Keyhole Neurosurgery: Primum non nocere

Medical intervention must primarily aim to be as nontraumatizing as possible. Otherwise the effect of treatment may be worse than the natural course of the disease itself.

—Hippocrates

Neurosurgeons have endeavored to make surgery safe for the patient ever since the inception of neurosurgery as a specialty. The limited capacity of the neural tissue to withstand sustained retraction coupled with rigid covering of the brain has been the major limitation in brain surgery. Besides the lesion itself, the surgical approach to it often results in poor outcome due to brain retraction or transgression of neural tissue. Brain, by virtue of its complex neurophysiology and neurochemical responses to injury, lends itself very poorly to retraction. Excessive intraoperative retraction can lead to cerebral infarction due to increased local cerebral pressure, diminished cerebral blood flow, sacrifice of bridging veins, and so on. The evolution of neurosurgery as a specialty has seen neurosurgeons devising methods to circumvent the need for brain retraction to minimize retraction and to combat the ill effects of retraction. In approaching the lesions of the anterior skull base, many different approaches have been described. Nearly all of them sacrifice large portions of the skull (to be later reconstituted as parts of a jigsaw puzzle), and thus expose large area of the brain, so as to minimize retraction. The other impediment was the absence of adequate illumination of the operative field, resulting in large craniotomies and much approach-related morbidity. This led to evolution of operative neurosurgery in the form of large craniotomies, even for small pathologies. Introduction of operating microscope was a landmark event to improve visualization with magnification. With pioneering works of Albert Rhoton Jr. and M. G. Yasargil, there was renewed understanding of anatomy and surgical approaches. The past two decades have witnessed an explosion in therapeutic technology, and neurosurgery has been in the forefront of devising and adopting newer technologies. The ambition of any neurosurgeon has been to achieve maximum therapeutic effect with least iatrogenic injury, and keyhole surgery has been a major advancement in achieving this goal.

• References

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