Neuroendoscopy: Past, Present, and Future

Khan W. Li, M.D.; Clarke Nelson; Ian Suk, B.S., B.M.C.; George I. Jallo, M.D.

Disclosures

Neurosurg Focus. 2005;19(6) 

In This Article

Abstract and Early History

Neuroendoscopy began with a desire to visualize the ventricles and deeper structures of the brain. Unfortunately, the technology available to early neuroendoscopists was not sufficient in most cases for these purposes. The unique perspective that neuroendoscopy offered was not fully realized until key technological advances made reliable and accurate visualization of the brain and ventricles possible. After this technology was incorporated into the device, neuroendoscopic procedures were rediscovered by neurosurgeons. Endoscopic third ventriculostomy and other related procedures are now commonly used to treat a wide array of neurosurgically managed conditions. A seemingly limitless number of neurosurgical applications await the endoscope. In the future, endoscopy is expected to become routine in modern neurosurgical practice and training.

The field of neuroendoscopy began with great promise; this new modality held the potential to allow neurosurgeons to visualize anatomical structures never before studied in live patients. The perspective would be unique, a magnified view of the ventricular system viewed from within its walls. In reality, however, the technology available to the pioneers of neuroendoscopy was far too primitive for these purposes.[1,54] Illumination was a major problem, and magnification was another. Although there were early reports of successful visualization of intracranial anatomy and even treatment of pathological entities within the ventricles, most attempts at early neuroendoscopic procedures were met with frustration because of the technical limitations imposed by the instruments available at the time.

Max Nitze is credited with designing the first modern endoscope in 1879. According to Schultheiss, et al.,[47] this was a crude device composed of a series of lenses with an illumination source at the tip. The first neurosurgical endoscopic procedure was performed by L'Espinasse. In 1910, he reported the use of a cystoscope to perform fulguration of the choroid plexus in two infants with hydrocephalus.[54] One patient died postoperatively, but the other was successfully treated. Twelve years later, in 1922, Walter Dandy described the use of an endoscope to perform choroid plexectomy.[8] This followed his descriptions several years earlier of open choroid plexectomy for the treatment of hydrocephalus.[9] This latest attempt to perform the procedure endoscopically, however, was ultimately unsuccessful. That same year, Dandy reported the first ventriculostomy for the treatment of hydrocephalus: fenestration of the lamina terminalis via a craniotomy and a transfrontal approach.

In 1923, Fay and Grant[12] were able to visualize and photograph successfully the interior of the ventricles of a child with hydrocephalus by using a cystoscope. The exposure times, however, ranged from 30 to 90 seconds, which demonstrates the poor illumination available to them with their cystoscope. That same year, Mixter performed the first successful ETV by using a urethroscope in a 9-month-old girl with obstructive hydrocephalus. Mixter's report, which is detailed in Abbott[1] and Walker,[54] went largely unnoticed, however, possibly because of the cumbersome size of his instruments and the poor illumination that they offered.

In 1932, Dandy again reported use of an endoscope for choroid plexectomy. This time the procedure was successful, but he found the results to be only comparable to those of open choroid plexectomy.[1] In 1934, Putnam[41] described cauterization of the choroid plexus with an endoscopic device. The procedure was performed 12 times in seven patients, was successful in at least three cases, and resulted in two deaths. As related in Abbott, 9 years later Putnam reported his series of endoscopic choroid plexectomy in 42 patients. There were 10 perioperative deaths (25%) and 15 patients failed to respond, although 17 had successful relief of increased intracranial pressure.

After Mixter's paper from 12 years earlier, there were no reports of ETV until 1935, when Scarff[45] described his initial results after using a novel endoscope equipped with a mobile cauterizing electrode, an irrigation system that prevented collapse of the ventricles, and a movable operating tip that could be used to perforate the floor of the third ventricle. He punctured the floor of the third ventricle in one patient and achieved dramatic results: a 3-cm decrease in head circumference 6 weeks postoperatively. The ventriculostomy eventually failed, however, and the patient died. A healed scar over the ventriculostomy site was found at autopsy. Scarff noted, "This case demonstrates clearly the feasibility of the procedure but points out also the necessity of enlarging the opening beyond a mere puncture wound."

In 1947, McNickle[38] described a percutaneous method of performing third ventriculostomy in patients with both obstructive and communicating hydrocephalus. Initially he used a 19-gauge needle and an endoscope for visualization. Later, he abandoned the endoscope, using only x-ray films and feel for localization. McKnickle reported few complications, and despite the inclusion of patients with non-obstructive hydrocephalus, he recounted success rates that were superior to Dandy's open approach.

Despite the numerous reports that demonstrated the potential utility of neuroendoscopy, the field never gained favor in general neurosurgical practice. The fact was that poor magnification and illumination made neuroendoscopy difficult and unreliable. Even in the hands of a skilled surgeon such as Dandy, endoscopic procedures were met mostly with frustration.

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