Ganglion impar block will be applied under ultrasound guidance

The procedure will be performed under sterile conditions and continuous monitoring. Using an ultrasound device with a 10-12 MHz linear probe, a 22G spinal needle will be advanced into the sacrococcygeal joint space using the out-of-plane technique. After confirming loss of resistance with a syringe containing normal saline as the needle exits the capsule anterior to the joint, approximately 1 mL of contrast medium will be injected. Anteroposterior (AP) and lateral fluoroscopic images will be obtained to verify the spread of the contrast agent. Once adequate contrast distribution is confirmed anterior to the coccyx on the lateral view, a mixture of dexamethasone and bupivacaine will be injected to complete the block. Procedures that cannot be completed or successfully visualized under ultrasound guidance will be finalized under fluoroscopic guidance.

In all patients, the sacrococcygeal or transcoccygeal space will be identified under ultrasound guidance. A 22-gauge spinal needle will be advanced into the joint space under ultrasound visualization. Using a saline-filled syringe, the loss-of-resistance technique will be employed to confirm passage through the joint space and entry into the retroperitoneal space. Subsequently, a lateral fluoroscopic image will be obtained, and contrast medium will be injected to verify needle placement. If appropriate contrast dispersion is observed along the midline, the procedure will be considered successful, and the medication will be administered. If contrast distribution is inadequate (e.g. vascular spread, non-midline spread), the procedure will be discontinued under ultrasound guidance and resumed under fluoroscopic guidance.

Pain intensity will be assessed using the Visual Analogue Scale (VAS), a 10-point scale where 1 indicates no pain and 10 represents the worst pain.