Ganglion impar block in chronic cancer-related pain - A review of the current literature

Oncologic chronic pain is often difficult to control, especially in anatomical areas with multiple and complex innervation, such as the pelvic/perineal region. The ganglion impar block (GIB) is a procedure with growing interest and varied applicability. It has been used in several benign and malignant causes of pelvic and perineal pain refractory to pharmacological treatment. We conducted a review of all articles published in PUBMED® until the 30th of October 2022 regarding GIB in oncologic pain. 19 articles were identified with a total of 278 patients. Both chronic cancer pain and chronic postcancer treatment pain patients were included. We reviewed the various techniques, approaches, and therapeutic options that were employed. No serious adverse effects were reported. GIB appears to be an effective and safe procedure that should be considered in patients with intractable perineal cancer-related pain.

Clinical efficacy of ultrasound-guided pulsed radiofrequency combined with ganglion impar block for treatment of perineal pain

BACKGROUND

Ganglion impar block alone or pulsed radiofrequency alone are effective options for treating perineal pain. However, ganglion impar block combined with pulsed radiofrequency (GIB-PRF) for treating perineal pain is rare and the puncture is usually performed with X-ray or computed tomography guidance.

AIM

To evaluate the safety and clinical efficacy of real-time ultrasound-guided GIB-PRF in treating perineal pain.

METHODS

Thirty patients with perineal pain were included and were treated by GIB-PRF guided by real-time ultrasound imaging between January 2015 and December 2016. Complications were recorded to observe the safety of the ultrasound-guided GIB-PRF procedure, and visual analogue scale (VAS) scores at 24 h before and after treatment and 1, 3, and 6 mo later were analyzed to evaluate clinical efficacy.

RESULTS

Ultrasound-guided GIB-PRF was performed successfully in all patients, and no complications occurred. Compared with pretreatment scores, the VAS scores were significantly lower (P < 0.05) at the four time points after treatment. The VAS scores at 1 and 3 mo were slightly lower than those at 24 h (P > 0.05) and were significantly lower at 6 mo after treatment (P < 0.05). There was a tendency toward lower VAS scores at 6 mo after treatment compared with those at 1 and 3 mo (P > 0.05).

CONCLUSION

Ultrasound-guided GIB-PRF was a safe and effective way to treat perineal pain. The 6-mo short-term clinical efficacy was favorable, but the long-term outcomes need future study.

Transcoccygeal neurolytic ganglion impar block for perineal pain: A case series

Background and Aims:

Chronic perineal pain (CPP) is a poorly localized pain. Its etiology may be benign or malignant. The ganglion impar is a solitary retroperitoneal structure at sacrococcygeal junction. It provides the nociceptive and sympathetic supply to the perineal structures. CPP has been effectively managed by ganglion impar block. Here, we describe a case series of neurolytic ganglion impar block by transcoccygeal approach, analyzing its safety and efficacy.

Material and Methods:

In this study, five consecutive patients who were given ganglion impar block for CPP using a transcoccygeal approach were followed up for 2 months. The visual analog scale (VAS) score for pain at presentation, time required for the pain to reduce by 50% after the block, VAS during a 2-month follow-up, time required to perform the procedure, number of attempts, and any complications were noted.

Results:

All the five patients had an excellent pain relief. The mean duration for decrease in VAS by 50% was 14.8 ± 3.1 min. The mean duration to perform the procedure was 10.2 ± 1.5 min. There were no complications. All the patients had clinically significant pain relief with VAS score of 2 till 2-month follow-up.

Conclusion:

Transcoccygeal ganglion impar block may offer a safe and effective treatment option for CPP as compared to opioids. This approach for neurolysis of the ganglion impar may be recommended in view of the direct course, appreciable end point, and smaller volume of neurolytic requirement.

A Review of Current Treatment Options for Coccygodynia

PURPOSE OF REVIEW

Coccygodynia is pain within the coccyx area. The diagnosis is made clinically with symptoms of pain in the coccyx region and worsening pain in sitting position. The initial treatment is conservative therapy. For patients who do not respond to conservative therapies, there are further interventions available. This includes local injection of local anesthetics and steroids, neurolysis of sacral nerve roots, caudal epidural block, pulse radiofrequency (PRF), intra-rectal massage and manipulation, ganglion impar block, levator ani massage and stretching, coccyx manipulation, and coccygectomy. The purpose of this review is to evaluate the efficacies of these interventions in the treatment of coccygodynia.

RECENT FINDINGS

Literature search was performed with the keywords including coccygodynia, treatment, and coccygectomy, on PubMed and Google Scholar between August 2012 and August 2017. Thirteen studies with patients age 18 and over who underwent treatments for coccygodynia were selected for analysis. These treatments include conservative therapies (physical therapy and capsaicin patch), interventional techniques (local injections with steroids and local anesthetic, pulsed radiofrequency ablation of ganglion impar, extracorporeal shock wave therapy), and surgical techniques (complete and partial coccygectomies). The results from these studies demonstrated that most patients had significant pain relief with these techniques. Our literature review demonstrated various interventions including coccygectomy can be effective in the treatment of coccygodynia refractory to conservative therapies. There is a growing body of clinical evidence to support that coccygectomy is an effective treatment for patients with debilitating pain who had failed interventional therapies. Further randomized control studies should be conducted to examine duration of pain relief after coccygectomy and associated surgical complications.

Interventional Treatments of Cancer Pain

Pain is a significant burden for patients with cancer and is particularly prevalent among those with advanced cancer. Appropriate interventional cancer pain therapies complement conventional pain management by reducing the need for systemic opioid therapy and its associated toxicity; however, these therapies are often underutilized. This article reviews techniques, indications, complications, and outcomes of the most common interventional approaches for the management of cancer-related pain. These approaches include intrathecal drug delivery, vertebral augmentation, neurolysis of the celiac, superior hypogastric and ganglion impar plexus', image-guided tumor ablation, and other less commonly performed but potentially beneficial interventions.

MR-guided perineural injection of the ganglion impar: technical considerations and feasibility

OBJECTIVE

Perineural ganglion impar injections are used in the management of pelvic pain syndromes; however, there is no consensus regarding the optimal image guidance. Magnetic resonance imaging (MRI) provides high soft tissue contrast and the potential to directly visualize and target the ganglion. The purpose of this study was to assess the feasibility of MR-guided percutaneous perineural ganglion impar injections.

MATERIALS AND METHODS

Six MR-guided ganglion impar injections were performed in six human cadavers. Procedures were performed with a clinical 1.5-Tesla MRI system through a far lateral transgluteus approach. Ganglion impar visibility, distance from the sacrococcygeal joint, number of intermittent MRI control steps required to place the needle, target error between the intended and final needle tip location, inadvertent punctures of non-targeted vulnerable structures, injectant distribution, and procedure time were determined.

RESULTS

The ganglion impar was seen on MRI in 4/6 (66 %) of cases and located 0.8 mm cephalad to 16.3 mm caudad (average 1.2 mm caudad) to the midpoint of the sacrococcygeal joint. Needle placement required an average of three MRI control steps (range, 2-6). The average target error was 2.2 ± 2.1 mm. In 6/6 cases (100 %), there was appropriate periganglionic distribution and filling of the presacrococcygeal space. No punctures of non-targeted structures occurred. The median procedure time was 20 min (range, 12-29 min).

CONCLUSION

Interventional MRI can visualize and directly target the ganglion impar for accurate needle placement and successful periganglionic injection with the additional benefit of no ionizing radiation exposure to patient and staff. Our results support clinical evaluation.

Treatment of post-traumatic pain, and autonomic and muscular dysfunction by ganglion impar block and medial branch block of the facet joints: A case report

Introduction Patients exposed to whiplash trauma are at risk of developing pain and dysfunction of the neck and shoulder. Although rarely discussed in the literature, some patients also develop autonomic dysfunction. Case presentation A previously healthy 41-year-old woman was involved in a "head-on" car crash. During the following 3 years she developed severe and complex post-traumatic pain syndrome, which consisted of neck pain, lumbar pain, sensory-motor dysfunction, and myoclonic muscular contractions. Despite pharmacotherapy, physiotherapy, and rehabilitation, her condition worsened, resulting in severe disability. Fourteen years after the car crash, an interventional pain therapy program was started, which consisted of sympathetic ganglion impar block and medial branch blocks of facet joints at different levels. These treatment strategies ultimately normalized her sensory-motor dysfunction, reduced her autonomic dysfunction, and stopped the myoclonic muscular contractions. Conclusion This case highlights a possible interaction between the pain-generating facet joints, the somatosensory nervous system, and the autonomic/sympathetic nervous systems. The case also highlights the importance of identifying autonomic dysfunction in patients with persisting pain syndromes. Implications This complex case shows that many clinical phenomena cannot be explained using our present knowledge of pain mechanisms. We hope that readers who have observed similar cases can learn from our case, and are encouraged to publish their observations.