Operative Techniques and Instrumentation for Neurosurgery

The introduction of the operating microscope for neurosurgery brought about the greatest improvements in operative techniques that have occurred in the history of the specialty. The microscope has resulted in profound changes in the selection and use of instruments and in the way neurosurgical operations are completed. The advantages provided by the operating microscope in neurosurgery were first demonstrated during the removal of acoustic neuromas (4). The benefits of magnified stereoscopic vision and intense illumination provided by the microscope were quickly realized in other neurosurgical procedures. The operating microscope is now used for the intradural portion of nearly all operations involving the head and spine and for most extradural operations involving the spine and cranial base, converting almost all of neurosurgery into a microsurgical specialty. Microsurgery has improved the technical performance of many standard neurosurgical procedures (e.g., brain tumor removal, aneurysm obliteration, neurorrhaphy, and lumbar and cervical discectomy) and has opened new, previously unattainable areas to the neurosurgeon. It has improved operative results by permitting neural and vascular structures to be delineated with greater visual accuracy, deep areas to be reached with less brain retraction and smaller cortical incisions, bleeding points to be coagulated with less damage to adjacent neural structures, nerves distorted by tumor to be preserved with greater frequency, and anastomosis and suturing of small vessels and nerves not previously possible to be performed. Its use has resulted in smaller wounds, less postoperative neural and vascular damage, better hemostasis, more accurate nerve and vessel repairs, and surgical treatment of some previously inoperable lesions. It has introduced a new era in surgical education, by permitting the observation and recording (for later study and discussion) of minute operative details not visible to the naked eye. Some general considerations are reviewed before discussion of instrument selection and operative techniques.