Syringosubarachnoid Shunt Research Articles

Treatment of Terminal Syrinx With a Syringo-Subarachnoid Shunt and the Novel Use of a Titanium Knot Fastener: A Case Report

Treatment of Terminal Syrinx With a Syringo-Subarachnoid Shunt and the Novel Use of a Titanium Knot Fastener: A Case Report

Epidemiological aspects of syringomyelia in a 19-year old cohort of spinal cord injury patients

ObjectiveTo determine the prevalence, clinical and radiological risk factors, and surgical management of post-traumatic syringomyelia (PTS) in a 19-year cohort study of Spinal Cord Injury (SCI) patients treated at a SCI rehabilitation center. MethodsRetrospective study of SCI patients in whom PTS was radiologically confirmed between January 2000 and December 2018. Protocols for assessing signs and symptoms of PTS were applied prior to PTS diagnosis and treatment and later at neurosurgical and rehabilitation reviews. The variables analyzed were prevalence, demographic data, trauma event, clinical and radiological risk factors, location and size of the syrinx, and effectiveness of the surgical procedures. ResultsOver the 19-year period, review of 920 SCI patients revealed 85 patients who met the clinical and neuroradiological criteria for the diagnosis of PTS and who were prospectively followed. Road traffic accidents were the leading cause of injury (n = 58; 68.2%), syringomyelia was most commonly observed in the thoracic spine (n = 56; 65.9%), and upper extremity paresis was the most common indication for surgical treatment (n = 27; 45%). Surgical treatment was indicated in 48 patients and the operative procedures included 29 syringopleural shunts (60.4%), 17 adhesiolysis (35.4%), and two syringosubarachnoid shunts (4.1%). The prevalence of PTS was 9% and was higher in patients with ASIA impairment scale grade A injuries. Most patients with PTS (63/85, 74.1%) were treated surgically at the time of injury. There was a significant reduction both in the extent (p = 0.05) and largest area (p = 0.001) of the syrinx after surgical treatment. Reoperation rates were 47% and 37.9% for adhesiolysis and syringopleural shunting, respectively. ConclusionFollow-up and routine clinical examination of SCI patients is critical for the diagnosis of PTS in patients with late neurological deterioration. Surgical treatment has a positive impact in reducing the size of the syrinx as seen on postoperative MRI.

Epidemiological aspects of syringomyelia in a 19-year old cohort of spinal cord injury patients

ObjectiveTo determine the prevalence, clinical and radiological risk factors, and surgical management of post-traumatic syringomyelia (PTS) in a 19-year cohort study of Spinal Cord Injury (SCI) patients treated at a SCI rehabilitation center. MethodsRetrospective study of SCI patients in whom PTS was radiologically confirmed between January 2000 and December 2018. Protocols for assessing signs and symptoms of PTS were applied prior to PTS diagnosis and treatment and later at neurosurgical and rehabilitation reviews. The variables analyzed were prevalence, demographic data, trauma event, clinical and radiological risk factors, location and size of the syrinx, and effectiveness of the surgical procedures. ResultsOver the 19-year period, review of 920 SCI patients revealed 85 patients who met the clinical and neuroradiological criteria for the diagnosis of PTS and who were prospectively followed. Road traffic accidents were the leading cause of injury (n = 58; 68.2%), syringomyelia was most commonly observed in the thoracic spine (n = 56; 65.9%), and upper extremity paresis was the most common indication for surgical treatment (n = 27; 45%). Surgical treatment was indicated in 48 patients and the operative procedures included 29 syringopleural shunts (60.4%), 17 adhesiolysis (35.4%), and two syringosubarachnoid shunts (4.1%). The prevalence of PTS was 9% and was higher in patients with ASIA impairment scale grade A injuries. Most patients with PTS (63/85, 74.1%) were treated surgically at the time of injury. There was a significant reduction both in the extent (p = 0.05) and largest area (p = 0.001) of the syrinx after surgical treatment. Reoperation rates were 47% and 37.9% for adhesiolysis and syringopleural shunting, respectively. ConclusionFollow-up and routine clinical examination of SCI patients is critical for the diagnosis of PTS in patients with late neurological deterioration. Surgical treatment has a positive impact in reducing the size of the syrinx as seen on postoperative MRI.

Syringosubarachnoid shunting with augmented reality navigation through a keyhole laminectomy of the upper thoracic spine: illustrative case.

A syringosubarachnoid (SS) shunt combined with keyhole hemilaminectomy is a beneficial procedure that can reduce the size of the skin incision and the risk of complications. However, ingenuity is needed to confirm the position of the syrinx during surgery. The authors present a case in which they treated syringomyelia in the upper thoracic spine using augmented reality (AR) to confirm syrinx formation, bone resection, and skin incision. Microscope-based AR was an appropriate and practical choice in this case. By placing the reference array at the Mayfield clamp, it was possible to use AR from the point of skin incision. Under AR navigation, an SS shunt tube can be placed in the short syrinx. AR navigation enables pinpoint SS shunt tube insertion with minimal skin incision and bone resection. It is particularly useful for upper thoracic and small syrinx lesions. https://thejns.org/doi/10.3171/CASE24130.

Tension hydrothorax complicating syringopleural shunt for post-traumatic syringomyelia.

Syringomyelia is a rare phenomenon that is typically associated with Chiari malformations. However, they can occur in the setting of post-traumatic spinal injury. Potential diversion treatments include syringopleural (SPS), syringoperitoneal and syringosubarachnoid shunts. Short-term complications have been reported in the literature, however, long term complications are not well documented. This case report is of a 43-year-old woman found deceased in bed. She had a history of a traumatic spinal injury following a motor vehicle accident 15 years prior to death. This was complicated by a syringomyelia/syrinx requiring a SPS insertion. Post-mortem imaging and autopsy findings demonstrated a large right tension hydrothorax with dense fibrosis of the pleural surfaces, contralateral diffuse alveolar damage lung changes histologically and a patent SPS. Her cause of death was registered as "Right tension hydrothorax and diffuse alveolar damage complicating right syringopleural shunt and thoracic syrinx".

Syringo-Subarachnoid Shunt with Tube Versus T-Tube via the Dorsal Root Entry Zone Approach for Eccentric Syringomyelia

OBJECTIVEThe objective of this study was to compare the clinical therapeutic efficacy of syringo-subarachnoid shunt with direct tube and T-tube via the dorsal root entry zone(DREZ) approach for the treatment of eccentric syringomyelia. METHODSA retrospective study was performed on the clinical data of 41 patients associated with idiopathic or secondary eccentric syringomyelia from November 2011 to December 2022. Syringo-subarachnoid shunt with a direct tube or T-tube via the DREZ approach were conducted. The modified Japanese Orthopedic Association (mJOA) low back pain scale was used to investigate the severity of clinical symptoms. MRI was used to investigate therapeutic efficacy（reduction of the cavity volume by over 10% was considered an improvement and 50% was considered a significant improvement）. RESULTSThe incision length of the spinal cortex in the direct tube group was shorter than in the T-tube group (3.10±0.28cm vs. 5.03±0.19cm), with a significant difference between this two groups(t=-52.56, P<0.001). JOA 3 months post-surgery was significantly better than pre-operation JOA both in direct tube group（t=40.954,P<0.001） and in T-tube group（t=24.769,P<0.001）. The statistical comparison revealed there were no difference in image improvement condition between direct tube group and T-tube group 3 months post-surgery( χ2=0.20，p=0.655) and 12 months post-surgery(χ2=0.21，p=0.647). CONCLUSIONSyringo-subarachnoid shunt with direct tube via the DREZ approach for the treatment of eccentric syringomyelia is safer than with T-tube via the DREZ approach due to more minimal incision length and lesser occupying effect with same therapeutic efficacy.

Glioependymal cyst in the medulla oblongata – A case report

Background: Glioependymal cysts (GECs) are rare benign lesions that can be found anywhere along the neuroaxis, with most of the reports denoting supratentorial location. Here, we introduce a rare case of successfully treated glioependymal cysts lying in an uncommon location, namely medulla oblongata. Case Description: A 69-year-old lady presented with progressive unsteadiness and swallowing disturbances, and brain magnetic resonance imaging showed a dorsally located lesion within the medulla oblongata; based on the presentation and radiological features, surgical intervention was deemed mandatory. The suboccipital midline approach was used to perform marsupialization of the cyst with shunting through a syringosubarachnoid shunt to prevent future recurrence, and the patient outcome was improved. Conclusion: Medulla Oblongata’s location for glioependymal cysts proposed unique diagnostic and operative challenges that may require highlighting for practicing neurosurgeons.

Management of Persistent Syringomyelia in Patients Operated for Chiari Malformation Type 1

The treatment of persistent syringomyelia associated with Chiari malformation type 1 (CM1) is unclear. This study aims to evaluate the clinical and radiologic outcomes of syringo-subarachnoid shunt (SSS) as a treatment for persistent syringomyelia following posterior fossa decompression (PFD) for CM1. Forty-nine cases treated for CM1 associated syringomyelia at a single center were analyzed, 17 of them undergoing reoperation due to persistent syrinx formation. The patients' demographic data, neurologic presentations, and radiologic results were analyzed, including cerebellar herniation, posterior fossa volume, the level at which the syrinx started and finished, the size and diameter of the syrinx. Seventeen patients underwent SSS placement, with 1 minor surgical complication (a cerebrospinal fluid leak) occurring and requiring revision. No morbidity or mortality was observed. Among these 17 reoperated patients, partial or complete resorption of the syrinx was observed in all cases. The results suggest that if the syrinx diameter is >10 mm at its thickest point, extends for more than 10 vertebrae, and starts from the upper cervical region and extends to the upper thoracic region, the syrinx may not regress after the first surgery and potentially predicting the need for a second operation before PFD. SSS placement for persistent syrinx following PFD for CM1 is a safe and effective surgical treatment method. These criteria may also help predict the need for a second surgery and the overall disease outcome for both the surgeon and patient.

Long-term outcome and prognostic factors of syringo-subarachnoid shunt for syringomyelia

BackgroundSyringo-subarachnoid shunt (SSS) is often considered a rescue procedure or a second-line treatment option for syringomyelia. However, the clinical efficacy of SSS in treating this condition remains controversial. ObjectiveTo evaluate the long-term outcome of the SSS and its relationship with the syrinx area, as well as to investigate the factors that influence the prognosis. MethodsThis retrospective study included twenty-seven consecutive patients who underwent SSS between 2014 and 2020. The study evaluated several independent variables such as age, sex, duration of progressive symptoms, morphological characteristics of the syrinx, changes in the syrinx area, and Chiari malformation. The long-term follow-up (>2 years) Japanese Orthopaedic Association (JOA) score was used to assess neurological function and outcome. Statistical analysis was performed using a stepwise logistic regression test. ResultsAll patients were followed up for an average of 48.6 ± 14.8(26.8 to 78.0) months. Follow-up magnetic resonance imaging showed syrinx collapse to different degrees occurred in 96.3% (26 of 27) patients. The JOA score was improvedinonly6patients (22.2%), remained stable in 5 patients (18.5%),and deteriorated in 16 patients(59.3%).A logistic regression test showed that the tension syrinx (odds ratio 0.111) and early shunting intervention (odds ratio 0.138) were favorable independent prognostic factors. ConclusionsIt is important to note that the shrinkage of the syrinx does not necessarily translate to an improvement in clinical outcomes. Therefore, the decision to perform SSS should be made with caution and considered as a last resort.

Revision Thoracic Syringo-Subarachnoid Shunt for Recurrent Syrinx With Syringobulbia: Technique and Surgical Video.

Syringomyelia and syringobulbia continue to remain a diagnosis without widely accepted treatment paradigms. Furthermore, the currently available treatment options can be complicated by delayed symptom recurrence and the need for revision surgery. Revision intradural surgery is challenging, and currently, there is a paucity of literature describing safe techniques for revision syringotomy and shunt placement. In this technical report, we present a surgical video describing the technique of revision syringo-subarachnoid shunt placement in a 61-year-old female with a history of multiple intradural surgeries who presented with progressively symptomatic ascending syringobulbia.

Comparing Two Improved Techniques With the Traditional Surgical Techniques for Intra and Extramedullary Spinal Tumor Resection: A Report of 280 Cases.

ObjectivesSpinal tumors remain a challenging problem in modern neurosurgery. The high rate of postoperative morbidity associated with intramedullary tumors makes the need for safer surgical techniques invaluable. This study analyses our experience with the treatment of spinal cord tumors and compares traditional management and a new different surgical approach to intramedullary tumors with an associated hydrosyringomyelia.Materials and MethodsThis retrospective study compared standard surgical techniques and 2 newer modified techniques for intra and extramedullary spinal tumors at the Neurosurgery center for spinal cord tumors of the Republic of Uzbekistan. Preoperative neurological status was recorded with the ASIA/ISNCSCI scale. Postoperative outcome was graded using the Nurrick score.ResultsOf the 280 cases, there were 220 (78.5%) extramedullary and 60 (21.5%) with intramedullary spinal tumors. The control and main group had 159 (56.8%) and 121 (43.2%) patients, respectively. Severe compression myelopathy (ASIA- A, B, C) was 217 (77.5%) patients i.e., ASIA A-39 (13.9%); B-74 (26.4%), and C-104 (37.1%). In 74 extramedullary tumors (33.6%) treated with the new method, good postoperative outcomes in 44 cases (59.5%) with OR = 1.9; 95% CI 1.1–3.3 (p < 0.05). Thirty-seven (61.7%) intramedullary tumors were treated with the newer modified technique. There was no difference with the standard method (p = 0.15). However, when comparing postoperative Nurick grade 1–2 with grade 3–4, the newer strategy was superior with improvement in 24 (65%) patients, OR = 3.46; 95% CI 1.2–10.3 (p < 0.05).ConclusionWhen compared with standard methods, the proposed newer modified strategy of surgical treatment of spinal cord tumors with the insertion of a syringosubarachnoid shunt in the presence of an associated hydrosyringomyelia is associated with better postoperative outcome (Nurick 1 and 2) in 64.8%.

Syrinx shunts for syringomyelia: a systematic review and meta-analysis of syringosubarachnoid, syringoperitoneal, and syringopleural shunting.

Syringomyelia is a debilitating, progressive disease process that can lead to loss of neurological function in patients already experiencing significant compromise. Syringosubarachnoid, syringoperitoneal, and syringopleural shunts are accepted treatment options for patients with persistent syringomyelia, but direct comparisons have been lacking to date. The authors conducted a systematic review of the literature and meta-analysis to compare clinical outcomes between these three syrinx shunt modalities. Utilizing PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews, Ovid Embase, PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, and Database of Abstracts of Review of Effectiveness were searched to identify all potentially relevant studies published from inception until July 2020. Data were extracted and analyzed using meta-analysis of proportions. The primary study outcome was the rate of reoperation based on the initial shunt modality. Secondary outcomes included clinical improvement, clinical deterioration, and complications following shunt placement. A total of 22 articles describing 27 distinct treatment cohorts published between 1984 and 2019 satisfied the inclusion criteria. This captured 473 syrinx shunt procedures, 193 (41%) by syringosubarachnoid shunt, 153 (32%) by syringoperitoneal shunt, and 127 (27%) by syringopleural shunt, with an overall median clinical follow-up of 44 months. The pooled incidences of revision surgery were estimated as 13% for syringosubarachnoid, 28% for syringoperitoneal, and 10% for syringopleural shunts, respectively (p-interaction = 0.27). The rate of clinical improvement was estimated as 61% for syringosubarachnoid, 64% for syringoperitoneal, and 71% for syringopleural shunts. The rate of clinical deterioration following placement was estimated as 13% for syringosubarachnoid, 13% for syringoperitoneal, and 10% for syringopleural shunts. The preferred modality of syrinx shunting remains a controversial topic for symptomatic syringomyelia. This study suggests that while all three modalities offer similar rates of clinical improvement and deterioration after placement, syringoperitoneal shunts have a greater rate of malfunction requiring surgical revision. These data also suggest that syringopleural shunts may offer the best rate of clinical improvement with the lowest rate of reoperation.

Observational outcome in surgery for Chiari malformation patients

Chiari malformation is the commonest anomaly of the craniovertebral junction involving both the skeletal as well as the neural structures. It is congenital anomaly of the hindbrain characterised by downward elongation of the brain stem and cerebellum into the cervical portion of spinal cord. Most common presenting symptoms was pain in the nape of neck with sub-occipital headache and weakness. If not intervened early in these cases they may progress to quadriparesis and respiratory failure. This study includes authors experience of 30 surgical corrections of Chiari malformation performed at civil hospital Ahmedabad from 2017 to 2019. The age and sex of the patient, the presence of syrinx, the type of surgical procedure and the clinical outcome were determined post-operatively and on follow up. Cerebro spinal fluid leak and collection were observed in patient who undergone duroplasty only with no leakage in patient undergone syringo-subarachnoid shunt. Overall, tingling/numbness had best improvement showed improvement in 13 out of 16 patients. Power showed improvement in 20 out of 27 patients and pain showed improvement in 18 patients. Wasting, clawing and cerebellar signs and bony deformity showed no improvement in any of the above procedures. Authors can conclude for Chiari malformation decompression with or without duroplasty with additional procedure with post-operative physiotherapy and analgesia is the suitable treatment.

Under pressure: Syringo-subarachnoid shunting and syrinx cyst videoscopy

BackgroundSyringomyelia is a well-known spinal cord pathology characterized by an intramedullary cyst that is often chronic and can be progressive. The earliest techniques of syrinx decompression began with simple aspiration after laminectomy and predated anatomic imaging. This was followed by early attempts at keeping communication open between the syrinx and the subarachnoid space using various materials as conduits, essentially creating the first attempts at syringo-subarachnoid shunting (SSS). Even in the modern era of high-quality anatomic imaging with MRI and use of modern materials as implants, novel ways to maintain communication between a syrinx cavity and the subarachnoid space continue to be reported. MethodsA total of 212 patients with imaging-proven syringomyelia presented to our center between 2014 and 2019 and were retrospectively reviewed. The majority of these patients (197) had an identifiable primary cause and surgical treatment was directed at the underlying condition. A total of 18 patients had a T-tube style SSS placed at our center using a K-tube shunt. The mean follow-up was 31.5 months, mean age was 38 years (2–59). The European Myelopathy Score (EMS) and Chicago Chiari Outcome Scale (CCOS) were used to categorize outcomes and progress in these 18 patients. Also we report clinical case to demonstrate technique of K-tube use for syringo-subarachnoid shunting and potential abilities of inner syrinx cyst videoscopy for treatment of syringomyelia in 2-year-old patient with multiple congenital vertebral and spinal cord abnormality. ResultsAmong 16 patients available for follow-up 4 patients (25%) had neurological improvement, 12 patients (75%) remained clinically stable, and no patient had a neurological deterioration based on EMS. Using the CCOS 8 patients (50%) improved, 7 patients (44%) remained stable, and 1 patient (6%) worsened during in the follow-up period. Complications occurred in six patients (33%). Two patients had gait ataxia. Two patients developed postoperative meningitis treated successfully with antibiotics leaving the shunt in place. One patient had a CSF leak successfully treated with a lumbar drain. One patient developed a new pain syndrome. There was no mortality, shunt migration/malposition or reoperation. ConclusionsSyringo-subarachnoid shunting is a well-known and well-described procedure used as “second-line” treatment of syringomyelia worldwide. Our results are consistent with others and make this another surgical option if treatment of a primary source fails or no primary source of the syrinx is found. Our series of 18 patients using a T-tube style SSS adds another good option to those already in use. Recurrence or deterioration following syringomyelia shunting remains a problem and further refinement of technique remains an ongoing process. Syrinx inner videoscopy seems to be safe procedure with possible application to simplify the anatomy of cyst and liquid flow relief.

Syringo-Subarachnoid Shunt Placement: A Minimally Invasive Technique Using Fixed Tubular Retractors-Three Case Reports and Literature Review.

Placement of a syringo-subarachnoid shunt as a surgical management for syringomyelia has been well described in the literature. Good results in terms of clinical and radiological improvement have been documented especially for posttraumatic syringomyelia. Traditionally, this has been performed using open approaches which are fraught with risks of cerebrospinal fluid leak, delayed wound healing, and increased postoperative pain. With the help of minimally invasive techniques that are currently being used to treat various degenerative spinal disorders, most of these complications may be minimized. However, few reports in literature describe similar approaches for accessing intradural intramedullary spinal cord lesions and especially for syringomyelia. Retrospective case review: using a 22-mm tubular retractor, a laminotomy was performed, durotomy done, and spinal cord identified. Myelotomy was performed at the dorsal root entry zone, syrinx visualized and entered, followed by placement of syringo-subarachnoid shunt. Three male patients aged 44, 57, and 37 underwent placement of syringo-subarachnoid shunts using minimally invasive fixed tubular retractors. Indications included posttraumatic or postsurgical spinal cord syrinx. Follow-up period was 1 year in all cases. There were no neurological or technique-related complications. All patients showed clinical improvement upon subsequent follow up. Our clinical experience on the treatment of syringomyelia via a minimally invasive fixed tubular retractor is presented. We find that this is an ideal approach for placement of syringo-subarachnoid shunts, as it provides direct access to the lesion with minimal collateral damage and wound-related complications. 4. Relevant - in demonstrating the effectiveness of an already established procedure through a novel, minimally invasive approach which has the potential to significantly reduce the overall morbidity, in view of the inherent approach-related benefits as compared to conventional open approaches.

Syringosubarachnoid shunt: insertion technique

Background Syringomyelia is a rare disorder but its impact on patients’ quality of life can be devastating. The exact pathophysiology remains unknown; the syrinx can either be idiopathic or associated with conditions such as Chiari malformation, scoliosis, malignancy, infection and trauma. Several techniques have been described to decompress syringomyelia with distal drainage to the subarachnoid space, pleura or peritoneum. Method We present a modification of the syringosubarachnoid shunt insertion technique with minimal myelotomy and the use of a T shaped shunt which does not require suturing to the pia matter to prevent shunt migration. Conclusion This technique for syringosubarachnoid shunt insertion is likely to prevent shunt migration and scarring whilst minimizing suturing and optimising syrinx decompression.

Idiopathic Intrasyringal Hemorrhage: A Case Report and Review of the Literature

Abstract INTRODUCTION Intrasyringal hemorrhages, also known as Gower's hemorrhages, are exceedingly rare entities. There are sporadic case reports of intrasyringal hemorrhages arising from intramedullary tumors, trauma, anticoagulation, or syringomyelic cavities secondary to Chiari malformations. Management is typically tailored to the underlying pathology. Given the paucity of literature, the clinical course and management modalities remain poorly defined. METHODS We present the case of a 19-yr-old male with a complex pasat medical history significant for Pierre Robin sequence, cervicomeddulary dysfunction with posterior fossa decompression and occipital-cervical fusion, hydrocephalus with fourth ventricular outlet fenestration, ventriculoperitoneal shunt conversion to ventriculoatrial shunt, and complex syringomyelia with thoracic syringo-subarachnoid shunt. Our patient presented to us with 3 wk of acute decompensation with complete loss of lower extremity function and a mid-thoracic sensory level. An magnetic resonance imaging (MRI) demonstrated an extensive dilation of his known syrinx with associated accumulation of heterogeneous blood products within the cavity encapsulating the syringo-subarachnoid shunt. RESULTS We performed a prompt revision thoracic laminectomy to identify the patient's existing syringo-subarachnoid shunt. Once the shunt was identified we performed a myelotomy overlying the existing shunt, and immediately noted high pressure chronic hematoma exiting from the myelotomy site. We placed a new syringo-subrachnoid shunt and gently advanced the catheter superiorly while gently irrigating the syrinx cavity. We continued to irrigate the cavity until the blood products cleared and fluid resembling cerebrospinal fluid returned from the cavity. The postoperative MRI demonstrated overall decreased size of the syrinx with less intrasyringal hemorrhage. The patient had a slight improvement in his thoracic sensory level at short-term follow-up. CONCLUSION Intrasyringal hemorrhages are exceedingly rare pathologic entity which may cause significant dilation of an existing syrinx even in the presence of a syringo-subrachnoid shunt. Exam features are variable but may demonstrate an acute and drastic progression. Prompt surgical intervention may improve functional neurologic prognosis.

Syringo-subarachnoid shunt: how I do it.

Syringo-subarachnoid shunt (SSS) is a valid method for the treatment of syringomyelia persisting after foramen magnum decompression (FMD) for Chiari I malformation. We give a brief overview on indication and outcome of SSS, followed by a detailed description of the surgical anatomy, and of the microsurgical technique. In particular, we highlight some key points for complication avoidance. SSS is a valid option to treat syringomyelia, since in experienced hands, the outcome is good in most patients, including those with holocord syringomyelia. Careful understanding of anatomy and spinal cord physiology is required to minimize complications.

Treatment of Holocord Syringomyelia-Chiari Complex by Posterior Fossa Decompression and a Syringosubarachnoid Shunt in a Single-Stage Single Approach.

Posterior fossa decompression with expansive duraplasty is the first-line surgical approach for the treatment of symptomatic syringomyelia associated with Chiari malformation. Despite good decompression, the clinical failure rate is reported to be up to 26%. A syringosubarachnoid (S-S) shunt may be used as a secondary option. In this paper we describe a single-institution experience of three cases of holocord syringomyelia-Chiari complex treated with foramen magnum decompression, expansive duraplasty and an S-S shunt carried out in a single-stage single approach. Following a standard suboccipital craniectomy, patients were submitted to syrinx fenestration and simultaneous insertion of an S-S shunt through a 1-mm posterior midline myelotomy at the C2 level prior to expansive dural reconstruction. Postoperative imaging showed immediate reduction of the holocord cavities. Preoperative neurological deficits rapidly improved significantly and were stabilized at follow-up. In our experience the positioning of the shunt catheter at a high level of the spinal cord (C2) did not add a significant risk of morbidity and obviated the need for a second operation and/or a separate incision in cases of clinical failure. This technique avoided the risk associated with a second surgery and its morbidity, and allowed prompt clinical recovery.

Treatment failure of syringomyelia associated with Chiari I malformation following foramen magnum decompression: how should we proceed?

The preferred treatment of patients with persistent, recurrent, or progressive syringomyelia after foramen magnum decompression (FMD) for Chiari I (CMI)-associated syringomyelia is controversial, and may include redo FMD, stabilization, or shunting procedures (such as syringopleural or syringo-subarachnoid shunts). We describe our experience in treating these patients and discuss the treatment modalities for these patients. We retrospectively collected data of CMI patients with persistent, recurrent, or progressive syringomyelia after FMD. In addition to baseline characteristics, surgical treatments and neurological and radiological outcomes were assessed. Further, we assessed through uni- and multivariate analyses possible technical, surgical, and radiological factors which might lead to failed FMD. Between 1998 and 2017, 48 consecutive patients (35 females (73%), average age 16.8 ± 11.5years) underwent FMD for a syringomyelia-Chiari complex. Twenty-four patients (50%) underwent surgical treatment for a persistent (n = 10), progressive (n = 12), or recurrent (n = 2) syringomyelia 21.4 ± 27.9months (median 14.6months, range 12days-134.9months) after FMD. Of all analyzed factors, only extradural FMD was significantly associated with lower failure rates. Two patients (8%) underwent redo FMD, 18 (75%) underwent 19 syringo-subarachnoid-shunts, and 4 (17%) had 6 cranial CSF diversion procedures. The overall follow-up time was 40.1 ± 47.4months (median 25months, range 3-230months). Based on our results, 50% of the patients undergoing FMD for syringomyelia-Chiari complex may require further surgical treatment due to persistent, progressive, or recurrent syringomyelia. Treatment should be tailored to the suspected underlying pathology. A subgroup of patients may be managed conservatively; however, these patients need close clinical and radiological follow-ups. The technical aspects of FMD in CMI-syrinx complex should be the focus of larger studies, as an effort to improve failure rates.