✓ The argon surgical laser has been used in 68 neurosurgical procedures that included the removal of intracranial and intraspinal tumors, spinal cord fenestration for syringomyelia, and the production of dorsal root entry zone lesions. Characteristics that make the argon surgical laser a useful microneurosurgical instrument include the availability of a fiberoptic delivery system, a laser spot size that can be varied continuously between 0.15 and 1.5 mm, a single laser-aiming and treatment beam, the transmission of argon laser light through aqueous media such as irrigating or cerebrospinal fluids, and improved hemostasis compared to conventional techniques. The argon laser is limited primarily by its relatively low power output (less than 16 W), which makes the excision of large tumors difficult. However, even with these limitations, which can be used to advantage in the proper setting, the authors' laboratory and clinical experience suggests that the argon surgical laser may be useful in certain microneurosurgical operations.
Stephen K. Powers, Michael S. B. Edwards, James E. Boggan, Lawrence H. Pitts, Philip H. Gutin, Yoshio Hosobuchi, John E. Adams and Charles B. Wilson
Lawrence H. Pitts, Charles B. Wilson, Herbert H. Dedo and Robert Weyand
✓ The authors describe a case of massive pneumocephalus following ventriculoperitoneal shunting for hydrocephalus. After multiple diagnostic and surgical procedures, congenital defects in the tegmen tympani of both temporal bones were identified as the sources for entry of air. A functioning shunt intermittently established negative intracranial pressure and allowed ingress of air through these abnormalities; when the shunt was occluded, air did not enter the skull, and there was no cerebrospinal fluid leakage. Repair of these middle ear defects prevented further recurrence of pneumocephalus.