A comparison of long-term outcomes between interposition with Teflon and autologous muscle in microvascular decompression for trigeminal neuralgia

A comparison of long-term outcomes between interposition with Teflon and autologous muscle in microvascular decompression for trigeminal neuralgia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article A comparison of long-term outcomes between interposition with Teflon and autologous muscle in microvascular decompression for trigeminal neuralgia Johann Klein, Barbara Carl This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7086552/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 10 Oct, 2025 Read the published version in Neurosurgical Review → Version 1 posted 9 You are reading this latest preprint version Abstract Objective : Microvascular decompression (MVD) is an established surgical procedure for treating classical trigeminal neuralgia (TN) by separating the trigeminal nerve from an offending vessel. Various materials can be used for interposition, Teflon being the standard in many centers. Autologous muscle is used as an alternative; however, comparative studies are sparse. We compared the outcomes of patients who underwent MVD for TN with either Teflon or muscle in the same center. Methods : We searched our database for patients who underwent MVD for TN between 2007 and 2024. The records were analyzed for outcome parameters, and patients or their relatives were contacted via phone if follow-up data were insufficient. Exclusion criteria included repeat MVD, lack of initial improvement after surgery, and loss to follow-up. The primary outcome parameter was treatment failure, defined as Barrow Neurological Institute (BNI) pain intensity score IV or V. Results : 70 patients were identified. After applying the exclusion criteria, 48 were available for the outcome analysis, among whom 21 had received interposition with muscle and 27 with Teflon. The mean patient age was 65 years, 56.25% were female, and the pain was right-sided in 62.5% of patients. At a mean follow-up of 85 months, 12.5% had experienced treatment failure (14.29% in the muscle group and 11.11% in the Teflon group; p = 0.741). Kaplan-Meier analysis with log-rank test and logistic regression analysis revealed no significant differences. Conclusions : We found no differences in the outcomes of MVD for TN when either autologous muscle or Teflon was used. Both materials are appropriate for interposition. trigeminal neuralgia facial pain Teflon autologous muscle graft Jannetta procedure Figures Figure 1 Figure 2 Introduction Classical trigeminal neuralgia is a severe facial pain syndrome caused by vascular compression of the trigeminal nerve.[ 36 ] While pharmacotherapy with carbamazepine or oxcarbazepine shows high success rates, treatment resistance does occur; additionally, adverse effects are frequent and can reach intolerable levels.[ 27 ] For patients in whom conservative therapy does not lead to satisfactory results, microvascular decompression (MVD) is widely established as a definitive treatment. The procedure involves separating the offending vessel from the nerve and interposing a graft to avoid neurovascular contact. Various materials have been used for interposition, including Teflon, Ivalon, gelatin sponge, and cotton gauze.[ 20 , 24 , 34 ] Teflon (polytetrafluoroethylene) is frequently used in surgical implants, including as interposition material in MVD, due to its chemical stability and relative biological inertness. While Teflon is established as the most common implant in MVD, there has been a recent resurgence of interest in autologous muscle as graft material, owing to its immediate availability, biological compatibility, and favorable intraoperative handling.[ 7 ] Ashraf et al. have published an impressive analysis of 1025 patients who underwent MVD with an autologous muscle graft for trigeminal neuralgia. The authors discussed the possibility of pain recurrence after successful MVD with Teflon due to adhesion or granuloma associated with the implant.[ 3 ] This article sparked an interesting exchange of views about the suspected advantages or disadvantages of the graft materials.[ 33 ] Although studies like the one by Ashraf et al. have shown encouraging results, there is a paucity of direct comparisons of the outcomes of MVD with Teflon vs. muscle. The only such study we are aware of was conducted by Haidar et al., who evaluated the rate of pain recurrence after MVD depending on the material used for interposition (muscle, Teflon, or a combination of both) and found 5.2% recurrences with muscle and 40% with Teflon.[ 12 ] Our study aimed to compare the outcomes of patients who had first-time MVD for trigeminal neuralgia and received either muscle or Teflon as interposition material. We hypothesized that there would be no significant difference in long-term failure rates. Materials and Methods Study design This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of the Medical Association of the state of Hesse. The need for informed consent was waived by the ethics committee due to the retrospective nature of the study. We identified all patients who had received MVD for trigeminal neuralgia at our department between 2007 and 2024. MVD for other indications, such as glossopharyngeal neuralgia or hemifacial spasm, was not included in this study. At our institution, muscle was used as interposing material until 2012, and Teflon was used from 2013 onwards, which allowed for the definition of two patient cohorts. Exclusion criteria included previous MVD on the same side and the use of more than one material for interposition; after this, the remaining patients were included in the complication analysis. For the outcome analysis, further exclusion criteria – the lack of initial improvement after surgery and loss to follow-up – were applied. MVD on both sides in the same patient at different time points were counted as two patients. Early repeat surgery due to incomplete decompression was not counted as repeat MVD nor as treatment failure, as this was not interpreted as a function of the interposed material; this was the case in two patients. Surgical procedure The operation was performed either in the lateral position or the supine position, with the head rotated contralaterally to the affected side. Monitoring of facial nerve and brainstem auditory evoked potentials was used routinely. A straight or C-shaped retromastoid incision was carried out, and after dissection through the subcutaneous and muscular tissue and harvesting of a muscle graft in patients in whom muscle was to be implanted as interposing material, a craniectomy of approximately 3x3 cm was performed abutting the transverse and sigmoid sinus. If the mastoid cells were opened, they were sealed with bone wax. After durotomy, the cerebellar hemisphere was gently mobilized medially with a retractor, the arachnoid was opened, and CSF was drained. The cerebellopontine angle was then visualized. The superior petrosal vein was either protected or sacrificed, depending on the surgeon’s preference and possible visual obstruction by the vein. The entire trigeminal root was exposed, and arachnoid adhesions were released. After identifying one or several offending vessels, they were carefully separated from the nerve and mobilized away from it. One or several Teflon or muscle grafts were then placed to eliminate any neurovascular contact and fixated with fibrin glue. The dura was then sutured in a watertight fashion; if necessary, with the use of muscle patches. In later years, dural sealants were frequently used. The craniectomy was either left open, filled with bone dust, or reconstructed using methylmethacrylate, depending on the surgeon. The subcutaneous layer was closed with interrupted sutures, and the skin with a running locking suture. Data collection We analyzed the electronic patient files retrospectively for pre-, intra-, and postoperative data such as the presence of arterial contact on preoperative magnetic resonance imaging (MRI), intraoperative findings, and complications including cerebrospinal fluid (CSF) leak and pseudomeningocele (which were counted together), wound infection, facial palsy, hypoacusis, and facial hypoesthesia. The outcome was evaluated according to the Barrow Neurological Institute (BNI) pain intensity score: BNI I = no pain, no medications; BNI II = occasional pain, no medications required; BNI III = some pain, adequately controlled with medications; BNI IV = some pain, not adequately controlled with medications; BNI V = severe pain or no relief.[ 25 ] For the primary endpoint we categorized the BNI score and defined treatment failure as BNI IV or V. If the electronic files did not provide sufficient information for the outcome analysis, the patients or, if they were unavailable, their relatives were contacted via phone and interviewed about the current presence or absence of facial pain, whether medication for facial pain was being taken and whether sequelae of the surgery such as hypoesthesia, hearing loss or facial palsy were present. However, as long-term information about these sequelae was not available for all patients, the reporting of complications in this study refers to the early postoperative period. If pain recurrence was reported during the phone interviews, we inquired about the time after surgery at which the recurrence was observed. The time of treatment failure was defined as the date of the last follow-up. Sample size calculation and statistical analysis We conducted an online sample size analysis (clincalc.com) using the results reported by Haidar et al.[ 12 ] At anticipated incidences of 5.2% and 40%, respectively, with a power of 80% and an alpha of 0.05, 21 patients would be required in each group. For statistical analysis, continuous variables are reported as mean ± standard deviation and were compared using a two-sided t-test. Ordinal variables are reported as median ± interquartile range and were compared with the Mann-Whitney U test. Categorical variables were analyzed using the Chi-squared test. For evaluating the primary endpoint (treatment failure), we employed a non-parametric survival analysis using Kaplan-Meier curves and the log-rank test. Additionally, we performed a logistic regression analysis with treatment failure as the dependent variable, age as a covariate, and sex, implant type (Teflon or muscle), intraoperative arterial contact, and the presence of arterial compression on preoperative MRI as factors. The model was built using forward selection. For all parameters, p < 0.05 was regarded as statistically significant. All statistical analyses were conducted with JASP 0.19.3.0. Results We identified 70 patients who had received MVD for trigeminal neuralgia. Two patients were excluded because they had both Teflon and muscle implants. Another six patients were excluded for having had MVD on the same side before. Thus, 62 patients were included in the analysis of complications. CSF leak or pseudomeningocele occurred in 9.68%, wound infection in 2.94%, facial palsy in 3.23%, hypoacusis in 4.84%, and hypoesthesia in 9.68% of patients. One 89-year-old patient suffered from a postoperative cerebellar hemorrhage and died. There was no statistically significant difference in complications between the Teflon and muscle groups (Table 1 ). Table 1 Patient demographics and characteristics. ASA = American Society of Anesthesiologists; BNI = Barrow Neurological Institute; CSF = cerebrospinal fluid; IQR = interquartile range; MRI = magnetic resonance imaging muscle teflon p age 68.67 ± 9.59 62.56 ± 12.87 0.076 sex (m : f) 11 : 10 (52.38 : 47.62%) 10 : 17 (37.04 : 62.96%) 0.288 side (left : right) 8 : 13 (38.10 : 61.90%) 10 : 17 (37.04 : 62.96%) 0.94 pain distribution V1: 4/21 (19.05%) V2: 12/21 (57.14%) V3: 14/21 (66.67%) V1: 8/27 (29.63%) V2: 26/27 (96.3%) V3: 18/27 (66.67%) constant pain 2 (9.53%) 2 (7.41%) 0.792 duration of pain (years) 6.81 ± 8.16 6.40 ± 7.45 0.881 median ASA grade ± IQR 2 ± 1 2 ± 1 0.475 neurovascular contact on MRI 13/16* (81.25%) 15/15* (100%) 0.078 intraoperative arterial contact 14/20* (70%) 24/27 (88.89%) 0.104 CSF leak / pseudomeningocele 3/28 (10.71%) 3/34 (8.82%) 0.802 infection 1/28 (3.57%) 1/34 (2.94%) 0.889 facial palsy 2/28 (7.14%) 0/34 (0%) 0.113 hypoacusis 1/28 (3.57%) 2/34 (5.88%) 0.673 hypoesthesia 3/28 (10.71%) 3/34 (8.82%) 0.802 follow-up time (months) 120.3 ± 68.51 57.26 ± 46.47 < 0.001 outcome at last follow-up BNI I: 15/21 (71.43%) BNI II: 0/21 (0%) BNI III: 3/21 (14.29%) BNI IV: 1/21 (4.76%) BNI V: 2/21 (9.52%) BNI I: 17/27 (62.96%) BNI II: 2/27 (7.41%) BNI III: 5/27 (18.52%) BNI IV: 1/27 (3.70%) BNI V: 2/27 (7.41%) treatment failure (BNI IV – V) 3/21 (14.29%) 3/27 (11.11%) 0.741 time to failure (months) 33.67 ± 18.50 15.67 ± 17.21 0.40 After applying the remaining exclusion criteria (Fig. 1 ), 48 patients were available for outcome analysis, out of which 21 had a muscle graft implanted, while 27 had Teflon used. Twenty-one patients (43.75%) were male, and 27 were female (56.25%). The mean age was 65.23 ± 11.84 years. The pain was left-sided in 18 (37.5%) and right-sided in 30 (62.5%) patients. 4 (8.33%) patients had constant pain; in all other patients, the pain was purely paroxysmal. We were able to retrieve information about preoperative MRI findings in only 31 of the 48 patients. Out of these, arterial compression was described in 28 (90.33%) cases. Follow-up duration was 84.85 ± 64.74 months. At the last follow-up, 6 patients (12.5%) had a BNI score of IV or V, corresponding to treatment failure, which had occurred at 2, 10, 22, 24, 35, and 55 months, respectively. In the chi-squared test, no difference between the groups could be found (p = 0.741). Likewise, the Kaplan-Meier analysis (Fig. 2 ), with a log-rank test, showed no differential outcomes (p = 0.97). Upon regression analysis, no covariates or factors were found to be significantly associated with the endpoint. Discussion We present a retrospective study that compares the outcomes in patients who underwent MVD for trigeminal neuralgia and received either Teflon or autologous muscle as interposition material. We found no difference in the long-term rates of treatment failure or the frequency of complications. Despite decades of experience with MVD, the search for the ideal interposition material is ongoing. Peter Jannetta chose Teflon over Ivalon after arguing that the latter is too hard to effectively dampen the pulsations of the offending artery.[ 16 ] However, subsequent studies found no difference in the outcomes between the two materials.[ 23 , 24 ] While Teflon is the standard implant for MVD in many centers, several author s have raised concerns about adhesions and the formation of granulomas associated with the material, which may potentially lead to pain recurrence. Teflon adhesions and granulomas are frequent findings in repeat MVDs.[ 4 , 9 , 13 , 18 , 28 , 35 ] To minimize the risks of such complications, it seems prudent to implant only as many Teflon grafts as necessary, which are only as large as required.[ 4 ] Fukushima developed a technique to transpose the offending artery and decompress the affected nerve without interposition material remaining in contact with it.[ 11 ] This should, in theory, improve the results of MVD as Teflon adhesions and granulomas can be largely ruled out. However, comparative studies have shown no difference in the outcomes of transposition vs. interposition.[ 29 , 30 ] With autologous muscle, pain recurrence may result from a shrinkage of the implant.[ 31 ] This issue may be avoided by inserting a sufficiently large muscle graft.[ 33 ] However, contrary to the reports on pain recurrences associated with Teflon, the literature on this finding is extremely sparse. Six patients with muscle implants had a repeat MVD for recurrent trigeminal neuralgia at our institution (among them, patients not included in the actual analysis). In three cases, the surgical report specifically described shrinkage of the muscle graft, whereas in three others, an arterial contact with the trigeminal nerve was described without mention of muscle shrinkage. Notably, in four of the six surgeries, strong adhesions were reported, making it challenging to separate the artery from the nerve. Another possible reason for pain recurrence is a new neurovascular contact, which has been regularly described in repeat MVDs irrespective of the type of implant.[ 8 , 9 , 35 ] One can consider two mechanisms that lead to a de novo neurovascular contact after successful separation during the first surgery: if a muscle graft shrinks, the original offending vessel may compress the trigeminal nerve again. Alternatively, a late displacement of an artery can cause a new compression. To address the latter issue, Paolini et al. developed a circumferential nerve wrapping technique using autologous muscle to shield the entire nerve root from new neurovascular contact, reporting excellent results.[ 21 ] Numerous studies described favorable results of MVD using autologous muscle.[ 3 , 7 , 15 , 17 , 21 ] This body of literature is a valuable complement to the wealth of reports that have demonstrated excellent results using Teflon.[ 2 , 5 , 19 , 32 ] We found no difference in outcomes depending on interposition with Teflon vs. muscle, which stands in contrast to the observations of Haidar et al., who found a 5.2% pain recurrence rate with muscle and 40% with Teflon.[ 12 ] A 40% recurrence rate does seem excessive; however, it is not unheard of. Herta et al. found a 39.4% failure rate (BNI IV or V) after a mean of 3.5 years.[ 14 ] At an overall failure rate of 12.5%, our results are in line with the literature.[ 6 ] Among the complications, we observed a CSF leak or pseudomeningocele in nearly 10%, which is undoubtedly higher than expected. We addressed this by adjusting key surgical steps: contrary to the former standard approach at our institution, we now routinely use dural sealants and reconstruct the skull after retrosigmoid craniectomy.[ 1 , 10 ] One 89-year-old patient died due to a postoperative cerebellar hemorrhage. Morbidity and mortality are higher in elderly patients undergoing MVD, and, in retrospect, a percutaneous rhizotomy may have been a more appropriate treatment.[ 22 , 26 ] Other complications are comparable to those reported in the literature. We evaluated complications in the early postoperative period when mild neurological deficits, such as facial palsy or hypoesthesia, were most present. These issues usually resolved over time, but we refrained from conducting a systematic analysis of complications at the last follow-up, as we didn’t have sufficient information on all patients. Our study is limited by several factors. Its retrospective nature with two patient groups treated during different periods may introduce bias. Particularly, it may be argued that the type of implant was not the only difference between the patient groups, as different surgeons used different techniques, which may have influenced the outcomes. While this is true, both groups involved several surgeons, which increases the generalizability of our results. Furthermore, our cohort was relatively small. However, it reached the previously calculated sample size. Some data were missing, most notably information on the presence of neurovascular contact on preoperative MRI, which could not be retrieved in a substantial fraction of the patients. This, however, does not influence the primary endpoint. Finally, as at our institution, Teflon has been in use more recently than muscle, the follow-up duration of the muscle group is significantly longer. Yet, this is unlikely to distort the outcome analysis as no treatment failures were observed later than 55 months after the initial surgery. Four out of six failures occurred within the first two years, which corresponds with the observations made by others.[ 5 ] Conclusions Our study found no difference in the outcomes of MVD for trigeminal neuralgia when either autologous muscle or Teflon was used as interposition material. Our results, therefore, add to the growing body of literature suggesting that muscle is a viable alternative to Teflon in MVD. As both implants feature specific advantages and disadvantages, it may be reasonable to use as little interposition material as possible when choosing Teflon, while implanting a generous piece of graft when opting for muscle. Declarations Conflict of Interest: The authors declare no conflict of interest. Funding : The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Competing Interests: The authors have no relevant financial or non-financial interests to disclose. Author Contribution: All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Johann Klein. The first draft of the manuscript was written by Johann Klein and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Clinical trial number: not applicable References Alhantoobi MR, Kesserwan MA, Khayat HA, Lawasi M, Sharma S (2023) Rates of cerebrospinal fluid leak and pseudomeningocele formation after posterior fossa craniotomy versus craniectomy: A systematic review and meta-analysis. 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Cite Share Download PDF Status: Published Journal Publication published 10 Oct, 2025 Read the published version in Neurosurgical Review → Version 1 posted Editorial decision: Revision requested 06 Sep, 2025 Reviews received at journal 28 Jul, 2025 Reviews received at journal 16 Jul, 2025 Reviewers agreed at journal 15 Jul, 2025 Reviewers agreed at journal 14 Jul, 2025 Reviewers invited by journal 14 Jul, 2025 Editor assigned by journal 14 Jul, 2025 Submission checks completed at journal 11 Jul, 2025 First submitted to journal 09 Jul, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7086552","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":486367071,"identity":"4b2948dd-99e3-4828-b202-b46ab4f7cbb2","order_by":0,"name":"Johann Klein","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABVUlEQVRIie2Rv0vDQBTH3xG4LJfOV9LafyHhICJG/5aEQl3Swc1BSkB4WVq6tv9FNutkS8EuwVlwaRGcihB0iBTUSyrVXnUXzHe59+M+fN+7AyhV6g+KhKw4rYoMIQ2hRr+aAYCXX/kFoTIkwxCYgng7CMAGAdCM8DPdILCLaFFv8nw6AkH1C3w4Grmsokdz8nLW8S/19mS+yKDeVwbr3jbNYQIOZZNItJMWoyyxtFoy9a+6T01LDiaG2zZkEFimgeBS7qPZximjPNBXVRz78V3gcIn48VhFxKpAGgs0D/BdIidzrfrWyZH9LEeudxAnd3EoJ2gSHEvEs0gaaoULFC7qLolzaCAXlPlY7WFzvQvcTEWcLAX3WlwMtl3sqCvuDXTtvj575K94vNeI5Itl5516PAvsNHPden97fXudcuXpv/2O0gJoqIX1uNmP5VKlSpX6p/oAOa9xXoigXP0AAAAASUVORK5CYII=","orcid":"","institution":"Helios Dr. Horst Schmidt Kliniken Wiesbaden","correspondingAuthor":true,"prefix":"","firstName":"Johann","middleName":"","lastName":"Klein","suffix":""},{"id":486367072,"identity":"557d680e-7b74-49de-b915-fae377a6e3b2","order_by":1,"name":"Barbara Carl","email":"","orcid":"","institution":"Helios Dr. Horst Schmidt Kliniken Wiesbaden","correspondingAuthor":false,"prefix":"","firstName":"Barbara","middleName":"","lastName":"Carl","suffix":""}],"badges":[],"createdAt":"2025-07-09 18:08:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7086552/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7086552/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10143-025-03882-7","type":"published","date":"2025-10-10T15:58:25+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":87270113,"identity":"7e2017d7-d571-4944-ab24-43f49937b356","added_by":"auto","created_at":"2025-07-22 08:18:11","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":131336,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of patient selection. MVD = microvascular decompression; TN = trigeminal neuralgia\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7086552/v1/9143577cd1fef644e560052e.jpeg"},{"id":87272272,"identity":"6c579d61-7954-4577-9658-dfc5ade06f5b","added_by":"auto","created_at":"2025-07-22 08:26:11","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":63930,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan-Meier survival curves visualizing the development of treatment failure over time. No failures occurred later than 55 months after the initial surgery, and no statistically significant difference was found between the groups in the log-rank test (p = 0.97). m = muscle, t = Teflon\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7086552/v1/11508a1accb65b42d27703e4.jpeg"},{"id":93419810,"identity":"358b5a27-6ee6-468d-bb9d-b2a2dd278e51","added_by":"auto","created_at":"2025-10-13 16:07:56","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":634818,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7086552/v1/cb32b3d4-7b98-4079-8cbb-b3a7b19632e5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A comparison of long-term outcomes between interposition with Teflon and autologous muscle in microvascular decompression for trigeminal neuralgia","fulltext":[{"header":"Introduction","content":"\u003cp\u003eClassical trigeminal neuralgia is a severe facial pain syndrome caused by vascular compression of the trigeminal nerve.[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e] While pharmacotherapy with carbamazepine or oxcarbazepine shows high success rates, treatment resistance does occur; additionally, adverse effects are frequent and can reach intolerable levels.[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] For patients in whom conservative therapy does not lead to satisfactory results, microvascular decompression (MVD) is widely established as a definitive treatment. The procedure involves separating the offending vessel from the nerve and interposing a graft to avoid neurovascular contact. Various materials have been used for interposition, including Teflon, Ivalon, gelatin sponge, and cotton gauze.[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] Teflon (polytetrafluoroethylene) is frequently used in surgical implants, including as interposition material in MVD, due to its chemical stability and relative biological inertness. While Teflon is established as the most common implant in MVD, there has been a recent resurgence of interest in autologous muscle as graft material, owing to its immediate availability, biological compatibility, and favorable intraoperative handling.[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] Ashraf et al. have published an impressive analysis of 1025 patients who underwent MVD with an autologous muscle graft for trigeminal neuralgia. The authors discussed the possibility of pain recurrence after successful MVD with Teflon due to adhesion or granuloma associated with the implant.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] This article sparked an interesting exchange of views about the suspected advantages or disadvantages of the graft materials.[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] Although studies like the one by Ashraf et al. have shown encouraging results, there is a paucity of direct comparisons of the outcomes of MVD with Teflon vs. muscle. The only such study we are aware of was conducted by Haidar et al., who evaluated the rate of pain recurrence after MVD depending on the material used for interposition (muscle, Teflon, or a combination of both) and found 5.2% recurrences with muscle and 40% with Teflon.[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eOur study aimed to compare the outcomes of patients who had first-time MVD for trigeminal neuralgia and received either muscle or Teflon as interposition material. We hypothesized that there would be no significant difference in long-term failure rates.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e\u003cem\u003eStudy design\u003c/em\u003e\u003c/p\u003e\u003cp\u003e This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of the Medical Association of the state of Hesse. The need for informed consent was waived by the ethics committee due to the retrospective nature of the study. We identified all patients who had received MVD for trigeminal neuralgia at our department between 2007 and 2024. MVD for other indications, such as glossopharyngeal neuralgia or hemifacial spasm, was not included in this study. At our institution, muscle was used as interposing material until 2012, and Teflon was used from 2013 onwards, which allowed for the definition of two patient cohorts. Exclusion criteria included previous MVD on the same side and the use of more than one material for interposition; after this, the remaining patients were included in the complication analysis. For the outcome analysis, further exclusion criteria \u0026ndash; the lack of initial improvement after surgery and loss to follow-up \u0026ndash; were applied. MVD on both sides in the same patient at different time points were counted as two patients. Early repeat surgery due to incomplete decompression was not counted as repeat MVD nor as treatment failure, as this was not interpreted as a function of the interposed material; this was the case in two patients.\u003c/p\u003e\u003cp\u003e\u003cem\u003eSurgical procedure\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe operation was performed either in the lateral position or the supine position, with the head rotated contralaterally to the affected side. Monitoring of facial nerve and brainstem auditory evoked potentials was used routinely. A straight or C-shaped retromastoid incision was carried out, and after dissection through the subcutaneous and muscular tissue and harvesting of a muscle graft in patients in whom muscle was to be implanted as interposing material, a craniectomy of approximately 3x3 cm was performed abutting the transverse and sigmoid sinus. If the mastoid cells were opened, they were sealed with bone wax. After durotomy, the cerebellar hemisphere was gently mobilized medially with a retractor, the arachnoid was opened, and CSF was drained. The cerebellopontine angle was then visualized. The superior petrosal vein was either protected or sacrificed, depending on the surgeon\u0026rsquo;s preference and possible visual obstruction by the vein. The entire trigeminal root was exposed, and arachnoid adhesions were released. After identifying one or several offending vessels, they were carefully separated from the nerve and mobilized away from it. One or several Teflon or muscle grafts were then placed to eliminate any neurovascular contact and fixated with fibrin glue. The dura was then sutured in a watertight fashion; if necessary, with the use of muscle patches. In later years, dural sealants were frequently used. The craniectomy was either left open, filled with bone dust, or reconstructed using methylmethacrylate, depending on the surgeon. The subcutaneous layer was closed with interrupted sutures, and the skin with a running locking suture.\u003c/p\u003e\u003cp\u003e\u003cem\u003eData collection\u003c/em\u003e\u003c/p\u003e\u003cp\u003eWe analyzed the electronic patient files retrospectively for pre-, intra-, and postoperative data such as the presence of arterial contact on preoperative magnetic resonance imaging (MRI), intraoperative findings, and complications including cerebrospinal fluid (CSF) leak and pseudomeningocele (which were counted together), wound infection, facial palsy, hypoacusis, and facial hypoesthesia. The outcome was evaluated according to the Barrow Neurological Institute (BNI) pain intensity score: BNI I\u0026thinsp;=\u0026thinsp;no pain, no medications; BNI II\u0026thinsp;=\u0026thinsp;occasional pain, no medications required; BNI III\u0026thinsp;=\u0026thinsp;some pain, adequately controlled with medications; BNI IV\u0026thinsp;=\u0026thinsp;some pain, not adequately controlled with medications; BNI V\u0026thinsp;=\u0026thinsp;severe pain or no relief.[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] For the primary endpoint we categorized the BNI score and defined treatment failure as BNI IV or V. If the electronic files did not provide sufficient information for the outcome analysis, the patients or, if they were unavailable, their relatives were contacted via phone and interviewed about the current presence or absence of facial pain, whether medication for facial pain was being taken and whether sequelae of the surgery such as hypoesthesia, hearing loss or facial palsy were present. However, as long-term information about these sequelae was not available for all patients, the reporting of complications in this study refers to the early postoperative period. If pain recurrence was reported during the phone interviews, we inquired about the time after surgery at which the recurrence was observed. The time of treatment failure was defined as the date of the last follow-up.\u003c/p\u003e\u003cp\u003e\u003cem\u003eSample size calculation and statistical analysis\u003c/em\u003e\u003c/p\u003e\u003cp\u003eWe conducted an online sample size analysis (clincalc.com) using the results reported by Haidar et al.[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] At anticipated incidences of 5.2% and 40%, respectively, with a power of 80% and an alpha of 0.05, 21 patients would be required in each group.\u003c/p\u003e\u003cp\u003eFor statistical analysis, continuous variables are reported as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation and were compared using a two-sided t-test. Ordinal variables are reported as median\u0026thinsp;\u0026plusmn;\u0026thinsp;interquartile range and were compared with the Mann-Whitney U test. Categorical variables were analyzed using the Chi-squared test. For evaluating the primary endpoint (treatment failure), we employed a non-parametric survival analysis using Kaplan-Meier curves and the log-rank test. Additionally, we performed a logistic regression analysis with treatment failure as the dependent variable, age as a covariate, and sex, implant type (Teflon or muscle), intraoperative arterial contact, and the presence of arterial compression on preoperative MRI as factors. The model was built using forward selection. For all parameters, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was regarded as statistically significant. All statistical analyses were conducted with JASP 0.19.3.0.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eWe identified 70 patients who had received MVD for trigeminal neuralgia. Two patients were excluded because they had both Teflon and muscle implants. Another six patients were excluded for having had MVD on the same side before. Thus, 62 patients were included in the analysis of complications. CSF leak or pseudomeningocele occurred in 9.68%, wound infection in 2.94%, facial palsy in 3.23%, hypoacusis in 4.84%, and hypoesthesia in 9.68% of patients. One 89-year-old patient suffered from a postoperative cerebellar hemorrhage and died. There was no statistically significant difference in complications between the Teflon and muscle groups (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePatient demographics and characteristics. ASA\u0026thinsp;=\u0026thinsp;American Society of Anesthesiologists; BNI\u0026thinsp;=\u0026thinsp;Barrow Neurological Institute; CSF\u0026thinsp;=\u0026thinsp;cerebrospinal fluid; IQR\u0026thinsp;=\u0026thinsp;interquartile range; MRI\u0026thinsp;=\u0026thinsp;magnetic resonance imaging\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003emuscle\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eteflon\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e68.67\u0026thinsp;\u0026plusmn;\u0026thinsp;9.59\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e62.56\u0026thinsp;\u0026plusmn;\u0026thinsp;12.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.076\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003esex (m : f)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11 : 10 (52.38 : 47.62%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10 : 17 (37.04 : 62.96%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.288\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eside (left : right)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8 : 13 (38.10 : 61.90%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10 : 17 (37.04 : 62.96%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.94\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epain distribution\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eV1: 4/21 (19.05%)\u003c/p\u003e\u003cp\u003eV2: 12/21 (57.14%)\u003c/p\u003e\u003cp\u003eV3: 14/21 (66.67%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eV1: 8/27 (29.63%)\u003c/p\u003e\u003cp\u003eV2: 26/27 (96.3%)\u003c/p\u003e\u003cp\u003eV3: 18/27 (66.67%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003econstant pain\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (9.53%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (7.41%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.792\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eduration of pain (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6.81\u0026thinsp;\u0026plusmn;\u0026thinsp;8.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.40\u0026thinsp;\u0026plusmn;\u0026thinsp;7.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.881\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003emedian ASA grade\u0026thinsp;\u0026plusmn;\u0026thinsp;IQR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.475\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eneurovascular contact on MRI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13/16* (81.25%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15/15* (100%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.078\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eintraoperative arterial contact\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14/20* (70%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24/27 (88.89%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.104\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCSF leak / pseudomeningocele\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3/28 (10.71%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3/34 (8.82%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.802\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003einfection\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1/28 (3.57%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1/34 (2.94%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.889\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003efacial palsy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2/28 (7.14%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0/34 (0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.113\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ehypoacusis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1/28 (3.57%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2/34 (5.88%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.673\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ehypoesthesia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3/28 (10.71%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3/34 (8.82%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.802\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003efollow-up time (months)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e120.3\u0026thinsp;\u0026plusmn;\u0026thinsp;68.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e57.26\u0026thinsp;\u0026plusmn;\u0026thinsp;46.47\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eoutcome at last follow-up\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eBNI I: 15/21 (71.43%)\u003c/p\u003e\u003cp\u003eBNI II: 0/21 (0%)\u003c/p\u003e\u003cp\u003eBNI III: 3/21 (14.29%)\u003c/p\u003e\u003cp\u003eBNI IV: 1/21 (4.76%)\u003c/p\u003e\u003cp\u003eBNI V: 2/21 (9.52%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eBNI I: 17/27 (62.96%)\u003c/p\u003e\u003cp\u003eBNI II: 2/27 (7.41%)\u003c/p\u003e\u003cp\u003eBNI III: 5/27 (18.52%)\u003c/p\u003e\u003cp\u003eBNI IV: 1/27 (3.70%)\u003c/p\u003e\u003cp\u003eBNI V: 2/27 (7.41%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003etreatment failure (BNI IV \u0026ndash; V)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3/21 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3/27 (11.11%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.741\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003etime to failure (months)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e33.67\u0026thinsp;\u0026plusmn;\u0026thinsp;18.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15.67\u0026thinsp;\u0026plusmn;\u0026thinsp;17.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.40\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAfter applying the remaining exclusion criteria (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), 48 patients were available for outcome analysis, out of which 21 had a muscle graft implanted, while 27 had Teflon used. Twenty-one patients (43.75%) were male, and 27 were female (56.25%). The mean age was 65.23\u0026thinsp;\u0026plusmn;\u0026thinsp;11.84 years. The pain was left-sided in 18 (37.5%) and right-sided in 30 (62.5%) patients. 4 (8.33%) patients had constant pain; in all other patients, the pain was purely paroxysmal. We were able to retrieve information about preoperative MRI findings in only 31 of the 48 patients. Out of these, arterial compression was described in 28 (90.33%) cases.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eFollow-up duration was 84.85\u0026thinsp;\u0026plusmn;\u0026thinsp;64.74 months. At the last follow-up, 6 patients (12.5%) had a BNI score of IV or V, corresponding to treatment failure, which had occurred at 2, 10, 22, 24, 35, and 55 months, respectively. In the chi-squared test, no difference between the groups could be found (p\u0026thinsp;=\u0026thinsp;0.741). Likewise, the Kaplan-Meier analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), with a log-rank test, showed no differential outcomes (p\u0026thinsp;=\u0026thinsp;0.97). Upon regression analysis, no covariates or factors were found to be significantly associated with the endpoint.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eWe present a retrospective study that compares the outcomes in patients who underwent MVD for trigeminal neuralgia and received either Teflon or autologous muscle as interposition material. We found no difference in the long-term rates of treatment failure or the frequency of complications.\u003c/p\u003e\u003cp\u003eDespite decades of experience with MVD, the search for the ideal interposition material is ongoing. Peter Jannetta chose Teflon over Ivalon after arguing that the latter is too hard to effectively dampen the pulsations of the offending artery.[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] However, subsequent studies found no difference in the outcomes between the two materials.[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] While Teflon is the standard implant for MVD in many centers, several author\u003c/p\u003e\u003cp\u003es have raised concerns about adhesions and the formation of granulomas associated with the material, which may potentially lead to pain recurrence. Teflon adhesions and granulomas are frequent findings in repeat MVDs.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e] To minimize the risks of such complications, it seems prudent to implant only as many Teflon grafts as necessary, which are only as large as required.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] Fukushima developed a technique to transpose the offending artery and decompress the affected nerve without interposition material remaining in contact with it.[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] This should, in theory, improve the results of MVD as Teflon adhesions and granulomas can be largely ruled out. However, comparative studies have shown no difference in the outcomes of transposition vs. interposition.[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eWith autologous muscle, pain recurrence may result from a shrinkage of the implant.[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] This issue may be avoided by inserting a sufficiently large muscle graft.[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] However, contrary to the reports on pain recurrences associated with Teflon, the literature on this finding is extremely sparse. Six patients with muscle implants had a repeat MVD for recurrent trigeminal neuralgia at our institution (among them, patients not included in the actual analysis). In three cases, the surgical report specifically described shrinkage of the muscle graft, whereas in three others, an arterial contact with the trigeminal nerve was described without mention of muscle shrinkage. Notably, in four of the six surgeries, strong adhesions were reported, making it challenging to separate the artery from the nerve.\u003c/p\u003e\u003cp\u003eAnother possible reason for pain recurrence is a new neurovascular contact, which has been regularly described in repeat MVDs irrespective of the type of implant.[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e] One can consider two mechanisms that lead to a de novo neurovascular contact after successful separation during the first surgery: if a muscle graft shrinks, the original offending vessel may compress the trigeminal nerve again. Alternatively, a late displacement of an artery can cause a new compression. To address the latter issue, Paolini et al. developed a circumferential nerve wrapping technique using autologous muscle to shield the entire nerve root from new neurovascular contact, reporting excellent results.[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eNumerous studies described favorable results of MVD using autologous muscle.[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] This body of literature is a valuable complement to the wealth of reports that have demonstrated excellent results using Teflon.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] We found no difference in outcomes depending on interposition with Teflon vs. muscle, which stands in contrast to the observations of Haidar et al., who found a 5.2% pain recurrence rate with muscle and 40% with Teflon.[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] A 40% recurrence rate does seem excessive; however, it is not unheard of. Herta et al. found a 39.4% failure rate (BNI IV or V) after a mean of 3.5 years.[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] At an overall failure rate of 12.5%, our results are in line with the literature.[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] Among the complications, we observed a CSF leak or pseudomeningocele in nearly 10%, which is undoubtedly higher than expected. We addressed this by adjusting key surgical steps: contrary to the former standard approach at our institution, we now routinely use dural sealants and reconstruct the skull after retrosigmoid craniectomy.[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] One 89-year-old patient died due to a postoperative cerebellar hemorrhage. Morbidity and mortality are higher in elderly patients undergoing MVD, and, in retrospect, a percutaneous rhizotomy may have been a more appropriate treatment.[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e] Other complications are comparable to those reported in the literature. We evaluated complications in the early postoperative period when mild neurological deficits, such as facial palsy or hypoesthesia, were most present. These issues usually resolved over time, but we refrained from conducting a systematic analysis of complications at the last follow-up, as we didn\u0026rsquo;t have sufficient information on all patients.\u003c/p\u003e\u003cp\u003eOur study is limited by several factors. Its retrospective nature with two patient groups treated during different periods may introduce bias. Particularly, it may be argued that the type of implant was not the only difference between the patient groups, as different surgeons used different techniques, which may have influenced the outcomes. While this is true, both groups involved several surgeons, which increases the generalizability of our results. Furthermore, our cohort was relatively small. However, it reached the previously calculated sample size. Some data were missing, most notably information on the presence of neurovascular contact on preoperative MRI, which could not be retrieved in a substantial fraction of the patients. This, however, does not influence the primary endpoint. Finally, as at our institution, Teflon has been in use more recently than muscle, the follow-up duration of the muscle group is significantly longer. Yet, this is unlikely to distort the outcome analysis as no treatment failures were observed later than 55 months after the initial surgery. Four out of six failures occurred within the first two years, which corresponds with the observations made by others.[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eOur study found no difference in the outcomes of MVD for trigeminal neuralgia when either autologous muscle or Teflon was used as interposition material. Our results, therefore, add to the growing body of literature suggesting that muscle is a viable alternative to Teflon in MVD. As both implants feature specific advantages and disadvantages, it may be reasonable to use as little interposition material as possible when choosing Teflon, while implanting a generous piece of graft when opting for muscle.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of Interest:\u0026nbsp;\u003c/strong\u003eThe authors declare no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests:\u003c/strong\u003e The authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contribution:\u003c/strong\u003e All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Johann Klein. The first draft of the manuscript was written by Johann Klein and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number: \u003c/strong\u003enot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAlhantoobi MR, Kesserwan MA, Khayat HA, Lawasi M, Sharma S (2023) Rates of cerebrospinal fluid leak and pseudomeningocele formation after posterior fossa craniotomy versus craniectomy: A systematic review and meta-analysis. Surg Neurol Int 14. doi: 10.25259/SNI_125_2023\u003c/li\u003e\n\u003cli\u003eAndersen ASS, Heinskou TB, Rochat P, Springborg JB, Noory N, Smilkov EA, Bendtsen L, Maarbjerg S (2022) Microvascular decompression in trigeminal neuralgia - a prospective study of 115 patients. J Headache Pain 23:145. doi: 10.1186/S10194-022-01520-X\u003c/li\u003e\n\u003cli\u003eAshraf M, Sajjad F, Hussain SS, Cheema HA, Ali S, Umar H, Gillespie CS, Faiz U, Shahid A, Akmal M, Ashraf N (2024) Long-term outcome of microvascular decompression for typical trigeminal neuralgia with autologous muscle: an analysis of 1025 patients from a developing country. J Neurosurg 141:849\u0026ndash;859. doi: 10.3171/2023.9.JNS231473\u003c/li\u003e\n\u003cli\u003eAydin L, Copur S, Kartum TA, Urgan C, Ozdemir B, Yilmaz A (2025) Repeat Microvascular Decompression for Recurrent Trigeminal Neuralgia. World Neurosurg 123854. doi: 10.1016/J.WNEU.2025.123854\u003c/li\u003e\n\u003cli\u003eBarker FG, Jannetta PJ, Bissonette DJ, Larkins M V., Jho HD (1996) The Long-Term Outcome of Microvascular Decompression for Trigeminal Neuralgia. N Engl J Med 334:1077\u0026ndash;1084. doi: 10.1056/NEJM199604253341701\u003c/li\u003e\n\u003cli\u003eBendtsen L, Zakrzewska JM, Abbott J, Braschinsky M, Di Stefano G, Donnet A, Eide PK, Leal PRL, Maarbjerg S, May A, Nurmikko T, Obermann M, Jensen TS, Cruccu G (2019) European Academy of Neurology guideline on trigeminal neuralgia. Eur J Neurol 26:831\u0026ndash;849. doi: 10.1111/ENE.13950\u003c/li\u003e\n\u003cli\u003eBezerra GM dos S, Leal PRL, Cavalcante-Neto JF, Rivera A, da Ponte KF, Cristino-Filho G (2023) Microvascular decompression using autologous muscle graft for trigeminal neuralgia: a case series and meta-analysis. Acta Neurochir. (Wien). 165:3833\u0026ndash;3843\u003c/li\u003e\n\u003cli\u003eCho DY, Chang CGS, Wang YC, Wang FH, Shen CC, Yang DY (1994) Repeat operations in failed microvascular decompression for trigeminal neuralgia. Neurosurgery 35:665\u0026ndash;670. doi: 10.1227/00006123-199410000-00012\u003c/li\u003e\n\u003cli\u003eEser P, Unal HS, Khezri MK, Turkkan A, Bekar A (2024) Repeat Microvascular Decompression for Recurrent Trigeminal Neuralgia. Turk Neurosurg 34. doi: 10.5137/1019-5149.JTN.45323-23.1\u003c/li\u003e\n\u003cli\u003eEsposito F, Angileri FF, Kruse P, Cavallo LM, Solari D, Esposito V, Tomasello F, Cappabianca P (2016) Fibrin Sealants in Dura Sealing: A Systematic Literature Review. PLoS One 11:e0151533. doi: 10.1371/JOURNAL.PONE.0151533\u003c/li\u003e\n\u003cli\u003eFukushima T (1982) [Posterior cranial fossa neurovascular decompression (Jannetta method) for trigeminal neuralgia and facial spasm]. No Shinkei Geka 10:1257\u0026ndash;61\u003c/li\u003e\n\u003cli\u003eHaidar H, Montava M, Collin M, Deveze A, Lavieille JP (2014) Endoscopy-assisted microvascular decompression for trigeminal neuralgia: The prognostic impact of interposing material. J Int Adv Otol 10:107\u0026ndash;112. doi: 10.5152/iao.2014.171\u003c/li\u003e\n\u003cli\u003eHatipoglu Majernik G, Wolff Fernandes F, Al-Afif S, Heissler HE, Krauss JK (2023) Microsurgical posterior fossa re-exploration for recurrent trigeminal neuralgia after previous microvascular decompression: common grounds-scarring, deformation, and the \u0026ldquo;piston effect.\u0026rdquo; Acta Neurochir (Wien) 165:3877\u0026ndash;3885. doi: 10.1007/S00701-023-05877-Z\u003c/li\u003e\n\u003cli\u003eHerta J, Schmied T, Loidl TB, Wang W te, Marik W, Winter F, Tomschik M, Ferraz-Leite H, R\u0026ouml;ssler K, Dorfer C (2021) Microvascular decompression in trigeminal neuralgia: predictors of pain relief, complication avoidance, and lessons learned. Acta Neurochir (Wien) 163:3321\u0026ndash;3336. doi: 10.1007/S00701-021-05028-2\u003c/li\u003e\n\u003cli\u003eJagannath P, Venkataramana N, Bansal A, Ravichandra M (2012) Outcome of microvascular decompression for trigeminal neuralgia using autologous muscle graft: A five-year prospective study. Asian J Neurosurg 7:125\u0026ndash;130. doi: 10.4103/1793-5482.103713\u003c/li\u003e\n\u003cli\u003eJannetta PJ, Bissonette DJ (1985) Management of the failed patient with trigeminal neuralgia. Clin Neurosurg 32:334\u0026ndash;47\u003c/li\u003e\n\u003cli\u003eKarki P, Joshi S, Paudel P, Shah DB, Sharma GR (2021) Microvascular Decompression using muscle graft for interposition: A retrospective study. Nepal J Neurosci 18:55\u0026ndash;60. doi: 10.3126/njn.v18i2.36673\u003c/li\u003e\n\u003cli\u003eLiu J, Wu G, Xiang H, Liu R, Li F, Hei B, Qian W, Song H, Liu Z (2020) Long-Term Retrospective Analysis of Microvascular Decompression in Patients With Recurrent Trigeminal Neuralgia. Front Neurol 11:584224. doi: 10.3389/FNEUR.2020.584224\u003c/li\u003e\n\u003cli\u003eMcLaughlin MR, Jannetta PJ, Clyde BL, Subach BR, Comey CH, Resnick DK (1999) Microvascular decompression of cranial nerves: Lessons learned after 4400 operations. J Neurosurg 90:1\u0026ndash;8. doi: 10.3171/jns.1999.90.1.0001\u003c/li\u003e\n\u003cli\u003eNannapaneni R, Satheesan K, Nath FP (2006) Lintene granuloma following microvascular decompression mimicking a cerebellopontine angle tumour. J Clin Neurosci 13:380\u0026ndash;383. doi: 10.1016/J.JOCN.2005.04.016\u003c/li\u003e\n\u003cli\u003ePaolini S, Mancarella C, Scafa AK, Arcidiacono U, Morace R, Chiarella V, Di Castelnuovo A, Esposito V (2025) Circumferential nerve wrapping with muscle autograft: a modified strategy of microvascular decompression for trigeminal neuralgia. Neurosurg Rev 48:32. doi: 10.1007/S10143-024-03100-W\u003c/li\u003e\n\u003cli\u003ePhan K, Rao PJ, Dexter M (2016) Microvascular decompression for elderly patients with trigeminal neuralgia. J Clin Neurosci 29:7\u0026ndash;14. doi: 10.1016/J.JOCN.2015.11.027\u003c/li\u003e\n\u003cli\u003ePressman E, Hasegawa H, Farooq J, Cohen-Cohen S, Noureldine MHA, Kumar JI, Chen L, Mhaskar R, van Loveren H, Van Gompel JJ, Agazzi S (2021) Teflon versus Ivalon in Microvascular Decompression for Trigeminal Neuralgia: A 2-Center 10-Year Comparison. World Neurosurg 146:e822\u0026ndash;e828. doi: 10.1016/J.WNEU.2020.11.027\u003c/li\u003e\n\u003cli\u003ePressman E, Jha RT, Zavadskiy G, Kumar JI, van Loveren H, van Gompel JJ, Agazzi S (2020) Teflon\u003csup\u003eTM\u003c/sup\u003e or Ivalon\u0026reg;: a scoping review of implants used in microvascular decompression for trigeminal neuralgia. Neurosurg Rev 43:79\u0026ndash;86. doi: 10.1007/S10143-019-01187-0\u003c/li\u003e\n\u003cli\u003eRogers CL, Shetter AG, Fiedler JA, Smith KA, Han PP, Speiser BL (2000) Gamma knife radiosurgery for trigeminal neuralgia: the initial experience of The Barrow Neurological Institute. Int J Radiat Oncol Biol Phys 47:1013\u0026ndash;1019. doi: 10.1016/S0360-3016(00)00513-7\u003c/li\u003e\n\u003cli\u003eRughani AI, Dumont TM, Lin CT, Tranmer BI, Horgan MA (2011) Safety of microvascular decompression for trigeminal neuralgia in the elderly: Clinical article. J Neurosurg 115:202\u0026ndash;209. doi: 10.3171/2011.4.JNS101924\u003c/li\u003e\n\u003cli\u003eDi Stefano G, La Cesa S, Truini A, Cruccu G (2014) Natural history and outcome of 200 outpatients with classical trigeminal neuralgia treated with carbamazepine or oxcarbazepine in a tertiary centre for neuropathic pain. J Headache Pain 15:1\u0026ndash;5. doi: 10.1186/1129-2377-15-34/FIGURES/1\u003c/li\u003e\n\u003cli\u003eSun T, Wang W, Huang Q, He L, Su Y, Li N, Liu J, Yang C (2022) Teflon Granuloma: A Common Cause of Recurrent Trigeminal Neuralgia. World Neurosurg 158:e612\u0026ndash;e617. doi: 10.1016/J.WNEU.2021.11.033\u003c/li\u003e\n\u003cli\u003eUhl C, Faraj L, Fekonja L, Vajkoczy P (2024) Transposition versus interposition method in microvascular decompression for trigeminal neuralgia: midterm analysis of both techniques in a single-center study. J Neurosurg 140:1777\u0026ndash;1784. doi: 10.3171/2023.11.JNS231658\u003c/li\u003e\n\u003cli\u003eUHL C, VAJKOCZY P (2023) Contact-free transposition and interposition techniques for trigeminal neuralgia: a systematic review. J Neurosurg Sci 67. doi: 10.23736/S0390-5616.22.05514-X\u003c/li\u003e\n\u003cli\u003eYamaki T, Hashi K, Niwa J, Tanabe S, Nakagawa T, Nakamura T, Uede T, Tsuruno T (1992) Results of reoperation for failed microvascular decompression. Acta Neurochir (Wien) 115:1\u0026ndash;7. doi: 10.1007/BF01400583\u003c/li\u003e\n\u003cli\u003eZhang H, Lei D, You C, Mao BY, Wu B, Fang Y (2013) The long-term outcome predictors of pure microvascular decompression for primary trigeminal neuralgia. World Neurosurg 79:756\u0026ndash;762. doi: 10.1016/J.WNEU.2012.01.040\u003c/li\u003e\n\u003cli\u003eZhang Z, Hao Q, Zheng W, Liu R (2025) Letter to the Editor. Is autologous muscle better than Teflon in MVD for trigeminal neuralgia? J Neurosurg 115:1\u0026ndash;2. doi: 10.3171/2024.9.JNS242271\u003c/li\u003e\n\u003cli\u003eZhang Z, Zhao H, Tang Y, Wang B, Yuan Q, Wang H, Cai X, Zhu W, Li S (2025) Microvascular Decompression Using the Gelatin Sponge Insertion Technique for Trigeminal Neuralgia: A Retrospective Cohort Study. Oper Neurosurg (Hagerstown, Md) 28. doi: 10.1227/ONS.0000000000001229\u003c/li\u003e\n\u003cli\u003eZhang Z, Zhao H, Tang Y, Wang B, Yuan Q, Zhang Y, Li Y, Zhong J, Li S (2024) Revisiting the Efficacy of Redo Microvascular Decompression for Trigeminal Neuralgia. World Neurosurg 186:e335\u0026ndash;e341. doi: 10.1016/J.WNEU.2024.03.131\u003c/li\u003e\n\u003cli\u003eHeadache Classification Committee of the International Headache Society (IHS) The International Classification of Headache Disorders, 3rd edition. Cephalalgia 38. doi: 10.1177/0333102417738202\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"trigeminal neuralgia, facial pain, Teflon, autologous muscle graft, Jannetta procedure","lastPublishedDoi":"10.21203/rs.3.rs-7086552/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7086552/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eObjective\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e: \u003c/em\u003eMicrovascular decompression (MVD) is an established surgical procedure for treating classical trigeminal neuralgia (TN) by separating the trigeminal nerve from an offending vessel. Various materials can be used for interposition, Teflon being the standard in many centers. Autologous muscle is used as an alternative; however, comparative studies are sparse. We compared the outcomes of patients who underwent MVD for TN with either Teflon or muscle in the same center.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e: \u003c/em\u003eWe searched our database for patients who underwent MVD for TN between 2007 and 2024. The records were analyzed for outcome parameters, and patients or their relatives were contacted via phone if follow-up data were insufficient. Exclusion criteria included repeat MVD, lack of initial improvement after surgery, and loss to follow-up. The primary outcome parameter was treatment failure, defined as Barrow Neurological Institute (BNI) pain intensity score IV or V.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/em\u003e\u003cem\u003e: \u003c/em\u003e70 patients were identified. After applying the exclusion criteria, 48 were available for the outcome analysis, among whom 21 had received interposition with muscle and 27 with Teflon. The mean patient age was 65 years, 56.25% were female, and the pain was right-sided in 62.5% of patients. At a mean follow-up of 85 months, 12.5% had experienced treatment failure (14.29% in the muscle group and 11.11% in the Teflon group; p = 0.741). Kaplan-Meier analysis with log-rank test and logistic regression analysis revealed no significant differences.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/em\u003e: We found no differences in the outcomes of MVD for TN when either autologous muscle or Teflon was used. Both materials are appropriate for interposition.\u003c/p\u003e","manuscriptTitle":"A comparison of long-term outcomes between interposition with Teflon and autologous muscle in microvascular decompression for trigeminal neuralgia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-22 08:18:06","doi":"10.21203/rs.3.rs-7086552/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-06T19:33:43+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-28T10:56:46+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-16T13:30:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"97671261356344829300483022279982486016","date":"2025-07-15T08:04:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"4779818545625050484005284056929654003","date":"2025-07-15T02:50:11+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-15T02:44:32+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-15T02:43:35+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-11T11:36:07+00:00","index":"","fulltext":""},{"type":"submitted","content":"Neurosurgical Review","date":"2025-07-09T17:53:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"48f6cd45-8229-4f9b-8345-56655b9d40e4","owner":[],"postedDate":"July 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-10-13T16:03:13+00:00","versionOfRecord":{"articleIdentity":"rs-7086552","link":"https://doi.org/10.1007/s10143-025-03882-7","journal":{"identity":"neurosurgical-review","isVorOnly":false,"title":"Neurosurgical Review"},"publishedOn":"2025-10-10 15:58:25","publishedOnDateReadable":"October 10th, 2025"},"versionCreatedAt":"2025-07-22 08:18:06","video":"","vorDoi":"10.1007/s10143-025-03882-7","vorDoiUrl":"https://doi.org/10.1007/s10143-025-03882-7","workflowStages":[]},"version":"v1","identity":"rs-7086552","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7086552","identity":"rs-7086552","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}