Anterior clivectomy: surgical technique and clinical applications

Abstract

Object Midline clival lesions, whether involving the clivus or simply situated anterior to the brainstem, present a technical challenge for adequate exposure and safe resection. The authors describe, as a minimally invasive technique, an anterior clivectomy performed via an expanded transsphenoidal approach coupled with the use of a neuronavigation on mobile head and endoscopic-assisted technique. Wide and direct exposure, with the ability to resect extra- and intradural tumors, was achieved without mortality and with a low rate of complications. Methods Cadaveric dissections were performed to outline the landmarks and measure the window that is created by resecting the clivus anteriorly. The technique was used in 43 patients to resect tumors located at or invading the clivus. The initial exposure of the clivus was obtained via the sublabial transsphenoidal approach. The wall of the anterior maxilla, often on 1 side, was removed to allow a wide side-to-side opening of the nasal speculum. Using neuronavigation, the authors made clivectomy windows by drilling the clivus between anatomical landmarks. Bilateral intraoperative neurophysiological monitoring was used (somatosensory evoked potentials, brainstem auditory evoked responses, and cranial nerves VI–XII). Results Of the 43 patients, 26 were female and 17 were male, and they ranged in age from 3.5 to 76 years (mean 41.5 years). Thirty-eight patients harbored a chordoma and 5 a giant invasive pituitary adenoma. Gross-total resection of the tumor was achieved in 34 cases (79%). Nine patients (21%) had residual tumor unreachable through the anterior clivectomy, and this required a second-stage resection. Four patients developed new transient extraocular movement deficits. One patient developed a permanent cranial nerve VI palsy. Twenty-seven patients with chordoma underwent postoperative proton-beam radiotherapy. Tumor recurred in 19% of these cases. In 3 patients a cerebrospinal fluid leak developed during hospitalization and was treated successfully. Two other patients presented with a delayed cerebrospinal fluid leak after radiotherapy. Only 1 patient, who had previously undergone Gamma Knife surgery, experienced postoperative hemiparesis. Conclusions A complete anterior clivectomy via a simple extension of the transsphenoidal approach allows the surgeon access to different lesions involving the clivus or situated anterior to the brainstem. The exposure is similar to that provided by more extensive transfacial approaches. Instrument manipulation is easy. Neuronavigation, endoscopy, and intraoperative monitoring are easily incorporated and enhance the capability and safety of this approach.

Clival Invasion on Multi-Detector CT in 390 Pituitary Macroadenomas: Correlation with Sex, Subtype and Rates of Operative Complication and Recurrence

“…The few reports published to date have not reported series of sufficient size to establish the characteristic clinical, pathologic, and imaging attributes of clival invasion by pituitary adenoma. [6][7][8][9] In our study population, most patients with macroadenoma presented in the fourth and fifth decades of life; the frequency and size of macroadenoma were nearly equal in men (53.33% of cases; 5.92 Ϯ 7.63 cm 3 ) and women (46.67%; 5.73 Ϯ 7.22 cm 3 ); the proportion of null-cell pituitary macroadenoma was 36.4% (142/390). These population statistics are similar to previous reports, [10][11][12][13] suggesting that this sample, though retrospective, may be a relatively good representation of the general population of patients with adenoma.…”

Level I to III craniofacial approaches based on Barrow classification for treatment of skull base meningiomas: surgical technique, microsurgical anatomy, and case illustrations

“…16 The absence of intraoperative shifts in skull base surgery provides the opportunity to use neuronavigation reliably and accurately and enhance the surgeon's ability to localize and verify the anatomical structures. 2 The use of the endoscope in addition to the surgical microscope has been reported to afford a wide panoramic view in the depths of the surgical field.…”

Critical Appraisal of Extent of Resection of Clival Lesions Using the Expanded Endoscopic Endonasal Approach

“…12,[14][15][16]20,[25][26][27][28][29][30] Our experience with clival lesions accessed using the EEEA complements the experience of others in that this approach can be highly effective in removing these surgically challenging lesions. We were able to achieve > 95% resection rate in 81% of the cases for which a GTR was attempted.…”