Background & Aims
Ganglion impar block (GIB) is indicated in coccygodynia, pelvic malignancies and chronic perineal pain (CPP). The use of ultrasound improves efficacy and reduce complications as it helps in real time visualization of Sacrococcygeal junction (SCJ). Improvements in transducer technology and imaging processing have increased interest in US-guided interventional pain management procedure. Also there is no need to palpate the rectum during needle placement, patient’s acceptance & comfort is enhanced. Ganglion impar block is useful for managing sympathetically mediated pain in coccygeal and perineal area. Improvements in transducer technology and imaging processing have increased interest in US-guided interventional pain management procedure. The use of ultrasound improves efficacy and reduce complications. Since literature on ultrasound guided ganglion impar block is limited, the feasibility of US-guided needle placement in SCJ was evaluated along with loss of resistance technique.
Methods
Patients aged between 25-65 yrs, suffering from CPP were included after obtaining permission from local ethical committee & IRB. All patients were assessed for pain by visual analog score (VAS) and concomitant drug therapy. Patients having VAS more than 4 were included. Patients having sepsis, local infection and coagulopathy were excluded.
Quality of life (QOL) was assessed by Karnofsky performance status (KS), linear analog scale Assessment (LASA) and constipation score (CS). A 23-gauge needle was advanced into the SCJ under real time US guidance. The needle was advanced slowly through the cleft of the SCJ using out -of -plane approach upto point of loss of resistance. Therapeutic block was performed with 10 ml of 0.25% bupivacaine and 40 mg of methyl-prednisolone acetate. Pain scores were noted at 10 minutes, 30 minutes, 1st hour, 1st week, 2nd week, 1st month and 2nd month. QOL was assessed at 2nd month. The oral drug treatment at 2nd month for pain control was noted.
Results
The SCJ was located easily in all patients under US guidance. Loss of resistance of sacrococcygeal ligament was used as the end point of depth insertion as needle was not visualised beyond bone. The mean time taken to perform the block was 7.67 ± 1.23 minutes. The mean depth of sacrococcygeal junction by ultrasound was 13.73± 0.52 mm. Depth of needle inserted to the point of injection was 15.38 ± 1.30 mm. Eleven patients had successful block in single attempt. Three patients required 2nd attempt and one patient needed 3rd attempt. The VAS reduced significantly from baseline at all intervals (p <0.001). It was lowest at 2nd week and persisted upto 2nd month (2.77± 1.77). The mean KS and LASA improved postblock significantly (p <0.001). Analgesic requirement decreased significantly. Quality of life of patients improved significantly as shown by KS, LASA (p < 0.05). There was statistically significant decrease in dose of NSAIDs (p 0.027) & number of patients taking drug therapy.
Conclusions
The use of ultrasound improves efficacy and reduce complications as it helps in real time visualization of SC junction. The advantage over conventional fluoroscopic techniques is reduced radiation exposure and no rectal examination.The patient’s comfort during the procedure is improved as there is no need to palpate the rectum during needle placement. .The risk of infections is decreased. The management of CPP needs a multimodal approach with primary goal directed towards maximal functional restoration and significant reduction in intensity of pain. Coccygeal cushions, nonsteroidal anti-inflammatory drugs, local analgesics, levator ani relaxation exercises, and transcutaneous electrical nerve stimulation have been used in conservative treatment, but few cases need direct injections around coccyx or ganglion impar blocks.Improvements in transducer technology and imaging processing have increased interest in US-guided interventional pain management procedure.
References
1. Narouze S. Ultrasonography in pain medicine: A sneak peak at the future. Pain Pract 2008;8:223–5.
2. Peng P, Narouze S. Ultrasound-guided Interventional procedures in pain medicine: A review of anatomy, sonoanaotmy and procedures. Part I: Non-axial structures. Reg Anesth Pain Med 2009;34:458–74.
3. Lin CS, Cheng JK, Hsu YW, Chen CC, Lao HC, Huang CJ, et al. Ultrasound-guided ganglion impar block: a technical report. Pain Med 2010; 11: 390-4.
4. Bhatnagar S, Khanna S, Roshni S, Goyal GN, Mishra S, Rana SP, et al. Early ultrasoundguided neurolysis for pain management in gastrointestinal and pelvic malignancies: an observational study in a tertiary care center of urban India. Pain Pract 2012;12: 23–32.