Surgical treatment of spinal extradural arachnoid cysts in the thoracolumbar spine

A novel subtype classification and corresponding surgical strategies for spinal dural cysts -a report of 104 cases

BACKGROUND

The nomenclature, classification, and surgical approaches for spinal dural cysts (SDCs) remain a subject of controversy.

PURPOSE

The present study proposes a novel subtype classification system and corresponding surgical strategies, with the aim of enhancing comprehension of this entity and standardizing surgical treatment.

STUDY DESIGN

A retrospective review.

PATIENT SAMPLE

A total of 104 patients with SDCs underwent novel subtype classification and corresponding surgical strategies from January 2015 to December 2021. Fifty-four patients who underwent conventional surgery from January 2012 to December 2014 as the control group for preliminary validation.

OUTCOME MEASURES

The outcomes are categorized into four levels: excellent, good, unchanged, and deteriorated, based on neurological improvement and pain relief. Grades of excellent and good were identified as improvements. Follow-up magnetic resonance imaging and complications were also evaluated.

METHODS

Based on the shared pathogenic factor of dural defects, the dural-associated cysts in the spinal canal are uniformly referred to as SDCs. They are further classified into Type 1 (no nerve roots) and Type 2 (containing nerve roots), with four additional subtypes based on the shape of the leak and the flow of leakage. The fissure-shaped leak of Type 1a SDCs is directly sutured, whereas the aperture-shaped leak of Type 1b is repaired using a patch. Low-flow leakage of Type 2a is directly sealed using a combination of adipose tissue and fibrin glue, whereas high-flow Type 2b necessitates suturing at the end of the leak to attenuate cerebrospinal fluid flow prior to sealing.

RESULTS

The follow-up period averaged 23.8 months. Excellent or good outcomes were achieved in 100%, 88.9%, 100%, and 97.3% for the four subtypes respectively. The overall improvement rate of SDCs was 97.1%, which was significantly higher than that of the conventional surgery group (85.2%, p=0.008). MRI follow-up showed a significant reduction in cyst size of 100%, 100%, 97.8%, and 97.3% for the four subtypes, respectively. The primary complications included pseudomeningocele in 4 cases (3.8%) and delayed wound healing in 5 cases (4.8%). The complication rate was also significantly lower than that of the control group (8.7% vs 24.1%, p=0.008).

CONCLUSIONS

Subtyping SDCs based on the variation of leaks and leakage can enable more targeted surgical strategies, which are helpful for improving treatment effectiveness and reducing complications.

Extradural spinal cyst in a pediatric patient: A case report

Background

Spinal extradural arachnoid cysts comprise <1% of all spinal lesions and are rare findings in pediatric patients. The pathogenesis of spinal extradural arachnoid cysts is not well known but is thought to most commonly be due to congenital dural defects. Other origins include trauma, inflammation, or infection, such as arachnoiditis. Spinal magnetic resonance imaging is the gold standard for diagnosis, showing a fluid-filled space dorsal to the spinal cord with signal intensity akin to cerebrospinal fluid (CSF) and often the site of dural defect with CSF leak. While most spinal extradural arachnoid cysts are asymptomatic, large cysts can compress the spinal cord or nerve roots, leading to myelopathy, radiculopathy, or focal pain symptoms. In such cases, surgical management is indicated.

Case Description

Here, we present a case of a 15-year-old female who presented with lower back pain radiating to her bilateral posterior thighs and knees, with imaging indicating a thoracolumbar spinal extradural arachnoid cyst. After failed conservative treatment, surgical intervention in the form of laminectomy, fenestration of the arachnoid cyst, and repair of the dural defect was required, resolving the patient's symptoms with no recurrence of the cyst.

Conclusion

Complete resolution of pain in our patient following surgical management of spinal arachnoid cyst suggests that treatment of the arachnoid cyst can be achieved through minimal exposure to the site of the CSF leak to fenestrate the cyst and repair the leak.

Spinal extradural arachnoid cysts: a rare entity and review of the literature

OBJECTIVE

Spinal extradural arachnoid cysts (SEDC) are rare primary spinal lesions, accounting for less than 1% of all spinal epidural lesions. The literature contains only case reports of this pathology, and treatment remains controversial due to its rarity. Major reported SEDC cases are caused by leaking out of cerebrospinal fluid through a dural defect in the thecal sac forming an extradural cyst. Other reports describe non-communicating SEDC cases where the dural defect was not identified. We report a literature review on SEDC and the case of a 53 year‑old female who presented with type IA extradural cyst with subarachnoid space communication.

METHODS

Literature review, preoperative imaging and surgical technique.

RESULTS

The extradural cyst was excised completely and the dural defect was repaired. After surgical decompression, neurological symptoms gradually recovered.

CONCLUSIONS

The extradural arachnoid cyst is an uncommon entity. Preoperative imaging is one of the determining elements in orienting the therapeutic management of the SEDCs. The choice of the surgical technique must be the least invasive in order to avoid postoperative complications. Subtotal or complete excision of the cyst, followed by obliteration of the communication stalk and repair of the dural defect is the gold standard treatment.

Expanding the Horizons of Minimally Invasive Spine Surgery: Experience of the Destandau Technique for the Treatment of Multiple Spinal Diseases

OBJECTIVE

Minimally invasive spine surgery is rapidly gaining popularity because of its versatile nature. Traditionally, prolapsed disc has been the most common disease targeted using this technique. However, its usefulness for various other diseases has also been shown in studies. We present our experience of using this technique for various spinal diseases apart from prolapsed discs.

METHODS

This is a retrospective study in which patients operated on by a single surgeon from January 2019 to April 2023 were included. Cases that required conversion to open technique were excluded. Intraoperative findings and postoperative courses were obtained from patient records.

RESULTS

A total of 47 patients were included in the study, of whom 29 were male and 18 were female. The various diseases treated comprised intradural extramedullary (IDEM) tumors (n = 23), hypertrophied/ossified ligamentum flavum (n = 9), arachnoid cysts (n = 6), dermoid/epidermoid cysts (n = 4), detethering of cord (n = 3), and posterior cervical decompression for an ossified posterior longitudinal ligament (n = 2). The average duration of surgery was 2.1 ± 1.2 hours and the mean intraoperative blood loss was 138.4 ± 59.1 mL. The mean length of hospital stay was 2.3 ± 0.9 days. Two patients had superficial wound infection and none of the operated patients had cerebrospinal fluid leakage. Re-exploration was not required in any of the operated patients.

CONCLUSIONS

Minimally invasive techniques for dealing with multiple diseases involving the spine are as good as traditional open techniques, with some additional advantages of lesser tissue trauma, early return to work, and so on. However, one must overcome the steep learning curve before adopting them in day-to-day practice.

Long-term outcomes following surgical treatment of spinal arachnoid cysts: a population-based consecutive cohort study

BACKGROUND CONTEXT

Spinal arachnoid cysts (SACs) are rare, cerebrospinal fluid-filled sacs lined by an arachnoid membrane in the spinal canal. Symptoms can develop due to pressure on the spinal cord or adjacent spinal nerves by the cyst itself or by interrupted flow of cerebrospinal fluid. If noninvasive management fails or neurological deterioration occurs, surgical treatment is recommended. However, data is lacking on long-term outcomes after surgery.

PURPOSE

To determine long-term outcomes in patients surgically treated for SACs.

STUDY DESIGN

Population-based cohort-study.

PATIENT SAMPLE

All consecutive patients treated for either intra- or extradural SACs with surgery between 2005 and 2020 at the author's institution were included.

OUTCOME MEASURES

American Spinal Injury Association Impairment Scale (AIS) and modified Japanese Orthopedic Association score (mJOA).

METHODS

Data was primarily extracted from electronic patient medical notes. Telephone interviews were performed to assess long-term postoperative outcomes. All analyses were conducted using the statistical software program R version 4.0.5. Statistical significance was set at p<.05.

RESULTS

Thirty-four patients were included. Cyst excision was performed in 11 (32%) cases, and fenestration in the remaining 23 (68%). The median follow-up time was 8.0 years. Surgery resulted in a significant long-term improvement in both AIS (p=.012) and mJOA (p=.005). Sensory deficit was the symptom that most often improved (81%), followed by pain (74%) and motor function (64%). AIS deteriorated in two patients, of which one case was attributed to a surgical complication. Local cyst recurrence requiring reoperation was seen in 4 (12%) cases, all of them following cyst fenestration. One patient (3%) required reoperation for progression of the cyst progression at a different level.

CONCLUSION

This study reports outcomes of surgically treated SACs with the longest follow-up time to date. Microsurgical cyst excision or fenestration were safe treatment options, and the neurological improvements seen in the immediate postoperative phase were maintained at long-term follow-up.

Spinal Arachnoid Cyst Analysis of Surgical Experience in a Single Tertiary Care Centre and Review of Literature

OBJECTIVE

To study patients with spinal arachnoid cysts, who underwent cyst excision with dural defect repair or marsupialization, and their outcomes.

METHODS

The retrospective analysis involved reviewing the records of 38 patients who underwent surgical treatment for spinal arachnoid cysts in the Department of Neurosurgery at Christian Medical College, Vellore, between August 2004 and December 2022. The study examined the demographics, clinical presentation, imaging, surgical intervention, and outcomes of these patients.

RESULTS

The majority of patients in the study were male (29/38, with 76.3%) and the thoracic region was the most common location for the cyst (17, with 44.7%). Weakness was the primary complaint and 94.7% of patients had myelopathy. The bladder was affected in 13 patients (34.2%). Of the 38 patients, 26 (71%) had cysts in extradural locations, while the rest were intradural. In total, 45.5% of intradural cysts were located in the ventral region. Seventeen (65.4%) had dural defects along the root sleeve and 29 (76.3%) underwent complete excision. All extradural cysts underwent complete excision and repair of the dural defect. Thirty patients (78.9%) experienced improved outcomes with reduced spasticity and improved weakness. One patient developed new-onset weakness postoperatively due to epidural hematoma. The mean follow-up period was 41 months and one patient experienced a recurrence.

CONCLUSIONS

Spinal arachnoid cyst is a rare benign spinal condition that is typically treated with surgery in symptomatic patients. Surgical intervention may involve either the excision of the cyst or marsupialization.

How to locate the fistula orifice of spinal extradural arachnoid cyst: Surgical experience and clinical outcome

BACKGROUND

In clinical practice, spinal extradural arachnoid cysts (SEAC) are relatively rare. The key to the treatment of SEAC is recognize and close the dural defects (fistula orifice), but there is currently no convenient method to locate and identify the fistula. We propose a method for predicting the location of lumbar/thoracolumbar SEAC fistula based on surgical experience, subsequently closing the fistula through posterior unilateral interlaminar fenestration. Evaluating its surgical efficacy and investigated its effect on patient prognosis.

METHODS

A stepped approach based on clinical experience is proposed. A retrospective analysis was performed on 6 patients diagnosed with thoracolumbar SEAC disease and treated with posterior unilateral interlaminar fenestration through the position by pre-estimated fistula orifice in our hospital's Department of Neurosurgery between January 2017 and January 2022.

RESULTS

All patients who received this treatment experienced significantly lower postoperative VAS pain scores and ODI index compared to their corresponding preoperative values (P < 0.01). During the ongoing follow-up after surgery, no unstable vertebral column, adverse effects, or complications were reported.

CONCLUSIONS

The use of posterior unilateral interlaminar fenestration for the treatment of large SEAC in the adult lumbar/thoracolumbar segment can reduce spinal cord manipulation and enhance spine stability. The disease can be treated by sealing the fistula orifice through a small fenestra, the position of which is assessed before surgery. This surgical method reduces trauma and improves the prognosis of patients with large SEAC.

Spinal extradural arachnoid cysts: A novel formation mechanism and dural defect location technology

Purpose

The formation mechanism of spinal extradural arachnoid cysts (SEACs) remains unclear. There are several hypotheses for the formation of SEACs, but none of them can fully explain its pathological findings and surgical procedures. In this study, we retrospectively analyzed the cases of SEACs, aiming to clarify the formation mechanism of SEACs. In addition, we summarize a concise method for locating dural defects preoperatively and formulate a putative explanation of this method.

Methods

The clinical data of 14 patients with SEACs underwent surgery in our hospital from January 2017 to December 2021 were retrospectively analyzed.

Results

Fourteen patients were identified during the study period. The cysts all spanned the T12/L1 segment, and dural defects were also located at the T12/L1 level (2 cases not recorded) as well as the middle or the upper-middle level of the cysts. Nine cases were treated with total cyst excision, 2 cases were treated with dural defect closure only, and 3 cases were treated with total cyst excision and dural defect closure. Histopathological examination demonstrated that the cyst wall contained both the arachnoid epithelial and compact fibrous connective tissue. The symptoms were relieved in all patients, and no recurrence was observed.

Conclusions

According to intraoperative and pathological findings, the dural outer layer cyst (DOLC) is a more reasonable hypothesis about SEACs formation. When CT myelography or cinematic MRI cannot determine the location of the dural defect preoperatively, it can be located according to the middle level of the SEACs with high accuracy.

Three-dimensional phase-contrast magnetic resonance imaging for the detention of a small communicating defect in a patient with a spinal extradural arachnoid cyst: illustrative case

BACKGROUND

Spinal extradural arachnoid cysts are thought to be pouches that communicate with the intraspinal subarachnoid space through a dural defect. The treatment for these cysts is resection of the cyst wall followed by obliteration of the communicating defect, which is often elusive.

OBSERVATIONS

The authors report the case of a 22-year-old man with an extradural arachnoid cyst with claudication and progressive motor weakness. Regular magnetic resonance imaging (MRI) and computed tomography did not reveal the location of the defect in the cyst. However, three-dimensional (3D) phase-contrast MRI clearly indicated the location of the defect and the flow of cerebrospinal fluid into the cyst. These findings allowed the authors to perform the least invasive surgery; the patient recovered motor function and could walk more smoothly.

LESSONS

3D phase-contrast MRI can reveal a subtle dural defect in patients with spinal extradural arachnoid cysts.

Idiopathic thoracolumbar spinal epidural arachnoid cysts: A case report and systematic review

Background

Idiopathic spinal epidural arachnoid cysts (SEACs) are rare and may cause myelopathy and cord compression. They typically arise from a congenital defect in the dura that communicates with the intrathecal subarachnoid space. Although the ideal treatment of SEACs is direct dural repair and cyst excision, there is as yet no clear standard of care for the management of these lesions.

Methods

A 47-year-old female presented with myelopathy attributed to an magnetic resonance imaging-documented posterior epidural T12-L2 cyst (i.e., 1.1 × 6 × 3.3 cm) lesion. The patient underwent a direct dural repair of the fistulous communication between the subarachnoid space and the cyst, along with cyst drainage/ excision through a right-sided laminotomy. Postoperatively, the patient was asymptomatic. We additionally reviewed the literature regarding the management of SEACs.

Results

Our review yielded 14 articles involving 18 patients with predominantly thoracolumbar (57%) SEACs that were either communicating (61%) or not communicating (39%) with the subarachnoid space. They averaged 35.5 years of age and exhibited a male preponderance (66%). Symptoms typically included pain (78%), followed by weakness/myelopathy (42%). Surgery frequently included bilateral laminectomies (57%) followed by unilateral laminectomies (50%) that typically resulted in symptom resolution.

Conclusion

SEACs are rare typically thoracolumbar lesions that may cause myelopathy which resolves following direct dural closure/subarachnoid fistulous occlusion.

Spinal extradural arachnoid cyst: A rare cause of thoracic myelopathy

A spinal extradural arachnoid cyst (SEAC) is a rare condition which can lead to back pain, radiculopathy, and compressive myelopathy. It accounts for approximately 1% of spinal tumours. The exact aetiology of SEACs is not well understood; however, this study is supportive of a traumatic aetiology of this disease in addition to supporting a uni-directional valve as a mechanism of CSF accumulation. The purpose of this study is to review the presentation, work-up, treatment and postoperative course of a patient with SEAC. We present the case of a 40-year-old male with a history of trauma who developed a SEAC and was treated surgically at our unit. Although a rare disease, we highlight the importance of early diagnosis and surgical treatment as it is a surgically curable disease with a good postoperative prognosis.

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SEAC is an important differential diagnosis for compressive myelopathy.

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Trauma may be an underlying cause of SEAC development.

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Uni-directional valve is the likely mechanism of CSF accumulation in a SEAC.

How to locate the dural defect in a spinal extradural meningeal cyst: a literature review

Spinal extradural meningeal cysts (SEMCs) are rare lesions of the spinal canal. Although closure of the dural defect can achieve satisfactory therapeutic effects, locating the fistula is difficult. This review summarizes the methods for locating the fistula of SEMCs and the distribution and features of fistula sites.

This was a non-systematic literature review of studies on SEMCs. We searched PubMed for English-language articles to summarize the methods of locating the defect. The search words were “epidural arachnoid cyst,” “dural cyst,” “epidural cyst,” and “epidural meningeal cyst.” For the defect location component of the study, case reports, studies with a sample size less than four, controversial ventral dural dissection(s), and undocumented fistula location reports were excluded.

Our review showed that radiography and computed tomography (CT) may show changes in the bony structure of the spine, with the largest segment of change indicating the fistula site. Occasionally, magnetic resonance imaging (MRI) can show a cerebrospinal fluid (CSF) flow void at the fistula site. The middle segment of the cyst on sagittal MRI, the largest cyst area, and cyst laterality in the axial view indicate the fistula location. Myelography can show the fistula location in the area of the enhanced cyst and subarachnoid stenosis. Digital subtraction or delayed CT can be used to observe the location of the initial cyst filling. Cine MRI and time-spatial labeling inversion pulse techniques can be used to observe CSF flow. Steady-state image construction interference sequence MRI has a high spatial resolution. Neuroendoscopy, MRI myelography, and ultrasound fistula detection can be performed intraoperatively. Moreover, the fistula was located most often in the T12–L1 segment.

Identifying the fistula location is difficult and requires a combination of multiple examinations and experience for comprehensive judgment.

Spinal arachnoid cysts: A case series & systematic review of the literature

INTRODUCTION

Spinal arachnoid cysts (SACs) are rare lesions with challenging and controversial management.

RESEARCH QUESTION

We analyzed our experiences from a case series and provide a systematic review to determine 1) Demographic and clinical features of SACs, 2) Optimal imaging for diagnosis and operative planning, 3) Optimal management of SACs, and 4) Clinical outcomes following surgery.

MATERIALS AND METHODS

A single-institution, ambispective analysis of patients with symptomatic SACs surgically managed between May 2005 and May 2019 was performed. Data were collected as per local ethics committee stipulations. A systematic review of SACs in adults was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and a preapproved protocol.

RESULTS

Our series consisted of 11 patients, M:F 8:3, mean age 47.8 years (range 18-73 years). Mean follow-up was 19 months (range 5-36 months). SACs were excised or marsupialised (7), fenestrated (3) or partially excised (1). Eight patients had expansile duroplasty, 3 primary dural closure. One patient had a cystoperitoneal shunt. All patients were AIS D preoperatively; 4 remained unchanged and 7 improved to AIS E at follow-up. Our systematic search retrieved 725 citations. Fourteen case series met the inclusion criteria. There was no evidence to support superiority of one surgical strategy over another. Surgery for symptomatic patients resulted in positive clinical outcomes.

DISCUSSION AND CONCLUSIONS

Symptomatic SACs require surgical intervention. Limited evidence suggests that decompressing the cord, breakdown of arachnoid adhesions, and establishing CSF flow by consideration of expansile duroplasty are important for positive outcomes.

Development of a Lumbar Extradural Arachnoid Cyst Associated with a Lumbar Catheter of Lumboperitoneal Shunt: A Case Report

A 78-year-old man, who had undergone lumboperitoneal shunt (LPS) placement for idiopathic normal-pressure hydrocephalus eight years prior, presented with intermittent claudication, lower back pain, and radicular pain on the inside of the right thigh. Magnetic resonance imaging (MRI) revealed an extradural arachnoid cyst (EDAC) above the lumbar catheter of the LPS. The EDAC compressed the spinal dural sac and cauda equina toward the anterior side at level L3/4, triggering his clinical manifestations. The LPS was removed and simultaneously converted into a ventriculoperitoneal shunt (VPS), which immediately improved the neurological deficits. Postoperative MRI showed shrinkage of the cyst and restoration of the compressed cauda equina. Spinal EDAC is a rare entity resulting from arachnoid membrane herniation due to a small defect in the dura mater. This is the first report showing that symptomatic EDAC can be accompanied by the lumbar catheter of the LPS and that a mere conversion from LPS to VPS or ventriculoatrial shunt might be sufficient to shrink LPS-related EDAC without invasive lumbar surgeries.

Clinical Profile and Treatment Outcome of Spinal Epidural Arachnoid Cysts: A Systematic Review of Case Studies and Reports

Background A spinal epidural arachnoid cyst (SEAC) is a rare clinical entity. We performed a systematic review of the literature to obtain information regarding demographics, clinical presentation, treatment modalities, and outcome of SEACs.

Methods A literature search was performed by using the databases PubMed/Medline, PubMed Central, Embase, Cochrane Library, Ovid MEDLINE, and Ovid Medline In-Process. A total of 170 articles were found on literature search. We found 575 cases of SEAC since 1904 for inclusion in the review including three cases which were operated by us. We studied the patient characteristics, clinical features, and management strategies, and evaluated their outcome.

Results The average age of presentation was 30 years with a male:female ratio of 1.03:1. They are commonly seen in the thoracic region (42.3%). The length of cyst was more than two vertebral levels in 85.81%. Mean symptom duration was 29 months, with most common presentation being that of compressive myelopathy. A good clinical outcome was present in symptomatic patients who had a shorter symptom duration and underwent complete surgical excision of the SEAC. Age, sex, length of lesion, and presence of dural defect did not have a bearing on the surgical outcome.

Conclusion For thoracic compressive myelopathy in a young patient, SEAC should be kept as a differential diagnosis. Surgical complete excision of the cyst with meticulous closure of the dural defect is the standard in management for a good clinical outcome.

Location Distribution of Fistulas and Surgical Strategies for Spinal Extradural Meningeal Cysts: A Retrospective Analysis of 30 Cases at a Single Center

Objective

This study aimed to illustrate the features of fistula location distribution, surgical strategies, and outcomes in spinal epidural meningeal cysts (SEMCs).

Methods

The authors searched and reviewed the medical records for cases of SEMCs. Imaging features, operative reports, and media were reviewed to accurately describe the surgical techniques employed. We recorded the level and laterality of the fistula according to the operative report and the media. Consistency analysis was performed on the dominant laterality of the cyst on preoperative axial magnetic resonance imaging and laterality of the fistula in the operative media or report. When cyst and fistula lateralities were the same, they were considered consistent. Finally, the Japanese Orthopedic Association (JOA) score was used to obtain patient-reported results at each follow-up.

Results

Thirty patients with SEMCs were identified. Fistula repair was performed in all patients. Two patients experienced cyst recurrence after surgery and were repaired during the second surgery. Based on imaging findings, SEMCs mostly occurred in the thoracolumbar junction. Most of the fistulas (87.88%) were at the T12 or L1 levels. In patients with multiple adjacent SEMCs, the fistula may be at one end of the cyst rather than in the middle level of the cyst. A fistula laterality of 72.72% was consistent with cyst laterality. The JOA improvement rate was 61.84%±26.63%.

Conclusion

Most fistulas were always located at the T12–L1 level as well as the middle level of the cyst, which is always consistent with cyst laterality. In patients with multiple adjacent SEMCs, the fistula may be at one end of the cyst. Cleft closure is key to healing SEMCs.

Early microsurgery on thoracolumbar spinal extradural arachnoid cysts: Analysis of a series of 41 patients

BACKGROUND

We designed this study to share our management experiences on spinal extradural arachnoid cysts (SEACs) to add more to the body of evidence for their treatment.

METHODS

We retrospectively reviewed 41 patients who underwent microsurgery for thoracolumbar SEACs at our hospital from June 2009 to June 2019. All clinical data, including medical history, clinical features, imaging manifestation, operative findings, and prognosis, were extracted from medical records and databases. Perioperative differences of the Visual Analogue Scale (VAS), the Oswestry disability index (ODI) score, and postoperative Odom's criteria were used to assess the surgical outcome.

RESULTS

The most common and very first clinical symptom in the 41 patients was pain (VAS = 2.82 ± 0.89), and the mean ODI value was 61.7 ± 8.9%. Imaging revealed that the cystic lesions in the thoracolumbar spine involved an average of 2.85 segments. Of the 41 patients, 39 underwent total cyst excisions, and 36 had their dural defect repaired by one of three methods. The mean postoperative follow-up time was 52.3 months. Postoperatively, one case developed kyphoscoliosis and two cases experienced a recurrence. The majority of patients showed excellent outcomes according to Odom's criteria, the postoperative VAS (0.80 ± 1.08), and the ODI (15.4 ± 9.3%).

CONCLUSIONS

Themost commonclinicalsymptoms of thoracolumbar SEACs included progressive discomfort and pain around the involved spinal segments. Early surgical intervention relieved the patients from their symptoms. Microsurgery was recommended to resect the complete cyst and to repair the dural defect, but resection of the complete cyst is more necessary than just repairment of the dural defect for providing promising outcomes.

A Single Vertebral Surgical Approach for Spinal Extradural Meningeal Cysts Spanning Multiple Vertebral Segments by Auxiliary Neuroendoscope

BACKGROUND

Spinal extradural meningeal cysts (SEMCs) are rare lesions, especially those spanning multiple vertebral segments, and the surgical strategy has remained controversial. In the present study, we have described the outcomes of 4 patients with SEMCs treated with dural defect repair alone assisted by neuroendoscopy.

METHODS

From January 2018 to January 2020, 4 patients with SEMCs spanning multiple vertebral segments had undergone single-vertebral laminectomy or hemilaminectomy.

RESULTS

The SEMCs in all 4 patients had spanned multiple vertebral segments, from T11 to L2. Using magnetic resonance imaging, the location of the dural defect was predicted correctly for 3 patients. Single-vertebral laminectomy was used in 2 patients and single-vertebral hemilaminectomy in 2 patients. Intraoperatively, the entire cyst, including the upper pole, lower pole, and middle segment of the cyst, was explored using neuroendoscopy. In each patient, only 1 dural defect was found, which had been located in the middle segment of the cyst (T12-L1). All cyst dural defects had been sutured under a microscope. In all cases, the cyst wall was not removed. Postoperatively, the symptoms for all the patients had improved significantly, and subsequent magnetic resonance imaging studies showed obvious cyst regression. During the follow-up period of 15-44 months, no recurrence was observed.

CONCLUSIONS

For SEMCs spanning multiple vertebral segments, dural defect repair without cyst wall resection through single-vertebral hemilaminectomy or laminectomy can be effective. Intraoperative neuroendoscopy can assist, not only in finding the dural defect, but also in avoiding the omission of multiple dural defects as much as possible.

Microsurgical treatment of symptomatic spinal extradural arachnoid cyst: a consecutive case series of 34 patients and literature review

PURPOSE

A spinal extradural arachnoid cyst (SEAC) is a rare condition with unclear etiology. Herein, we report a series of symptomatic SEACs to illustrate features of SEACs in adults, surgical management, and outcomes.

METHODS

A total of 34 consecutive patients who underwent microsurgical treatment were retrospectively reviewed. Patient characteristics were recorded in each case, including presenting symptoms, imaging findings, neurologic status, a surgical procedure performed and follow-up.

RESULTS

There were 19 (56%) male and 15 (44%) female patients, with the ages ranging from 16 to 71 years (average 45 years). The lesions were located in the cervical segment (n = 4, 12%), thoracic segment (n = 6, 18%), thoracolumbar segment (n = 10, 29%) and lumbar segment (n = 14, 41%). Clinical presentations included back pain (n = 18, 53%), sensory deficits (n = 14, 41%), weakness (n = 4, 12%) and gait ataxia (n = 4, 12%), with a mean duration of symptoms of 17 months. The lesion was hypointense with the spinal cord on T1-weighted images and hyperintense on T2-weighted images and showed no homogeneous enhancement after contrast medium injection. Communication between the cyst and subarachnoid space was found in 23 patients and the cyst was resected after fistula ligation. Postoperatively, patients were followed up for an average of 80 months. The patients' symptoms dramatically improved and follow-up radiological images showed a complete disappearance of the cyst in all patients. No recurrence was observed in the dural repair group.

CONCLUSION

Patients with symptomatic SEAC present with obvious and persistent symptoms. Complete microsurgical cyst removal with the closure of the dural defect is the standard treatment procedure with good results and a low recurrence rate.

Endoscopic treatment of spinal arachnoid cysts

Background/objective

Spinal arachnoid cysts (SAC) are intradural lesions, which may provoke a compression of the spinal cord and roots. Endoscopic techniques are increasingly used to minimize the surgical access and the postoperative scar tissue. Shunts may also represent an option. The aim of this paper is to illustrate the technique of endoscopic-assisted fenestration and positioning of a cysto-peritoneal diversion in a thoracic SAC using a flexible endoscope and to perform a systematic literature review on this subject.

Material and methods

We reported our case and we performed a review of the literature, searching for all the adult cases of Type III SACs in English language treated through endoscopic procedures.

Results

We found 5 articles matching our search criteria and we included 9 adult patients in our analysis. Six patients were females and the most common localization was the thoracic spine. Six patients underwent selective laminectomies followed by endoscopic fenestration without cyst wall resection. Three patients had a percutaneous endoscopic inspection of the cyst and in two cases a cysto-subarachnoid shunt space was performed. Improvement of pre-operative neurological deficit was reported in six patients, no patients experienced clinical deterioration. The mean follow-up was 22 months and no progression or recurrence was reported.

Conclusion

The implementation of endoscopy allows a minimally invasive treatments with good visualization of cyst anatomy and precise shunt positioning under real-time guidance. Endoscopy is technically demanding but it can offer similar clinical outcomes when compared to microscopic procedures with a limited rate of post-operative complications.

The long-term risk of recurrence should be established by prospective studies.

Surgical Treatment of Ten Adults with Spinal Extradural Meningeal Cysts in the Thoracolumbar Spine

Objective

To retrospectively analyze the clinical characteristics and surgical experience of 10 adults with spinal extradural meningeal cysts (SEMCs) in the thoracolumbar spine which may further provide evidence for surgical decision-making.

Methods

Ten adults with SEMCs in the thoracolumbar spine were surgically treated and enrolled in this study. Clinical manifestations, imaging data, intraoperative findings and postoperative outcome were recorded.

Results

Clinical manifestations of SEMCs included motor and sensory dysfunction of the lower limbs and urination and defecation disturbance. The cysts presented as intraspinal occupying lesions dorsal to the spine, ranging from the T8 to L3 level. Defects of eight cases were found on preoperative magnetic resonance imaging (MRI). Selective hemilaminectomy or laminectomy were used to reveal the defect within the cyst, which was further sutured with microscopic technique. The final outcome was excellent or good in seven cases and fair in three cases. No recurrence was observed during follow-up.

Conclusion

SEMCs are rare intraspinal cystic lesions. Radiography and MRI are clinically practical methods to assess defects within SEMCs. Selective hemilaminectomy or laminectomy may reduce surgical trauma. Detection and microscopic suturing of the defects are the key steps to adequately decompress the nervous tissue and prevent postoperative recurrence.

Spinal extradural arachnoid cyst: Rare cases from Indian Institutes

Background:

Spinal extradural arachnoid cyst (SEDAC), accounting for approximately 1% of all spinal lesions, rarely causes compressive myelopathy. It is usually found at lower thoracic or upper lumbar levels in males in their forties to sixties. The standard surgical procedures include direct dural repair.

Case Description:

A 37-year-old male presented with myelopathy attributed to a type I meningeal cyst (SEDAC) that was successfully managed with a laminectomy, cyst excision, and direct dural sleeve repair. Similar cases reported in the literature were also reviewed.

Conclusion:

SEDACs, although rare, must be considered among the differential diagnoses for compressive myelopathy/neurogenic bladder.

Nonfusion Muscle-Sparing Technique to Treat Long-Segment Thoracolumbar Extradural Arachnoid Cyst in a Child: A Case Report and Review of the Literature

BACKGROUND

Spinal extradural arachnoid cyst is an uncommon cause of spinal cord compression. It results from a small dural defect that leads to cerebrospinal fluid (CSF) accumulation in the cyst and subarachnoid space, and the cyst can compress the spinal cord and nerve roots. Surgery is the treatment of choice in symptomatic patients, and most cases have an immediately satisfying outcome after surgery.

CASE DESCRIPTION

A 10-year-old Thai boy presented with progressive weakness in both legs. Magnetic resonance imaging (MRI) demonstrated a giant cystic lesion 23 cm in length from T1-L2 level. To our knowledge, this is the longest arachnoid cyst that has been reported in children. The operation included unilateral paraspinal muscle dissection with spinous process translation techniques, T1-L4 laminectomy, total cyst excision, and dural defect repair at the T4 level. The symptoms were fully resolved within 2 months after surgery. However, thoracic kyphosis was slightly increased, but the patient still has a normal sagittal profile.

CONCLUSIONS

Spinal arachnoid cyst is rare, especially in children. Early diagnosis and treatment are essential for improving the chance of full recovery, and for avoiding complication and irreparable defect. Total cyst removal with dural repair remains the best treatment alternative; however, potential complications, especially spinal malalignment after extensive laminectomy, must be considered. Postoperative MRI showed normal CSF flow and no spinal cord compression. The muscle-sparing technique with multiple-level laminectomy without spinal fusion that we used in this case provided a satisfying outcome.

Occurrence of spinal extradural arachnoid cysts in a child with concomitant intracranial midline abnormalities: case report

Spinal extradural arachnoid cysts (SEACs) are uncommon spinal lesions that may cause myelopathy, most frequently in the 2nd decade of life. There are multiple theories of their pathogenesis, and associated entities include spinal trauma, spina bifida, and the lymphedema-distichiasis syndrome. The authors report the case of an otherwise healthy, developmentally normal 13-year-old boy who presented with multiple SEACs. Upon further neuroimaging workup, he was found to have an asymptomatic retrocerebellar arachnoid cyst, cavum septi pellucidi, and cavum vergae. Three contiguous but separate spinal cysts were identified intraoperatively, and they were completely excised with closure of the dural defects. The patient recovered motor and sensory function of the lower extremities. This collection of uncommon neuroimaging findings provides important clues to the pathogenesis of the disease and guides the optimal management of patients with SEACs. The unusual presentation of SEACs, together with uncommon midline abnormalities, provides further evidence of their congenital, midline origin. Therefore, it is reasonable to pursue imaging of the brain in atypical cases of SEACs.

Transdural Approach to Resection of Intraspinal Extradural Ventral Cysts in the Lumbar Spine

BACKGROUND

Intraspinal extradural ventral cysts in the lumbar spine can cause back pain and neurological deficits of the lower extremities. For the resection of this type of space-occupying lesion, the transdural approach has not been reported in the literature.

CASE DESCRIPTION

A 66-year-old man presented, suffering from progressive radiation pain of his bilateral lower extremities. Imaging examination revealed a cystic lesion in ventral side of lumbar spinal canal. We conducted the excision of the cyst with the transdural approach. The symptoms of the patient disappeared immediately after the operation and recurrence of the symptoms has not been observed in the 3-month follow-up.

CONCLUSIONS

This operation approach is safe and effective. Compared with the previous surgical approach reported in the literature, by this approach surgeons could achieve less injury, shorter operation time, and the same surgical outcomes in the short term. Therefore, we would like to present this approach to provide an alternative to deal with similar lesions.

Spinal intradural extramedullary arachnoid cysts in adults-operative therapy and clinical outcome

BACKGROUND

Spinal arachnoid cysts (SAC) are rare mostly idiopathic intradural lesions with compression of the spinal cord and clinical signs of radiculo- and/or myelopathy. We retrospectively analyzed radiological and clinical characteristics of patients with surgical treatment of SAC including a subgroup evaluation of long-term outcome and QoL.

METHOD

Patients with SAC treated between 1993 and 2017 were evaluated. Craniocaudal (c.c.) and anteroposterior (a.p) cyst diameters were measured pre- and post-OP. McCormick and Odom score for myelopathy, general outcome and QoL (SF-36, EORTC-QLQ30) were recorded.

RESULTS

A total of 72 patients (female:male = 1.9:1) were analyzed with mean FU of 44.8 ± 60 months (long-term data from 25 patients with FU 78.2 ± 63.9 months). All had surgery due to solitary cysts: 10 cervical (13.9%), 45 thoracic (62.5%), and 17 lumbosacral (23.6%), the majority (79.2%) located dorsally. Main symptoms were gait disturbance (80%), dysesthesia (64%) and paresis (80%). Patients had (hemi-)laminectomy with cyst fenestration in 48 (66.7%) and complete resection in 18 cases (25.0%). Four cases (5.5%) were treated by cystoperitoneal shunt, 2 by marsupialization (2.8%). In total, 11 revisions were necessary in 9/72 (12.5%) patients (one patient underwent 3 revisions). Two patients were reoperated for wound revision/epidural hematoma (each n = 1). Seven patients needed additional cyst wall resection after 1.5-31.0 months due to insufficient cyst shrinking and persistent clinical symptoms after first surgery; most of the cysts were multiple septated and of post-hemorrhagic origin. The mean c.c. size decreased from 5.2 ± 3.7 cm pre-OP to 2.7 ± 3.9 cm (p < 0.05); the a.p. diameter decreased from 1.0 ± 0.5 cm to 0.3 ± 0.3 cm (p < 0.0001) without significant differences between fenestration and resection. McCormick and Odom scores revealed improved symptoms, particularly of gait disturbance, sensory deficits, and general performance. Long-term FU displayed satisfying QoL performance without differences of fenestration or resection.

CONCLUSION

SAC mostly affect women and are predominantly located in the thoracic spine, becoming apparent with clinical myelopathy. For cysts without intracystic septae and compartments, both fenestration and resection of the cyst wall provided significant reduction of cyst size and clinical improvement.

True Dural Spinal Epidural Cysts: Report of 5 Cases

BACKGROUND

Spinal arachnoid cysts are a rare cause of compressive myelopathy. Spinal extradural arachnoid cysts (SEACs) are even rarer.

METHODS

We retrospectively reviewed the SEACs operated on in our hospital between 2015 and 2019, according to their clinical and radiologic findings, treatments performed, and outcomes.

RESULTS

We identified 5 cases (2 males and 3 females), ranging in age from 21 months to 78 years. Except for the pediatric case, all patients presented with pain and 3 had some grade of neurologic impairment. Preoperative magnetic resonance imaging showed multiloculated cyst in 4 cases, and the communication with the dura was properly identified in only 1 case. The patients were operated through a laminectomy or laminoplasty and total removal of the cyst, and the communication with the dura was identified and repaired in all cases. In all cases, the defect was near the exit of a nerve root, and rootlets were seen through it, producing a ball-like valve mechanism. Histology of the cyst wall showed true dura in every case. One patient needed a reoperation for evacuation of a fluid collection (related to the dural sealant). Following Odom's criteria, 3 patients had an excellent outcome and 2 had a fair outcome.

CONCLUSIONS

Total excision of a symptomatic SEAC through either laminectomy or laminoplasty is a safe and effective treatment option. Although isolated repair of the dural communication without cyst removal may seem appealing, we have found it very difficult to identify the point of communication preoperatively.

Huge multiple spinal extradural meningeal cysts in infancy

BACKGROUND

Multiple spinal extradural meningeal cysts (SEMCs) are rare lesions. SEMCs communicate with the subarachnoid space through multiple dural defects and expand into the extradural space with progressive spinal cord compression.

CASE PRESENTATION

We report a 5-month-old boy with hydronephrosis involving nine huge SEMCs that were distributed from the T1-L5 levels. Eight SEMCs, except for one small noncommunicating cyst, were exposed through laminoplastic laminotomy at the T10-L5 and T3-5 levels. Five transdural communications with dural defects were packed with a piece of autologous muscle and fibrin glue. Tenting sutures to lift up the dura to the vertebral arch were added to minimize the extradural dead space. Postoperatively, cord compression was relieved and hydronephrosis improved.

CONCLUSION

In conclusion, packing of all dural defects and dural tenting sutures at a one-staged operation is useful in the surgical management of huge and multiple SEMCs in infancy.

Severe Kyphoscoliosis Associated with Multiple Giant Intraspinal Epidural Cysts: A Case Report and Literature Review

BACKGROUND

Severe kyphoscoliosis associated with multiple giant spinal epidural arachnoid cysts (SEACs) is an extremely rare condition and remains a challenge in clinical practice. This study aimed to present a case of severe spinal deformity associated with multiple giant SEACs and to discuss strategies for the preoperative diagnosis and treatment.

CASE DESCRIPTION

A 22-year-old man with severe thoracolumbar kyphoscoliosis associated with multiple giant SEACs presented with progressive scoliosis, spastic paralysis, numbness, and abnormal gait. X-ray and magnetic resonance imaging revealed severe rigid kyphoscoliosis, extensive diffuse cystic space-occupying lesions, and diffuse spinal cord compression. After multidisciplinary consultation and discussion, the patient underwent a cyst-peritoneal shunting surgery followed by posterior vertebral column resection (PVCR) correction. The postoperative course was uneventful. Both kyphosis and scoliosis were significantly corrected, and muscle weakness of the lower extremities and sensory disturbance partially improved. At the 2-year follow-up visit, the patient could freely walk without the aid of crutches, but there were some residual neurologic deficits in both legs. A plain radiograph showed that bony fusion was achieved, and the correction was well maintained.

CONCLUSIONS

Cyst-peritoneal shunting surgery followed by PVCR, as in our case, could be an alternative surgical strategy for multiple giant SEACs associated with severe rigid kyphoscoliosis.

Symptomatic extradural spinal arachnoid cyst: More than a simple herniated sac

Introduction and Study Design:

Spinal arachnoid cyst is an uncommon entity, presenting with radiculopathy or paraparesis. These cysts are usually found in intradural extramedullary region; and the extradural region is a rare location. The exact pathogenesis in the existence of these cysts in the extradural region is still debated. In this article, we have retrospectively analyzed the clinical profile of the rare extradural arachnoid cyst (EDAC).

Methodology:

In this study, 19 patients of EDAC operated at our institute between January 2006 to June 2016 are analyzed. All patients with the Oswestry disability index score of >20 were managed surgically (open laminectomy and cyst excision). The clinical outcome was assessed at using 5-point satisfaction scale and McCormick grading.

Results:

All 13 operated patients had EDACs with communication with the intradural compartment. In 11 (84.6%) patients, cyst wall was excised completely, in 2 (15.3%) patients underwent partial excision of cyst wall; dural communication was closed in all patients (n = 13). None of the patients had clinical deterioration or radiological recurrence till the last follow-up. Mean follow-up was 52.2 months (range 1–160); all patients were satisfied after surgery (median score was 3).

Discussion:

Symptomatic EDACs account <2% of all spinal tumors. The EDACs have communication with the intradural compartment. In our article, we have discussed the approach and management of EDAC, including minimally invasive percutaneous procedures.

Conclusion:

One should aim for preoperative or intraoperative localization of dural communication and try to disconnect the extradural cyst from the intradural connection to prevent recurrence. Surgical treatment is complete excision of the cyst.

Spinal arachnoid cysts in adults: diagnosis and management. A single-center experience

OBJECTIVEAdult spinal arachnoid cysts (SACs) are rare entities of indistinct etiology that present with pain or myelopathy. Diagnosis is made on imaging studies with varying degrees of specificity. In symptomatic cases, the standard treatment involves surgical exploration and relief of neural tissue compression. The aim of this study was to illustrate features of SACs in adults, surgical management, and outcomes.METHODSThe authors searched medical records for all SACs in adults in the 10-year period ending in December 2016. Radiology and pathology reports were reviewed to exclude other spine cystic disorders. Recurrent or previously treated patients were excluded. Demographic variables (age, sex) and clinical presentation (symptoms, duration, history of infection or trauma, and examination findings) were extracted. Radiological features were collected from radiology reports and direct interpretation of imaging studies. Operative reports and media were reviewed to accurately describe the surgical technique. Finally, patient-reported outcomes were collected at every clinic visit using the SF-36.RESULTSThe authors' search identified 22 patients with SACs (mean age at presentation 53.5 years). Seventeen patients were women, representing an almost 3:1 sex distribution. Symptoms comprised back pain (n = 16, 73%), weakness (n = 10, 45%), gait ataxia (n = 11, 50%), and sphincter dysfunction (n = 4, 18%). The mean duration of symptoms was 15 months. Seven patients (32%) exhibited signs of myelopathy. All patients underwent preoperative MRI; in addition, 6 underwent CT myelography. SACs were located in the thoracic spine (n = 17, 77%), and less commonly in the lumbar spine (n = 3, 14%) and cervical/cervicothoracolumbar region (n = 2, 9%). Based on imaging findings, the cysts were interpreted as intradural SACs (n = 11, 50%), extradural SACs (n = 6, 27%), or ventral spinal cord herniation (n = 2, 9%); findings in 3 patients (14%) were inconclusive. Nineteen patients underwent surgical treatment consisting of laminoplasty in addition to cyst resection (n = 13, 68%), ligation of the connecting pedicle (n = 4, 21%), or fenestration/marsupialization (n = 2, 11%). Postoperatively, patients were followed up for an average of 8.2 months (range 2-30 months). Postoperative MRI showed complete resolution of the SAC in 14 of 16 patients. Patient-reported outcomes showed improvement in SF-36 parameters. One patient suffered a delayed wound infection.CONCLUSIONSIn symptomatic patients with imaging findings suggestive of spinal arachnoid cyst, surgical exploration and complete resection is the treatment of choice. Treatment is usually well tolerated, carries low risks, and provides the best chances for optimal recovery.

Clinical and radiological features of spinal extradural arachnoid cysts: Valve-like mechanism involving the nerve root fiber as a possible cause of cyst expansion

BACKGROUND

Although a valve-like mechanism has been proposed for expansion of spinal extradural arachnoid cysts (SEACs), the detailed mechanism remains unclear. Moreover, closure of the communication site is essential during surgery, but the method to identify the communication site remains unclear. The aim of this study was to determine the detailed mechanism of expanding SEACs through retrospective analysis of SEAC cases undergoing surgery and to elucidate the characteristics of the communication sites.

METHODS

The authors retrospectively evaluated 12 patients with SEACs who underwent surgery between 2000 and 2014 and analyzed their perioperative findings.

RESULTS

Dural defects were detected in 11 out of 12 patients, and a valve-like mechanism was observed in 7 patients, wherein a nerve root fiber moved back and forth through the dural defect along with the flow of cerebrospinal fluid (CSF) between the intradural space and the extradural arachnoid cysts. The dural defect was located at the thoracolumbar junction in 7 patients, below the distal end of the bridging ossification in 2, at the level of vertebral wedge deformity in 2, and at the level of disc herniation in 1.

CONCLUSIONS

A valve-like mechanism was observed in 7 of the 12 patients, which suggests that it could serve as a mechanism of SEAC formation. The communication sites were variously located at the end of ossification in patients with diffuse idiopathic skeletal hyperostosis (DISH), wedge deformity of the vertebral body, or disc herniation, indicating the contribution of mechanical stress to SEAC formation.

Development of Neuromyelitis Optica Spectrum Disorder and Spinal Arachnoid Cysts in a Patient With Intractable Epilepsy

Neuromyelitis optica is an inflammatory, demyelinating disease of the central nervous system that is characterized by severe relapsing attacks of optic neuritis and transverse myelitis. The current case describes a 29-year-old man with intractable epilepsy and diplegic spastic cerebral palsy who was given the diagnosis of neuromyelitis optica spectrum disorder after presenting with weakness, incontinence, and decreased visual acuity. His symptoms recurred 21 months after initial presentation. Magnetic resonance imaging of his spine revealed arachnoid cysts with regional mass effects. Differentiation of arachnoid cysts from a demyelinating process may be difficult in the early stages of the disease. Close monitoring of patients with neuromyelitis optica spectrum disorder is important, especially in patients with recurrent or refractory symptoms.

A New Classification for Pathologies of Spinal Meninges, Part 1: Dural Cysts, Dissections, and Ectasias

BACKGROUND: The clinical significance of pathologies of the spinal dura is often unclear and their management controversial.

OBJECTIVE: To classify spinal dural pathologies analogous to vascular aneurysms, present their symptoms and surgical results.

METHODS: Among 1519 patients with spinal space-occupying lesions, 66 patients demonstrated dural pathologies. Neuroradiological and surgical features were reviewed and clinical data analyzed.

RESULTS: Saccular dural diverticula (type I, n = 28) caused by defects of both dural layers, dissections between dural layers (type II, n = 29) due to defects of the inner layer, and dural ectasias (type III, n = 9) related to structural changes of the dura were distinguished. For all types, symptoms consisted of local pain followed by signs of radiculopathy or myelopathy, while one patient with dural ectasia presented a low-pressure syndrome and 10 patients with dural dissections additional spinal cord herniation. Type I and type II pathologies required occlusion of their dural defects via extradural (type I) or intradural (type II) approaches. For type III pathologies of the dural sac no surgery was recommended. Favorable results were obtained in all 14 patients with type I and 13 of 15 patients with type II pathologies undergoing surgery.

CONCLUSION: The majority of dural pathologies involving root sleeves remain asymptomatic, while those of the dural sac commonly lead to pain and neurological symptoms. Type I and type II pathologies were treated with good long-term results occluding their dural defects, while ectasias of the dural sac (type III) were managed conservatively.

Spinal Extradural Arachnoid Cyst

A spinal extradural arachnoid cyst (SEAC) results from a rare small defect of the dura matter that leads to cerebrospinal fluid accumulation and communication defects between the cyst and the subarachnoid space. There is consensus for the treatment of the dural defect, but not for the treatment of the cyst. Some advocate a total resection of the cysts and repair of the communication site to prevent the recurrence of a SEAC, while others recommended more conservative therapy. Here we report the outcomes of selective laminectomy and closure of the dural defect for a 72-year-old and a 33-year-old woman. Magnetic resonance imaging of these patients showed an extradural cyst from T12 to L4 and an arachnoid cyst at the posterior epidural space of T12 to L2. For both patients, we surgically fenestrated the cyst and repaired the dural defect using a partial hemi-laminectomy. The patient's symptoms dramatically subsided, and follow-up radiological images show a complete disappearance of the cyst in both patients. Our results suggest that fenestration of the cyst can be a safe and effective approach in treating SEACs compared to a classical complete resection of the cyst wall with multilevel laminectomy.

Digital Subtraction Cystography for Detection of Communicating Holes of Spinal Extradural Arachnoid Cysts

Objective

The purpose of this study was to demonstrate the usefulness of digital subtraction cystography to identify communicating holes between a spinal extradural arachnoid cyst (SEAC) and the subarachnoid space prior to cyst removal and hole closure.

Materials and Methods

Six patients with SEAC were enrolled in this retrospective study. Digital subtraction cystography and subsequent CT myelography were performed for every patient. The presence and location of the communicating holes on cystography were documented. We evaluated the MRI characteristics of the cysts, including location, size, and associated spinal cord compression; furthermore, we reviewed cystographic images, CT myelograms, procedural reports, and medical records for analysis. If surgery was performed after cystography, intraoperative findings were compared with preoperative cystography.

Results

The location of the communicating hole between the arachnoid cyst and the subarachnoid space was identified by digital subtraction cystography in all cases (n = 6). Surgical resection of SEAC was performed in 4 patients, and intraoperative location of the communicating hole exactly corresponded to the preoperative identification.

Conclusion

Fluoroscopic-guided cystography for SEAC accurately demonstrates the presence and location of dural defects. Preoperative digital subtraction cystography is useful for detection of a communicating hole between a cyst and the subarachnoid space.

Time-Spatial Labeling Inversion Pulse Magnetic Resonance Imaging of Cystic Lesions of the Spinal Cord

BACKGROUND

Cystic lesions of the spinal cord such as spinal intradural arachnoid cysts (SIACs) and spinal extradural arachnoid cysts (SEACs) contain cerebrospinal fluid (CSF). The pathology of these lesions is often difficult to understand because it is difficult to detect abnormal CSF flow by conventional magnetic resonance imaging (MRI) or myelography. We preliminarily evaluated the usefulness of time-spatial labeling inversion pulse magnetic resonance imaging (T-SLIP MRI) of cystic lesions of the spinal cord.

METHODS

T-SLIP MRI was applied to the following 6 consecutive cystic lesions of the spinal cord: 3 SEACs, 1 SIAC, 1 spinal intramedullary cyst associated with adhesive arachnoiditis, and 1 chronic pseudomeningocele. Information obtained by T-SLIP MRI was evaluated with regard to the following: 1) whether exclusive pathologic information was obtained, 2) whether this information affected the therapeutic strategy, and 3) the time required for T-SLIP MRI.

RESULTS

Exclusive information was obtained in all 6 cases. In SEACs and the intramedullary cyst, pathologic CSF flow into the cyst was directly visualized, enabling us to narrow the therapeutic intervention targets. In SIAC, exclusive information involved detection of the cystic cranial wall and the absence of the caudal wall, enabling us to omit the exploration of the caudal wall. The examination required as long as 80 minutes for SIAC and <30 minutes for the other cases.

CONCLUSIONS

T-SLIP MRI is useful for obtaining pathologic information about cystic lesions of the spinal cord.

Clinical characteristics and treatment strategies for idiopathic spinal extradural arachnoid cysts: a single-center experience

BACKGROUND

Idiopathic spinal epidural arachnoid cysts (SEACs) are relatively rare lesions with diverse clinical manifestations depending on the affected spinal region and nerve roots. To assess the relationship between clinical presentation and surgical outcome, we conducted a retrospective review of medical records and neuroimages from idiopathic SEAC patients.

METHODS

Of 15 consecutive patients with idiopathic SEACs, 14 underwent surgical treatment at the Beijing Tiantan Hospital between January 2008 and July 2013. Case histories, clinical presentations, imaging findings, operative findings, and surgical outcomes were reviewed.

RESULTS

Of the 15 patients, 5 were children (median age, 13 years) and 10 were adults (median age, 35 years). The male-to-female ratio was 4:1. The median disease duration was 1 year in children and 4 years in adults. The most common manifestations were progressive paraparesis (73.3 %) and radiculopathy (66.7 %). All pediatric lesions affected thoracic segments, while 80 % of adult lesions affected lumbar segments. Fourteen patients underwent microsurgical treatment, with cyst excision in nine (combined with fistula closure in four) and partial cyst excision in five (with fistula closure in three). No recurrences were observed during follow-up (average of 23 months). Excellent outcome was achieved in six cases, good outcome in four, fair in two, and poor in two.

CONCLUSIONS

Idiopathic SEAC mainly affect the thoracic segments in children and the lumbar segments in adults, and often results in progressive paraparesis and radiculopathy. Early surgical intervention is suggested for progressive symptomatic patients to restore neurological function.

Adult-onset spastic paraparesis: an approach to diagnostic work-up

Adult-onset, chronic progressive spastic paraparesis may be due to a large number of causes and poses a diagnostic challenge. There are no recent evidence-based guidelines or comprehensive reviews to help guide diagnostic work-up. We survey the literature on chronic progressive spastic paraparesis, with special emphasis on myelopathies, and propose a practical, MRI-based approach to facilitate the diagnostic process. Building on neuro-anatomic and radiographic conventions, we classify spinal MRI findings into six patterns: extradural; intradural/extramedullary; Intramedullary; Intramedullary-Tract specific; Spinal Cord Atrophy; and Normal Appearing Spinal Cord. A comprehensive differential diagnosis of chronic progressive myelopathy for each of the six patterns is generated. We highlight some of the more common and/or treatable causes of progressive spastic paraparesis and provide clinical pointers that may assist clinicians in arriving at the diagnosis. We outline a practical, comprehensive MRI-based algorithm to diagnosing adult-onset chronic progressive myelopathy.

Detection of the communicating hole(s) of spinal extradural arachnoid cysts using time-spatial labeling inversion pulse magnetic resonance imaging

STUDY DESIGN

Report of 2 cases.

OBJECTIVE

To report the usefulness of time-spatial labeling inversion pulse magnetic resonance imaging (T-SLIP MRI) for detection of the communicating hole(s) of spinal extradural arachnoid cysts (SEACs).

SUMMARY OF BACKGROUND DATA

SEACs normally communicate with the subarachnoid space via small communicating hole(s) in the dura. It is necessary to identify the accurate locations of these communicating hole(s) before attempting to close them through limited laminotomy/laminectomy. Myelocomputed tomography or conventional MRI may fail to detect the locations of the hole(s) because they comprise small dural defects.

METHODS

Case 1: A 33-year-old female presented with an SEAC at the T11–L2 vertebral level. Case 2: An 82-year-old female presented with an SEAC at T12–L4 vertebral level.

RESULTS

Case 1: T-SLIP MR image of the left parasagittal plane (not the midsagittal or right parasagittal plane) revealed cerebrospinal fluid flow from the subarachnoid space into the cyst at L1. After limited laminotomy at T12–L1 and partial cyst resection, we identified 2 contiguous dural holes immediately medial to the left L1 pedicle; this corroborated the preoperative T-SLIP MRI findings. The holes were sutured. Postoperative conventional MR image confirmed significant cyst shrinkage. Case 2: T-SLIP MR image revealed a curved line at the L1 pedicle in the right parasagittal plane. After L1 laminectomy and partial cyst resection, a dural hole was identified L1 pedicle, which was in agreement with the preoperative T-SLIP MRI findings. After surgery, the lower extremity pain disappeared. Postoperative conventional MR image revealed significant cyst shrinkage.

CONCLUSION

T-SLIP MRI is useful for detection of the communicating hole(s) of SEACs.

LEVEL OF EVIDENCE

N/A.