Endoscopy in Meningioma Surgery: Basic Principles, Applications, and Indications

Abstract

No doubt surgery of benign intracranial lesions is among the most exciting and satisfying aspects of everyday neurosurgical practice, because the precise, elegant, safe, and effective surgical deed can give the patient back his or her normal life. As a matter of fact, meningioma surgery follows a general principle: the complete removal of an intracranial meningioma often means cure for the patient. Several exceptions to this rule exist: even though surgery of brain convexity meningiomas is considered something not particularly difficult to be done, surgery of skull base meningiomas or other deeply located lesions could be particularly challenging and requires a particular technical expertise. The evolution of surgical techniques, with the advent of the operating microscope and the concept of microdissection, has resulted in the last decades in a progressive reduction of invasiveness, with a dramatic improvement in the morbidity and mortality rates. Consequently, the whole concept of daily surgical practice in the field of neurosurgery changed greatly and led to the arousal of the new concept of microneurosurgery. With it, neurosurgeons became able to explore areas that had not been accessed before, define intraoperative pathologic tissues much more accurately, and refine their surgical procedures and approaches, with the end result of decreasing both morbidity and mortality. Technological advances through the years added more and more to the surgical microscopic capabilities and led to complete dependence of the neurosurgeons on it in virtually every discipline of neurosurgical practice. Furthermore, after the introduction of the concept of minimalism in the whole field of surgery, specifically neurosurgery, surgeons became more dependent on it. Now neurosurgical microscopic techniques constitute a fundamental part of any neurosurgical training program. More or less parallel to the introduction of the surgical microscope, endoscopes have also been introduced. They have been used in a limited way for treatment of hydrocephalus or for attaining tumor biopsies. The endoscope has not gained the same popularity in neurosurgery as the surgical microscope due to technological drawbacks and the far poorer quality of surgical field images. It was not until the last decade—with the many different technological advancements of telescopes, light sources, and digital video cameras leading to an overall improvement of endoscopy—that the endoscope has enjoyed increased acceptance and popularity. This technology assisted many other neurosurgical fields, first as an adjunct to the surgical microscope, then as the sole viewing tool in the whole procedure with the advent of the new concept of endoneurosurgery. The development of modern endoscopes with their great illuminating power, wider viewing angle, and the possibility to look around the corners with angled scopes made these instruments useful tools in modern neurologic surgery. The extensive use of endoscopy in neurosurgery in the last several years has helped transform neurosurgical thinking about the possibilities of surgery for deeplocated lesions—among them, meningiomas. Although many surgeons around the world use endoscopic techniques both in cranial and spinal procedures, it is worth considering that, so far, endoscopic techniques in neurosurgery have not gained the same wide acceptance and popularity as microscopic ones. The following causes have led to the relatively limited or slower shift of surgeons from microscopic to endoscopic techniques: