Shaan M. Raza and Theodore H. Schwartz
Sascha Marx and Henry W. S. Schroeder
Ali Tayebi Meybodi and Arnau Benet
Alberto Feletti and Pierluigi Longatti
Mark M. Souweidane, Caitlin E. Hoffman, and Theodore H. Schwartz
Intraventricular anatomy has been detailed as it pertains to endoscopic surgery within the third ventricle, particularly for performing endoscopic third ventriculostomy (ETV) and endoscopic colloid cyst resection. The expanding role of endoscopic surgery warrants a careful appraisal of these techniques as they relate to frequent anatomical variants. Given the common occurrence of cavum septum pellucidum (CSP) and cavum vergae (CV), the endoscopic surgeon should be familiar with that particular anatomy especially as it pertains to surgery within the third ventricle.
From a prospective database of endoscopic surgical cases were selected those cases in which the defined pathology necessitated surgery within the third ventricle and there was coexistent CSP and CV. Pertinent radiographic studies, operative notes, and archived video files were reviewed to define the relevant anatomy. Features of the intracavitary anatomy were assessed regarding their importance in approaching the third ventricle.
Four cases involving endoscopic surgery within the third ventricle (2 colloid cyst resections and 2 ETVs) were identified in which the surgical objective was accomplished through a septal cavum. In each case the width of the body of the lateral ventricle was reduced and the foramen of Monro was obscured. Because of the ventricular distortion, a stereotactic transcavum route was used for approaching the third ventricle. Entry into the third ventricle was accomplished through an interforniceal fenestration immediately behind the anterior commissure. The surgical goal was met in each case without any neurological change or postoperative morbidity. During the follow-up period, there has been no recurrence of a colloid cyst and no need of a secondary cerebrospinal fluid diversionary procedure.
In the presence of a CSP and CV, endoscopic navigation into the third ventricle can be problematic via a transforaminal approach. Alternatively, a transcavum interforniceal route for endoscopic surgery in the third ventricle is suggested, with the rostral lamina and the anterior commissure as important anatomical landmarks. Endoscopic third ventriculostomy and endoscopic colloid cyst resection performed via a transcavum interforniceal route in patients with a coexistent septal cavum is a feasible and safe option.
Edward D. McCoul, Vijay K. Anand, and Theodore H. Schwartz
Endoscopic skull base surgery (ESBS) is a minimal-access technique that provides an alternative to traditional approaches. Patient-reported outcomes are becoming increasingly important in measuring the success of surgical interventions. Endoscopic skull base surgery may lead to improvements in quality of life (QOL) since natural orifices are used to reach the pathology; however, sinonasal QOL may be negatively affected. The purpose of this study was to assess the impact of ESBS on both site-specific QOL, using the Anterior Skull Base Questionnaire (ASBQ), and sinonasal-related QOL, using the Sino-Nasal Outcome Test (SNOT-22).
Consecutive patients from a tertiary referral center who were undergoing ESBS were prospectively enrolled in this study. All patients completed the ASBQ and SNOT-22 preoperatively as well as at regular intervals after ESBS.
Sixty-six patients were included in the study, and 57.6% of them had pituitary adenoma. There was no significant decline or improvement in the ASBQ-measured QOL at 3 and 6 weeks after ESBS, but there were significant improvements at 12 weeks and 6 months postoperatively (p < 0.05). Improvements were noted in all but one ASBQ subdomain at 12 weeks and 6 months postsurgery (p < 0.05). Preoperative QOL was significantly worse in patients who had undergone revision surgery and significantly improved postoperatively in patients who underwent gross-total resection (p < 0.05). Scores on the SNOT-22 worsened at 3 weeks postoperatively and returned to baseline thereafter. The presence of a nasoseptal flap or a graft-donor site did not contribute to a decreased QOL.
Endoscopic skull base surgery is associated with an improvement in postoperative site-specific QOL as compared with the preoperative QOL. Short-term improvements are greater if gross-total resection is achieved. Sinonasal QOL transiently declines and then returns to preoperative baseline levels. Endoscopic skull base surgery is a valuable tool in the neurosurgical management of anterior skull base pathology, leading to improvements in site-specific QOL.
Fred G. Barker II, Rudolf Fahlbusch, Theodore H. Schwartz, and Jeffrey H. Wisoff
Charles Kulwin, Theodore H. Schwartz, and Aaron A. Cohen-Gadol
Over the past decade, advances in endoscopic microsurgical techniques have resulted in an increasingly aggressive endonasal approach to tumors of the midline skull base. Meningiomas of the tuberculum sellae are often closely associated with cerebrovascular structures, and their removal has traditionally required a transcranial approach. An endonasal approach offers many advantages, including early tumor devascularization and tumor debulking (without manipulation of the optic apparatus), direct access to the medial optic canal, and a minimal-access corridor.
Although recent articles have focused on techniques for reaching and approaching the area of the pathology (how to get there), the authors of this report discuss the technical nuances of endoscopic microsurgery when the operator is already “there.” They describe their 6-step technique for endoscopic skull base bone removal, tumor dissection/resection, and closure. They also augment their description with elaborate illustrations.
Theodore H. Schwartz, Orrin Devinsky, Werner Doyle, and Kenneth Perrine
Object. Although it is known that 5 to 10% of patients have language areas anterior to the rolandic cortex, many surgeons still perform standard anterior temporal lobectomies for epilepsy of mesial onset and report minimal long-term dysphasia. The authors examined the importance of language mapping before anterior temporal lobectomy.
Methods. The authors mapped naming, reading, and speech arrest in a series of 67 patients via stimulation of long-term implanted subdural grids before resective epilepsy surgery and correlated the presence of language areas in the anterior temporal lobe with preoperative demographic and neuropsychometric data.
Naming (p < 0.03) and reading (p < 0.05) errors were more common than speech arrest in patients undergoing surgery in the anterior temporal lobe. In the approximate region of a standard anterior temporal lobectomy, including 2.5 cm of the superior temporal gyrus and 4.5 cm of both the middle and inferior temporal gyrus, the authors identified language areas in 14.5% of patients tested. Between 1.5 and 3.5 cm from the temporal tip, patients who had seizure onset before 6 years of age had more naming (p < 0.02) and reading (p < 0.01) areas than those in whom seizure onset occurred after age 6 years. Patients with a verbal intelligence quotient (IQ) lower than 90 had more naming (p < 0.05) and reading (p < 0.02) areas than those with an IQ higher than 90. Finally, patients who were either left handed or right hemisphere memory dominant had more naming (p < 0.05) and reading (p < 0.02) areas than right-handed patients with bilateral or left hemisphere memory lateralization. Postoperative neuropsychometric testing showed a trend toward a greater decline in naming ability in patients who were least likely to have anterior language areas, that is, those with higher verbal IQ and later seizure onset.
Conclusions. Preoperative identification of markers of left hemisphere damage, such as early seizure onset, poor verbal IQ, left handedness, and right hemisphere memory dominance should alert neurosurgeons to the possibility of encountering essential language areas in the anterior temporal lobe (1.5–3.5 cm from the temporal tip). Naming and reading tasks are required to identify these areas. Whether removal of these areas necessarily induces long-term impairment in verbal abilities is unknown; however, in patients with a low verbal IQ and early seizure onset, these areas appear to be less critical for language processing.