Spinal Extradural Arachnoid Cyst

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.

Preoperative examination and intraoperative cerebrospinal fluid leakage test for minimally invasive surgery of spinal extradural arachnoid cysts: illustrative case

BACKGROUND

Spinal extradural arachnoid cysts (SEACs) are rare and can cause spinal dysfunction. Total cyst removal and duraplasty via multiple laminectomies are commonly performed. However, to avoid postoperative spinal deformity and axial pain, a minimally invasive surgery via selective laminectomy may be optimal. Therefore, preoperative detection of the dural fistula site is required.

OBSERVATIONS

A 25-year-old male presented with a 2-month history of progressive gait disturbance and back pain. Conventional magnetic resonance imaging (MRI) revealed SEACs at the T9 to L2 level but did not reveal the dural fistula. Further examinations were performed using sagittal time-spatial labeling inversion pulse MRI and cone-beam computed tomography myelography with a spinal intrathecal catheter, which indicated a dural fistula on the left side at the T12 level. On the basis of these results, dural repair was performed via selective laminectomy. Furthermore, an intraoperative cerebrospinal fluid leakage test by intrathecally injecting saline via a spinal catheter confirmed complete closure of the dural fistula, with no other fistulas.

LESSONS

These comprehensive pre and intraoperative examinations may be useful for minimally invasive and selective surgeries in patients with SEACs.

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 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.

Clinical and imaging features of spinal extradural arachnoid cysts: a retrospective study of 50 cases

PURPOSE

Spinal extradural arachnoid cysts (SEDACs) are thought to arise from leakage of CSF through a spinal dural defect. This study investigates the demographics and imaging spectrum of SEDACs at our academic institution and compares them with those reported in the literature.

METHODS

Fifty cases with documented MRI diagnosis of SEDAC, Nabors criteria type I meningeal cyst (MC), were identified from retrospective review of imaging records between 1999 and 2020. Patient demographics, presenting symptoms, cyst characteristics, and management outcomes were studied. Statistical analysis was performed to determine associations between maximum cyst size and presenting symptoms along with other imaging findings.

RESULTS

In all 50 subjects, SEDACs were solitary (single) and sporadic (non-familial). The majority were incidental (62%), located posteriorly (92%) and laterally (80%) in the thoracic and thoracolumbar regions (34%, 30%). They were associated with mild mass effect upon the thecal sac (50%) and bone remodeling (92%). Among symptomatic SEDACs, back pain and radiculopathy were the most reported (68%). Larger cysts were located caudally in the spinal canal, and were associated with greater thecal mass effect, bone remodeling, and septations. Four out of six subjects who underwent surgical management had complete or partial remission. One had cyst recurrence.

CONCLUSION

In this largest series of SEDACs, most were discovered incidentally, stable over time, and located in the thoracic spine dorsal to the thecal sac. When symptomatic, back pain and radiculopathy were the most common presenting symptoms. Treatment with complete surgical excision may yield the best results for symptomatic lesions.

Gluteus Maximus Muscle Flap in Tongue in Groove and Wrap Around Pattern for Refractory CSF Leakage in Extradural Cyst Patient

Spinal extradural arachnoid cyst (SEAC) is a rare disease and has surgical challenges because of the critical surrounding anatomy. We describe the rare case of a 58-year-old woman who underwent extradural cyst total excision with dural repair and presented with refractory cerebrospinal fluid (CSF) leakage even though two consecutive surgeries including dural defect re-repair and lumbar-peritoneal shunt were performed. The authors covered the sacral defect using bilateral gluteus maximus muscle flap in tongue in groove and wrap around pattern for protection of visible sacral nerve roots and blockage of CSF leakage point. With the flap coverage, the disappearance of cyst and fluid collection was confirmed in the postoperative radiological finding, and the clinical symptoms were significantly improved. By protecting the sacral nerve roots and covering the base of sacral defect, we can minimize the risk of complication and resolve the refractory fluid collection. Our results suggest that the gluteus muscle flap can be a safe and effective option for sacral defect and CSF leakage in extradural cyst or other conditions.

Thoracic spinal extradural arachnoid cyst: A case report and literature review

Background:

Spinal extradural arachnoid cysts (SEDACs) are rare and are variously attributed to congenital, traumatic, or inflammatory etiologies. Here, we report a 70-year-old male who presented with a T11-T12 SEDAC and an incidental craniovertebral junction (CVJ) meningioma.

Case Description:

A 70-year-old male presented with progressive bilateral lower limb weakness and paresthesias. The thoracic MRI identified an extradural arachnoid cystic lesion at the T11-T12 level. In addition, the brain/ cervical MR documented an incidental meningioma at the CVJ. The patient underwent T11-T12 laminectomy for fenestration/removal of the extradural arachnoid cyst resulting in immediate cord decompression and neurological recovery. The histologic examination was consistent with a SEDAC who underwent successful resection of the SEDAC that resulted in symptom resolution.

Conclusion:

We presented a 71-year-old male with a thoracic SEDAC and an incidental CVJ meningioma, where resection of the SEDAC resulted in symptom resolution.

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.

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.

Transforaminal endoscopic excision of bi-segmental non-communicating spinal extradural arachnoid cysts: A case report and literature review

BACKGROUND

Spinal extradural arachnoid cysts (SEACs) are a rare cause of spinal cord compression. Typically, these cysts communicate with the intradural subarachnoid space through a small defect in the dural sac. For symptomatic SEACs, the standard treatment is to remove the cyst in total with a (hemi)laminectomy or laminoplasty. We present a rare case of bi-segmental non-communicating SEACs and describe our experience of using an endoscopic minimal access technique to remove bi-segmental non-communicating SEACs.

CASE SUMMARY

A 79-year-old female presented with pain related to bi-segmental SEACs at the T11-L1 segments. She underwent sequential transforaminal percutaneous endoscopic thoracic cystectomy of the SEACs. Following her first procedure, spinal magnetic resonance imaging demonstrated complete excision of the cyst at the T12-L1 segment. However, the cyst at the T11-T12 segment was still present. Thus, a second procedure was performed to remove this lesion. The patient’s right-sided lumbar and abdominal pain improved significantly postoperatively. Her Japanese Orthopaedic Association score increased from 11 to 25, her visual analogue scale score was reduced from 8 to 1. The physical and mental component summary of the 36-item short-form health survey (SF-36) were 15.5 and 34.375 preoperatively, and had increased to 79.75 and 77.275 at the last follow-up visit, respectively.

CONCLUSION

Bi-segmental non-communicating SEACs are extremely rare. Endoscopic surgery is a safe, effective, and reliable method for treating these cysts. In the event of bi-segmental SEACs, it is important to identify whether both cysts are communicating before surgery, and if not, to remove both cysts separately during the index surgery to avoid re-operation.

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.

Extradural Spinal Arachnoid Cyst as a Cause of Cauda Equina Syndrome in a Child

Although spinal arachnoid cysts are relatively common findings observed incidentally in adults, they are much rarely reported in children. They are usually asymptomatic and are mainly located in the middle and lower thoracic regions. However, in rare circumstances, these cysts can cause mass effects that lead to neurologic symptoms. We report the rare case of a spinal extradural arachnoid cyst in a 12-year-old boy who showed signs and symptoms of cauda equina syndrome. Magnetic resonance imaging of the lumbar spine revealed a huge extradural arachnoid cyst extending from L2 to L5. Emergent laminectomy and repair of dural defect was performed after total resection of the extradural arachnoid cyst. There were no postoperative complications. Total recovery was achieved 6 months after surgery. Here, we report this rare case with a review of the literature.

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.

Extradural thoracic meningeal cyst without spinal dysraphism causing adulthood myelopathy: Case illustration and review of the literature

Extradural spinal meningeal cysts are rare lesions in the adult spine and are an uncommon cause of neurologic deficits. We present the case of an adult who presented with myelopathic symptoms related to a dorsally based extradural thoracic meningeal cyst in the absence of any defect in the posterior spinal elements and no history of spinal dysraphism or trauma. We also performed a review of the literature to evaluate the surgical techniques for extradural meningeal cysts. Most thoracic cysts are intradural arachnoid cysts, yet this lesion is an extradural meningeal cyst, not an intradural arachnoid cyst. Because of the rarity of this lesion, its anatomic characterization can be difficult to conceptualize. An artist's illustration helps illustrate the anatomic characteristics of this cyst and our surgical management.

Spinal extradural arachnoid cyst in cervicothoracic junction

Introduction

Spinal extradural arachnoid cysts (SEACs) are rare expansive lesions that account for ~1% of all spinal tumors. They develop as the result of arachnoid membrane herniation through a small dural defect and are mostly reported to be located at lower thoracic region and thoracolumbar junction.

Case presentation

We report a rare case of SEAC located in the cervicothoracic junction causing neurologic compression.

Discussion

Only 3% of all SEACs are observed in the cervical spine. They are the most common in young men and present with compressive symptoms. SEACs have potential to enlarge. As they are surgically removable lesions, early and definite diagnosis is important in preventing clinical deterioration. MRI is recommended for the diagnosis and preoperative planning.

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.

A Rare Cause of Thoracic Spinal Cord Compression by Multiple Large Tarlov Cysts

Spinal extradural arachnoid cyst (SEAC) is a rare cause of spinal cord compression. Bifocal location of thoracic and sacral SEACs is rarely reported in the literature. We report a case of thoracic spinal cord compression by SEAC associated with asymptomatic multiple sacral Tarlov cysts (TC). The surgical management and postoperative outcome of the patient are discussed. A 34-year-old woman was referred to the hospital for acute thoracic pain with a history of chronic long-standing back pain. She complained of walking difficulties. Neurological examination demonstrated incomplete spastic paraplegia with sensory level in T9. Magnetic resonance imaging revealed a large cystic formation from T7-11 and at the level of the sacrum. We performed laminectomies at the level of interest from T7-11. The cysts were dissected from the underlying dura after removal of the cerebrospinal fluid. We found nerve tissue in the cysts. We excised the cyst and preserved the nerve roots. Subsequently, a duraplasty was performed with autologous grafts from the lumbar fascia. The condition of the patient improved after surgery and he was recovering well at follow-up. Although the surgical treatment of TC is controversial, especially at the sacral lumbar level, decompression at the dorsal level in this case is indisputable.

Intraoperative Visualization of a Spinal Arachnoid Cyst Using Pyoktanin Blue

BACKGROUND

Spinal arachnoid cysts (SACs) are filled with cerebrospinal fluid, and they include the arachnoid membrane, making it difficult to distinguish the walls of the cyst from the arachnoid membrane and excise the cyst as a lump. Here we report a technique for the intraoperative visualization of SACs, involving the use of pyoktanin blue.

METHODS

Four patients with spinal intradural arachnoid cysts underwent total excision of the cysts between October 2016 and April 2017. In 1 case, magnetic resonance imaging revealed the cyst clearly, but in the other cases, the cysts were unclear. All cysts were injected with 1% pyoktanin blue (Wako Pure Chemical Industries, Osaka, Japan) diluted 500 times with physiological saline before excision. When it was difficult to distinguish the cyst from the normal arachnoid membrane, 1% pyoktanin blue diluted 1000 times with physiological saline was injected into both the cyst and the subarachnoid space, and the spread of the stain was observed.

RESULTS

The cysts were better visualized after pyoktanin blue injection than before injection. When it was difficult to distinguish the cyst from the normal arachnoid space, pyoktanin blue injection was useful for judging the cyst space. There were no perioperative complications, and the patients' symptoms improved partially or completely after treatment.

CONCLUSIONS

Our technique of pyoktanin blue injection into SACs could make their excision easy and safe.