One is the loneliest number: a review of the ganglion impar and its relation to pelvic pain syndromes

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.

Novel approach for pericapsular radiofrequency ablation of sacrococcygeal junction for patients with coccydynia

Introduction

Coccydynia is a multifactorial complex clinical challenge. A multimodal approach with both conservative measures and procedural interventions is often recommended. We described a novel approach of radiofrequency (RF) ablation for the management of coccydynia.

Methods

Three patients with known history of coccydynia refractory to conservative therapy were referred to our clinic. All received different types of RF ablation before: one with anterior bipolar lesion with no analgesia benefit, one with posterior stripped lesion with good benefit but only after 8 weeks of pain flare and one received anterior monopolar lesion with 50% pain reduction for 2–3 months. All subjects underwent a novel RF ablation to the anterior surface of the sacrococcygeal and intercoccygeal joints with two bipolar lesions using multi-tined needles under fluoroscopy guidance. One bipolar lesion was between two needles: one in the sacrococcygeal and another in the intercoccygeal (between first and second coccyx) joints. Another bipolar lesion was between needles on both side of the sacrococcygeal joint.

Results

All experienced at least 65% pain relief for 6 months. The sitting endurance increased from less than 5 min to an average of 70 min. No adverse effect was observed in two and in the patient who used to have pain flare after lesioning, the pain flare lasted only for 2 weeks.

Discussion

The configuration of the two bipolar lesions with multi-tined needles in this case series stimulates the thinking of new approach for the ablation technique for pain from coccyx. Further prospective large case cohort study is needed.

The American Society of Pain and Neuroscience (ASPN) Best Practices and Guidelines for the Interventional Management of Cancer-Associated Pain

Moderate to severe pain occurs in many cancer patients during their clinical course and may stem from the primary pathology, metastasis, or as treatment side effects. Uncontrolled pain using conservative medical therapy can often lead to patient distress, loss of productivity, shorter life expectancy, longer hospital stays, and increase in healthcare utilization. Various publications shed light on strategies for conservative medical management for cancer pain and a few international publications have reviewed limited interventional data. Our multi-institutional working group was assembled to review and highlight the body of evidence that exists for opioid utilization for cancer pain, adjunct medication such as ketamine and methadone and interventional therapies. We discuss neurolysis via injections, neuromodulation including targeted drug delivery and spinal cord stimulation, vertebral tumor ablation and augmentation, radiotherapy and surgical techniques. In the United States, there is a significant variance in the interventional treatment of cancer pain based on fellowship training. As a first of its kind, this best practices and interventional guideline will offer evidenced-based recommendations for reducing pain and suffering associated with malignancy.

Conus infarction after non-guided transcoccygeal ganglion impar block using particulate steroid for chronic coccydynia

Introduction

Ganglion impar block (GIB) is a well-recognised treatment for chronic coccydynia. Several side effects have previously been described with this procedure, including transient motor dysfunction, bowel, bladder, and sexual dysfunction, neuritis, rectal perforation, impingement of the sciatic nerve, cauda equina syndrome, and infection.

Case presentation

We describe the first report of imaging-documented conus infarction after an unguided-GIB performed in theatre using particulate steroids for a 17-year-old patient with coccydynia. Immediately post-GIB, patient developed transient neurological deficits in her lower limbs of inability to mobilise her legs that lasted for 24 h. These include back and leg pain, decreased power and movement, increased tone, brisk reflexes, reduced light touch sensation and proprioception of legs up to the T10 level. Urgent MRI spine showed intramedullary hyperintense signal within the conus and mild restricted diffusion on the distal cord and conus, suggestive of an acute conus infarction. On follow-up, the GIB did not result in symptom improvement of coccydynia and there was persistent altered sensation of her legs.

Discussion

Various approaches of ganglion impar block have been described and performed in the past with different imaging techniques and injectants. A few cases of unusual neurological complications have been reported with the use of epidural steroid injections and ganglion impar block. Clinicians should be aware of the possible neurological complications following ganglion impar blocks and the risk of inadvertent intravascular injection of particulate steroids can potentially to be minimised by using imaging guidance.

The influence of coccygeal dynamic patterns on ganglion impar block treatment results in chronic coccygodynia

Objective Ganglion impar block (GIB) can be performed in patients with chronic coccygodynia who do not respond to conservative treatments. We investigated the effect of coccygeal dynamic patterns on the treatment outcome in patients with chronic coccygodynia treated with GIB. Materials and methods We retrospectively analyzed the data for patients diagnosed with chronic coccygodynia who underwent GIB only once by a transsacrococcygeal method under fluoroscopy guidance in our Pain Medicine Clinic. Patients were assessed with standard and dynamic coccyx radiographs and classified according to coccygeal mobility. Pain scores were assessed with a numerical rating scale (NRS) before and after the intervention (at 1 hour and 4, 12 and 24 weeks). A 50% or more reduction in the NRS score was accepted as significant pain relief. Results Of the 37 patients included in the study, 14 had normal coccyx (Group I) and 23 had immobile coccyx (Group II) based on the radiological evaluation. The NRS scores were significantly reduced in both groups on each follow-up visit but there was no significant difference between the two groups in terms of pre- and post-intervention NRS scores. Significant pain relief was achieved in 42.9% and 61.9% of patients in Group I and II at the last examination, respectively. Conclusion GIB administered by transsacrococcygeal method in patients with chronic coccygodynia is a safe and alternative treatment approach with reduced pain scores and low complication rates. In patients with chronic coccygodynia, having a normal or immobile coccyx does not appear to affect treatment outcomes.

Ganglion blocks as a treatment of pain: current perspectives

The inputs from sympathetic ganglia have been known to be involved in the pathophysiology of various painful conditions such as complex regional pain syndrome, cancer pain of different origin, and coccygodynia. Sympathetic ganglia blocks are used to relieve patients who suffer from these conditions for over a century. Many numbers of local anesthetics such as bupivacaine or neurolytic agents such as alcohol can be chosen for a successful block. The agent is selected according to its duration of effect and the purpose of the injection. Most commonly used sympathetic blocks are stellate ganglion block, lumbar sympathetic block, celiac plexus block, superior hypogastric block, and ganglion Impar block. In this review, indications, methods, effectiveness, and complications of these blocks are discussed based on the data from the current literature.

Incidence and risk factors for rectal pain after laparoscopic rectal cancer surgery

Objective This study was performed to investigate the incidence of and potential risk factors for rectal pain after laparoscopic rectal cancer surgery. Methods We retrospectively analyzed data from 300 patients who underwent laparoscopic rectal cancer surgery. We assessed the presence of rectal pain and categorized patients into Group N (no rectal pain) or Group P (rectal pain). Results In total, 288 patients were included. Of these patients, 39 (13.5%) reported rectal pain and 14 (4.9%) had rectal pain that persisted for >3 months. Univariate analysis revealed that patients in Group P had more preoperative chemoradiotherapy, more ileostomies, longer operation times, more anastomotic margins of <2 cm from the anal verge, more anastomotic leakage, and longer hospital stays. Multivariate analysis identified an anastomotic margin of <2 cm from the anal verge and a long operation time as risk factors. The presence of diabetes mellitus was a negative predictor of rectal pain. Conclusions In this study, the incidence of rectal pain after laparoscopic rectal cancer surgery was 13.5%. An anastomotic margin of <2 cm from the anal verge and a long operation time were risk factors for rectal pain. The presence of diabetes mellitus was a negative predictor of rectal pain. Thus, the possibility of postoperative rectal pain should be discussed preoperatively with patients with these risk factors.

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.