Ganglion Impar Block FAQs from a Houston Pain Clinic

Ganglion impar block is a safe and highly successful way to alleviate chronic, neuropathic pelvic, genital, anal, visceral, and perineal pain. According to a New Jersey Medical School report published in the American Journal of Physical Medicine & Rehabilitation, the procedure is over 80% effective in treating coccyx pain associated with fall injuries, pregnancy dislocation, chronic inflammation, or recurring muscle trauma.

What is Ganglion Impar Block?

Ganglion impar block is an outpatient procedure aimed at blocking nerve impulses to provide relief from originating from painful conditions impacting rectum, anus, genital organs, perineum, tail bone, and urethra. The ganglion impar is positioned in the front of the tail bone where both pelvic sympathetic trunks unite.

The plexus receives afferent pain fibers from the above mentioned pelvic and perineal organs and transmit pain sensation to the brain through sacral sympathetic chains. A ganglion impar block has the potential to cause sympathetic innervations and disrupt pain sensations from being transmitted via nerves in the neural structure.

When Patients Require Ganglion Impar Block? What Conditions Are Treated Through Ganglion Impar Block?

Researchers have discovered that a ganglion impar block inhibits pain associated with an array of organs “connected” to the plexus, including

  • coccyx pain
  • perineum pain
  • pain in urethra and distal rectum
  • anus pain
  • scrotal pain
  • pain in vagina and vulva
  • pain from cervical, prostate, testicular, colorectal cancers

The therapy is also useful for patients with pain due to

  • sacral postherpetic neuralgia
  • post-surgical thrombosis of perineal veins
  • atypical localized perineal pain
  • cancer in pelvic organs
  • spinal cord malformations
  • perineal hyperhidrosis
  • chronic prostatiti and proctitis
  • vulvodynia
  • endometriosis
  • proctalgia fugax
  • vaginal protrusion

How Is Ganglion Impar Block Performed?

The transsacrococcygeal method is the most preferred way to perform ganglion impar blocks as it is simple and more successful. Patients are asked to lie down in a prone position with their face downwards. The skin above and the tissues adjacent to the sacrum are numbed up and a needle is inserted into the plexus under fluoroscopic guidance.

Houston pain management doctors inject dye to confirm that the needle is positioned appropriately and close to the coccyx area. Numbing medication is put through the needle and injected into the ganglion impar. An injection of phenol is added to the procedure to make the block effects last longer. Alternatively, patients can undergo a follow-up radiofrequency ablation therapy.

What Is Injected During Ganglion Impar Block?

The injected medication is a local anesthetic, such as Lidocaine. In addition, steroid medication may be injected and possibly phenol for longer lasting results.

How Long Does It Take?

A ganglion impar block takes around 15 minutes.

Do I Need Rest After Ganglion Impar Block?

Take rest for a day and avoid putting stress on the injection site. Patients are discharged as soon as the procedure is over unless there is any complication.

How Many Ganglion Impar Block Injections Should I Have?

If you experience pain relief with the first procedure, you may repeat it. The time gap depends on the lasting of the first procedure and your medical condition.

What Are The Side Effects of Ganglion Impar Block?

  • Immediate and temporary side effects: Injection-sire soreness, stiffness, and pain.
  • Long-term and major side effects: No major risk of injury
  • Human error/ rare risks: Doctors unaware of the significant variation in the position of the ganglion impar in patient are likely to end up causing bleeding, spread of dye into caudal canal, failure of the block puncture of surrounding organs, damage to nerves or blood vessels.
  • Caution: It is advisable to take utmost caution for those
  • allergic to anesthetic medication
  • with active infections
  • suffering from metastatic cancer, as masses may be centralized in the targeted area
  • with thrombocytopenia or reduced platelet count
  • suffering from allodynia or reduced ability to tolerate pain
  • with abdominal distension or skin breakdown in the area
  • with rectal fistula

How Well Does Ganglion Impar Block Work? What Are The Benefits of Ganglion Impar Block?

  • A 1990-report published in the Anesthesiology journal claimed that ganglion impar blocks assure 60% to 100% pain relief for patients suffering from “perineal pain linked to cervical, endometrial, bladder, colon, and rectal cancers.”
  • The Clinical Journal of Pain reported findings in 2009 suggesting four-fold decrease in pain associated with “clot in perineal vein, perineal pain, postherpetic neuralgia, vaginal protrusion, and testicular ablation” after patients went for ganglion impar block.
  • The provcedure is also highly beneficial for those with perineal hyperhidrosis claimed Korean J Anesthesiol in 2005.
  • Chronic perineal pain subsides over 50% in the two months following ganglion impar block, says a 2007 report in the Pain Physician journal.


Plancarte R, Amescua C, Patt RB: Presacral blockade of the ganglion of Walther (ganglion impar). Anesthesiology. 1990; 73:A751.

Agarwal-Kozlowski K, Lorke DE, Habermann CR, Am Esch JS, Beck H. CT-guided blocks and neuroablation of the ganglion impar (Walther) in perineal pain: anatomy, technique, safety, and efficacy. Clin J Pain. 2009; 25:570-6.

Kim ST, Ryu SJ. Treatment of Hyperhidrosis Occurring during Hemodialysis: Ganglion Impar Block: A case report. Korean J Anesthesiol. 2005 May;48(5):553-556.

Toshniwal GR, Dureja GP, Prashanth SM. Transsacrococcygeal approach to ganglion impar block for management of chronic perineal pain: a prospective observational study. Pain Physician. 2007 Sep;10(5):661-6.

McAllister RK, Carpentier BW, Malkuch G: Sacral postherpetic neuralgia and successful treatment using a paramedial approach to the ganglion impar. Anesthesiology 2004; 101:1472-4

Hong JH, Jang HS. Block of the ganglion impar using a coccygeal joint approach. Reg Anesth Pain Med. 2006 Nov-Dec;31(6):583-4.