Intracranial AneurysmNCT07910864
Effect of Bilateral Greater Occipital Nerve Block on Headache After Intracranial Aneurysm Coiling
A study testing Ultrasound-Guided Bilateral Greater Occipital Nerve Block in people with Intracranial Aneurysm and Postoperative Pain, run by Konya City Hospital at 1 site in Turkey (Türkiye).
Trial summary
Postoperative headache is a common complication following endovascular coil embolization of intracranial aneurysms and may increase analgesic requirements, impair patient comfort, and contribute to hemodynamic instability. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Intracranial Aneurysm, Postoperative Pain
- What is being tested?
- Ultrasound-Guided Bilateral Greater Occipital Nerve Block
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 76 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 2 Nov 2026to 2 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients aged 18-65 years.
- American Society of Anesthesiologists (ASA) physical status I-III.
- Patients scheduled for elective endovascular coil embolization of a unilateral unruptured intracranial aneurysm under general anesthesia.
- Ability and willingness to provide written informed consent.
Who cannot join
- Refusal to provide informed consent or subsequent withdrawal of consent.
- Ruptured intracranial aneurysm or acute subarachnoid hemorrhage requiring emergency intervention.
- Clinical contraindications to greater occipital nerve block, including infection or skin lesions at the injection site, local anesthetic allergy, or anatomical conditions preventing safe needle placement.
- Platelet count below 100,000/mm³, international normalized ratio (INR) greater than 1.5, activated partial thromboplastin time (aPTT) greater than 1.5 times normal, or clinically significant coagulopathy.
- Antithrombotic or antiplatelet treatment that does not meet the predefined safety intervals for deep peripheral nerve blocks according to the ASRA 2025 and ESAIC/ESRA guidelines.
- Moderate-to-severe preoperative headache, defined as a resting Numeric Rating Scale score of 3 or higher.
Show all 13Show fewer
- Known history of severe hypersensitivity or allergic reactions to local anesthetics.
- Chronic opioid use, chronic pain syndrome, or regular analgesic use that may substantially interfere with postoperative pain assessment.
- Uncontrolled hypertension or clinically significant uncontrolled cardiac arrhythmia.
- Pregnancy or breastfeeding.
- Neurological deficits, aphasia, impaired consciousness, cognitive impairment, or communication difficulties preventing reliable pain assessment using the Numeric Rating Scale.
- Body mass index greater than 35 kg/m².
- Clinical circumstances requiring initiation of intravenous unfractionated heparin within one hour after the planned study-related needle intervention.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Konya City Hospital
Konya, Konya, 42090
Ömer Keklicek, +905399291702, drkeklicek@gmail.com
About this study
Official title: Effect of Preoperative Ultrasound-Guided Bilateral Greater Occipital Nerve Block on Postoperative Headache Following Endovascular Coiling of Unruptured Intracranial Aneurysms: A Prospective, Randomized, Sham-Controlled Trial
Postoperative headache is a common complication following endovascular coil embolization of intracranial aneurysms and may increase analgesic requirements, impair patient comfort, and contribute to hemodynamic instability.
The greater occipital nerve (GON) has anatomical and functional connections with the trigeminocervical complex, suggesting that greater occipital nerve blockade may modulate headache-related pain pathways. However, the effectiveness of prophylactic greater occipital nerve block in patients undergoing elective endovascular coiling of unruptured intracranial aneurysms remains uncertain.
Read more
This prospective, randomized, sham-controlled, single-center clinical trial aims to investigate whether preoperative ultrasound-guided bilateral greater occipital nerve block reduces postoperative headache intensity during the first 24 hours following endovascular coil embolization.
A total of 76 patients will be randomly allocated in a 1:1 ratio to receive either ultrasound-guided bilateral greater occipital nerve block with 0.25% bupivacaine or bilateral superficial sham injections with 0.9% normal saline.
The active intervention will consist of 3 mL of 0.25% bupivacaine administered on each side in the fascial plane between the semispinalis capitis and obliquus capitis inferior muscles. The control intervention will consist of a superficial subcutaneous injection of 0.5 mL of 0.9% normal saline on each side.
All participants will receive standardized general anesthesia and postoperative multimodal analgesia.
The primary outcome will be the time-weighted average resting pain score during the first 24 postoperative hours, calculated from the area under the Numeric Rating Scale (NRS) pain score-time curve.
- Conditions
- Intracranial Aneurysm, Postoperative Pain
- Being tested
- Ultrasound-Guided Bilateral Greater Occipital Nerve Block, Bilateral Superficial Subcutaneous Sham Injection
- Keywords
- Greater Occipital Nerve Block, Endovascular Coiling, Unruptured Intracranial Aneurysm, Ultrasound-Guided Regional Anesthesia, Postoperative Analgesia
- Medical subject headings
- Intracranial Aneurysm, Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasound-Guided Bilateral Greater Occipital Nerve BlockProcedure or surgery
Ultrasound-guided bilateral greater occipital nerve block will be performed before general anesthesia induction using a high-frequency linear ultrasound transducer.
The greater occipital nerve will be identified between the semispinalis capitis and obliquus capitis inferior muscles. A 25-gauge, 50-mm echogenic needle will be advanced under continuous ultrasound guidance using an in-plane approach.
Following color Doppler assessment and negative aspiration, 3 mL of 0.25% bupivacaine (7.5 mg) will be injected slowly and incrementally on each side.
The total bilateral dose will be 15 mg of bupivacaine.
Bilateral Superficial Subcutaneous Sham InjectionProcedure or surgery
A bilateral superficial subcutaneous sham injection will be performed before general anesthesia induction.
Following standardized positioning, skin antisepsis, and ultrasound examination, a short 27-gauge needle will be used to administer 0.5 mL of 0.9% normal saline subcutaneously on each side of the occipital region.
The total bilateral injection volume will be 1 mL.
The needle will not be advanced into the deep interfascial plane, and the greater occipital nerve will not be directly targeted.
| Study group | Role | What they receive |
|---|---|---|
| Postoperative headache is a common complication following endovascular coil embolization of intracra | Experimental | Participants assigned to the experimental group will receive preoperative ultrasound-guided bilateral greater occipital nerve block with 0.25% bupivacaine before induction of general anesthesia.
A total of 3 mL of 0.25% bupivacaine (7.5 mg) will be administered on each side into the interfascial plane between the semispinalis capitis and obliquus capitis inferior muscles. The total bilateral dose will be 15 mg of bupivacaine in 6 mL.
The intervention will be performed while the patient is awake and able to communicate, without routine deep sedation.
All participants will subsequently receive standardized general anesthesia and postoperative multimodal analgesia. Receives: Procedure: Ultrasound-Guided Bilateral Greater Occipital Nerve Block |
| Bilateral Superficial Sham Injection | Sham comparator | Participants assigned to the control group will receive bilateral superficial subcutaneous sham injections with 0.9% normal saline before induction of general anesthesia.
Following the same general preparation, positioning, and ultrasound examination as the experimental group, 0.5 mL of 0.9% normal saline will be injected subcutaneously on each side of the occipital region using a short 27-gauge needle.
The total bilateral injection volume will be 1 mL.
The needle will not be advanced into the deep interfascial plane, and no injection will be performed around the greater occipital nerve.
All participants will receive standardized general anesthesia and postoperative multimodal analgesia. Receives: Procedure: Bilateral Superficial Subcutaneous Sham Injection |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time-Weighted Average Resting Pain Score During the First 24 Postoperative Hours
Postoperative resting pain intensity will be assessed using the 11-point Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain).
NRS scores will be recorded at postoperative hours 0, 2, 4, 6, 8, 12, and 24.
The area under the NRS pain score-time curve (AUC0-24) will be calculated using the linear trapezoidal method and divided by 24 hours to obtain the time-weighted average NRS score.
The resulting patient-level value will range from 0 to 10, with higher scores indicating greater overall postoperative pain intensity.
Measured: From postoperative hour 0 to postoperative hour 24
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Nov 2026
- Study start2 Nov 2026 (estimated)
- Primary completion2 Nov 2027 (estimated)
- Study completion2 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intracranial AneurysmStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 76 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Konya City Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ömer Keklicek, Konya City Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07910864
- Sponsor's protocol ID
- 2026_KAEK-64_28
- Status last verified
- Oct 2026
- First submitted
- 27 Oct 2026
- Last updated
- 2 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Preoperative Ultrasound-Guided Bilateral Greater Occipital Nerve Block on Postoperative Headache Following Endovascular Coiling of Unruptured Intracranial Aneurysms: A Prospective, Randomized, Sham-Controlled Trial
- ClinicalTrials.gov ID
- NCT07910864
- Acronym / sponsor ID
- 2026_KAEK-64_28
- Conditions
- Intracranial Aneurysm, Postoperative Pain
- Keywords
- Greater Occipital Nerve Block, Endovascular Coiling, Unruptured Intracranial Aneurysm, Ultrasound-Guided Regional Anesthesia, Postoperative Analgesia
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 76 participants (estimated)
- Lead sponsor
- Konya City HospitalUniversity, hospital or other
- Study start
- 2 Nov 2026 (estimated)
- Primary completion
- 2 Nov 2027 (estimated)
- Study completion
- 2 Dec 2027 (estimated)
- First posted
- 2 Nov 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Postoperative headache is a common complication following endovascular coil embolization of intracranial aneurysms and may increase analgesic requirements, impair patient comfort, and contribute to hemodynamic instability.
The greater occipital nerve (GON) has anatomical and functional connections with the trigeminocervical complex, suggesting that greater occipital nerve blockade may modulate headache-related pain pathways. However, the effectiveness of prophylactic greater occipital nerve block in patients undergoing elective endovascular coiling of unruptured intracranial aneurysms remains uncertain.
This prospective, randomized, sham-controlled, single-center clinical trial aims to investigate whether preoperative ultrasound-guided bilateral greater occipital nerve block reduces postoperative headache intensity during the first 24 hours following endovascular coil embolization.
A total of 76 patients will be randomly allocated in a 1:1 ratio to receive either ultrasound-guided bilateral greater occipital nerve block with 0.25% bupivacaine or bilateral superficial sham injections with 0.9% normal saline.
The active intervention will consist of 3 mL of 0.25% bupivacaine administered on each side in the fascial plane between the semispinalis capitis and obliquus capitis inferior muscles. The control intervention will consist of a superficial subcutaneous injection of 0.5 mL of 0.9% normal saline on each side.
All participants will receive standardized general anesthesia and postoperative multimodal analgesia.
The primary outcome will be the time-weighted average resting pain score during the first 24 postoperative hours, calculated from the area under the Numeric Rating Scale (NRS) pain score-time curve.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Postoperative headache is a common complication following endovascular coil embolization of intracra | Experimental | Procedure: Ultrasound-Guided Bilateral Greater Occipital Nerve BlockParticipants assigned to the experimental group will receive preoperative ultrasound-guided bilateral greater occipital nerve block with 0.25% bupivacaine before induction of general anesthesia. A total of 3 mL of 0.25% bupivacaine (7.5 mg) will be administered on each side into the interfascial plane between the semispinalis capitis and obliquus capitis inferior muscles. The total bilateral dose will be 15 mg of bupivacaine in 6 mL. The intervention will be performed while the patient is awake and able to communicate, without routine deep sedation. All participants will subsequently receive standardized general anesthesia and postoperative multimodal analgesia. |
| Bilateral Superficial Sham Injection | Sham comparator | Procedure: Bilateral Superficial Subcutaneous Sham InjectionParticipants assigned to the control group will receive bilateral superficial subcutaneous sham injections with 0.9% normal saline before induction of general anesthesia. Following the same general preparation, positioning, and ultrasound examination as the experimental group, 0.5 mL of 0.9% normal saline will be injected subcutaneously on each side of the occipital region using a short 27-gauge needle. The total bilateral injection volume will be 1 mL. The needle will not be advanced into the deep interfascial plane, and no injection will be performed around the greater occipital nerve. All participants will receive standardized general anesthesia and postoperative multimodal analgesia. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patients aged 18-65 years.
- American Society of Anesthesiologists (ASA) physical status I-III.
- Patients scheduled for elective endovascular coil embolization of a unilateral unruptured intracranial aneurysm under general anesthesia.
- Ability and willingness to provide written informed consent.
Key exclusion criteria (13 listed)
- Refusal to provide informed consent or subsequent withdrawal of consent.
- Ruptured intracranial aneurysm or acute subarachnoid hemorrhage requiring emergency intervention.
- Clinical contraindications to greater occipital nerve block, including infection or skin lesions at the injection site, local anesthetic allergy, or anatomical conditions preventing safe needle placement.
- Platelet count below 100,000/mm³, international normalized ratio (INR) greater than 1.5, activated partial thromboplastin time (aPTT) greater than 1.5 times normal, or clinically significant coagulopathy.
- Antithrombotic or antiplatelet treatment that does not meet the predefined safety intervals for deep peripheral nerve blocks according to the ASRA 2025 and ESAIC/ESRA guidelines.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ultrasound-Guided Bilateral Greater Occipital Nerve BlockUltrasound-guided bilateral greater occipital nerve block will be performed before general anesthesia induction using a high-frequency linear ultrasound transducer. The greater occipital nerve will be identified between the semispinalis capitis and obliquus capitis inferior muscles. A 25-gauge, 50-mm echogenic needle will be advanced under continuous ultrasound guidance using an in-plane approach. Following color Doppler assessment and negative aspiration, 3 mL of 0.25% bupivacaine (7.5 mg) will be injected slowly and incrementally on each side. The total bilateral dose will be 15 mg of bupivacaine. | Procedure or surgery | Postoperative headache is a common complication following endovascular coil embolization of intracra |
| Bilateral Superficial Subcutaneous Sham InjectionA bilateral superficial subcutaneous sham injection will be performed before general anesthesia induction. Following standardized positioning, skin antisepsis, and ultrasound examination, a short 27-gauge needle will be used to administer 0.5 mL of 0.9% normal saline subcutaneously on each side of the occipital region. The total bilateral injection volume will be 1 mL. The needle will not be advanced into the deep interfascial plane, and the greater occipital nerve will not be directly targeted. | Procedure or surgery | Bilateral Superficial Sham Injection |
Primary outcome
Time-Weighted Average Resting Pain Score During the First 24 Postoperative Hours
Time frame: From postoperative hour 0 to postoperative hour 24
Postoperative resting pain intensity will be assessed using the 11-point Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain). NRS scores will be recorded at postoperative hours 0, 2, 4, 6, 8, 12, and 24. The area under the NRS pain score-time curve (AUC0-24) will be calculated using the linear trapezoidal method and divided by 24 hours to obtain the time-weighted average NRS score. The resulting patient-level value will range from 0 to 10, with higher scores indicating greater overall postoperative pain intensity.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Nov 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultrasound-Guided Bilateral Greater Occipital Nerve Block in people with Intracranial Aneurysm and Postoperative Pain, run by Konya City Hospital at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 2 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ömer Keklicek, Principal Investigator (+905399291702, drokeklicek@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time-Weighted Average Resting Pain Score During the First 24 Postoperative Hours (time frame: From postoperative hour 0 to postoperative hour 24). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Nov 2026; AzTrials last refreshed its copy on 7 Nov 2026.