1.1 Early Development of Endoscopy

The term endoscopy (to see inside) derives from the Greek words èndon (inside) and skopê (to see).1 The current drive toward minimally invasive surgery has been kindled by robotic and endoscopic techniques, and yet the first “endoscopic surgery” dates back to the time of Hippocrates (ca. 400 BC), who described various ancient speculums that used ambient light for inspection of rectal and vaginal cavities (Table 1.1). Subsequent models were designed and described by Abulkaism of Cordoba in the eleventh century and Giulio Cesare Aranzi in the sixteenth century. They both designed systems using closed tubes and mirrors that reflected ambient lighting, although visualization was poor and their use was extremely limited.2,3 The first use of an external light source was described in the early nineteenth century when Philip Bozzini (1773–1809), considered the godfather of modern endoscopy, developed his lichtleiter, or light conductor (Fig. 1.1). He used candlelight at the end of an instrument with a long funnel and a reflecting mirror, and he was able to look into cavities such as the ear, urethra, rectum, female bladder, cervix, mouth, and nasal cavity. His instrument was first tested in cadavers and eventually approved for patients. However, due to the internecine rivalry in the nineteenth century in Vienna, his invention was ridiculed by the University of Vienna. He was severely criticized for his curiosity and his “magic lantern.” He succumbed to typhoid and the first chapter in the development of endoscopy ended. Nevertheless, his original design formed the basis of endoscopes. It was not until 1853, however, that Antonin Jean Desormeaux coined the term endoscopy and was able to incorporate the endoscope into his clinical practice. He used a kerosene lamp and a 45-degree concave mirror to reflect light into the bladder (Fig. 1.2). The lamp was placed between the reflector and the lenses, and the light generated was focused down the shaft of the scope with a lens. For the first time, he was able to use instruments to remove pathologies from the genitourinary tract. For the first time, the endoscope was used for surgical and therapeutic purposes. Desormeaux is therefore credited as the father of modern cystoscopy.3

The next landmark in endoscopy came in 1879 when Maximillan Carl-Fredrich Nitze created an endoscope from a series of lenses and a platinum filament lamp at the distal end (Fig. 1.3). Nitze’s work incorporated the light source within the endoscope (“the lamp inside”); however, there were still challenges with the heat generated from the light source and the need for cooling systems to prevent burns. These problems ceased with the incorporation of the lightbulb (invented in 1880) into the endoscope in 1883 by David Newman.4 Another important step came in 1889 with the advent of the multichambered endoscope by Boisseau du Rocher, through which catheters or other tools could be passed, thereby transforming endoscopy from a purely diagnostic to a therapeutic instrument. The development of flexible endoscopes was also instrumental in this transformation. In 1881, Johann Mikulicz developed a scope that could be angled at its distal end, and he went on to perform the first esophagoscopy.2,3,4 Over the next few decades, further refinements in telescope and lens design, light sources, and instrumentation contributed to the development of the endoscope, which had become a routine instrument for cystoscopy, bronchoscopy, and gastroscopy.

1.2 Early Neuroendoscopy

By the twentieth century, endoscopy was part of routine surgical practice, and it did not take long for this technology to cross over to the neurosurgical world (Table 1.2). In 1910, Victor de L’Espinasse, a Chicago-based urologist well known at that time as the American pioneer of testicular transplantation, introduced a cystoscope into the lateral ventricles of two infants and resected their choroid plexus to treat their hydrocephalus. One of his patients died postoperatively, and the second lived 5 years. His findings were, however, not documented until the 1930s in the textbook Neurological Surgery.5,6 The only direct proof of L’Espinasse’s neurosurgical interest is his application form to the American College of Surgeons in 1913, where he listed among his research interests “destruction of the choroid plexus for internal hydrocephalus.”

In 1923, William Jason Mixter (born in Vienna, Austria, December 5, 1880 and died in 1958), chief of neurosurgery at Massachusetts General Hospital, performed the first successful endoscopic third ventriculostomy using a flexible probe through a urethroscope on a 9-month-old patient with hydrocephalus. Postoperatively, the patient’s fontanelle decreased in size and pressure and the head circumference decreased by 12 mm in 10 days.3,6,7 Additionally, in 1923, Fay and Grant from Philadelphia used a cystoscope to photograph the ventricular system; they published their findings in the JAMA.3,8 John Volkmann, professor at the University Surgical Clinic in Halle, was concurrently working on modifications to the endoscope to make it more suitable for intraventricular work. In 1923, he published his first experience with an enzephaloskopie. He developed a lighter endoscope with two irrigation channels; in addition, he created a modification that covered the lens during insertion, which prevented debris from accumulating on it.6 The optical apparatus was positioned in the sheath so that during insertion into the brain the lens was covered, and by rotating, it became available in the ventricles. His first endoscopic procedure was on an infant with hydrocephalus. These improvements and modifications continued, and the next milestone came in 1934, when Tracy Putnam adapted electrocautery to endoscopy by developing the ventriculoscope, which had two curved coagulating probes welded to the glass distally.3

The real catalyst and father of modern neuroendoscopy was Walter Dandy (born in Sedalia, Missouri, on April 6, 1886, and died in Baltimore, Maryland, on April 19, 1946), a neurosurgeon at Johns Hopkins Hospital who worked out the physiology of cerebrospinal fluid. In the 1920s, as a chief resident, he developed a keen interest in visualizing the ventricular system and published his findings on air ventriculography, describing an X-ray technique allowing neurosurgeons to visualize the ventricles for the first time. In 1922, Dandy published the first endoscopic observations of the ventricles, using an endoscope with light reflected from an exterior lamp via a head mirror. He was able to see the entire lateral ventricles, foramen of Monro, septum pellucidum, and choroid plexus. In 1923, he introduced a cystoscope into the lateral ventricles and successfully removed the choroid plexus in two patients. At the time, his method was crude. He used a nasal dilator to keep the trajectory open, and after removing all the cerebrospinal fluid, the choroid plexus was ligated with a clip and avulsed. He continued to routinely perform these resections while further refining the neuroendoscope in collaboration with the Wappler Electric Company (Fig. 1.4).3,6 However, in 1945, Walter Dandy acknowledged that there were limitations to neuroendoscopy, and he wrote the following9: