Drug-Resistant EpilepsyNCT07689617
Ultrasound-Guided Intermediate Cervical Plexus Block for Postoperative Analgesia in Vagus Nerve Stimulation Surgery
An observational study of Drug-Resistant Epilepsy and Epilepsy, run by Firat University at 1 site in Turkey (Türkiye).
Trial summary
This retrospective cohort study evaluated the medical records of adult patients who underwent vagus nerve stimulator (VNS) implantation under general anesthesia for drug-resistant epilepsy at Fırat University Hospital between January 2019 and December 2021. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Drug-Resistant Epilepsy, Epilepsy, Postoperative Pain
- What is being tested?
- Ultrasound-guided intermediate cervical plexus block and Bupivacaine
- Type of treatment
- Surgery or procedure
- How many people
- 76 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 May 2022to 30 Sep 2022
- Phase
- Observational
- Are there results?
- None posted in the registry
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 60 years
- All sexes
- No healthy volunteers
- Adult
Study population: Adult patients aged 18-60 years with ASA physical status II-III who underwent elective vagus nerve stimulator implantation under general anesthesia for drug-resistant epilepsy at Fırat University Hospital, Elazığ, Türkiye, between January 2019 and December 2021, identified through retrospective review of medical records.
Who may be able to join
- Adults aged 18-60 years
- American Society of Anesthesiologists (ASA) physical status II-III
- Elective vagus nerve stimulator implantation for drug-resistant epilepsy under general anesthesia between January 2019 and December 2021
Who cannot join
- Insufficient perioperative records
- Concurrent major surgery
- Deviation from the planned surgical procedure
- Inability to assess postoperative follow-up
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Fırat University Faculty of Medicine Hospital
Elâzığ, Elâzığ, 23100
About this study
Official title: Intermediate Cervical Plexus Block as the Sole Regional Technique for Two-Site Vagus Nerve Stimulator Implantation: A Retrospective Cohort Study
This retrospective cohort study evaluated the medical records of adult patients who underwent vagus nerve stimulator (VNS) implantation under general anesthesia for drug-resistant epilepsy at Fırat University Hospital between January 2019 and December 2021. Patients who received a left-sided ultrasound-guided intermediate cervical plexus block (ICPB) with 10 mL of 0.25% bupivacaine as part of routine care were compared with patients who did not receive a regional block. The primary outcome was total intravenous morphine consumption during the first 24 postoperative hours. Secondary outcomes included intraoperative remifentanil consumption, postoperative pain intensity assessed using the Numeric Rating Scale (NRS) at rest and during movement, rescue morphine requirement, time to first rescue analgesia, length of hospital stay, and postoperative seizures within 24 hours, and block-related adverse events.
Read the detailed description
VNS implantation requires two incisions: a cervical incision for electrode placement and an infraclavicular incision for the pulse generator pocket. This study examined the postoperative analgesic profile associated with ICPB used as the sole regional technique for this two-site procedure. Data were obtained retrospectively from anesthesia, post-anesthesia care unit, ward, and electronic medical records of patients operated on between January 2019 and December 2021. The study was approved by the Fırat University Non-Interventional Research Ethics Committee (Approval No. 7996, April 7, 2022). Study start and completion dates refer to the period of retrospective data extraction (May-September 2022).
This record was initially registered with an incorrect interventional (randomized, placebo-controlled) design, based on an earlier manuscript draft that inaccurately described the study. It has been corrected to reflect the retrospective observational design. In this study, no prospective enrollment, randomization, blinding, or placebo administration took place.
- Conditions
- Drug-Resistant Epilepsy, Epilepsy, Postoperative Pain
- Being tested
- Ultrasound-guided intermediate cervical plexus block, Bupivacaine
- Keywords
- Vagus Nerve Stimulation, Cervical Plexus Block, Pain, Postoperative, Analgesics, Opioid, Regional Anesthesia, Epilepsy, Retrospective Studies
- Medical subject headings
- Drug Resistant Epilepsy, Epilepsy, Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultrasound-guided intermediate cervical plexus blockProcedure or surgery
Ultrasound-guided intermediate cervical plexus block performed after induction of general anesthesia.
BupivacaineDrug
10 mL of 0.25% bupivacaine administered during ultrasound-guided intermediate cervical plexus block.
| Study group | Role | What they receive |
|---|---|---|
| Intermediate Cervical Plexus Block | Patients who received a left-sided ultrasound-guided intermediate cervical plexus block (10 mL 0.25% bupivacaine) after induction of general anesthesia as part of routine care. Receives: Procedure: Ultrasound-guided intermediate cervical plexus block; Drug: Bupivacaine | |
| Control | Patients who underwent VNS implantation under general anesthesia without a regional block. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total postoperative morphine consumption during the first 24 hours after surgery
Total cumulative intravenous morphine consumption during the first 24 hours after vagus nerve stimulation implantation surgery, recorded in milligrams (mg).
Measured: From PACU admission through 24 hours postoperatively
Secondary outcomes (7)
Intraoperative remifentanil consumption
Total intraoperative remifentanil consumption, including the induction bolus and maintenance infusion, recorded in micrograms (µg) from induction of anesthesia until completion of surgery.
Measured: From induction of anesthesia until the end of surgery
Postoperative pain intensity at rest and during movement
Pain intensity was assessed using the Numeric Rating Scale (NRS; 0 = no pain, 10 = worst imaginable pain) at rest and during active head rotation at PACU admission, 30 minutes after PACU admission, and at postoperative 1, 6, 12, and 24 hours.
Measured: From admission to the post-anesthesia care unit (PACU) through 24 hours postoperatively
Time to first rescue analgesia
Time from PACU admission to the first administration of rescue intravenous morphine, measured in minutes. Patients who did not receive rescue analgesia were censored at hospital discharge or at 24 hours, whichever occurred first.
Measured: From PACU admission up to 24 hours
Length of hospital stay
Time from post-anesthesia care unit (PACU) admission to hospital discharge, measured in hours.
Measured: From PACU admission until hospital discharge (assessed up to 83 hours after PACU admission).
Postoperative seizure incidence
Occurrence of clinically observed postoperative seizure episodes during the first 24 postoperative hours.
Measured: Within 24 hours after surgery
Rescue morphine requirement
Proportion of patients who received at least one dose of rescue intravenous morphine.
Measured: Within 24 hours after surgery
Block-related adverse events
Occurrence of adverse events potentially related to the intermediate cervical plexus block, assessed retrospectively from post-anesthesia care unit (PACU) and ward records: Horner syndrome, dysphagia, hoarseness, respiratory distress, phrenic nerve dysfunction, and local anesthetic systemic toxicity. Because VNS implantation itself may cause hoarseness, attribution to the block was based on documented clinical assessments.
Measured: From PACU admission until hospital discharge (assessed up to 83 hours after PACU admission).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jul 2026
- Study start1 May 2022
- Primary completion1 Sep 2022
- Study completion30 Sep 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Drug-Resistant EpilepsyStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 76 participants (actual)
Sponsor and investigators
- Lead sponsor
- Firat University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, AHMET AKSU, Firat University
- Investigators
- Ahmet Aksu, Assistant Professor, Principal investigator, Fırat University Faculty of Medicine Department of Anaesthesiology and Reanimation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07689617
- Sponsor's protocol ID
- 7996
- Status last verified
- Oct 2026
- First submitted
- 30 Jun 2026
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data underlying the reported results will be available from the corresponding author upon reasonable request after publication, subject to approval by the Fırat University ethics committee and a data use agreement.
Study at a glance
From the registry record, last updated by the sponsor on 16 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intermediate Cervical Plexus Block as the Sole Regional Technique for Two-Site Vagus Nerve Stimulator Implantation: A Retrospective Cohort Study
- ClinicalTrials.gov ID
- NCT07689617
- Acronym / sponsor ID
- 7996
- Conditions
- Drug-Resistant Epilepsy, Epilepsy, Postoperative Pain
- Keywords
- Vagus Nerve Stimulation, Cervical Plexus Block, Pain, Postoperative, Analgesics, Opioid, Regional Anesthesia, Epilepsy, Retrospective Studies
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 76 participants (actual)
- Lead sponsor
- Firat UniversityUniversity, hospital or other
- Study start
- 1 May 2022 (actual)
- Primary completion
- 1 Sep 2022 (actual)
- Study completion
- 30 Sep 2022 (actual)
- First posted
- 8 Jul 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.
This retrospective cohort study evaluated the medical records of adult patients who underwent vagus nerve stimulator (VNS) implantation under general anesthesia for drug-resistant epilepsy at Fırat University Hospital between January 2019 and December 2021. Patients who received a left-sided ultrasound-guided intermediate cervical plexus block (ICPB) with 10 mL of 0.25% bupivacaine as part of routine care were compared with patients who did not receive a regional block. The primary outcome was total intravenous morphine consumption during the first 24 postoperative hours. Secondary outcomes included intraoperative remifentanil consumption, postoperative pain intensity assessed using the Numeric Rating Scale (NRS) at rest and during movement, rescue morphine requirement, time to first rescue analgesia, length of hospital stay, and postoperative seizures within 24 hours, and block-related adverse events.
Detailed description
VNS implantation requires two incisions: a cervical incision for electrode placement and an infraclavicular incision for the pulse generator pocket. This study examined the postoperative analgesic profile associated with ICPB used as the sole regional technique for this two-site procedure. Data were obtained retrospectively from anesthesia, post-anesthesia care unit, ward, and electronic medical records of patients operated on between January 2019 and December 2021. The study was approved by the Fırat University Non-Interventional Research Ethics Committee (Approval No. 7996, April 7, 2022). Study start and completion dates refer to the period of retrospective data extraction (May-September 2022).
This record was initially registered with an incorrect interventional (randomized, placebo-controlled) design, based on an earlier manuscript draft that inaccurately described the study. It has been corrected to reflect the retrospective observational design. In this study, no prospective enrollment, randomization, blinding, or placebo administration took place.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intermediate Cervical Plexus Block | – | Procedure: Ultrasound-guided intermediate cervical plexus block, Drug: BupivacainePatients who received a left-sided ultrasound-guided intermediate cervical plexus block (10 mL 0.25% bupivacaine) after induction of general anesthesia as part of routine care. |
| Control | – | –Patients who underwent VNS implantation under general anesthesia without a regional block. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Adult patients aged 18-60 years with ASA physical status II-III who underwent elective vagus nerve stimulator implantation under general anesthesia for drug-resistant epilepsy at Fırat University Hospital, Elazığ, Türkiye, between January 2019 and December 2021, identified through retrospective review of medical records.
Key inclusion criteria (3 listed)
- Adults aged 18-60 years
- American Society of Anesthesiologists (ASA) physical status II-III
- Elective vagus nerve stimulator implantation for drug-resistant epilepsy under general anesthesia between January 2019 and December 2021
Key exclusion criteria (4 listed)
- Insufficient perioperative records
- Concurrent major surgery
- Deviation from the planned surgical procedure
- Inability to assess postoperative follow-up
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 intermediate cervical plexus blockUltrasound-guided intermediate cervical plexus block performed after induction of general anesthesia. | Procedure or surgery | Intermediate Cervical Plexus Block |
| Bupivacaine10 mL of 0.25% bupivacaine administered during ultrasound-guided intermediate cervical plexus block. | Drug | Intermediate Cervical Plexus Block |
Primary outcome
Total postoperative morphine consumption during the first 24 hours after surgery
Time frame: From PACU admission through 24 hours postoperatively
Total cumulative intravenous morphine consumption during the first 24 hours after vagus nerve stimulation implantation surgery, recorded in milligrams (mg).
7 secondary outcomes
Intraoperative remifentanil consumption
Time frame: From induction of anesthesia until the end of surgery
Postoperative pain intensity at rest and during movement
Time frame: From admission to the post-anesthesia care unit (PACU) through 24 hours postoperatively
Time to first rescue analgesia
Time frame: From PACU admission up to 24 hours
Length of hospital stay
Time frame: From PACU admission until hospital discharge (assessed up to 83 hours after PACU admission).
Postoperative seizure incidence
Time frame: Within 24 hours after surgery
Rescue morphine requirement
Time frame: Within 24 hours after surgery
Block-related adverse events
Time frame: From PACU admission until hospital discharge (assessed up to 83 hours after PACU admission).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Oct 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data underlying the reported results will be available from the corresponding author upon reasonable request after publication, subject to approval by the Fırat University ethics committee and a data use agreement.
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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. This study is not recruiting at the moment.
Ahmet Aksu, Assistant Professor principal investigator
Fırat University Faculty of Medicine Department of Anaesthesiology and Reanimation
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Drug-Resistant Epilepsy and Epilepsy, run by Firat University 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 3 inclusion and 4 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: finished, as of the sponsor's last update on 16 Oct 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. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total postoperative morphine consumption during the first 24 hours after surgery (time frame: From PACU admission through 24 hours postoperatively). 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 16 Oct 2026.