Novel Single Puncture Approach for Simplicity 3 Sacral Plexus Radiofrequency Ablation: Technical Note

Radiofrequency (RF) ablation of the lateral sacral plexus has been used for the treatment of sacroiliac joint pain including as an adjunct to other palliative therapies for the treatment of painful osseous metastasis. The treatment goal is targeted ablation of the dorsal lateral branches of S1-S4. Though several techniques have been described, the Simplicity III (Neurotherm, Middleton, MA) system allows for ablation to be achieved with a single RF probe by utilizing a multi-electrode curved RF probe to create a continuous ablation line across all sacral nerves. In the standard approach, there is sequential introduction of a spinal needle along the desired ablation tract for local anesthesia followed by separate placement of the ablation probe. Though fluoroscopic guidance is utilized, multiple needle passes increase the risk of complication such as bowel perforation or probe insertion through a neural foramen. It may also extend procedure time and increase radiation dose. We illustrate a technique for Simplicity III RF ablation of the dorsal sacral plexus using a modified Seldinger approach for treatment of a patient with sacroiliac joint pain due to osseous renal cell carcinoma metastasis. The desired ablation tract is initially anesthetized via a hollow micropuncture needle. The needle is then exchanged for a peelaway sheath. The RF probe is inserted through the peelaway sheath thus ensuring the probe is placed precisely along the previously anesthetized tract allowing the procedure to be completed using a single percutaneous puncture. We believe that this approach decreases the risks of bowel perforation, patient discomfort as a result of multiple percutaneous punctures, and procedure time. Key words: Simplicity 3, sacral plexus ablation, image-guided approach, modified Seldinger, chronic sacral pain, thin wall introducer needle