Ganglion impar block is used to treat chronic pelvic and perineal pain conditions in case of pharmacotherapy failure to control pain. In this case report, we present a neurolytic ganglion impar block as an effective method to control chronic pelvic pain resulting from post-surgical intra-pelvic adhesions in a 35-year-old female. We used a fluoroscopy-guided trans-sacrococcygeal ganglion impar block due to its simplicity. Pain level was evaluated using a numerical rating scale (NRS). We conclude that the trans-sacrococcygeal ganglion impar block is a simple and effective method to treat chronic pelvic pain due to post-surgical intra-pelvic adhesions, thus decreasing the consumption of analgesic medications and sick leave days.
Keywords: Ganglion impar, chronic pelvic pain, Neurolytic block, Numerical rating scale
JRMS April 2020; 27(1): 10.12816/0055470
Ganglion impar (Walther) block is used to treat many chronic pelvic pain conditions, adding neurolytic agent such as phenol or alcohol may prolong the block duration for more than six months. Intra-pelvic adhesions can cause moderate to severe pain, which in many cases is difficult to treat by ordinary analgesic medications and makes patients disrupt their work for many days. Ganglion impar block has been introduced to treat these types of pain. Ganglion impar is the only solitary sympathetic ganglion consists of fusion of the last two sacral ganglia, located retroperitoneal and anteriorly to the coccygeal bone between the sacrococcygeal junction and the tip of coccyx.  The significant correlation between the wide ranges of coccyx bone sizes and distances of the ganglion impar from the coccygeal tip was studied by Chang-Seak and colleagues. 
Ganglion impar block was first reported by Plancarte et al. (1990) to treat perineal neuralgia,  and since that time, it was used with some modifications to treat many pelvic and perineum related pain conditions. In this case study, we present a successful ganglion impar block in a patient who suffered from chronic pelvic pain resulting from post-surgical adhesions. Malec-Milewska et al. used this technique, aided by pharmacological, pudendal nerve block and topical
treatment, to achieve reduction of chronic pelvic pain due to either endometriosis or pelvic adhesions in 18 women.  In this case study, we report the effectiveness of neurolytic ganglion impar block without the need to use other methods.
A 35-year-old female patient who suffered from intra-pelvic adhesions due to multiple surgical procedures complained of a lower abdominal pain for a long time. The diagnosis was based on intra-operative findings and follow-up ultrasonography and magnetic resonance imaging. She was treated with NSAIDs, spasmolytics and tramadol with little benefit. The patient refused any further surgical intervention so she was referred to the pain clinic. On the first visit, the patient was complaining of a lower abdominal pain which radiates to the perineum. The numerical rating scale (NRS) was 8/10. Ganglion impar block procedure was explained to both the patient and her husband, and they signed an informed consent form.
The patient was positioned prone, and vital signs were continuously monitored. Two milligrams of midazolam was given. Under aseptic technique, the needle entry point was identified using fluoroscopy. A 22-gauge spinal needle was advanced through the sacrococcygeal ligament until it reached the ventral surface of the sacrococcygeal junction. Proper needle tip position was then confirmed by injecting 3 cc of diluted iodixanol. After a mixture of 3 cc of 2% lidocaine, 2 cc of 0.5% bupivacaine and 80 mg of depot methylprednisolone were injected, the NRS score fell from 8 to 4 in the first 20 minutes, then to 2 after one hour. On the third day, the NRS was 3 and the patient returned to normal daily activities. Thus, we decided to perform neurolytic ganglion impar block using 8 cc of 6% phenol after 2 weeks using the same technique. The NRS score was monitored in each monthly visit, and the patient was satisfied.
pelvic pain is defined as a continuous pain that lasts 6 months or more. It occurs
in 4–14% of women,  and its management is sometimes challenging.
Furthermore, it can be caused by a variety of conditions related to the reproductive
organs, urinary tract or bowel.
The goal of treatment is to reduce symptoms and to improve
the patient quality of life and overall function though that curative treatment
is elusive, and evidence-based therapies are limited. The treatment
options vary according to underlying cause.
for adhesiolysis or endometrial tissue removal is an effective solution in the patients
who are diagnosed with post surgical adhesions and endometriosis respectively.
They may offer significant long-term pain relief in some patients. 
In rare complicated cases hysterectomy, salpingectomy or oophorectomy are
recommended. Because of its high morbidity hysterectomy is the last resort. Up
to 40% will have persistent pain and at least 5% will have worse pain after
hysterectomy.  In the case of failure of the surgery to control
pelvic pain or patient refusal of the surgery the use of other modalities is
Using over the
counter pain remedies, such as acetaminophen, aspirin, ibuprofen and naproxen
may provide partial pain relief. Cochrane review indicates lack of non-steroidal
anti-inflammatory drugs effectiveness for endometriosis.  Opioid
medications such as codeine, tramadol or fentanyl patch may provide
long-term pain control when the other
options have failed.
are recommended if the pain coincides with a particular phase of the menstrual
cycle or endometriosis. They include birth control pills,
gonadotropin-releasing hormone injections or progestin-releasing intrauterine
Some types of
antidepressant such as tricyclic antidepressants (e.g.; amitriptyline,
nortriptyline) and serotonin-noradrenaline reuptake inhibitors (e,g.;
venalfaxine, duloxetine) or anticonvulsants (e.g.; gabapentin, pregabaline )
may be helpful in relieving chronic pain if neuropathic pain is suspected. 
In literature there was a small study shows that the combination of
gabapentin and amitriptyline was more effective than amitriptyline alone. 
has an important role in many cases and it may improve the pain effectively. It
includes stretching exercises, massage and other relaxation therapy. In some
cases the use of
transcutaneous electrical nerve stimulation (TENS) which delivers electrical
impulses that inhibit pain pathways may be helpful. In literature there was one
study of 58 women diagnosed with chronic pelvic pain and treated with TENS after
failure of multidisciplinary management. The result was reduction of skin pain
sensitivity associated with an increase in pelvic pain threshold (p<
of Psychotherapy such as cognitive behavioral therapy and biofeedback may be
helpful in many cases that associated with depression, personality disorders or
sexual abuse. When combined with standard gynecologic care, somatocognitive
therapy improved psychological stress, pain and motor function of women with
chronic pelvic pain. 
pain management may have an important role in chronic pelvic pain control. It
includes trigger point injections with local anesthetic and steroid mixture or
botulinum toxin, selective nerve blockade, superior hypogastric plexus block,
ganglion impar block and spinal cord stimulation. Ganglion impar block is a
preferred method to control pain due its safety and simplicity.
Ganglion impar controls the sympathetic and
nociceptive nerves from most of the pelvic structures. Ganglion
impar block techniques include different approaches; transsacrococcygeal
ligament approach (Toshniwal et al., 2007), transsacrococcygeal joint approach,
paramedial approach (Allister, 2007) and paracoccygeal cork screw approach
(Foye and Patel 2009); various positions prone, lateral and lithotomy and
lastly different guidance techniques like fluoroscopic, ultrasound and computed
tomography guidance. The transsacrococcygeal joint remains the most popular
approach due to its simplicity and effectiveness. The procedure is done under a
strict sterile technique and the needle is advanced under fluoroscopy guidance
through the sacrococcygeal disk and correct needle placement is then confirmed
by administration of contrast dye and appearance of comma sign in the
retroperitoneal space on lateral fluoroscopic projection. (Figure
1) A successful diagnostic block is assessed by significant pain relief. Following
that a therapeutic block is performed with neurolytic agent like phenol or
alcohol. The procedure usually takes 15 minutes and the patient can leave the
hospital at the same day.
Lateral fluoroscopy view showed the trans-sacrococcygeal approach for ganglion
impar block and dye contrast injection at the retroperitoneal area (Comma sign)
This study presents a case of chronic pelvic pain that
indicates block of the ganglion impar. The trans-sacrococcygeal approach to the
ganglion was used under fluoroscopy guidance to confirm correct placement of
the needle tip and to avoid rectal perforation. Nebab and Florence described an
alternative method using curved spinal needle insertion through the
anococcygeal ligament to avoid excessive tissue damage.
For long-term effect, we performed ganglion impar
neurolysis using 6% phenol after a successful block with local anaesthetics and
steroid without any recorded complication. Pain NRS was significantly reduced
after the procedure. Phenol (carbolic acid) was introduced in the 1950s.
It has local anaesthetic effects and can provide significant pain relief,
lasting from 6 to 12 months. It`s mechanism of action includes
nervous tissue destruction by protein denaturation, protein coagulation,
segmental demyelination and Wallerian degeneration.
ganglion impar block is an effective method in the treatment of chronic pelvic
pain with minimal or no complication. It can reduce the consumption of variable
analgesic agents and decrease sick leave days.
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