Comparison of Ganglion Impar Radiofrequency Ablation and Phenol Neurolysis Techniques for Chronic Coccydynia Treatment

NCT07021365 | Not Yet Recruiting

• 1 other identifier: 09.2024.1470
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Radiofrequency ablation and phenol neurolysis of the ganglion impar are methods used in cases unresponsive to medication, particularly in patients who derive short-term or partial relief from the initial ganglion impar block. In clinical practice, clinicians frequently use these two injections in patients with treatment-resistant pain who only partially benefit from the initial blockade procedure. To date, the medical literature lacks a comprehensive study comparing the efficacy of radiofrequency ablation and phenol neurolysis in patients who partially benefit from ganglion impar block. Therefore, this study is designed to compare the effectiveness of these two methods in patients with chronic coccydynia.

Conditions

Coccygodynia; Coccydynia

Keywords

coccygodinia; chronic; radiofrequency ablation; phenol neurolysis; coccydynia

Outcome Measures

Primary Outcomes (1)

• Numeric Rating Scale-11

  A subjective outcome measure to assess pain (Min:0 Max:10). Higher scores indicate more severe pain.

  Treatment to 6 months post-treatment

Secondary Outcomes (2)

• Short Form-12 Health Survey

  Treatment to 6 months post-treatment.

• Douleur Neuropathique 4

  Treatment to 6 months post-treatment.

Study Arms (2)

Ganglion Impar Radiofrequency Ablation

ACTIVE COMPARATOR

Device: Radiofrequency ablation alone

Ganglion Impar Phenol Neurolysis

ACTIVE COMPARATOR

Drug: Phenol Injection

Interventions

Phenol Injection DRUG

n patients diagnosed with chronic coccydynia, a ganglion impar block is initially performed following conservative treatment. In cases where this intervention provides limited benefit, ganglion impar phenol neurolysis is performed. A short-acting local anesthetic (3-4 mL of 1% prilocaine) will be administered into the skin and subcutaneous tissues. A 90 mm 22-gauge Quincke-tipped spinal needle will be advanced via the trans-coccygeal route under fluoroscopic guidance with intermittent imaging. The needle's position in the area anterior to the coccyx, where the ganglion impar is located, will be confirmed using 1-2 mL of contrast agent (iohexol). If the desired spread of contrast is observed, 5 mL of 7% phenol will be injected.

Ganglion Impar Phenol Neurolysis

Radiofrequency ablation alone DEVICE

In patients diagnosed with chronic coccydynia, a ganglion impar block is initially performed following conservative treatment. In cases where this intervention provides limited benefit, ganglion impar radiofrequency (RF) ablation-routinely used in clinical practice-will be performed by an experienced pain specialist (SŞ) with at least 10 years of expertise in this procedure. Using fluoroscopic guidance and intermittent imaging, a 100 mm RF cannula with an injection tube will be advanced trans-coccygeally. After confirming the needle's position at the site of the ganglion impar in front of the coccyx with 1-2 mL of contrast agent (iohexol), sensory stimulation will be applied via the RF generator to confirm that the needle tip is at the patient's pain site. Motor stimulation will also be performed to ensure there is no muscle contraction. At this stage, 2 mL of lidocaine will be administered before initiating ablation at 80°C for 90 seconds.

Ganglion Impar Radiofrequency Ablation

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age between 18 and 65 years
• Presence of chronic coccydynia lasting at least 3 months
• Pre-procedural pain score of 4 or higher on the Numeric Rating Scale (NRS)
• Patients who have undergone a ganglion impar block within the last 3 months and experienced limited benefit (i.e., less than 50% reduction in pain compared to pre-treatment) and/or short-term relief (less than 4 weeks)

You may not qualify if:

• History of surgery involving the sacrococcygeal region
• Prior treatment with ganglion impar phenol neurolysis or radiofrequency ablation
• Coagulopathies (bleeding disorders)
• Infection
• Spondylolisthesis, scoliosis, or lumbar spinal stenosis
• Malignancy
• Pregnancy
• History of allergic reaction to the administered injectates
• History of major psychiatric illness

Sponsors & Collaborators

• Marmara University: lead

Study Sites (1)

Marmara University

Istanbul, Istanbul, 34854, Turkey (Türkiye)

Location

Related Publications (6)

• Sagir O, Demir HF, Ugun F, Atik B. Retrospective evaluation of pain in patients with coccydynia who underwent impar ganglion block. BMC Anesthesiol. 2020 May 11;20(1):110. doi: 10.1186/s12871-020-01034-6.

  PMID: 32393277 BACKGROUND

• Demircay E, Kabatas S, Cansever T, Yilmaz C, Tuncay C, Altinors N. Radiofrequency thermocoagulation of ganglion impar in the management of coccydynia: preliminary results. Turk Neurosurg. 2010 Jul;20(3):328-33. doi: 10.5137/1019-5149.JTN.2852-09.0.

  PMID: 20669105 BACKGROUND

• Howard PD, Dolan AN, Falco AN, Holland BM, Wilkinson CF, Zink AM. A comparison of conservative interventions and their effectiveness for coccydynia: a systematic review. J Man Manip Ther. 2013 Nov;21(4):213-9. doi: 10.1179/2042618613Y.0000000040.

  PMID: 24421634 BACKGROUND

• Kircelli A, Demircay E, Ozel O, Coven I, Isik S, Civelek E, Kabatas S. Radiofrequency Thermocoagulation of the Ganglion Impar for Coccydynia Management: Long-Term Effects. Pain Pract. 2019 Jan;19(1):9-15. doi: 10.1111/papr.12698. Epub 2018 May 16.

  PMID: 29617062 BACKGROUND

• Sencan S, Kenis-Coskun O, Demir FGU, Cuce I, Ercalik T, Gunduz OH. Ganglion Impar block improves neuropathic pain in coccygodynia: A preliminary report. Neurol Neurochir Pol. 2018 Sep-Oct;52(5):612-617. doi: 10.1016/j.pjnns.2018.08.006. Epub 2018 Aug 28.

  PMID: 30195465 BACKGROUND

• Karadimas EJ, Trypsiannis G, Giannoudis PV. Surgical treatment of coccygodynia: an analytic review of the literature. Eur Spine J. 2011 May;20(5):698-705. doi: 10.1007/s00586-010-1617-1. Epub 2010 Nov 3.

  PMID: 21046173 BACKGROUND

MeSH Terms

Conditions

Bronchiolitis Obliterans Syndrome

Interventions

Phenol; Radiofrequency Ablation

Condition Hierarchy (Ancestors)

Organizing Pneumonia; Bronchiolitis Obliterans; Bronchiolitis; Bronchitis; Bronchial Diseases; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Graft vs Host Disease; Immune System Diseases

Intervention Hierarchy (Ancestors)

Phenols; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Organic Chemicals; Radiofrequency Therapy; Therapeutics; Ablation Techniques; Surgical Procedures, Operative

Central Study Contacts

Savas Sencan, Associate Professor

CONTACT

00905370665713; savas-44@hotmail.com

Merve Sekizkardes, Medical Doctor

CONTACT

00905367445551; merve.sekizkardes@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 29, 2025
• First Posted: June 15, 2025
• Study Start: July 1, 2025
• Primary Completion: November 1, 2025
• Study Completion: March 1, 2026
• Last Updated: June 17, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE

Locations

TU (1)