Quadrantectomy for resection of spinal ependymomas with a new classification of unilateral approaches regarding bone drilling and the use of a new tool: The Balak ball-tipped water jet dissector

Trimming of sheep spinal cord by waterjet; an experimental study

The spinal cord is a structure of nervous tissue that primarily transmits nerve signals from the motor cortex to the body and from the afferent fibers of the sensory neurons to the sensory cortex. It is enveloped by three layers of meninges. Covering provides a supportive framework for the cerebral and cranial vasculature and protects the central nervous system (CNS) from mechanical damage. Surgical operation in the vicinity of the spinal cord is complicated and risky because it exposes it to probably irreversible damage. To reduce the risk of these operations, attempts have been made to remove the tumor using safer methods like waterjet operation. In these methods, the waterjet and spinal cord interaction are inevitable. To secure interaction of operation, a standard development of waterjet criteria is necessary. In this study, a system of waterjet is designed to perform sheep spinal cord as a tissue with a good resemblance to the human spinal cord. Effects of interaction between waterjet and sheep spinal cord are investigated to define a safe operation threshold. The impact of the liquid density of waterjet on failure criteria of spinal cord surgery is also investigated. Results show that meninges are stiff enough to protect the sheep spinal cord from rupture for pressures up to 8 bar; however internal spinal cord tissue cannot be guaranteed any damage. Three essential parameters represent the spinal cord meninges and spinal cord deformation during the tests. These parameters lead us to provide standard criteria for damage prevention of the spinal cord.

Cervical Oblique Corpectomy: Revitalizing the Underused Surgical Approach With Step-By-Step Simulation in Cadavers

ABSTRACT

Recently, the World Federation of Neurosurgical Societies Spine committee recommended that additional research on cost-benefit analysis of various surgical approaches for cervical spondylotic myelopathy be carried out and their efficacy with long-term outcomes be compared. Unfortunately, it is highly probable that the oblique corpectomy (OC) will not be included in cost-benefit investigations due to its infrequent application by neurosurgeons dealing with the spine. In this cadaveric study, head and necks of 5 adult human cadavers stained with colored latex and preserved in 70% alcohol solution were dissected under a table-mounted surgical microscope using 3× to 40× magnifications. The OC approach was performed to simulate real surgery, and the neurovascular structures encountered during the procedure and their relations with each other were examined. Oblique corpectomy was performed unilaterally, although neck dissections were performed bilaterally on 10 sides in all 5 cadavers. At each stage of the dissection, multiple three-dimensional photographs were obtained from different angles and distances. For an optimal OC, both the anterior spinal cord must be sufficiently decompressed and sufficient bone must be left in place to prevent instability in the cervical spine. Oblique corpectomy is a valid and potentially low cost alternative to other anterior and posterior approaches in the surgical treatment of cervical spondylotic myelopathy. However, meticulous cadaver studies are essential before starting real surgical practice on patients in order to perform it effectively and to avoid the risks of the technique.