SHORT REVIEW Teflon™ or Ivalon®: a scoping review of implants used in microvascular decompression for trigeminal neuralgia Elliot Pressman 1 & R. Tushar Jha 1 & Gleb Zavadskiy 2 & Jay I. Kumar 1 & Harry van Loveren 1 & Jamie J. van Gompel 3 & Siviero Agazzi 1 Received: 24 June 2019 /Revised: 18 September 2019 /Accepted: 30 September 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Background Trigeminal neuralgia (TN) is characterized by jolts of pain along the distribution of the trigeminal nerve. If patients fail conservative management, microvascular decompression (MVD) is the next step in treatment. MVD is largely done by placing implant pads between the nerve and compressing vessels. We conducted a literature review to assess effectiveness and safety of Teflon™ and Ivalon® sponges for treatment of TN with MVD. Methods In January 2019, PubMed was searched for manuscripts published in English using permutations of “Microvascular decompression”, “Teflon”, “Ivalon”, “Granuloma”, “Polytetrafluoroethylene”, “Trigeminal Neuralgia”, and “Exploration”. Success and relapse rates, causes of relapse, and complication rates were analyzed. We analyzed for relationships with ANCOVA at an alpha threshold of .05. Results Thirty-six studies representing 4273 patients fit inclusion criteria. Twenty-five dealt with initial MVD, 12 with re-do MVD. Initial MVD initial success rates were 85% in patients receiving Teflon™ (57–100%*) and 91% in patients receiving Ivalon® (79–100%*). Recurrence rates were 12% in Teflon™ patients (0*–30%) and 9.1% in Ivalon® patients (0*–19%). In patients with relapses, implants were the cause in 49% of Teflon™ patients (0*–100%*) and 50% of Ivalon® patients (0*– 100%*). Complication rates for patients receiving Teflon™ were 12% (0*–34%) and 19% for patients receiving Ivalon® (0*– 40%). Conclusion Teflon™ and Ivalon® are two materials used in MVD for TN. It is an effective treatment with long-term symptom relief and recurrence rates of 1–5% each year. Ivalon® has been used less than Teflon™ though is associated with similar success rates and similar complication rates. Keywords Ivalon . Microvascular decompression . Teflon . Trigeminal neuralgia Introduction Trigeminal neuralgia (TN) is in most cases a unilateral pain disorder classically described as paroxysmal, lancinating pains confined to one or more division of the trigeminal nerve. Initial treatment is typically with administration of medica- tions such as carbamazepine, which can relieve patients with mild symptoms. If patients fail this conservative medical man- agement, microvascular decompression (MVD) is typically used as the next step in treating TN in patients without a contraindication to open surgery. As the incidence for TN is estimated to be about 4.7 persons per 100,000, MVD is a mainstay in general neurological surgery practice.[23] The foundation for MVD as a treatment for TN began to be laid in 1925 when Walter Dandy began partial sectioning of the trigeminal sensory root via a posterior fossa approach. By approaching through the posterior fossa, he was able to ob- serve that in many cases, there was a compressive lesion (typ- ically arterial loops, venous lesions, and tumors) crossing the nerve and compressing it.[1] Peter Jannetta developed the MVD procedure based on this theory and outlined the new technique in an article published in 1967. In it, he described freeing an artery from arachnoidal membranes to “assume a * Siviero Agazzi sagazzi@health.usf.edu 1 Department of Neurosurgery and Brain Repair, University of South Florida, Tampa, FL 33606, USA 2 Muma College of Business, University of South Florida, Tampa, FL, USA 3 Department of Neurosurgery, Mayo Clinic, Rochester, MN, USA Neurosurgical Review https://doi.org/10.1007/s10143-019-01187-0