A Novel Minimally Invasive Surgical Technique for Treating Non-Traumatic Adhesive Syringomyelia Associated with a History of Previous Spinal Canal Surgical Interventions

A Novel Minimally Invasive Surgical Technique for Treating Non-Traumatic Adhesive Syringomyelia Associated with a History of Previous Spinal Canal Surgical Interventions | 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 Novel Minimally Invasive Surgical Technique for Treating Non-Traumatic Adhesive Syringomyelia Associated with a History of Previous Spinal Canal Surgical Interventions can zhang, Chenghua Yuan, Jiachen Wang, Hao Wu, Zan Chen, Jian Guan, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6290624/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 11 Aug, 2025 Read the published version in European Spine Journal → Version 1 posted 19 You are reading this latest preprint version Abstract Purpose Current surgical options for treating nontraumatic adhesive syringomyelia, particularly in patients with a history of previous spinal canal surgical intervention (PSCAS), lack clear standardization and frequently lead to common complications such as recurrent adhesions, tube disconnections, and neurological injuries related to myelotomy, resulting in the need for multiple revision surgeries. This study aims to introduce a novel, minimally invasive technique of modified subarachnoid-subarachnoid (S−S) bypass procedure for PSCAS and to prospectively evaluate its surgical outcomes. Methods This prospective study included 11 consecutive non-traumatic patients with symptomatic PSCAS who underwent modified S-S bypass surgery, with a mean follow-up period of 18.3 months (range: 16-20 months). Neurological function was assessed using standardized grading systems, and changes in syrinx size were evaluated using MRI. Results Ten patients demonstrated clinical improvement, while one patient remained stable. Notably, the preoperative and postoperative ASIA motor and sensory scores showed significant improvement (88.45 ± 11.01 vs. 89.64 ± 9.99, p < 0.05; 200.73 ± 15.52 vs. 203.09 ± 15.29, p < 0.001). The mean syrinx tension index postoperatively was significantly lower than the preoperative value (74.28 ± 14.34% vs. 29.87 ± 17.62%, p < 0.0001), and the syrinx length was also significantly reduced (9.46 ± 4.59 vs. 8.00 ± 6.05, p < 0.05). Conclusions This study highlights that the modified S-S bypass can be performed without myelotomy or intratubal interaction with CSF circulation, representing not only a safe and effective surgical technique but also a potentially more physiological approach for treating PSCAS. syringomyelia cerebrospinal fluid spinal cord injury surgery tumor bypass Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 INTRODUCTION Disturbances in cerebrospinal fluid (CSF) flow are the most common cause of syringomyelia. Spinal canal surgical intervention, particularly involving meningiomas, is prone to complications such as subdural hemorrhage or inflammatory adhesion, which can result in secondary syringomyelia (PSCAS) due to obstructions in CSF flow 1 – 5 . Based on these pathophysiological phenomena, treatment methods may focus on restoring normal CSF flow around the spinal cord similar to Post-Traumatic Syringomyelia (PTS). Therefore, cord untethering and arachnolysis appear to be the most logical procedures 6 . While this approach may offer clinical improvement and radiological regression of the syrinx, the high rate of complications and recurrence following arachnolysis has led many surgeons to consider shunting, especially in cases with a history of previous intradural surgery or extensive arachnoiditis spanning more than three levels 1 , 5 . Non-physiologic shunting of the syrinx to the subarachnoid, pleural, or peritoneal space remains a widely accepted alternative for patients with syringomyelia resulting from arachnoiditis 7 . However, the effectiveness of shunt surgery is limited by the risks of neurological complications associated with myelotomy, a high disconnection rate, and potential intracranial hypotension resulting from over-drainage 7 – 9 . Additionally, we proposed a novel surgical technique for post-traumatic syringomyelia progressing to the medulla oblongata 10 , . More advanced treatments such as stem cell transplantation are being explored 11 , 12 , however, their clinical viability remains uncertain. In a previous study, some authors introduced a new physiologic bypass technique involving reconstruction of intradural channels for syringomyelia 13 – 16 . Nevertheless, additional intradural maneuvers especially in cases with a history of previous intradural surgery may result in further neurological complications 17 . It is also conceivable that placing two large tubes within the intradural space could lead to additional adhesions potentially exacerbating issues arising from spinal cord injury, infection or tuberculous meningitis (TBM), thus limiting the use of traditional subarachnoid-subarachnoid bypass S − S bypass in clinical practice. 8 Drawing on insights from S-S bypass procedures, we conducted a novel form of minimally invasive modified S-S bypass to restore normal CSF circulation around the spinal cord without any intradural maneuvers. The aim of this study was to assess the efficacy of the modified S-S bypass in addressing PSCAS. METHOD Study Sample This study included eleven consecutive patients (Fig. 1) with symptomatic PSCAS treated at the ** hospital between Jan 2022 and 2023 and part of patients participated in prospective cohort study (Clinicaltrials.gov NCT ***). All patients had progressive neurological symptoms and underwent S–S bypass. The inclusion criteria were as follows: 1) history of previous spinal canal surgical intervention; 2) evidence of progressive neurological deficit, and/or pain syndrome; 3) MRI showing without tumor recurrence, loose screw, kyphosis deformity; and 4) minimum follow-up period of more than 1 year. Patients with only myelomalacia, intradural cyst, or syringomyelia due to other spinal diseases (such as spinal infection, spinal cord injury, tuberculous) were excluded from this review. All participants provided written informed consent before the surgery, and our institutional review board approved the study. Clinical and Radiological Assessments Preoperative status and postoperative clinical progression were evaluated using various grading systems: the Frankel grading system 18 for overall neurological status, the American Spinal Injury Association ASIA motor and sensory score for motor weakness or sensory disturbances 19 , and the modified Japanese Orthopedics Association (mJOA) system 20 for bladder function. Surgical outcomes were assessed by comparing preoperative and postoperative scores. Major presenting symptoms or signs were self-assessed by patients regarding symptom improvement, stabilization, or deterioration. 13 . All patients underwent preoperative MRI as well as postoperative MRIs at three months, one year, and annually thereafter. Pre- and post-operative MR images were analyzed to determine syrinx size and craniocaudal extension. The syrinx tension index 21 was calculated using the syrinx/spinal canal index to evaluate syrinx size. Measurements were performed on T1 low-intensity areas with two investigators blinded to patient details. Surgical Methods The patient was placed under general anesthesia in prone position. Based on preoperative MRI and myelography findings showing normal subarachnoid space above and below the level of previous intradural surgery, two laminae fenestration to expose the normal dura mater. After dissections of the normal dura mater at the cephalic and caudal sites, a tunneling device was used to create a subcutaneous tunnel, 2 tubes made of medical grade silicone (internal diameter 1.1 mm, external diameter 2.5 mm, Sophysa Systems Corporation) were inserted into the cephalic and caudal ends of the normal subarachnoid space (Fig. 2, 3). Under the surgical microscope, the normal dura was incised bilaterally about 3 mm on either side of the midline at the cranial end, and the arachnoid was opened, with the proximal ends of the drainage tubes inserted approximately 5 cm into the normal subarachnoid space. The same procedure was performed bilaterally at the caudal end of the normal dura. Notably, the S–S bypass procedure did not require any arachnolysis (Fig. 3). The movement of bubbles and flow of CSF in the bypass tube could be observed when the tips of the tubes reached the normal CSF area. After completely inserting the tip and tail of one bypass tube into the subarachnoid space, and inserting only one end of the other bypass tube, sterile saline can be injected into the subarachnoid space through the uninserted end to fill the dural sac on both ends, allowing observation of the liquid flow in the other tube through its transparent wall. Subsequently, the dura mater was water tightly sutured with 6/0 non-absorbable sutures, and the tubes were secured to the dura mater to prevent displacement. Additionally, the drainage tube was again secured over the fascia with 4-0 non-absorbable sutures. The tubes were only inserted into the normal subarachnoid space, with the remaining portions running subcutaneously, and no loosening operations were performed at the site of injury. The incisions were sutured layer by layer. Statistical Analysis SPSS software version25, IBMCorp and Prism version9.0, LLC were used for analyses, Paired t-test or Wilcoxon signed-rank test were used to assess changes in parameters in an individual within a group, as appropriate. Analysis of variance was used for the comparative analysis of multiple groups. Comparison of categorical variables were done using chi-square and Fisher exact test. Statistical significance was defined as: * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. RESULT Eleven patients (3 men and 8women) underwent modified S-S bypass for symptomatic PSCAS. The patients' data are summarized in Tables 1 and 2. The mean age at the time of surgery was 49.5 years (range 31−71 years). The average time interval between intradural history and symptom onset was 123.7 months (range 5−384 months). The mean follow-up period was 18.3 month (range16−20 months). Among the patients, all had thoracic surgical intervention history. All eleven patients had functionally incomplete SCI. The average duration of surgery and amount of intraoperative bleeding, were 151 ± 73 minutes and 32 ± 26 ml, respectively. Following the procedure, 10 patients showed clinical improvement, while 1 remained stable (Tab. 1 and 2). The mean preoperative and postoperative ASIA motor scores were 88.45±11.01 and 89.64±9.99 ( p <0.05),respectively, and the mean sensory scores were 200.73±15.52 and 203.09±15.29( p <0.001),respectively. There was little change in the mean preoperative and postoperative bladder function scores according to the JOA system(2.27±0.65 vs. 2.36±0.50, p ＞ 0.05).The preoperative and postoperative syrinx lengths were 9.46 ± 4.59 and 8.00 ± 6.05(p < 0.05), respectively. The mean postoperative Syrinx tension index was significantly lower than the preoperative values (74.28 ± 14.34% and 29.87 ± 17.62%, p < 0.0001). The length or width of the syrinx was reduced in 10 patients, while no change was observed in 1 patient (Tab. 2 and Supplementary Fig. 1). No patient had a CSF leak requiring intervention. Illustrative Cases Case 3 A 7*-year-old woman with a history of meningioma resection at the T12 level three years prior gradually developed leg discomfort. Preoperative MRI showed a T6-12 syrinx. Two bypass tubes were inserted into the cephalic and caudal ends of the normal subarachnoid space from T9 to L1. The patient's symptoms improved, and significant regression of the syrinx was observed on postoperative MRI (Fig. 4). Case 6 A 3*-year-old man presented with numbness and weakness in his leg for one year. Five years earlier, he underwent enterogenous cyst resection at the T2 level and thoracic fusion at the T12 level. Magnetic resonance imaging revealed a T1-7 syrinx. Two bypass tubes were inserted into the cephalic and caudal ends of the normal subarachnoid space from T2 to T9. Postoperatively, his symptoms stabilized, and there was evident regression in both length and width of the syrinx on postoperative MRI (Fig. 5). Case 11 A 5*-year-old woman with a surgical history of thoracic stenosis five years prior gradually developed leg numbness and weakness. Preoperative MRI showed a T3-12 syrinx. Two bypass tubes were inserted into the cephalic and caudal ends of the normal subarachnoid space from T3 to T11. The patient's symptoms improved, and significant regression of the syrinx was observed on postoperative MRI (Fig. 6). DISUCSSION Postoperative arachnoiditis-associated syringomyelia is a rare clinical complication that arises as a secondary complication of spinal canal surgery. It most commonly occurs following spinal surgeries, particularly those involving intraspinal tumors that require opening the dura mater. The condition presents with progressively worsening symptoms, including limb pain, numbness, movement disorders, spasms, and other manifestations that may emerge after a significant interval post-surgery. On imaging, the manifestation of syringomyelia typically appears similar to cerebrospinal fluid signals; as the disease progresses, the cavity may extend toward the cranial or caudal ends 1 , 7 , 22 , 11 , 12 . The pathological mechanism of syringomyelia following spinal canal surgery remains incompletely unclear, with the primary cause believed to be obstruction of CSF circulation due to spinal adhesive arachnoiditis 2 , 3 , 6 , 23 – 26 . Statistics suggest that among the various types of postoperative secondary syringomyelia except spinal cord injury, spinal meningioma cases are most prevalent. This is attributed to the fact that resection of meningiomas often involves removal of either part or all of the inner dura, leading to scar fibrosis and local adhesions. Meningiomas typically require dissection, and blood flow into the subarachnoid space can trigger inflammation and adhesion formation locally. In patients with dural defects or localized effusion, reconstruction of subarachnoid fluid tension may not be achieved, resulting in direct contact between the dural membrane and the spinal cord or cauda equina, ultimately leading to local adhesions. Local subarachnoid obstruction increases subarachnoid pressure, driving CSF into central canal, increasing syrinx pressure, outward expansion, and progression toward the cranial and caudal ends, thereby compressing nerve bundles and neurons, affecting microcirculation, and causing pain and neurological dysfunction 4 . Preoperative myelography was performed in all cases in this series, revealing subarachnoid obstruction at the trauma site in all cases where CSF could not flow freely 4 . Postoperatively, myelography re-examination in some cases after 5 days showed significant relief of subarachnoid obstruction, with contrast medium entering the subarachnoid space above the obstruction in the short term. Spinal cord untethering aims to relieve subarachnoid obstruction and improve CSF circulation in both posttraumatic syringomyelia and PSCAS. However, it carries a high risk of re-adhesion after duraplasty and potential damage to the spinal cord at the site of adhesions, worsening neurological dysfunction. Shunting procedures redirect fluid from the syrinx to different cavities but have their own drawbacks such as myelotomy-related neurological complications and risks of shunt occlusion or recurrence. 1 , 5 , 7 . Hayashi et al. 13 proposed S-S bypass treatment for 20 patients with PTS. Twelve patients showed clinical improvement, 4 remained stable, and 4 showed deteriorations. However, its treatment efficacy of long follow-up remains unclear. Toshiya et al. 13 proposed S-S bypass treatment for spinal adhesive arachnoiditis patients. Further, it is easily to suggest that 2 such large tube within intradural space and intradural maneuverer may cause extra adhesion. The modified S-S bypass technique was used in all PSCAS cases. In our modified S-S bypass technique for PSCAS cases, we did not open the dura mater at the adhesive site. Instead, small incisions were made at the normal dura mater at both ends to insert the tubes, simplifying the procedure and reducing suture difficulty and operation time while minimizing the risk of spinal cord injury caused by opening adhesions. Subcutaneous tunneling was used when there was considerable distance between the bypass ends. No new neurological deficits occurred in this series due to SCI because arachnolysis or myelotomy was not required. Mid-term follow-up showed no bypass occlusion, indicating that proper placement within the normal subarachnoid space is crucial to avoid inflammation or scar spread causing obstruction. Placing two bypass tubes in each case offered advantages such as double safeguard against re-occlusion and distribution of side holes across different stages of the normal subarachnoid space. No cases in this series had incision infections or subcutaneous fluid thanks to minimal skin and muscle detachment and small dural incisions. S-S bypass surgery addresses the underlying cause of PSCAS and shows good mid-term outcomes by improving CSF circulation, reducing subarachnoid pressure, shrinking syrinx size. The modified S-S bypass surgery is minimally traumatic with few complications and satisfactory clinical outcomes, making it an effective treatment for patients with PSCAS, spinal cord injury or other inflammation history that deserves wider adoption in clinical practice. Continued advancements in microsurgical techniques and bypass tube advancement hold promise for even better outcomes with reduced complications. Limitation The follow-up period for the modified S-S bypass procedure was relatively short in this study. However, the primary aim was to introduce and establish a foundation for further research on this modified technique. To address this limitation, a randomized controlled trial comparing two surgical procedures is currently underway Clinicaltrials.govNCT∗∗∗. Although we did not compare the modified S-S bypass with other shunting techniques due to the limited follow-up duration, evidence from existing literature on shunting surgeries suggests that the modified S-S bypass significantly reduces surgery-related complications and shows comparable efficacy 7 , it can be concluded that the modified S-S bypass significantly reduces surgery-related complications and has comparable surgical efficacy to shunting surgery. Long-term patency of the bypass tubes could not be definitively confirmed in our study, despite assessing flow using CT myelography which may not be clinically practical. Additionally, being a single-center study with a small sample size similar to previous publications, future large-scale multicenter clinical studies are necessary for further validation of our findings 13 , 22 , 27 . Conclusions Modified SS bypass, which can be performed without myelotomy and tube interaction CSF circulation, was not only a safe and effective surgical technique, but may also be a more physiological way of treating PSCAS. Declarations Author Contribution Conceptualization: Chenghua Yuan, Can Zhang, Jian Guan, Fengzeng JianInvestigation: Can Zhang, Chenghua Yuan, Jian GuanMethodology: Chenghua Yuan, Can Zhang, Jiachen WangProject Administration: Can Zhang, Chenghua Yuan, Hao Wu, Zan ChenWriting – Original Draft: Chenghua Yuan, Can Zhang, Jian GuanWriting – Review & Editing: Can Zhang, Chenghua Yuan, Fengzeng Jian Acknowledgement We would like to thank John D Heiss(NIH) and Marcus Stoodley(Macquarie University) for the constructive suggestion. And we would like to thank Hui Zhan(The Chinese University of Hong Kong) for the selfless assistance. References Bonfield CM, Levi AD, Arnold PM, Okonkwo DO. Surgical management of post-traumatic syringomyelia. 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Flexible thecoscopy for extensive spinal arachnoiditis. J Neurosurg Spine. 2022;36(2):325-335.https://dx.doi.org/10.3171/2021.4.SPINE21483 Tables Table 1 Characteristics of eleven adult patients who underwent modified S-S bypass. Patient Age (yrs) Gender Surgery to onset (mos) Onset to S-S pass(mos) Main complaint Frankle Grade Previous surgery Preoperative Syrinx Obstructed levels Surgical treatment Follow-up (mos) Symptom evolution 1 5* F 48 36 Numbness in the limb and weakness in the leg C T8meningioma C0T8 T8 T6T9 20 Improvement 2 3* M 204 48 Discomfort in the left upper limb D T2meningioma, syringosubarachnoid shunt C2T11 T2 C2T3 19 Improvement 3 7* F 36 6 Discomfort in the leg D T12meningioma T6T12 T12 T9L1 19 Improvement 4 6* F 156 18 Numbness and weakness in the leg C T8meningioma C7T9 T8 T28 17 Improvement 5 5* F 384 96 Ataxia and pain in the leg C T9meningioma T6T9 T10 T3T11 17 Improvement 6 3* M 60 60 Numbness and weakness in the leg C T8enterogenous cyst, thoracic fusion T1T7 T8 T2T9 19 Improvement 7 3* F 192 1 Numbness in the left leg D T8enterogenous cyst C7T8 T8 T4T9 18 Improvement 8 6* F 5 1 Discomfort in the leg D T10enterogenous cyst T8T10 T10 T7L1 17 Improvement 9 5* F 120 84 Back pain and weakness in the leg C T11schwannoma C7T12 T11 T9T12 20 Stable 10 3* M 96 3 Numbness and weakness in the leg D T8schwannoma C7T11 T8 T5T11 16 Improvement 11 5* F 60 12 Numbness and weakness in the leg B Thoracic spinal stenosis, thoracic fusion T3T12 T11 T3T11 19 Improvement *yrs, years; mos, months. Table 2 Additional characteristics of eleven adult patients who underwent modified S-S bypass. Case no. VAS ASIA sensory score ASIA motor score Bladder function Syrinx length Syrinx Tension index * (%) Complication Number of tubes Follow-up Pre-op Po-op Pre-op Po-op Pre-op Po-op Pre-op Po-op Pre-op Po-op Pre-op Po-op 1 0 0 184 186 90 92 2 2 16 14 92.3% 26. 5% 0 2 20 2 0 0 200 204 85 87 3 3 17 12 84.3% 25.7% 0 2 19 3 0 0 218 220 100 100 3 3 6 2 68. 9% 20.8% 0 2 19 4 0 0 182 184 90 92 2 2 10 3 61.1% 23.8% 0 2 17 5 8 6 204 206 90 90 2 2 3 3 65.2% 40.2% 0 2 17 6 0 0 186 188 75 77 2 2 7 3 80.9% 9.3% 0 2 19 7 3 3 218 220 98 98 3 3 9 3 85.4% 24.9% 0 2 18 8 3 3 218 220 100 100 3 3 3 3 47.8% 22.9% 0 2 17 9 3 1 198 200 75 75 2 2 12 12 89.2% 78.3% 0 2 20 10 0 0 218 220 100 100 2 2 11 11 60.2% 28.5% 0 2 16 11 8 6 182 186 70 75 1 2 10 5 81.8% 27. 7% 0 2 19 p -value 0.083 0.001 0.034 0.317 0.004 0.003 *The maximum diameter of syrinx/ spinal canal. Additional Declarations No competing interests reported. Supplementary Files floatimage7.png Supplementary Fig. 1: Changes in various indicators before and after surgery: VAS Score (Supplementary Fig. 1A); ASIA Sensory Score (Supplementary Fig. 1B); ASIA Motor Score (Supplementary Fig. 1C); Syrinx length (Supplementary Fig. 1D); Syrinx Tension index (Supplementary Fig. 1E); Bladder function Score (Supplementary Fig. 1F). Cite Share Download PDF Status: Published Journal Publication published 11 Aug, 2025 Read the published version in European Spine Journal → Version 1 posted Editorial decision: Revision requested 14 May, 2025 Reviews received at journal 13 May, 2025 Reviews received at journal 10 May, 2025 Reviews received at journal 09 May, 2025 Reviews received at journal 26 Apr, 2025 Reviewers agreed at journal 19 Apr, 2025 Reviews received at journal 17 Apr, 2025 Reviewers agreed at journal 16 Apr, 2025 Reviewers agreed at journal 16 Apr, 2025 Reviewers agreed at journal 16 Apr, 2025 Reviewers agreed at journal 16 Apr, 2025 Reviewers agreed at journal 16 Apr, 2025 Reviewers agreed at journal 16 Apr, 2025 Reviewers agreed at journal 30 Mar, 2025 Reviewers agreed at journal 27 Mar, 2025 Reviewers invited by journal 25 Mar, 2025 Editor assigned by journal 24 Mar, 2025 Submission checks completed at journal 24 Mar, 2025 First submitted to journal 23 Mar, 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. 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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-6290624","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":436008036,"identity":"f6028700-4ee2-4fd1-b2d7-29526f5c695b","order_by":0,"name":"can zhang","email":"","orcid":"","institution":"Department of Neurosurgery, The First Hospital of Hebei Medical University, Shijiazhuang 050000, China","correspondingAuthor":false,"prefix":"","firstName":"can","middleName":"","lastName":"zhang","suffix":""},{"id":436008037,"identity":"013be334-58f1-42d5-bbc9-7cb5bde4dabd","order_by":1,"name":"Chenghua Yuan","email":"","orcid":"","institution":"Department of Neurosurgery, Xuanwu Hospital, Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"Chenghua","middleName":"","lastName":"Yuan","suffix":""},{"id":436008038,"identity":"3138b5ee-38ba-4184-aaf6-40476cf6811a","order_by":2,"name":"Jiachen Wang","email":"","orcid":"","institution":"Department of Neuro-oncology, Cancer Center, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100071, China.","correspondingAuthor":false,"prefix":"","firstName":"Jiachen","middleName":"","lastName":"Wang","suffix":""},{"id":436008039,"identity":"c0cd644a-6beb-4cf4-bc45-af02dddeb343","order_by":3,"name":"Hao Wu","email":"","orcid":"","institution":"Department of Neurosurgery, Xuanwu Hospital, Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hao","middleName":"","lastName":"Wu","suffix":""},{"id":436008040,"identity":"efc3656d-1848-4fee-b890-0340ef0de19c","order_by":4,"name":"Zan Chen","email":"","orcid":"","institution":"Department of Neurosurgery, Xuanwu Hospital, Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zan","middleName":"","lastName":"Chen","suffix":""},{"id":436008041,"identity":"50f53cd5-06cc-40cb-90f5-b5e8478974b6","order_by":5,"name":"Jian Guan","email":"","orcid":"","institution":"Department of Neurosurgery, Xuanwu Hospital, Capital Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Guan","suffix":""},{"id":436008042,"identity":"7ac523f5-819d-49c4-b903-cc285f7abc97","order_by":6,"name":"Fengzeng Jian","email":"data:image/png;base64,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","orcid":"","institution":"Department of Neurosurgery, The First Hospital of Hebei Medical University, Shijiazhuang 050000, China","correspondingAuthor":true,"prefix":"","firstName":"Fengzeng","middleName":"","lastName":"Jian","suffix":""}],"badges":[],"createdAt":"2025-03-24 01:08:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6290624/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6290624/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00586-025-09197-x","type":"published","date":"2025-08-11T15:57:07+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":79908850,"identity":"cd9e4c98-b272-4b91-a484-638c2f0bca2e","added_by":"auto","created_at":"2025-04-04 11:22:53","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":53698,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart for screening patients.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/aaea8db6b7d0f218b71fa1b4.png"},{"id":79908861,"identity":"caecf558-bbd8-4941-985a-6529814f38a7","added_by":"auto","created_at":"2025-04-04 11:22:53","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":590673,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram illustrating the surgical procedure of modified bypass procedure. After dissecting the normal arachnoid mater at the cephalic and caudal sites, bypass tubes were inserted into the normal subarachnoid spaces without any arachnolysis at both ends through a subcutaneous tunnel(The narrow subarachnoid space within the spinal canal is indicated by red dots).\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/99262ee700c09c14d6ddcf25.png"},{"id":79908856,"identity":"076a1745-4746-4363-a827-72f885c003ab","added_by":"auto","created_at":"2025-04-04 11:22:53","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1175747,"visible":true,"origin":"","legend":"\u003cp\u003eIntraoperative photograph showing the two bypass tubes positioned in the subcutaneous tunnel (A). Bypass tubes were inserted into the normal subarachnoid spaces at the cephalic (B, red arrow) and caudal (C, white arrow) locations, above and below the level of injury.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/3aac840a01b0c03dcffc5fe3.png"},{"id":79910349,"identity":"f383dd78-6cc1-4733-828f-94c9fcfd213e","added_by":"auto","created_at":"2025-04-04 11:30:53","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":760031,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative MRI (Fig. 4A) revealed a T12 meningioma. After resection, a slight syrinx was observed at T11-T12 (Fig. 4B). After three years (Fig. 4C), the syrinx had significantly enlarged. Marked regression of the syrinx was noted on postoperative MRI (Fig. 4D). X-ray and CT myelogram (Fig. 4E, F, G) obtained following lumbar injection demonstrated a T12 block on the lumbar myelogram with dorsal arachnoid adhesion at T12. Postoperative CT revealed a bypass tube extending from T9 to L1 (Fig. 4H).\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/bc94b2852b62b682517ceb94.png"},{"id":79910352,"identity":"465e8c87-a44c-4644-9ec0-d37a0213a9d3","added_by":"auto","created_at":"2025-04-04 11:30:53","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":680950,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative MRI (Fig. 5A) revealed a T2 enterogenous cyst. After resection, a slight syrinx was observed at T2 (Fig. 5B). After five years (Fig. 5C), the syrinx had significantly enlarged. Marked regression of the syrinx was noted on postoperative MRI (Fig. 5D). X-ray and CT myelogram (Fig. 5E, F, G) obtained following lumbar injection demonstrated a T8 block on the lumbar myelogram. Postoperative CT revealed a bypass tube extending from T2 to T9 (Fig. 5H).\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/64311207d5e34b903c3a0d14.png"},{"id":79908862,"identity":"fda8a4a7-f78e-43e3-9ad2-f11436b671c6","added_by":"auto","created_at":"2025-04-04 11:22:53","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":924754,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative MRI revealed a T3-T11 syrinx and T4-10 surgical intervention history (Fig. 6A, B). CT myelogram(Fig.6C) obtained following lumbar injection, and T2-weighted MR images demonstrating a T11 block on lumbar myelogram with dorsal arachnoid adhesion at T11. The patient’s symptoms improved, and marked regression of the syrinx was observed on postoperative MRI (Fig. 6D,E). Postoperative CT(Fig. 6F) revealed bypass tube from T3 to T11.\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/44be006ffca7b26dc5ae1f88.png"},{"id":89310677,"identity":"6a39f0f9-d586-4751-a392-cf63569419af","added_by":"auto","created_at":"2025-08-18 16:09:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4910501,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/4ad7ac69-4a50-4635-acaa-22ed96c9162c.pdf"},{"id":79908853,"identity":"7fca48ab-0ad7-4913-a1ba-28b01dec9dea","added_by":"auto","created_at":"2025-04-04 11:22:53","extension":"png","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":77403,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplementary Fig. 1\u003c/strong\u003e: Changes in various indicators before and after surgery: VAS Score (Supplementary Fig. 1A); ASIA Sensory Score (Supplementary Fig. 1B); ASIA Motor Score (Supplementary Fig. 1C); Syrinx length (Supplementary Fig. 1D); Syrinx Tension index (Supplementary Fig. 1E); Bladder function Score (Supplementary Fig. 1F).\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-6290624/v1/d19bc71f27383354434a414c.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Novel Minimally Invasive Surgical Technique for Treating Non-Traumatic Adhesive Syringomyelia Associated with a History of Previous Spinal Canal Surgical Interventions","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eDisturbances in cerebrospinal fluid (CSF) flow are the most common cause of syringomyelia. Spinal canal surgical intervention, particularly involving meningiomas, is prone to complications such as subdural hemorrhage or inflammatory adhesion, which can result in secondary syringomyelia (PSCAS) due to obstructions in CSF flow \u003csup\u003e\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Based on these pathophysiological phenomena, treatment methods may focus on restoring normal CSF flow around the spinal cord similar to Post-Traumatic Syringomyelia (PTS).\u003c/p\u003e \u003cp\u003eTherefore, cord untethering and arachnolysis appear to be the most logical procedures\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. While this approach may offer clinical improvement and radiological regression of the syrinx, the high rate of complications and recurrence following arachnolysis has led many surgeons to consider shunting, especially in cases with a history of previous intradural surgery or extensive arachnoiditis spanning more than three levels\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eNon-physiologic shunting of the syrinx to the subarachnoid, pleural, or peritoneal space remains a widely accepted alternative for patients with syringomyelia resulting from arachnoiditis\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. However, the effectiveness of shunt surgery is limited by the risks of neurological complications associated with myelotomy, a high disconnection rate, and potential intracranial hypotension resulting from over-drainage\u003csup\u003e\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. Additionally, we proposed a novel surgical technique for post-traumatic syringomyelia progressing to the medulla oblongata\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003c/sup\u003e. More advanced treatments such as stem cell transplantation are being explored\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e, however, their clinical viability remains uncertain.\u003c/p\u003e \u003cp\u003eIn a previous study, some authors introduced a new physiologic bypass technique involving reconstruction of intradural channels for syringomyelia\u003csup\u003e\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. Nevertheless, additional intradural maneuvers especially in cases with a history of previous intradural surgery may result in further neurological complications\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. It is also conceivable that placing two large tubes within the intradural space could lead to additional adhesions potentially exacerbating issues arising from spinal cord injury, infection or tuberculous meningitis (TBM), thus limiting the use of traditional subarachnoid-subarachnoid bypass S\u0026thinsp;\u0026minus;\u0026thinsp;S bypass in clinical practice.\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eDrawing on insights from S-S bypass procedures, we conducted a novel form of minimally invasive modified S-S bypass to restore normal CSF circulation around the spinal cord without any intradural maneuvers. The aim of this study was to assess the efficacy of the modified S-S bypass in addressing PSCAS.\u003c/p\u003e"},{"header":"METHOD","content":"\u003cp\u003e\u003cstrong\u003eStudy Sample\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study included eleven consecutive patients (Fig. 1) with symptomatic PSCAS treated at the ** hospital between Jan 2022 and 2023 and part of patients participated in prospective cohort study (Clinicaltrials.gov NCT ***).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll patients had progressive neurological symptoms and underwent S\u0026ndash;S bypass. The inclusion criteria were as follows: 1) history of previous spinal canal surgical intervention; 2) evidence of progressive neurological deficit, and/or pain syndrome; 3) MRI showing without tumor recurrence, loose screw, kyphosis deformity; and 4) minimum follow-up period of more than 1 year. Patients with only myelomalacia, intradural cyst, or syringomyelia due to other spinal diseases (such as spinal infection, spinal cord injury, tuberculous) were excluded from this review.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll participants provided written informed consent before the surgery, and our institutional review board approved the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical and Radiological Assessments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePreoperative status and postoperative clinical progression were evaluated using various grading systems: the Frankel grading system\u003csup\u003e18\u003c/sup\u003e for overall neurological status, the American Spinal Injury Association ASIA motor and sensory score for motor weakness or sensory disturbances\u003csup\u003e19\u003c/sup\u003e, and the modified Japanese Orthopedics Association (mJOA) system\u003csup\u003e20\u003c/sup\u003e for bladder function. Surgical outcomes were assessed by comparing preoperative and postoperative scores. Major presenting symptoms or signs were self-assessed by patients regarding symptom improvement, stabilization, or deterioration.\u003csup\u003e13\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eAll patients underwent preoperative MRI as well as postoperative MRIs at three months, one year, and annually thereafter. Pre- and post-operative MR images were analyzed to determine syrinx size and craniocaudal extension. The syrinx tension index\u003csup\u003e21\u003c/sup\u003e was calculated using the syrinx/spinal canal index to evaluate syrinx size. Measurements were performed on T1 low-intensity areas with two investigators blinded to patient details. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurgical Methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe patient was placed under general anesthesia in prone position. Based on preoperative MRI and myelography findings showing normal subarachnoid space above and below the level of previous intradural surgery, two laminae fenestration to expose the normal dura mater. After dissections of the normal dura mater at the cephalic and caudal sites, a tunneling device was used to create a subcutaneous tunnel, 2 tubes made of medical grade silicone (internal diameter 1.1 mm, external diameter 2.5 mm, Sophysa Systems Corporation) were inserted into the cephalic and caudal ends of the normal subarachnoid space (Fig. 2, 3).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUnder the surgical microscope, the normal dura was incised bilaterally about 3 mm on either side of the midline at the cranial end, and the arachnoid was opened, with the proximal ends of the drainage tubes inserted approximately 5 cm into the normal subarachnoid space. The same procedure was performed bilaterally at the caudal end of the normal dura. Notably, the S\u0026ndash;S bypass procedure did not require any arachnolysis (Fig. 3). The movement of bubbles and flow of CSF in the bypass tube could be observed when the tips of the tubes reached the normal CSF area. After completely inserting the tip and tail of one bypass tube into the subarachnoid space, and inserting only one end of the other bypass tube, sterile saline can be injected into the subarachnoid space through the uninserted end to fill the dural sac on both ends, allowing observation of the liquid flow in the other tube through its transparent wall. Subsequently, the dura mater was water tightly sutured with 6/0 non-absorbable sutures, and the tubes were secured to the dura mater to prevent displacement. Additionally, the drainage tube was again secured over the fascia with 4-0 non-absorbable sutures. The tubes were only inserted into the normal subarachnoid space, with the remaining portions running subcutaneously, and no loosening operations were performed at the site of injury. The incisions were sutured layer by layer.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSPSS software version25, IBMCorp and Prism version9.0, LLC were used for analyses, Paired t-test or Wilcoxon signed-rank test were used to assess changes in parameters in an individual within a group, as appropriate. Analysis of variance was used for the comparative analysis of multiple groups. Comparison of categorical variables were done using chi-square and Fisher exact test. Statistical significance was defined as: *\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05, **\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.01, ***\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001, ****\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.0001.\u003c/p\u003e"},{"header":"RESULT","content":"\u003cp\u003eEleven patients (3 men and 8women) underwent modified S-S bypass for symptomatic PSCAS. The patients\u0026apos; data are summarized in Tables 1 and 2. The mean age at the time of surgery was 49.5 years (range 31\u0026minus;71 years). The average time interval between intradural history and symptom onset was 123.7 months (range 5\u0026minus;384 months). The mean follow-up period was 18.3 month (range16\u0026minus;20 months). Among the patients, all had thoracic surgical intervention history. All eleven patients had functionally incomplete SCI.\u003c/p\u003e\n\u003cp\u003eThe average duration of surgery and amount of intraoperative bleeding, were 151 \u0026plusmn; 73 minutes and 32 \u0026plusmn; 26 ml, respectively. Following the procedure, 10 patients showed clinical improvement, while 1 remained stable (Tab. 1 and 2).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe mean preoperative and postoperative ASIA motor scores were 88.45\u0026plusmn;11.01 and 89.64\u0026plusmn;9.99 (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05),respectively, and the mean sensory scores were 200.73\u0026plusmn;15.52 and 203.09\u0026plusmn;15.29(\u003cem\u003ep\u003c/em\u003e\u0026lt;0.001),respectively. There was little change in the mean preoperative and postoperative bladder function scores according to the JOA system(2.27\u0026plusmn;0.65 \u003cem\u003evs.\u003c/em\u003e 2.36\u0026plusmn;0.50, \u003cem\u003ep\u003c/em\u003e\u003cem\u003e＞\u003c/em\u003e0.05).The preoperative and postoperative syrinx lengths were 9.46 \u0026plusmn; 4.59 and 8.00 \u0026plusmn; 6.05(p \u0026lt; 0.05), respectively. The mean postoperative Syrinx tension index was significantly lower than the preoperative values (74.28 \u0026plusmn; 14.34% and 29.87 \u0026plusmn; 17.62%, p \u0026lt; 0.0001). The length or width of the syrinx was reduced in 10 patients, while no change was observed in 1 patient (Tab. 2 and Supplementary Fig. 1).\u003c/p\u003e\n\u003cp\u003eNo patient had a CSF leak requiring intervention.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIllustrative Cases\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase 3\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 7*-year-old woman with a history of meningioma resection at the T12 level three years prior gradually developed leg discomfort. Preoperative MRI showed a T6-12 syrinx. Two bypass tubes were inserted into the cephalic and caudal ends of the normal subarachnoid space from T9 to L1. The patient\u0026apos;s symptoms improved, and significant regression of the syrinx was observed on postoperative MRI (Fig. 4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase 6\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 3*-year-old man presented with numbness and weakness in his leg for one year. Five years earlier, he underwent enterogenous cyst resection at the T2 level and thoracic fusion at the T12 level. Magnetic resonance imaging revealed a T1-7 syrinx. Two bypass tubes were inserted into the cephalic and caudal ends of the normal subarachnoid space from T2 to T9. Postoperatively, his symptoms stabilized, and there was evident regression in both length and width of the syrinx on postoperative MRI (Fig. 5).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase 11\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 5*-year-old woman with a surgical history of thoracic stenosis five years prior gradually developed leg numbness and weakness. Preoperative MRI showed a T3-12 syrinx. Two bypass tubes were inserted into the cephalic and caudal ends of the normal subarachnoid space from T3 to T11. The patient\u0026apos;s symptoms improved, and significant regression of the syrinx was observed on postoperative MRI (Fig. 6).\u003c/p\u003e"},{"header":"DISUCSSION","content":"\u003cp\u003ePostoperative arachnoiditis-associated syringomyelia is a rare clinical complication that arises as a secondary complication of spinal canal surgery. It most commonly occurs following spinal surgeries, particularly those involving intraspinal tumors that require opening the dura mater. The condition presents with progressively worsening symptoms, including limb pain, numbness, movement disorders, spasms, and other manifestations that may emerge after a significant interval post-surgery. On imaging, the manifestation of syringomyelia typically appears similar to cerebrospinal fluid signals; as the disease progresses, the cavity may extend toward the cranial or caudal ends \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe pathological mechanism of syringomyelia following spinal canal surgery remains incompletely unclear, with the primary cause believed to be obstruction of CSF circulation due to spinal adhesive arachnoiditis \u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan additionalcitationids=\"CR24 CR25\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e. Statistics suggest that among the various types of postoperative secondary syringomyelia except spinal cord injury, spinal meningioma cases are most prevalent. This is attributed to the fact that resection of meningiomas often involves removal of either part or all of the inner dura, leading to scar fibrosis and local adhesions. Meningiomas typically require dissection, and blood flow into the subarachnoid space can trigger inflammation and adhesion formation locally. In patients with dural defects or localized effusion, reconstruction of subarachnoid fluid tension may not be achieved, resulting in direct contact between the dural membrane and the spinal cord or cauda equina, ultimately leading to local adhesions. Local subarachnoid obstruction increases subarachnoid pressure, driving CSF into central canal, increasing syrinx pressure, outward expansion, and progression toward the cranial and caudal ends, thereby compressing nerve bundles and neurons, affecting microcirculation, and causing pain and neurological dysfunction\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Preoperative myelography was performed in all cases in this series, revealing subarachnoid obstruction at the trauma site in all cases where CSF could not flow freely\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Postoperatively, myelography re-examination in some cases after 5 days showed significant relief of subarachnoid obstruction, with contrast medium entering the subarachnoid space above the obstruction in the short term.\u003c/p\u003e \u003cp\u003eSpinal cord untethering aims to relieve subarachnoid obstruction and improve CSF circulation in both posttraumatic syringomyelia and PSCAS. However, it carries a high risk of re-adhesion after duraplasty and potential damage to the spinal cord at the site of adhesions, worsening neurological dysfunction. Shunting procedures redirect fluid from the syrinx to different cavities but have their own drawbacks such as myelotomy-related neurological complications and risks of shunt occlusion or recurrence.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eHayashi et al.\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e proposed S-S bypass treatment for 20 patients with PTS. Twelve patients showed clinical improvement, 4 remained stable, and 4 showed deteriorations. However, its treatment efficacy of long follow-up remains unclear. Toshiya et al.\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e proposed S-S bypass treatment for spinal adhesive arachnoiditis patients. Further, it is easily to suggest that 2 such large tube within intradural space and intradural maneuverer may cause extra adhesion. The modified S-S bypass technique was used in all PSCAS cases. In our modified S-S bypass technique for PSCAS cases, we did not open the dura mater at the adhesive site. Instead, small incisions were made at the normal dura mater at both ends to insert the tubes, simplifying the procedure and reducing suture difficulty and operation time while minimizing the risk of spinal cord injury caused by opening adhesions. Subcutaneous tunneling was used when there was considerable distance between the bypass ends. No new neurological deficits occurred in this series due to SCI because arachnolysis or myelotomy was not required. Mid-term follow-up showed no bypass occlusion, indicating that proper placement within the normal subarachnoid space is crucial to avoid inflammation or scar spread causing obstruction. Placing two bypass tubes in each case offered advantages such as double safeguard against re-occlusion and distribution of side holes across different stages of the normal subarachnoid space. No cases in this series had incision infections or subcutaneous fluid thanks to minimal skin and muscle detachment and small dural incisions.\u003c/p\u003e \u003cp\u003eS-S bypass surgery addresses the underlying cause of PSCAS and shows good mid-term outcomes by improving CSF circulation, reducing subarachnoid pressure, shrinking syrinx size. The modified S-S bypass surgery is minimally traumatic with few complications and satisfactory clinical outcomes, making it an effective treatment for patients with PSCAS, spinal cord injury or other inflammation history that deserves wider adoption in clinical practice. Continued advancements in microsurgical techniques and bypass tube advancement hold promise for even better outcomes with reduced complications.\u003c/p\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eLimitation\u003c/h2\u003e \u003cp\u003eThe follow-up period for the modified S-S bypass procedure was relatively short in this study. However, the primary aim was to introduce and establish a foundation for further research on this modified technique. To address this limitation, a randomized controlled trial comparing two surgical procedures is currently underway Clinicaltrials.govNCT\u0026lowast;\u0026lowast;\u0026lowast;. Although we did not compare the modified S-S bypass with other shunting techniques due to the limited follow-up duration, evidence from existing literature on shunting surgeries suggests that the modified S-S bypass significantly reduces surgery-related complications and shows comparable efficacy\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e, it can be concluded that the modified S-S bypass significantly reduces surgery-related complications and has comparable surgical efficacy to shunting surgery. Long-term patency of the bypass tubes could not be definitively confirmed in our study, despite assessing flow using CT myelography which may not be clinically practical. Additionally, being a single-center study with a small sample size similar to previous publications, future large-scale multicenter clinical studies are necessary for further validation of our findings\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e,\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eModified SS bypass, which can be performed without myelotomy and tube interaction CSF circulation, was not only a safe and effective surgical technique, but may also be a more physiological way of treating PSCAS.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eConceptualization: Chenghua Yuan, Can Zhang, Jian Guan, Fengzeng JianInvestigation: Can Zhang, Chenghua Yuan, Jian GuanMethodology: Chenghua Yuan, Can Zhang, Jiachen WangProject Administration: Can Zhang, Chenghua Yuan, Hao Wu, Zan ChenWriting \u0026ndash; Original Draft: Chenghua Yuan, Can Zhang, Jian GuanWriting \u0026ndash; Review \u0026amp; Editing: Can Zhang, Chenghua Yuan, Fengzeng Jian\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe would like to thank John D Heiss(NIH) and Marcus Stoodley(Macquarie University) for the constructive suggestion. And we would like to thank Hui Zhan(The Chinese University of Hong Kong) for the selfless assistance.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBonfield CM, Levi AD, Arnold PM, Okonkwo DO. Surgical management of post-traumatic syringomyelia. \u003cem\u003eSpine (Phila Pa 1976). \u003c/em\u003e2010;35(21 Suppl):S245-258.https://dx.doi.org/10.1097/BRS.0b013e3181f32e9c\u003c/li\u003e\n\u003cli\u003eYuan C, Xia P, Duan W, et al. Long-Term Impairment of the Blood-Spinal Cord Barrier in Patients With Post-Traumatic Syringomyelia and its Effect on Prognosis. \u003cem\u003eSpine (Phila Pa 1976). \u003c/em\u003e2024;49(6):E62-E71.https://dx.doi.org/10.1097/BRS.0000000000004884\u003c/li\u003e\n\u003cli\u003eXia P, Lv H, Yuan C, et al. Role of Preoperative Albumin Quotient in Surgical Planning for Post-Traumatic Syringomyelia: A Comparative Cohort Study. \u003cem\u003eNeurospine. \u003c/em\u003e2024.https://dx.doi.org/10.14245/ns.2347152.576\u003c/li\u003e\n\u003cli\u003eHeiss JD. Cerebrospinal Fluid Hydrodynamics in Chiari I Malformation and Syringomyelia: Modeling Pathophysiology. \u003cem\u003eNeurosurgery clinics of North America. \u003c/em\u003e2023;34(1):81-90.https://dx.doi.org/10.1016/j.nec.2022.08.007\u003c/li\u003e\n\u003cli\u003eJ K, Batzdorf U Fau - Samii M, Samii M Fau - Bothe HW, HW B. - Treatment of syringomyelia associated with arachnoid scarring caused by arachnoiditis or trauma. \u003cem\u003eJ Neurosurg. \u003c/em\u003e1997;86(2):233-240\u003c/li\u003e\n\u003cli\u003eHeiss JD, Jarvis K, Smith RK, et al. Origin of Syrinx Fluid in Syringomyelia: A Physiological Study. \u003cem\u003eNeurosurgery. \u003c/em\u003e2019;84(2):457-468.https://dx.doi.org/10.1093/neuros/nyy072\u003c/li\u003e\n\u003cli\u003eRothrock RJ, Lu VM, Levi AD. Syrinx shunts for syringomyelia: a systematic review and meta-analysis of syringosubarachnoid, syringoperitoneal, and syringopleural shunting. \u003cem\u003eJ Neurosurg Spine. \u003c/em\u003e2021;35(4):535-545.https://dx.doi.org/10.3171/2020.12.SPINE201826\u003c/li\u003e\n\u003cli\u003eJohnson AR, Rugilo CA, Arga\u0026ntilde;araz RA. Case report: CSF hypotension secondary to a free syringo-subarachnoid-peritoneal shunt. \u003cem\u003eChild Nerv Syst. \u003c/em\u003e2024;40(12):4365-4368.https://dx.doi.org/10.1007/s00381-024-06613-3\u003c/li\u003e\n\u003cli\u003eKleindienst A, Laut FM, Roeckelein V, Buchfelder M, Dodoo-Schittko F. Treatment of posttraumatic syringomyelia: evidence from a systematic review. \u003cem\u003eActa Neurochir. \u003c/em\u003e2020;162(10):2541-2556.https://dx.doi.org/10.1007/s00701-020-04529-w\u003c/li\u003e\n\u003cli\u003eChenghua Yuan GJ, Fengzeng Jian. A novel surgical technique for post-traumatic syringomyelia that progresses to the medulla oblongata: Evidence of Upward draniage of central canal fluid within the spinal cord. \u003cem\u003eNEUROSURGERY. \u003c/em\u003e2025\u003c/li\u003e\n\u003cli\u003eLi M, Wang X, Qi B, et al. Treatment of Syringomyelia Characterized by Focal Dilatation of the Central Canal Using Mesenchymal Stem Cells and Neural Stem Cells. \u003cem\u003eTissue Eng Regen Med. \u003c/em\u003e2024;21(4):625-639.https://dx.doi.org/10.1007/s13770-024-00637-1\u003c/li\u003e\n\u003cli\u003eVaquero J, Zurita M, Rico MA, et al. Cell therapy with autologous mesenchymal stromal cells in post-traumatic syringomyelia. \u003cem\u003eCytotherapy. \u003c/em\u003e2018;20(6):796-805.https://dx.doi.org/10.1016/j.jcyt.2018.04.006\u003c/li\u003e\n\u003cli\u003eHayashi T, Ueta T, Kubo M, Maeda T, Shiba K. Subarachnoid-subarachnoid bypass: a new surgical technique for posttraumatic syringomyelia. \u003cem\u003eJ Neurosurg Spine. \u003c/em\u003e2013;18(4):382-387.https://dx.doi.org/10.3171/2013.1.SPINE12828\u003c/li\u003e\n\u003cli\u003eTachibana T, Moriyama T, Maruo K, Inoue S, Arizumi F, Yoshiya S. Subarachnoid-subarachnoid bypass for spinal adhesive arachnoiditis. \u003cem\u003eJ Neurosurg Spine. \u003c/em\u003e2014;21(5):817-820.https://dx.doi.org/10.3171/2014.7.SPINE131082\u003c/li\u003e\n\u003cli\u003eOzer AF, Marandi HJ, Sasani M, Oktenoglu T, Suzer T. Posttraumatic syringomyelia: a technical note. \u003cem\u003eTurk Neurosurg. \u003c/em\u003e2014;24(4):618-622.https://dx.doi.org/10.5137/1019-5149.JTN.8609-13.1\u003c/li\u003e\n\u003cli\u003eFujiwara Y, Manabe H, Izumi B, Shima T, Adachi N. Microscope and Fiberscope-assisted Subarachnoid-Subarachnoid (S-S) Bypass: A Novel Surgical Technique to Reestablish Cerebrospinal Fluid Flow in Treating Dorsal Spinal Arachnoid Webs, Diagnosed by Cine-MRI. \u003cem\u003eClin Spine Surg. \u003c/em\u003e2018;31(2):58-64.https://dx.doi.org/10.1097/BSD.0000000000000569\u003c/li\u003e\n\u003cli\u003eSgouros S, Williams B. A Critical-Appraisal of Drainage in Syringomyelia. \u003cem\u003eJ Neurosurg. \u003c/em\u003e1995;82(1):1-10.https://dx.doi.org/DOI 10.3171/jns.1995.82.1.0001\u003c/li\u003e\n\u003cli\u003eFrankel HL, Hancock DO, Hyslop G, et al. The value of postural reduction in the initial management of closed injuries of the spine with paraplegia and tetraplegia. I. \u003cem\u003eParaplegia. \u003c/em\u003e1969;7(3):179-192.https://dx.doi.org/10.1038/sc.1969.30\u003c/li\u003e\n\u003cli\u003eKirshblum SC, Burns SP, Biering-Sorensen F, et al. International standards for neurological classification of spinal cord injury (revised 2011). \u003cem\u003eJ Spinal Cord Med. \u003c/em\u003e2011;34(6):535-546.https://dx.doi.org/10.1179/204577211X13207446293695\u003c/li\u003e\n\u003cli\u003eBaba H, Maezawa Y, Uchida K, Furusawa N, Wada M, Imura S. Plasticity of the spinal cord contributes to neurological improvement after treatment by cervical decompression. A magnetic resonance imaging study. \u003cem\u003eJ Neurol. \u003c/em\u003e1997;244(7):455-460.https://dx.doi.org/10.1007/s004150050122\u003c/li\u003e\n\u003cli\u003eGuan J, Yuan C, Yao Q, et al. A novel scoring system for assessing adult syringomyelia associated with CM I treatment outcomes. \u003cem\u003eActa Neurol Belg. \u003c/em\u003e2023;123(3):807-814.https://dx.doi.org/10.1007/s13760-023-02264-4\u003c/li\u003e\n\u003cli\u003eLaxton AW, Perrin RG. Cordectomy for the treatment of posttraumatic syringomyelia. Report of four cases and review of the literature. \u003cem\u003eJ Neurosurg Spine. \u003c/em\u003e2006;4(2):174-178.https://dx.doi.org/10.3171/spi.2006.4.2.174\u003c/li\u003e\n\u003cli\u003eJiang C, Wang X, Lu C, et al. The Physiological Occlusion of the Central Canal May Be a Prerequisite for Syringomyelia Formation. \u003cem\u003eNeurospine. \u003c/em\u003e2023;20(4):1346-1357.https://dx.doi.org/10.14245/ns.2346834.417\u003c/li\u003e\n\u003cli\u003eYuan C, Guan J, Du Y, et al. Spinal Obstruction-Related vs. Craniocervical Junction-Related Syringomyelia: A Comparative Study. \u003cem\u003eFront Neurol. \u003c/em\u003e2022;13:900441.https://dx.doi.org/10.3389/fneur.2022.900441\u003c/li\u003e\n\u003cli\u003eYuan C, Guan J, Jian F. Rapid progression of acute cervical syringomyelia: A case report of delayed complications following spinal cord injury. \u003cem\u003eJ Spinal Cord Med. \u003c/em\u003e2020:1-5.https://dx.doi.org/10.1080/10790268.2020.1733336\u003c/li\u003e\n\u003cli\u003eHemley SJ, Bilston LE, Cheng S, Stoodley MA. Aquaporin-4 expression and blood-spinal cord barrier permeability in canalicular syringomyelia. \u003cem\u003eJ Neurosurg Spine. \u003c/em\u003e2012;17(6):602-612.https://dx.doi.org/10.3171/2012.9.SPINE1265\u003c/li\u003e\n\u003cli\u003eMastorakos P, Pomeraniec IJ, Bryant JP, Chittiboina P, Heiss JD. Flexible thecoscopy for extensive spinal arachnoiditis. \u003cem\u003eJ Neurosurg Spine. \u003c/em\u003e2022;36(2):325-335.https://dx.doi.org/10.3171/2021.4.SPINE21483\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 Characteristics of eleven adult patients who underwent modified S-S bypass.\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"98%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003ePatient\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003eAge (yrs)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eSurgery to onset (mos)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003eOnset to S-S pass(mos)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eMain complaint\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eFrankle Grade\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003ePrevious surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003ePreoperative Syrinx\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eObstructed levels\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eSurgical treatment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eFollow-up\u003c/p\u003e\n \u003cp\u003e(mos)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eSymptom evolution\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e5*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eNumbness in the limb and weakness in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT8meningioma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC0T8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT6T9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e3*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e204\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eDiscomfort in the left upper limb\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT2meningioma, syringosubarachnoid shunt\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC2T11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eC2T3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e\u0026nbsp;3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e7*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eDiscomfort in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT12meningioma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eT6T12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT9L1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e6*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e156\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eNumbness and weakness in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT8meningioma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC7T9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e5*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e384\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eAtaxia and pain in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT9meningioma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eT6T9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT3T11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e3*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eNumbness and weakness in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT8enterogenous cyst, thoracic fusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eT1T7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT2T9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e3*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e192\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eNumbness in the left leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT8enterogenous cyst\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC7T8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT4T9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e6*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eDiscomfort in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT10enterogenous cyst\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eT8T10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT7L1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e5*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eBack pain and weakness in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT11schwannoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC7T12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT9T12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eStable\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e3*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eNumbness and weakness in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eT8schwannoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eC7T11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT5T11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 4.12371%;\"\u003e\n \u003cp\u003e5*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 3.09278%;\"\u003e\n \u003cp\u003eF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7.21649%;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 23.7113%;\"\u003e\n \u003cp\u003eNumbness and weakness in the leg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.433%;\"\u003e\n \u003cp\u003eThoracic spinal stenosis, thoracic fusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003eT3T12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.18557%;\"\u003e\n \u003cp\u003eT3T11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5.15464%;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3093%;\"\u003e\n \u003cp\u003eImprovement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e*yrs, years; mos, months.\u003c/p\u003e\n\u003cp\u003eTable 2 Additional characteristics of eleven adult patients who underwent modified S-S bypass.\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"98%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 5px;\"\u003e\n \u003cp\u003eCase no.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 12px;\"\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 12px;\"\u003e\n \u003cp\u003eASIA sensory score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 12px;\"\u003e\n \u003cp\u003eASIA motor score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 12px;\"\u003e\n \u003cp\u003eBladder function\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 12px;\"\u003e\n \u003cp\u003eSyrinx length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 14px;\"\u003e\n \u003cp\u003eSyrinx Tension index\u003csup\u003e*\u003c/sup\u003e (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 9px;\"\u003e\n \u003cp\u003eComplication\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 5px;\"\u003e\n \u003cp\u003eNumber of tubes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 5px;\"\u003e\n \u003cp\u003eFollow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePo-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePo-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePo-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePo-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003ePo-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003ePre-op\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003ePo-op\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e184\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e186\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e92.3%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e26. 5%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e204\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e84.3%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e25.7%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e218\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e220\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e68. 9%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e20.8%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e182\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e184\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e61.1%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e23.8%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e204\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e206\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e65.2%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e40.2%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e186\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e188\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e80.9%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 7px;\"\u003e\n \u003cp\u003e9.3%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n 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\u003cp\u003e0.317\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 12px;\"\u003e\n \u003cp\u003e0.004\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 14px;\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 5px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e*The maximum diameter of syrinx/ spinal canal.\u003c/p\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":"european-spine-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"esjo","sideBox":"Learn more about [European Spine Journal](http://link.springer.com/journal/586)","snPcode":"586","submissionUrl":"https://submission.springernature.com/new-submission/586/3","title":"European Spine Journal","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"syringomyelia, cerebrospinal fluid, spinal cord injury, surgery, tumor, bypass","lastPublishedDoi":"10.21203/rs.3.rs-6290624/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6290624/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e Current surgical options for treating nontraumatic adhesive syringomyelia, particularly in patients with a history of previous spinal canal surgical intervention (PSCAS), lack clear standardization and frequently lead to common complications such as recurrent adhesions, tube disconnections, and neurological injuries related to myelotomy, resulting in the need for multiple revision surgeries. This study aims to introduce a novel, minimally invasive technique of modified subarachnoid-subarachnoid (S−S) bypass procedure for PSCAS and to prospectively evaluate its surgical outcomes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e This prospective study included 11 consecutive non-traumatic patients with symptomatic PSCAS who underwent modified S-S bypass surgery, with a mean follow-up period of 18.3 months (range: 16-20 months). Neurological function was assessed using standardized grading systems, and changes in syrinx size were evaluated using MRI.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e Ten patients demonstrated clinical improvement, while one patient remained stable. Notably, the preoperative and postoperative ASIA motor and sensory scores showed significant improvement (88.45 ± 11.01 \u003cem\u003evs.\u003c/em\u003e 89.64 ± 9.99, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05; 200.73 ± 15.52 \u003cem\u003evs.\u003c/em\u003e 203.09 ± 15.29, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). The mean syrinx tension index postoperatively was significantly lower than the preoperative value (74.28 ± 14.34% \u003cem\u003evs. \u003c/em\u003e29.87 ± 17.62%, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.0001), and the syrinx length was also significantly reduced (9.46 ± 4.59 \u003cem\u003evs.\u003c/em\u003e8.00 ± 6.05, \u003cem\u003ep \u003c/em\u003e\u0026lt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e This study highlights that the modified S-S bypass can be performed without myelotomy or intratubal interaction with CSF circulation, representing not only a safe and effective surgical technique but also a potentially more physiological approach for treating PSCAS.\u003c/p\u003e","manuscriptTitle":"A Novel Minimally Invasive Surgical Technique for Treating Non-Traumatic Adhesive Syringomyelia Associated with a History of Previous Spinal Canal Surgical Interventions","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-04 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