Medical policy: Ganglion Impar Block

Policy number: MP 2.378

Effective date: 9/1/2026

Policy

Ganglion impar block may be considered medically necessary for the treatment of malignant rectal or perineal pain.

Ganglion impar block for other conditions is considered investigational, as there is insufficient evidence to support a general conclusion concerning the health outcomes or benefits associated with this procedure.

Policy guidelines

Adult patient should have no contraindication to the procedure, no evidence of infection, and no indicators of psychogenic origin of pain.

Cross-references:

• MP 4.046 Sphenopalatine Ganglion Block For Headache

Product variations

This policy is only applicable to certain programs and products administered by Capital Blue Cross and subject to benefit variations. Please see additional information below.

FEP PPO - Refer to FEP medical policy manual. The FEP medical policy manual can be found at: FEP Medical Policy Manual.

Description/Background

The ganglion impar (ganglion of Walther) block is an example of a sympathetic nerve block. The ganglion impar is a sympathetic ganglion that can be found on the ventral surface of the coccyx or behind the rectum around the sacrococcygeal joint. This is where it creates the caudal origin of the bilateral sympathetic chain. This ganglion can supply sympathetic nerve fibers to the perineum, distal rectum, and other locations in the pelvic region.

Technique

Recent techniques approach the ganglion impar by inserting a thin needle into the sacrococcygeal junction. Radiographic contrast can be used to confirm needle placement. Fluoroscopic guidance is needed to ensure safe and accurate needle placement. Ganglion impar block can be performed with fluoroscopy, using either a transsacrococcygeal or Plancarte technique. CT and ultrasound guidance may also be used. The choice of technique is often influenced by the preference of the physician and the availability of adequate equipment. There is limited data to show one technique is superior to another.

Rationale

Interventional therapies such as ganglion impar block may be a valuable option for treatment of adult cancer pain that is refractory to other interventions. Individuals who suffer from malignant rectal or perineum pain may benefit from ganglion impar block.

For individuals with acute or chronic non-malignant rectal or perineum pain, there is a lack of research or evidence to show long-term effects or overall efficacy of the procedure. There is insufficient evidence to determine the effects of the technology on health outcomes and efficacy.

In a study by Gunduz et al. (2015), twenty-two patients with chronic coccygodonia despite conservative treatments were treated with ganglion impar block. Inclusion criteria were intractable pain over the coccyx despite conservative treatment for at least 6 months and no abnormalities on laboratory findings or imaging that explained the pain. Exclusion criteria included local infection, bleeding diathesis, contrast allergy, or previous lumbar-region surgery. Patient were evaluated using the visual analog scale (VAS) before the intervention, 1 hr. post-injection, and 3 weeks post-injection. Successful block (at least 50% relief of pain) was achieved by 82% of patients following the first injection; three technical failures were noted. Relief lasted for a median duration of 6 months. Second injection was given in nine patients with median period of relief of 17 months. No relief had been achieved in two of these patients when they presented for the third treatment. The results of this study must be interpreted with caution. The study did show effective treatment yet did not indicate the mechanism of relief. Controlled studies are required to determine if the effect is nonspecific, due to the steroid used, or is an effect of temporarily anesthetizing the ganglion. Also, benefits need to be assessed beyond pain relief to evaluate restoration of function and use of other health care.

In a study by Gonnade et al. (2017), thirty-five patients with coccydynia were considered for fluoroscopy-guided trans-sacro-coccygeal ganglion impar block, referred to as the “needle inside needle” technique. Inclusion criteria included coccygeal pain for more than 3 months, lack of response to conservative treatments (NSAIDs, local analgesics, hot or cold application, modified wedge-shaped cushions, and exercises), and no etiology of pain revealed by laboratory findings or imaging. Exclusions included local skin infections, history of coccygectomy, sacrococcygeal joint fusion, bleeding disorders, uncontrolled diabetes mellitus, or pregnancy. A follow-up period of 6 months was completed. Four patients were lost to follow-up with sample size of 31. Oswestry Disability Index (ODI) and Numerical Rating Scale (NRS) scores decreased immediately after the procedure; statistically significant differences persisted through the end of the study. Limitations of this study included the absence of a control group and follow-up of only six months.

The NCCN guideline for Adult Cancer Pain (v1.2026) recommends interventional consultation for pain likely to be relieved with nerve block, failure to achieve adequate analgesia and/or the presence of intolerable adverse effects, and desire to avoid or limit systemic opioid administration. Commonly used interventional procedures include neurodestructive procedures for well-localized pain syndromes which include ganglion impar block for rectal or perineal pain.

Definitions

N/A

Disclaimer

Capital Blue Cross’ medical policies are used to determine coverage for specific medical technologies, procedures, equipment, and services. These medical policies do not constitute medical advice and are subject to change as permitted by law or applicable clinical evidence from independent treatment guidelines. Treating providers are solely responsible for medical advice and treatment of members. These policies are not a guarantee of coverage or payment. Payment of claims is subject to a determination regarding the member’s benefit program and eligibility on the date of service, and a determination that the services are medically necessary and appropriate. Final processing of a claim is based upon the terms of contract that applies to the member’s benefit program, including benefit limitations and exclusions. If a provider or a member has a question concerning this medical policy, please contact Capital Blue Cross’ Provider Services or Member Services.

Coding information

Note: This list of codes may not be all-inclusive, and codes are subject to change at any time. The identification of a code in this section does not denote coverage as coverage is determined by the terms of member benefit information. In addition, not all covered services are eligible for separate reimbursement.

Covered when medically necessary for Ganglion impar block:

References

1. Adult Cancer Pain. NCCN Clinical Practice Guidelines for Oncology, January 23, 2026, V.1 2026
2. Oh, Chang-Seok, et al. “Clinical Implications of Topographic Anatomy on the Ganglion Impar.” Anesthesiology, vol. 101, no. 1, 2004, pp. 249–250.
3. Nalini, KB, et al. “Transcoccygeal Neurolytic Ganglion Impar Block for Perineal Pain. A Case Series.” Journal of Anaesthesiology Clinical Pharmacology, vol. 34, no. 4, 2018, p. 544.
4. Gunduz, Osman Hakan, et al. “Pain Relief Due to Transsacrococcygeal Ganglion Impar Block in Chronic Coccygodynia: A Pilot Study.” Pain Medicine, vol. 16, no. 7, 2015, pp. 1278–1281.
5. Gonnade, Nitesh, et al. “Ganglion Impar Block in Patients with Chronic Coccydynia.” Indian Journal of Radiology and Imaging, vol. 27, no. 3, 2017, p. 324.
6. Le Cler, Quentin-Come, et al. “Repeated Ganglion Impar Block in a Cohort of 83 Patients with Chronic Pelvic and Perineal Pain.” Pain Physician Journal, 2017, pp. 823–828.
7. “Other Medical Treatments for Cancer Pain.” American Cancer Society
8. Practice Guidelines for Chronic Pain Management: An Updated Report by the American Society of Anesthesiologists Task Force on Chronic Pain Management and the American Society of Regional Anesthesia and Pain Medicine. Anesthesiology 2010 112:810–833
9. Gunduz, Osman Hakan, and Ozge Kenis Coskun. “Ganglion Blocks as a Treatment of Pain: Current Perspectives.” Journal of Pain Research, Volume 10, 2017, pp. 2815–2826.
10. Michalek, P., Dolecek, L., & Stadler, P. (2005). Ganglion Impar Block in Noncancer Perineal Pain: What Drugs, What Strategy? Anesthesiology, 103(1), 212–212.
11. Kim CS, Jang K, Leem JG, Shin JW, Kim DH, Choi SS. Factors associated with Successful Responses to Ganglion Impar Block: A Retrospective Study. Int J Med Sci. 2021; 18(13):2957-2963.
12. Foye, P. Coccydynia (coccygodynia). In: UpToDate Online Journal [serial online]. Waltham, MA: UpToDate; Updated June 14, 2024. Literature review current through June 2025
13. Sukun A, Cankurtaran T, Agildere M, Weber MA. Imaging findings and treatment in coccydynia - update of the recent study findings. RöFo Fortschritte Auf Dem Gebiet Der Röntgenstrahlen Und Der Bildgebenden Verfahren. Published online November 9, 2023. doi:10.1055/a-2185-8585
14. Ghai A, Jangra P, Wadhera S, et al. A prospective study to evaluate the efficacy of ultrasound-guided ganglion impar block in patients with chronic perineal pain. Saudi J Anaesth. 2019;13(2):126-130. PMID 31007658 PMCID PMC6448437