| Ultrasound Innovation Award |
| Online Abstract Submission |
| (Author: Carina Li ) |
| Abstract |
| Type: New block technique |
| Title: Ultrasound Guided Radiofrequency Ablation of Post amputation neuroma for intractable neuropathic stump pain |
| Disclosure Statements |
| My research & development of my invention is not supported by a commercial company |
| Abstract |
| Introduction and background After nerve injury and regeneration, significant post trauma and operative pain associated with the scar and fibrosis leading to alternation of nerve sensation with neuralgia of the distribution of the injured nerve. A bulbous mass may form at the injured nerve end with a traumatic neuroma. Patient with neuroma after trauma is known to have severe disabling pain especially for post below knee amputation, affecting the fitting of prosthesis and quality of life. Effective treatment of the painful neuroma remains to be a difficult problem. Ultrasound is an established modality for the evaluation of neuromas, like Mortons neuromas and amputation stump neuromas. Ultrasound has been used to guide for the diagnosis of nerve injury or neuroma block procedure for temporary relief of pain for amputee. Surgical resection for painful neuroma success rate depends on individual assessment and with either total denervation or with a high chance of recurrence and post surgical adhesions may lead to more pain. Treatment of Morton neuroma with sonographic guided alcohol injection has been described but nerve with radiofrequency. The use of ultrasound guided RFA neuroma for an amputee when the nerve serves no motor functions allows prolong pain control and enhances quality of life. Radiofrequency ablation (RFA) procedure has been performed to treat tumors in lung, liver, kidney and other body organs under image guidance (such as CT scan or ultrasound). A RFA needle probe is placed inside the lesion and the radiofrequency waves passing through the probe increase the temperature within lesion that results in destruction of the lesion with coagulation. Ultrasound guidance is commonly used for RFA for real time insertion of needle and confirmation complete destruction of tissue with vaporization by bubbles appearance of the lesion on real time Ultrasound images. Generally RFA is used to treat patients with small tumors in organs. For chronic pain management, RFA has been performed for ablation of trigeminal nerve for trigeminal neuralgia, Sacroiliac joint or facet joint denervation of peripheral nerve or mortons neuroma for foot pain. Noval Clinical Application: A 61 years old lady who was known to have multiple medical problems with history of diabetes mellitus on insulin injection, Hypertension, ischemic cardiomyopathy, past history of ischemia stroke and deep vein thrombosis on long term warfarin aiming Inetrantional Normlasied Ratio ( INR) at 3-3.5. She had severe left post- below knee amputation (BKA) stump pain with failed numerous conservative treatment. She was referred by another pain specialist for pain interventional procedure for her neuroma stump pain. She had positive provocative sign at the stump region preventing her had proper fitting of her prosthesis and severely limited her life home and wheel chair bounded. She had a positive diagnostic block with ultrasound guidance in out- patient setting with real time insertion of 22G 50mm Stimuplex Needle A under ultrasound guidance. The common peroneal nerve was identified and neuroma, needl tip position was confirmed with peripheral stimulation at current 0.6-8mA with similar pain complaint. Diagnostic block was done with local anesthetic 20ml Ropivaicane 0.2% in divided doses after negative aspiration with nice halo around the nerve . She had good pain relief and no pain after the nerve block even with rocking onto the stump end, left fibular head and mid thigh after procedure but not sustainable in follow up clinic session 1 week later. Percutaneous Pulsed Radiofrequency of ablation therapy left common peroneal neuroma with ultrasound guidance has been performed with Sonosite Micromaxx System high frequency linear probe. The sciatic nerve and bifurcation of which was identified and scout scan to common peroneal nerve branch near to fibular head at knee level to identify the neuroma. Neuroma was identified by appearance of mixture of hypoechoic and hyperechoic mass with intersepta. The procedure was done in operation room with strict aseptic technique. After skin infiltration with 1 ml 2% Lignocaine, real time insertion of 21G 100 mmx5mm, active tip 4mm Radiofrequency needle was done to reach the neuroma which is located 1 cm from skin and the neuroma was confirmed with Pain Mangement RF generator sensory stimulation at current 0.3mA with similar pain elicited as she had before and confirmed with patient who is under mild sedation. Motor stimulation also applied to ensure no direct muscles stimulation. Pulsed radiofrequency at temperature 42 degrees applied for 120seconds at 3 locations to ensure the whole neuroma being ablated at 3 sites anterior , middle and posterior within the nerve complex at with 3 separate cycles as technique used in RFA of liver tumor. After the radiofrequency procedure, total 20ml ropivacaine 2% was injected around the remains for post-operative pain control. There was neither bleeding nor haematoma as noted with real time ultrasound scanning. She had no pain after the nerve block even with rocking onto the stump end, left fibular head and mid thigh in followed up clinic sessions. With the ultrasound guidance of radiofrequency needle, the neuroma can be located precisely at particular peripheral nerve. Radiofrequency needle was then inserted and confirmed with sensory stimulation with peripheral nerve stimulation before RFA. Destruction of the neuroma can be confirmed with bubbling appearance (dissolution) of the lesion during the RFA thermo coagulation. The procedure can be repeated with minimal invasive technique if regeneration of neuroma recurs in day care setting even in similar high medical risks patient. References 1.Joaquin Andres, Eli Gibson, et al. Estimation of nerve dimensions from MRI of the human Thigh. High field MR centre , Univerisy of British Columbia , Vancouver , British Columbia , Canada 2.Richard J.Hughes, Kaline Ali, et al. Treatment of Morton’s neuroma with sonographic guidance: follow up of 101 cases. Am. J. Roentgenol. 2007; 188:1535-1539 3.G. J. van Geffena1 c1, J. Bruhna1, M. J. Gielena1 and G. J. Scheffera1Pain relief in amputee patients by ultrasound-guided nerve blocks. European Journal of Anaesthesiology (2008), 25:424-425 4.Napolean A. Campos, John H. Chiles, and Anthony R. Plunkett. Ultrasound-Guided Cryoablation of Genitofemoral Nerve for Chronic Inguinal Pain. Pain Physician Journal 2009;12;997-1000. 5.A. Fischler, J. Gross.Ultrasound-guided sciatic neuroma block for treatment of intractable stump pain. Journal of Clinical Anesthesia 2007, 19(8): 626-628 6.Ernberg LA, Adler RS, Lane J. Ultrasound in the detection and treatment of a painful stump neuroma. Skeletal Radiol. 2003 May;32(5):306-9. 7.Solbiati L.New applications of ultrasonography: interventional ultrasound. Eur J Radiol. 1998 May;27 Suppl 2:S200-6. 8.Antonio Giorgio, Luciano Tarantino, Giorgio de Stefano, et al. Percutaneous Sonographically Guided Saline-Enhanced Radiofrequency Ablation of Hepatocellular Carcinoma. Am. J. Roentgenol., 2003; 181:479-484. |
| Clinical Significance |
| Clinical Advantages of this noval application are as follows: 1. Perform real time guidance to locate the exact site of neuroma and confirm the pain with sensory stimulation mode of RF needle. 2. Minimal invasive ablation procedure for simple effective pain control as compared to surgical resection with high chance of recurrence and further adhesions can potential leading to more neuropathic pain 3. Destruction of the neuroma can be confirmed with real time vaporisation of the lesion and post procedure sensory stimulation of the nearby area to confirm no residual neuronal tissue left 4. Can be safety perform in patent with co-morbidity and high anesthetic risk 5. Can minimize the risk of bleeding in patient on anti-coagulants or coagulopathy such as warfarin as RFA has coagulation function. |
| Ultrasound Equipment |
| Manufacturer: hand-carried ultrasound machine, SonoSite |
| Model: MicroMaxx |
| Probe Used |
| Type: linear high frequency, L38 |
| Size: 38 mm |
| Frequency: 8-12 MHz |
| Files |
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