Endoscope-assisted microsurgery

Abstract

The fi rst published description of endoscope use in neurosurgery was in 1917, when a urologist in Chicago named V. L. L‘Espinasse used a cystoscope to perform an endoscopic choroid plexus coagulation [ 1, 2 ]. Subsequently, the endoscope was used by Dandy in the early 1920s to address intraventricular pathologies [ 3 ]. Because initial fi berscopes had poor optical quality for neurosurgical procedures, endoscopes were not widely adopted. The development by Hopkins of the rigid rod lens endoscope in the 1960s dramatically improved optics and regenerated interest in neurosurgical applications [ 4 ]. Since then, neurosurgeons have expanded the role of the endoscope to work within the subarachnoid space and cisterns. The term “endoscopic-assisted microsurgery” (EAM) was coined by Hopf and Perneczky to indicate the use of an endoscope as a surgical adjunct in a procedure in which surgical manipulations are primarily made under microscopic visualization [ 5 ]. This differs from “endoscopic-controlled” procedure in which the primary surgical manipulations are made under endoscopic visualization [ 5 ]. The primary goal in employing the endoscope is to improve visualization of the operative fi eld and minimize brain retraction and trauma to neurovascular structures. The benefi t of the endoscope is that it provides increased illumination of the operative fi eld, higher magnifi cation with a wider angle of view, and increased depth of fi eld [ 6 ]. The limitations of the endoscope are that images are two-dimensionsal (although this can be offset by dynamic movement), it takes up room in the surgical corridor, it can damage neurovascularstructures not in the fi eld of view, it requires either a holder or an assistant surgeon, and there exists a learning curve associated with its use. Technological advancements have helped to mitigate some of these limitations as will be discussed later. The purpose of this chapter is to review established indications and techniques for endoscopic-assisted microsurgery, present clinical cases, and discuss current technology and future directions.