Pial and arachnoid welding for restoration of normal cord anatomy after excision of intramedullary spinal cord tumors

Arachnoid Welding-A Simple and Economical Method of Arachnoid Closure to Prevent Cerebrospinal Fluid Leak

BACKGROUND

Collection of cerebrospinal fluid (CSF) in the subdural compartment is a major cause of postoperative morbidity, especially for posterior fossa surgeries. Arachnoid closure techniques, including suturing of the arachnoid and use of synthetic sealants, have been described in the literature. However, they are not always feasible or effective and have not been universally adopted.

METHODS

We describe the technique of arachnoid welding for a case of brainstem cavernoma. This is a simple, cost-effective, and easily reproducible technique using readily available bipolar cautery kept at a low-current setting. At the end of surgery, the arachnoid leaflets are closely approximated, and bipolar cautery is used to seal the edges together. An illustrative video shows the technical nuances of this procedure. This technique can also be applied for arachnoid closure at other cranial and spinal sites.

RESULTS

Arachnoid closure can act as an effective natural barrier to keep CSF in its physiological subarachnoid compartment. It provides an additional barrier to prevent CSF leak. It also prevents morbidity associated with adhesions and arachnoiditis. Proper closure of arachnoid makes durotomy during repeat surgery much easier and avoids injury to the underlying pia. A brief review of related literature shows the benefits of closing the arachnoid before dural closure and the different techniques that have been described so far.

CONCLUSIONS

The arachnoid welding technique has a wide application, is easy to learn, and can be used especially for posterior fossa surgeries in which rates of CSF leak are the highest.

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.

Intramedullary hemangioblastoma: Microsurgical resection technique

Spinal hemangioblastomas are benign and highly vascular tumors accounting for 1-5% of intramedullary spinal tumors in surgical series. Surgery is curative in sporadic cases. We present the description of a surgical technique to safely resect an intramedullary hemangioblastoma. A dorsal midline myelotomy provides an excellent exposure of the tumor and identification of the feeding arteries. Interruption of these arteries and precise dissection of the tumor from the cord tissue followed by division of the venous drainage allow the in toto excision of the tumor. Closure of the dorsal myelotomy may be achieved with sequential fusion of the pial and arachnoid edges using a "welding" technique.

Unilateral, multilevel, interlaminar fenestration in the removal of a multisegment cervical intramedullary ependymoma

BACKGROUND CONTEXT

Laminectomy is the traditional approach to intramedullary ependymomas and may lead to spinal instability and spinal deformities. Hemilaminectomy and laminoplasty have been developed to preserve the spinal stability and have been found to be effective. Unilateral, multilevel, interlaminar fenestration is another approach that may have more advantages in preserving the spinal stability; however, it has rarely been used by now.

PURPOSE

Unilateral, multilevel, interlaminar fenestration was often used in the surgical treatment of degenerative lumbar stenosis; however, it was rarely used for tumors. The aim of this study was to discuss the characteristics and advantages of its use for a multisegment intramedullary ependymoma.

STUDY DESIGN

Case report and literature review.

METHODS

The 22-year-old man suffered from muscular atrophy of the left hand and the right hand for a period of 1.5 years and 3 months, respectively, and the cervical magnetic resonance imaging revealed an intramedullary mass of C4-C7. A right, unilateral, multilevel, interlaminar fenestration of the C3-C7 was performed with the help of high-speed air drills, and a midline myelotomy was made under microscope. The tumor was removed totally using piecemeal resection.

RESULTS

The magnetic resonance imaging, obtained 1 year after the operation, revealed that there were no residual mass lesion and no spinal instability, and the patient acquired an excellent functional outcome. So, this technique proved to be safe and easy in this case.

CONCLUSIONS

Unilateral, multilevel, interlaminar fenestration allows good access to a long intraspinal segment, protects the structures essential to spinal stability as much as possible, preserves the spinal stability, and results in no additional injury to the spinal cord. It may be applicable to many other kinds of intraspinal tumors.