German neuroendoscopy above the skull base

Abstract

<jats:p>Endoscopy plays an important part in current minimally invasive neurosurgery. The concepts, indications, and standards of current neuroendoscopy were developed in the beginning of the 1990s by several groups of neurosurgeons. Several factors contributed to its success and acceptance, including technical development, influence of other disciplines, and adaptation to neurosurgical requirements. This historical survey focuses on the period when this technique initially emerged, including the scientific discussions of each group as well as the arguments and reasons that led to present intraventricular neuroendoscopy. Interestingly, despite the almost independent development of neuroendoscopic systems and techniques, the available systems and techniques applied these days grossly correspond. Rigid rod-lens endoscopes are generally accepted as the best option among the various available instrument sets. Nevertheless, frameless as well as frame-based stereotactic endoscopy and flexible steerable endoscopes might have their applications as well.</jats:p>

A Journey into the Technical Evolution of Neuroendoscopy

“…Hopkins, a physicist who specialized in optics, is widely credited for his contribution to the field of neuroendoscopy (1,13,33,35,36,62). In 1948, 22 years after John L. Baird (1888e1946; United Kingdom) suggested the idea of the transmission of images through flexible glass cables, Hopkins invented the zoom lens, which was suggested by the British Broadcasting Corporation (1,35,62).…”

“…This invention depicted his strong understanding of optical systems that allowed him to minimize image defects in image systems. Shortly after this invention, in 1951, Hugh Gainsborough approached Hopkins commenting on the insufficient optical quality of the present endoscopes, and Hopkins developed the idea of using glass fibers for the transmission of image and light (1,35,36). With this idea, he gathered a bundle of glass fibers that had a higher refraction in the center to improve the transport of images and increase the total reflection within the scope (36).…”

“…His new method of ETV was ready for routine clinical practice in 1963, with reports of better results compared with ventriculoatrial shunts in treating hydrocephalus (67). Although new innovations were constantly being made to the existing scopes at the time, endoscopic techniques for neurosurgery were not popular for many reasons, including the introduction of other surgical techniques and poor technology in terms of lighting and optics in the instrument (17,30,36,38,48,90). Surgical discomfort and high death rates also prevented neuroendoscopy from becoming an option in clinical practice (23,30,48,51,50,70).…”

“…Shortly after this invention, in 1951, Hugh Gainsborough approached Hopkins commenting on the insufficient optical quality of the present endoscopes, and Hopkins developed the idea of using glass fibers for the transmission of image and light (1,35,36). With this idea, he gathered a bundle of glass fibers that had a higher refraction in the center to improve the transport of images and increase the total reflection within the scope (36). The idea of bundles of glass fiber to transmit light was first demonstrated by Heinrich Lamm in 1932, but his system included only about 400 glass fibers, and Hopkins improved on this idea (2,90).…”

“…Hopkins also developed 2 important types of endoscopes known today: rigid and flexible endoscopes (30,33,90). To name a few, the integration of glass-rod scopes, fiberoptics in transmitting cold light (23,30,33,36,70), viewing lenses that allow smaller diameters and wider viewing angles, cameras and video cameras, working channels in the sheath of the endoscope, and navigation systems all have emerged to the improvement of the endoscopic instrument for brain surgery as well as for other kinds of surgeries (14,15,17,29,30,33,45,52,53,65,68,74,90). These developments are still in progress as scientists and physicists introduce and test new tools and apply modern concepts and ideas to endoscopic neurosurgery (15,16).…”