Abstract
Microvascular decompression of the cranial nerves has proved effective for a number of conditions. In each case, the rationale for the operation is that direct vascular compression of a given cranial nerve causes symptoms that can be relieved by separating the vessel from the nerve and the nerve root entry zone. Only compression that is exposed at surgery can be decompressed. Traditionally, this operation is ably performed with the microscope. However, addition of an endoscope improves visualization of the entire nerve complex and ensures adequate decompression with less retraction. This article discusses the technique for using the endoscope as an adjunct to a retrosigmoid craniotomy for microvascular decompression, especially for trigeminal neuralgia and hemifacial spasm.