CurrentCapital BluecrossPolicy MP 2.378

Ganglion impar block

This policy governs coverage and medical necessity criteria for ganglion impar block procedures for Capital BlueCross members, specifying when the procedure is considered medically necessary (malignant rectal or perineal pain) and when it is investigational (other indications).

Policy Summary

PayerCapital Bluecross

PolicyGanglion impar block

Policy CodePolicy MP 2.378

Change TypeNo material change

Effective Date11/1/2025

Next Review Date

Key ActionVerify product/program variations and member benefits for prior authorization requirements before performing ganglion impar block for malignant rectal or perineal pain.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

1Medically necessary indication

investigationalOther conditions

64999Procedure code

fluoroscopyImaging guidance

Coverage Criteria

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Medical necessity criteria

Covered when ALL of the following are met

Medically necessary indication: Procedure is for malignant rectal or perineal pain.

Supported by policy statement and rationale referencing interventional therapy for cancer pain (NCCN).

Patient selection and contraindications: Adult patient with no contraindication to the procedure, no evidence of infection, and no indicators of psychogenic origin of pain.

Per Policy Guidelines; standard exclusions noted in studies include local infection, bleeding diathesis, uncontrolled diabetes, pregnancy, prior coccygectomy or sacrococcygeal fusion.

Procedure technique and guidance: Fluoroscopic guidance is used to ensure safe and accurate needle placement; radiographic contrast may be used to confirm needle position. CT or ultrasound guidance may be alternatives.

Technique options described; fluoroscopy noted as preferred for safety.

Investigational indications

Not covered / Investigational when ANY of the following apply

Non-malignant pain indications: Ganglion impar block for acute or chronic non-malignant rectal or perineal pain is considered investigational due to insufficient evidence of long-term efficacy.

Policy explicitly states investigational for conditions other than malignant rectal or perineal pain; rationale cites lack of controlled studies and limited follow-up in existing cohorts.

Examples of specific study exclusion conditions reported in the literature include local skin infections, bleeding diathesis/bleeding disorders, contrast allergy (when contrast is used), history of coccygectomy or sacrococcygeal joint fusion, uncontrolled diabetes mellitus, and pregnancy. Clinical guidance in the policy also emphasizes that patients should have no evidence of active infection and no contraindication to the procedure prior to proceeding.

Use of ganglion impar block for indications other than malignant rectal or perineal pain is considered investigational because there is insufficient evidence demonstrating long‑term efficacy or consistent improvement in health outcomes for non‑malignant indications.

Provider Actions and Requirements

Prior Authorization

Coverage subject to product variations and member benefits

This policy is applicable only to certain Capital BlueCross programs and products and is subject to member benefit variations. Verify the member's specific product, program, and benefits before rendering coverage decisions or prior authorization determinations.

FEP PPO: Refer to FEP Medical Policy Manual (see policy for link).

Documentation Required

Conservative therapy context

Some studies and clinical reports required failure of conservative therapy prior to considering ganglion impar block for nonmalignant pain (for example, failure of nonsteroidal anti-inflammatory drugs, local analgesics, cushion modification, exercises, heat/cold, or other conservative measures for weeks to months). Document prior conservative treatments and duration in the medical record when applicable.

Examples of conservative therapies: NSAIDs, topical/local analgesics, activity modification, cushioning, physical therapy, hot/cold application.

Documentation Required

Pre-procedure requirements and technique

Adult patients considered for ganglion impar block should have no contraindication to the procedure, no evidence of active infection at the injection site, and no clinical indicators suggesting a psychogenic origin of pain. Ensure appropriate screening and documentation of these pre-procedure requirements.

Contraindications/precautions: active local infection, bleeding diathesis, contrast allergy when contrast will be used, or other standard procedural contraindications.
Technique note: fluoroscopic guidance (transsacrococcygeal or Plancarte) is commonly used; CT or ultrasound guidance may be used per operator preference.

Denial Risk

Investigational indications

Ganglion impar block is considered investigational for non-malignant indications (procedures performed for non-malignant rectal or perineal pain) per this policy and may be denied if submitted for those indications.

Medically necessary indication: malignant rectal or perineal pain.
Investigational / Not covered: non-malignant rectal or perineal pain and other non-malignant indications.

Conservative Treatment Requirements

Conservative treatment requirements

Studies of ganglion impar block for non-malignant indications required prior failure of conservative therapy before inclusion in cohorts.

Conservative treatment requirement in cited studies: Prior failure of conservative measures (examples: NSAIDs, local analgesics, hot/cold application, modified cushions, exercises) for a defined duration (typically at least 3–6 months) was required in study inclusion criteria for non-malignant pain cohorts.3-6 months

Gunduz et al. required ≥6 months; Gonnade et al. required >3 months of conservative treatment before block was attempted; these study requirements inform but do not change the policy stance that non-malignant indications are investigational.

Policy application: Although study cohorts required prior conservative therapy, the policy considers ganglion impar block for non-malignant rectal or perineal pain investigational and not covered.

Policy requires cancer pain refractory to other interventions for coverage; non-malignant indications remain investigational despite study entry criteria.

Imaging and Guidance Requirements

Billing Rule

Use fluoroscopic guidance (preferred) for ganglion impar block

Use fluoroscopic guidance to ensure safe and accurate needle placement; radiographic contrast may be used to confirm needle position. CT or ultrasound guidance may be used when appropriate, but fluoroscopy is noted as the preferred/required guidance for safety.

Fluoroscopic guidance is needed to ensure safe and accurate needle placement.
CT and ultrasound guidance may also be used as alternatives; radiographic contrast can confirm needle placement.

Background

The ganglion impar (also called the ganglion of Walther) is a solitary sympathetic ganglion located near the sacrococcygeal junction on the ventral surface of the coccyx or posterior to the rectum. It provides sympathetic innervation to the perineum, distal rectum, and adjacent pelvic structures. Ganglion impar block is an interventional sympathetic nerve block performed by advancing a needle to the sacrococcygeal region (commonly via a trans‑sacrococcygeal or Plancarte approach) with imaging guidance to deliver local anesthetic and/or steroid to the ganglion to reduce sympathetically mediated pain.

Definitions

Ganglion impar — definition and anatomic description

Anatomic locationA sympathetic ganglion located on the ventral surface of the coccyx or behind the rectum around the sacrococcygeal joint.

Alternate nameGanglion of Walther.

Functional roleSupplies sympathetic nerve fibers to the perineum, distal rectum, and pelvic region.

Clinical relevanceTarget for sympathetic nerve block (ganglion impar block) to treat malignant rectal or perineal pain.

Common needle approachesTranssacrococcygeal (sacrococcygeal junction) approaches are described for needle placement; radiographic contrast and fluoroscopic guidance may be used to confirm position.