ENDOSCOPE-ASSISTED BRAIN SURGERY - PART-2 - ANALYSIS OF 380 PROCEDURES

OBJECTIVES: Microsurgical techniques and instruments that help to redu ce intraoperative retraction of normal intracranial neuronal and vascu lar structures contribute to improved postoperative results. To achiev e sufficient central of the operating field without retraction of neur ovascular components, the resection of dura and bone edges is frequent ly required, which, On the other hand, increases operating time and op eration-related trauma. The use of endoscopes may help to reduce retra ction and, at the same time, may help to avoid additional dura and bon e resection. The aim of this study is to describe the principles on wh ich the technique of endoscope-assisted brain surgery is based, to giv e an impression of possible indications for endoscope-assisted microsu rgical procedures, and, with illustrative cases, to delineate the adva ntages of endoscopes used as surgical instruments during microsurgical approaches to intracranial lesions. METHODS: During a period of 1.5 y ears, 380 microsurgical procedures were performed as endoscope-assiste d microneurosurgical operations. This surgical series was analyzed for time of surgery, usefulness of intraoperative endoscopy, and complica tion rates. Lens scopes with viewing angles of 0 to 110 degrees and wi th diameters of 2.0) to 5.0 mm as well as newly designed ''viewing dis sectors'' (curved, rigid fiberscopes) with diameters of 1.0 to 1.5 mm connected to a video unit were used as microsurgical instruments, the positioning of the endoscopes was achieved by retractor arms fixed to the Mayfield headholder, Thus, the surgeon was able to perform customa ry microsurgical manipulations with both hands under simultaneous endo scopic and microscopic control. RESULTS: The lesions treated with endo scope-assisted microsurgery comprised 205 tumors, 53 aneurysms, 86 cys ts, and 36 neurovascular compression syndromes, Eighty-nine of these l esions were localized in the ventricular system, 242 in the subarachno id space or intracerebral, and 49 in the sella. Endoscope-assisted mic rosurgery was advantageous to reduce the size and the operation-relate d tissue trauma of approaches to lesions within the ventricular system , in the brain tissue as well as in the subarachnoid space at the base of the brain. Using less retraction during tumor removal, the visual control of retrosellar, endosellar, retroclival, and infratentorial st ructures was improved. Video-endoscope instrumentation was especially helpful during procedures in the posterior cranial fossa and at the cr aniocervical junction. it allowed iol inspection of channels and hidde n structures (e.g., the internal auditory meatus, tile ventral surface of the brain stem, the ventral aspect of root entry zones of cranial nerves, the content of the foramen magnum, and the upper cervical cana l), both without retraction and without resection of dura and bone edg es. Endoscope Instrumentation during surgery for large or giant aneury sms was useful to dissect perforators on the back side of the aneurysm s and to control the completeness of clipping, CONCLUSION: Although th e results reported herein cannot be compared directly with those of ex clusive microsurgical procedures performed during the same period of t ime, videoendoscope-assisted microsurgery can be recommended as a time -saving, trauma-reducing procedure apt to improve postoperative outcom es.