibility Study of Intra-operative Middle Meningeal Artery Coagulation During Burr-Hole Surgery for Chronic Subdural Haematoma

Chronic subdural haematoma (cSDH) is a common condition in older adults, usually treated by burr-hole surgery to drain the collection. Even with good surgery, around 1 in 10 patients develop a recurrence and need a second operation. Research shows that the outer lining of the haematoma is fed by small branches of the middle meningeal artery (MMA), and interrupting these branches may lower the risk of recurrence.

This study looks at whether surgeons can safely and reliably coagulate these small MMA branches at the same time as standard burr-hole drainage, using the routine pre-operative CT scan and surgical navigation already used in everyday practice. Adults (aged 18 years and over) scheduled for burr-hole drainage of a chronic or subacute subdural haematoma will be invited to take part. The procedure, recovery, drain management, and 90-day follow-up will otherwise follow standard NHS care.

No additional imaging is required for the study, and participants are not exposed to any extra radiation. The main purpose is feasibility and safety, not to prove effectiveness. Findings will inform the design of a future multicentre study.

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Subdural Hematomas
• Intervention / Treatment: Procedure: CT-Guided Intra-Operative Middle Meningeal Artery Interruption

Detailed Description

Recurrence after burr-hole drainage of chronic subdural haematoma is driven largely by a vascularised outer membrane supplied by distal convexity branches of the middle meningeal artery. Endovascular MMA embolisation can reduce recurrence but requires a separate interventional radiology procedure and is not uniformly available across NHS centres.

BURR-MMA evaluates an alternative, in-workflow approach: limited bipolar coagulation of distal convexity MMA branches performed through the planned burr-hole during standard evacuation. Pre-operative non-contrast CT is used to map the MMA bony groove, and routine CE-marked neuronavigation is used to standardise targeting. No additional burr-holes, implants, drugs, or research-specific imaging are introduced.

This is an IDEAL Stage 2a, single-centre, single-arm feasibility study enrolling 20-30 adults undergoing burr-hole surgery for cSDH. The primary focus is technical deliverability, safety, procedural fidelity, and characterisation of iterative technique refinement. Exploratory clinical outcomes are collected to Day 90 to inform endpoint selection and sample-size calculations for a future IDEAL Stage 2b multicentre cohort study. All CT imaging is performed as part of routine clinical care; participants receive no additional ionising radiation because of study participation. The study is not powered to assess clinical effectiveness.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jigishaa Moudgil-Joshi, MRCS, MBChB; Phone Number: 020 3456 7890; Email: burrmmatrial@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age ≥18 years.
• Chronic or subacute subdural haematoma scheduled for burr-hole evacuation.
• Treating surgeon considers the CT- and navigation-guided MMA adjunct technically feasible and safe to attempt, recognising that the adjunct may be abandoned intra-operatively according to protocol bail-out criteria.
• Written informed consent, or consultee declaration under the Mental Capacity Act (MCA), with re-consent if capacity returns.

Consented participants who meet eligibility criteria will be enrolled sequentially until the target sample size of 20-30 participants is reached. No randomisation is used in this feasibility phase.

Exclusion Criteria:

• Acute subdural haematoma requiring craniotomy or decompressive surgery.
• Prior ipsilateral MMA embolisation.
• Clear contraindication to pre-operative CT
• Inability to complete Day-90 follow-up.
• Pregnancy or breastfeeding (due to radiation exposure from CT imaging as part of standard clinical care).

If CT is non-diagnostic or cannot be performed, participants will continue with standard burr-hole evacuation without the MMA adjunct; this does not constitute a protocol deviation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Burr-Hole Evacuation With CT-Guided Intra-Operative MMA Interruption; Participants in this single-arm feasibility study will undergo standard burr-hole evacuation of chronic subdural haematoma with subdural drain placement, in accordance with routine clinical practice. In addition, a CT- and neuronavigation-guided intra-operative adjunct will be attempted to identify and interrupt distal convexity branches of the middle meningeal artery (MMA) supplying the haematoma membrane, where this is considered safe and technically feasible by the operating surgeon. The adjunct involves minor adjustment of burr-hole position within the haematoma footprint and limited bipolar coagulation of target MMA branches. If safe identification or access is not possible, the adjunct will be omitted and standard surgery completed. All imaging and peri-operative care are part of standard clinical practice. The study is designed to assess feasibility, safety, procedural fidelity and workflow integration rather than clinical effectiveness.

Procedure: CT-Guided Intra-Operative Middle Meningeal Artery Interruption; This intervention is a surgical adjunct performed during standard burr-hole evacuation of chronic subdural haematoma. Using pre-operative non-contrast CT and intra-operative neuronavigation, the surgeon identifies distal convexity branches of the middle meningeal artery (MMA) supplying the haematoma membrane. Where safely accessible, limited bipolar coagulation is applied to interrupt these branches through the planned burr-hole. Burr-hole position may be slightly adjusted within the haematoma footprint to facilitate safe targeting. If branches cannot be confidently identified or safely accessed, the adjunct is omitted and standard surgery is completed. No additional imaging or devices are introduced beyond routine clinical care.; Other Names: MMA coagulation during burr-hole surgery; Intra-operative MMA interruption

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Technical Success of the MMA Adjunct	Proportion of procedures in which one or more intended distal convexity MMA branches are successfully identified and coagulated by the operating surgeon, confirmed intra-operatively and by post-operative non-contrast CT showing burr-hole placement over the expected MMA bony groove. Reported as a percentage (0-100%); higher values indicate greater technical deliverability.	Intra-operative (during index procedure) and on first post-operative non-contrast CT, up to 72 hours post-operatively.
Incidence of Technique-Related Adverse Events	Number of participants experiencing at least one adverse event judged by the investigator to be related to the MMA adjunct (e.g., thermal injury, additional bleeding, equipment-related events). Reported as a count and percentage of enrolled participants.	Intra-operative through 90 days post-operatively.
Incidence of Serious Adverse Events	Number of participants experiencing at least one serious adverse event (as defined by ICH-GCP), regardless of causality. Reported as a count and percentage of enrolled participants	From index procedure through 90 days post-operatively.
Completeness of Day-90 Outcome Data Capture	Proportion of enrolled participants with complete primary outcome data available at the Day-90 follow-up, against a pre-specified feasibility target of ≥95%. Reported as a percentage.	At 90 days post-operatively.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of cSDH Recurrence Requiring Re-Intervention	Proportion of participants with radiological recurrence (increase in subdural collection size) accompanied by clinical deterioration requiring re-drainage, repeat burr-hole surgery, or rescue MMA embolisation, as determined by the treating neurosurgeon. Reported as a percentage.	Up to 90 days post-operatively
Length of Hospital Stay	Total duration of the index hospital admission, from date of surgery to date of discharge, measured in days.	During index admission (up to discharge, assessed up to 90 days post-operatively).
Incidence of Peri-Operative Complications	Number of participants experiencing one or more peri-operative surgical or medical complications (e.g., wound infection, seizure, pneumonia, venous thromboembolism, acute subdural haematoma). Reported as a count and percentage.	Intra-operative through 30 and 90 days post-operatively.
Incidence of Unplanned Hospital Readmission	Proportion of participants with at least one unplanned readmission to any hospital following discharge from the index admission. Reported as a percentage.	From discharge through 90 days post-operatively.
Functional Outcome Measured by the Modified Rankin Scale (mRS)	Functional status measured using the Modified Rankin Scale (mRS), a 7-point ordinal scale ranging from 0 (no symptoms) to 6 (death). Lower scores indicate better functional outcome.	At 90 days post-operatively.
Health-Related Quality of Life Measured by the EQ-5D-5L Utility Index	Health-related quality of life measured using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) instrument, reported as a single utility index value derived using the UK value set. Scores range from less than 0 (worse than dead) to 1 (full health); higher scores indicate better health-related quality of life.	At 90 days post-operatively.
Added Operative Time Attributable to the MMA Adjunct	Additional intra-operative time required to perform the MMA coagulation adjunct, measured from adjunct start to adjunct stop, in minutes.	Intra-operative (during index procedure).
Procedural Fidelity to the Pre-Specified Surgical SOP	Proportion of procedures in which all pre-specified SOP steps (navigation registration within tolerance, targeting of distal convexity branches only, adherence to avoidance zones, documentation completeness) are fully executed without protocol-defined deviation. Reported as a percentage.	Intra-operative (during index procedure).
Learning Effect on Added Operative Time Across Sequential Cases	Change in added operative time for the MMA adjunct across sequential cases, analysed descriptively using cumulative sum (CUSUM) methodology to identify the case number at which added operative time stabilises. Reported in minutes per case.	Through study completion (up to 12 months).
Concordance Between Pre-Operative CT MMA Groove and Intra-Operative Findings	Proportion of cases in which the distal convexity MMA branch location identified on pre-operative thin-slice non-contrast CT (via the MMA bony groove) is confirmed by intra-operative visualisation through the planned burr-hole. Reported as a percentage.	Intra-operative (during index procedure), compared against pre-operative CT performed within 7 days prior to surgery.
Feasibility of Prospective Healthcare Resource-Use Data Collection	Proportion of enrolled participants with complete prospective records of pre-defined healthcare resource-use items (length of stay, critical care days, re-operations, readmissions, rescue MMA embolisation, discharge destination) captured via the study eCRF. Reported as a percentage against a pre-specified target of ≥90%.	Through 90 days post-operatively.

Collaborators and Investigators

• Sponsor: University College, London
• Collaborators: University College London Hospitals

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: April 9, 2026
• First Submitted That Met QC Criteria: April 17, 2026
• First Posted (Actual): April 24, 2026

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 17, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: chronic subdural haematoma; middle meningeal artery; burrholes
• 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, Subdural; Hematoma; Hematoma, Subdural, Chronic
• Other Study ID Numbers: 204843

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data (IPD) underlying the results reported in publications will be made available. This will include demographic data, clinical characteristics, imaging-derived variables, intra-operative procedural data, and outcome measures (including feasibility metrics, adverse events, and 90-day outcomes). All data will be pseudonymised, with no directly identifiable information shared.
• IPD Sharing Time Frame: Data will be available beginning 6-12 months following publication of the primary study results and will remain available for up to 5 years thereafter, subject to data governance and sponsor approval.
• IPD Sharing Access Criteria: Access will be provided to researchers with a methodologically sound proposal that is consistent with the aims of the original study. Requests will be reviewed by the study team and Sponsor. Data will be shared under a formal data sharing agreement and in accordance with applicable data protection regulations. Access will be limited to de-identified data and may be provided via secure institutional platforms.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

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