Surgical treatment of thoracic arachnoiditis with multiple subarachnoid cysts caused by epidural anesthesia

Association between perioperative neuraxial local anesthetic neurotoxicity and arachnoiditis: a narrative review of published reports

BACKGROUND/IMPORTANCE

Arachnoiditis is a rare but devastating disorder caused by various insults, one of which is purported to be local anesthetic neurotoxicity following neuraxial blockade. However, the relationship between local anesthetics administered into the neuraxis and the development of arachnoiditis has not been clearly elucidated.

OBJECTIVE

We aimed to summarize the existing complex body of literature and characterize both the essential features and strength of any association between neuraxial local anesthetic neurotoxicity and arachnoiditis with a view toward mitigating risk, enhancing prevention, and refining informed consent discussions.

EVIDENCE REVIEW

We reviewed all published reports of arachnoiditis attributed to local anesthetic neurotoxicity following perioperative neuraxial anesthesia. This narrative review was based on a systematic search methodology, which included articles published up until December 2022.

FINDINGS

Thirty-eight articles were included, comprising 130 patients, over one-half of which were published prior to this century and inconsistent with modern practice. Neuraxial techniques included 78 epidurals, 48 spinals, and 5 combined spinal-epidurals, mostly for obstetrics. Reporting of essential procedural data was generally incomplete. Overall, at least 57% of patients experienced complicated needle/catheter insertion, including paresthesia, pain, or multiple attempts, irrespective of technique. The onset of neurological symptoms ranged from immediate to 8 years after neuraxial blockade, while the pathophysiology of arachnoiditis, if described, was heterogeneous.

CONCLUSIONS

The existing literature attributing arachnoiditis to local anesthetic neurotoxicity is largely outdated, incomplete, and/or confounded by other potential causes, and thus insufficient to characterize the features and strength of any association.

Spinal Adhesive Arachnoiditis: A Literature Review

Adhesive arachnoiditis (AA) is a rare inflammatory and scar-forming disease with several etiologies that may lead to incapacitating sequelae if not managed early. Nevertheless, as the onset of symptoms varies from days to years, the etiology is not often discovered. The disease is characterized by adhesions disrupting the cerebrospinal fluid flow and causing encapsulation and atrophy of the nerve root. Therefore, a range of clinical features may be present, including urinary, gastroenterology, dermatologic, and neurologic. In terms of diagnosis, magnetic resonance imaging is the gold standard showing pseudocysts with adherent and narrow nerve roots toward the center of the dural sac or peripherally cluster and narrow nerve roots with empty thecal sac. Despite its sensitivity and specificity, the imaging findings are not often associated with clinical manifestations, requiring treatment being based on anamneses and clinical findings. Nowadays, AA can be managed with pharmacological and non-pharmacological treatment, although none provides a completely satisfying result.

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

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.

Visualization of regional cerebrospinal fluid flow with a dye injection technique in focal arachnoid pathologies

Surgical lysis of the thickened arachnoid membrane is the first choice of treatment in spinal arachnoid pathologies that cause flow disturbances or blockage of CSF. However, it is important to consider that while extensive lysis of the arachnoid may temporarily provide a wide pathway for CSF, an extensive lytic procedure may later cause secondary adhesion. Thus, it is ideal for the proper extent of the arachnoid lysis to be determined after careful analysis of regional CSF flow. The authors report their limited experience with intraoperative visualization of CSF flow in spinal arachnoid pathologies. Two patients with a dorsal arachnoid web (DAW) with cervical syringomyelia and 1 patient with focal adhesive arachnoiditis causing edema of the spinal cord were surgically treated at the authors' institution between 2007 and 2013. In all cases, the presence of a DAW or focal adhesive arachnoiditis was suspected from the findings on MRI, namely 1) an indentation on the upper thoracic spinal cord and 2) syringomyelia and/or edema of the spinal cord above the indentation. Exploratory surgery disclosed a transversely thickened arachnoid septum on the dorsal side of the indented cord. To prove blockage of the CSF by the septum and to decide on the extent of arachnoid lysis, regional CSF flow around the arachnoid septum was visualized by subarachnoid injection of gentian violet solution close to the web. Injected dye stagnated just close to the arachnoid septum in all cases, and these findings documented CSF blockage by the septum. In 2 cases, a 2-minute observation showed that the injected dye stayed close to the web without diffusion. The authors performed not only resection of the web itself but also lysis of the thickened arachnoid on both sides of the spinal cord to make a CSF pathway on the ventral side. In the third case, the dye stagnated close to the web at first but then diffused through the nerve root to the ventral CSF space. The lysis procedure was completed after exclusive removal of the dorsal web. Postoperative MR images confirmed reduction of the syrinx and/or improvement of the edema in all cases, suggesting that the extent of arachnoid lysis was optimal in each case. No adverse effect was observed after subarachnoid injection of gentian violet. The authors believe that their technique of visualizing regional CSF flow will be helpful to decide the optimal extent of lysis in some local arachnoid pathologies.

Surgical manifestations of thoracic arachnoid pathology: series of 28 cases

Object

Various pathologies involving the thoracic arachnoid mater uniformly manifest as thoracic myelopathy and may present a significant management dilemma. The authors undertook this study to assess outcome in cases of thoracic myelopathy due to thoracic arachnoid pathology.

Methods

The authors have cared for and followed 28 patients with thoracic myelopathy from thoracic arachnoid pathology over the last 17 years. A chart review and contemporary follow-up of these patients was performed and outcomes were reported.

Results

Patients with thoracic myelopathy from thoracic arachnoid pathology often have improvement in their condition after surgical decompression/detethering procedures. While not universal, patients in this series had improvement in mJOA scores at 1 year after surgery (p = 0.0001) and at last follow-up (p = 0.04). Results indicated that across a wide variety of pathologies the extent of thoracic spinal cord involvement is a predictor of the disease course and outcome. Comparison of the group of patients with cord involvement limited to 2 vertebral segments (short-segment pathology) versus the group with cord tethering of more than 2 segments (long-segment pathology) showed that patients in the short-segment group more frequently had ventral or dorsal arachnoid bands (p = 0.003), more frequently had signal change in the cord on MRI (p = 0.02), and less frequently presented with a syrinx (p = 0.02), and a smaller percentage of patients in this group underwent reoperation (p = 0.02). While patients with short-segment pathology typically improved after a single operative intervention, patients with long-segment pathology typically improved after multiple operations, frequently for CSF diversion.

Conclusions

Thoracic arachnoid pathology causing thoracic cord dysfunction and myelopathy is varied, has multiple etiologies, and can be difficult to treat over the long term. Surgical management, when indicated, is case specific. Serial long-term follow-up is essential to document enduring clinical and radiographic success.

L’arachnoïdite médullaire adhésive : une complication tardive de l’analgésie péridurale obstétricale

A 30-year-old woman, G3P3, was progressively affected by spastic paraparesis with loss of sensitivity and urinary incontinence due to medullar adhesive arachnoiditis occurring five months after an epidural analgesia for repeat cesarean section. Magnetic resonance imaging showed a voluminous subarachnoid cyst and a septated syringomyelic cavitation attributed to metabisulfite, the preservative of epinephrine and to multiple lidocaine injections through the catheter in the postoperative period. Despite two decompressive neurosurgical operations, the neurological state of the patient continues to worsen.