Matteo Bellini

Sciatica due to a lumbar disc herniation and nerve root irritation is a huge public health problem not yet benefiting from an unequivocal treatment approach. Even cervical hernias with brachialgia afflict a substantial range of the population.

Medical and physical therapies represent the first therapeutic steps. When these fail, minimally invasive treatments may play an important role; percutaneous techniques can be applied as intermediate measures between conservative treatment and surgery, avoiding the adverse events of surgical discectomy.

In the last 2 decades, we have witnessed a consistent development of percutaneous materials and techniques for the treatment of symptomatic herniations. Chemonucleolysis is a minimally invasive percutaneous technique allowing the intradiscal injection of materials that dehydrate or “digest” discal portions. Evidence regarding the safety and efficacy of various materials, such as oxygen-ozone and radiopaque gelified ethanol (RGE), has increased. Notably, RGE is a viscous solution containing ethyl alcohol and cellulose derivative products associated with the contrast agent tungsten, recently introduced into clinical practice. Theron et al,^1,2 Stagni et al,³ and Volpentesta et al⁴ reported encouraging outcomes of using RGE in disc herniations. Thus, we decided to apply percutaneous RGE discal injection in patients with radicular pain caused by both lumbar and cervical disc herniations.

Our diagnostic neuroradiologic team in Siena, Tuscany, Italy, led by our colleague Dr. Alfonso Cerase, has immense expertise and experience in neuroradiology of the spine. In daily clinical practice, we interpret many spinal CTs and MRIs of patients accessing the emergency department because of radiculopathy and, unfortunately, failed back surgery syndrome. I have always thought that there should be alternative and more conservative methods for the treatment of symptomatic hernias other than those that temporarily relieve pain. Thus, my work was inspired by the goal to give a valid alternative for the treatment of disc herniation and reduce leg or brachial pain as soon as possible. This was then possible after observing the preliminary, amazing results obtained by my mentors and instructors Dr. Stefano Marcia (Cagliari, Sardinia, Italy) and Dr. Mario Muto (Napoli, Campania, Italy). Thus, we decided to use RGE which, different from other similar products, can dehydrate only the herniated part of the disc while preserving the disc space.

In our study published in AJNR in 2015, a reduction of at least 4 points on the Visual Analog Scale (VAS) and at least 40% on the Oswestry Disability Index (ODI) score (P < 0.001) occurred in the first 3 months after treatment in 85% of patients, who were then able to resume their normal activity without intraperiprocedural complications. In our experience, percutaneous RGE for cervical and lumbar disc herniations was safe and had good clinical outcomes. We received quite a lot of positive feedback about this paper and subsequent studies on this topic that we have presented at a variety of international meetings.

These results have changed our practice. Currently, neurologists, neurosurgeons, and orthopedic surgeons refer to our unit patients with back pain and recurrent drug-resistant symptoms, with no benefit of rest and medical therapy and minimal pain reduction after 4 to 6 weeks of physical therapy.

If CT and/or MRI show a disc herniation at the same metameric level of symptoms after a clinical evaluation performed by the spinal interventional neuroradiologist, mini-invasive treatment with RGE is suggested. Most notably, inclusion criteria are disc herniations contained or not contained with posterior longitudinal ligament integrity and no free fragments assessed with CT and/or MRI. Exclusion criteria are evidence of significant disc degeneration (ie, the so-called "black disc" or disc thinning with disc height loss greater than two-thirds), free isolated fragments, stenosis of the intervertebral foramina or spinal canal, asymptomatic disc bulging, primary tumor or metastatic disease, active local or systemic infection, pregnancy, and hemorrhagic diathesis. Since publication in AJNR, we have continued treating patients with RGE injection, achieving good outcomes in 85–90% of patients, even in the very early stage after treatment. Nowadays, we have treated 104 more patients and a total of 164 disc herniations.

Furthermore, this is a minimally invasive technique, allowing a day-surgery approach and a short recovery period. In the case of no response, RGE injection is not a contraindication to perform surgical discectomy. Thus, considering the low rate of side effects, we do believe that chemonucleolysis with RGE is an important option in the management of patients with radicular back pain before surgery.

Additionally, I am expanding the research in this field with the introduction of percutaneous intervertebral disc coagulation therapy (PDCT), based on plasma thermal reaction, for the treatment of lumbar and cervical disc herniations. PDCT is a type of percutaneous treatment that uses plasma light for coagulation, evaporation, and disc decompression, and it can be a minimally invasive option for herniation refractory to conservative treatment. The operative procedure, apparatus, advantages of the procedure, and early results were recently presented at the RSNA congress in Chicago, and we are currently working on a concise manuscript that should be submitted for peer review later this year.

Finally, together with our colleague Dr. Lucia Monti, a diagnostic neuroradiologist who is highly skilled in ultrasound and color Doppler ultrasound, we are evaluating the pertinent role of advanced ultrasound fusion imaging for the guidance of percutaneous spinal approach, in order to reduce exposure to x-rays.

Acknowledgments: We want to thank Dr. Dario Notaro, a young member of the radiology residency program (University of Siena, Tuscany, Italy) for the passion and devotion shown in the last months in the percutaneous spinal training techniques, providing a highly valuable support to our interventional team.

References

1. Theron J, Guimaraens L, Casasco A, et al. Percutaneous treatment of lumbar intervertebral disk hernias with radiopaque gelified ethanol: a preliminary study. J Spinal Disord Tech 2007;20:526–32, 10.1097/BSD.0b013e318033e860.
2. Theron J, Cuellar H, Sola T, et al. Percutaneous treatment of cervical disk hernias using gelified ethanol. AJNR Am J Neuroradiol 2010;31:1454–56, 10.3174/ajnr.A1923.
3. Stagni S, de Santis F, Cirillo L, et al. A minimally invasive treatment for lumbar disc herniation: discogel chemonucleolysis in patients unresponsive to chemonucleolysis with oxygen-ozone. Interv Neuroradiol 2012;18:97–104, 10.1177/159101991201800113.
4. Volpentesta G, De Rose M, Bosco D, et al. Lumbar percutaneousintradiscal injection of radiopaque gelified ethanol (“Discogel”) in patients with low back and radicular pain. J Pain Relief 2014;3:145, 10.4172/2167-0846.1000145.

Read this article at AJNR.org …