electromyography. The seventh, 11th, and 12th cranial nerves were monitored unilaterally by needle insertion into the corresponding muscle. Surgical Approach The surgical approach was tailored according to the findings of preoperative imaging, the local anatomy, and the tumor's characteristics and extension in each patient. This is a paradigm applied to skull base meningiomas. 14 Although the approaches for tumor resection, in a broader sense, were variations of the transcondylar approach, in detail and concept three different routes were used ( Fig. 1 ): 1) the
Kenan I. Arnautović and Ossama Al-Mefty
Benedicto O. Colli and Ossama Al-Mefty
makes surgical access to these tumors difficult, and the patterns of spread of various skull base chordomas preclude the use of a single surgical approach. Approaches to skull base chordomas should be based on the characteristics of growth in each case, and sometimes two or more procedures may be necessary to achieve a radical removal. Extensive excision has an important role in the treatment of skull base chordomas; however, sometimes unacceptable procedure-related morbidity may occur. Currently, many authors consider that most cases of chordoma should be treated by
Jason A. Heth and Ossama Al-Mefty
Cavernous sinus meningiomas were once considered unresectable. The development of microsurgical and skull base techniques as well as advances in anesthesia and neuroradiology have allowed safe and systematic treatment of these lesions. Proper evaluation and patient counseling are required. A thorough understanding of the anatomy and surgical approaches are crucial to success, as is knowledge of the possible adverse outcomes including cranial neuropathy and stroke. The authors discuss these issues in the treatment of cavernous sinus meningiomas.
Benedicto O. Colli and Ossama Al-Mefty
Chordomas are rare tumors that arise from the remnants of the notochord. Because of their deep location, local infiltrative nature, and involvement of surrounding bone, treatment of chordoma is a challenge. The authors analyze the data and prognostic factors obtained during the follow-up period (range 1–150 months, median 38 months) in 53 patients with craniocervical junction chordoma and 10 patients with chondrosarcoma.
Several surgical approaches were used, and some tumor excisions required staged procedures. Survival was calculated according the Kaplan–Meier method. Statistical analysis was performed using the Fisher exact and Kruskal–Wallis tests. Radical/subtotal resection was achieved in 77.8% of the patients. The mortality rate during the follow-up period was 14.3%. In patients harboring chondrosarcoma better 5-year recurrence-free survival (RFS) rates were demonstrated than in those with chordoma (100% and 50.7%, respectively). Histological patterns (typical or chondroid chordoma) and patient age at onset of symptoms had no effect on the RFS rates. Radical/subtotal resections were associated with better RFS rates than partial resection. Adjuvant proton-beam radiotherapy was shown to increase the RFS rates compared with conventional radiotherapy (90.9% and 19.4%, respectively at 4 years posttreatment). Karyotypically abnormal tumors were associated with worst RFS rates as compared with karyotypically normal lesions (44.5% and 90.3%, respectively at 3 years). Cases of cranial nerve palsy, followed by CSF leakages were the most frequent postoperative complication. Permanent postoperative neurological deficit was observed in 28.6% of the patients.
A better prognosis was observed in patients with chondrosarcoma compared with those harboring chordoma. Histological pattern and the patient's age at symptom onset were not factors that influenced prognosis in cases of chordoma. Extensive resection and possibly adjuvant proton-beam radiotherapy provided better prognosis for these patients.
Paulo A. S. Kadri and Ossama Al-Mefty
Schwannomas of the jugular foramen are rare, comprising between 2 and 4% of intracranial schwannomas. The authors retrospectively analyzed their surgical experience with schwannomas of the lower cranial nerves that presented with intra- and extracranial extensions through an enlarged jugular foramen. The transcondylar suprajugular approach was used without sacrificing the labyrinth or the integrity of the jugular bulb. In this report the clinical and radiological features are discussed and complications are analyzed.
This retrospective study includes six patients (three women and three men, mean age 31.6 years) with dumbbell-shaped jugular foramen schwannomas that were surgically treated by the senior author during a 5.5-year period. One patient had undergone previous surgery elsewhere. Glossopharyngeal and vagal nerve deficits were the most common signs (appearing in all patients), followed by hypoglossal and accessory nerve deficits (66.6%). Two or more signs or symptoms were present in every patient. Three tumors presented with cystic degeneration. In four patients the jugular bulb was not patent on neuroimaging studies. The suprajugular approach was used in five patients; the origin of the tumor from the 10th cranial nerve could be defined in three of them. All lesions were completely resected. No death or additional postoperative cranial nerve deficits occurred in this series. Aspiration pneumonia developed in one patient. Preoperative deficits of the ninth and 10th cranial nerves improved in one third of the patients and half recovered mobility of the tongue. No recurrence was discovered during the mean follow-up period of 32.8 months.
With careful, extensive preoperative evaluation and appropriate planning of the surgical approach, dumbbell-shaped jugular foramen schwannomas can be radically and safely resected without creating additional neurological deficits. Furthermore, recovery of function in the affected cranial nerves can be expected.
Ossama Al-Mefty and Luis A. B. Borba
tumors. Nevertheless, their uncertain biological behavior and patterns of extension through the base of the skull remain the main limiting factors for treating skull base chordomas. In this article, we review the management of 25 patients with pathologically determined skull base chordomas, among them 23 patients who underwent skull base surgical procedures by the senior author (O.A.). We used a variety of surgical approaches to achieve radical removal. We present a critical review of the indications and limitations of the surgical approaches and radiation effects
Ossama Al-Mefty and Aramis Teixeira
an attempt at total tumor removal. Gross-total removal was determined intraoperatively and confirmed by postoperative MR images in 24 patients. Four patients harbored small residual tumors. The surgical approach was tailored according to the patient's anatomy, condition, and deficits ( Table 4 ). Transposition of the facial nerve was avoided in all patients with bilateral lesions and was necessary in only five cases. Three technical maneuvers deserve particular emphasis and are described in the following subsections. TABLE 4 Surgical approaches in 28
Ossama Al-Mefty and Vinod K. Anand
temporal muscle, obviating basal obstruction which occurs if the muscle is folded downward. Discussing surgical approaches to tumors of the infratemporal fossa in 1964, Conley 5 stated that “the simplest approach is through the temple, following the temporalis muscle underneath the zygomatic arch to the coronoid process.” This simple and direct approach, however, was overshadowed by more extensive and radical approaches, ranging from a posterior transtemporal to an anterior transmaxillary approach. We encountered descriptions of similar exposures by Wetmore, et al
Kenan I. Arnautović and Ossama Al-Mefty
towels are replaced, and a clean set of instruments and new gloves are used to perform closure. We also use a clean set of instruments and new gloves and drapes when harvesting fat from the abdomen. In general, all instruments that came in contact with the tumor are considered contaminated. If seeding of the chordoma is diagnosed during the follow-up period, it is treated aggressively and radically, as is any recurrence at the primary site or metastasis. As the results of this study suggest, no particular surgical approach is predisposed to the seeding of tumor cells
Uğur Türe, M. Gazi Yaşargil and Ossama Al-Mefty
experienced neurosurgeons. The numerous publications describing various surgical approaches attest to the difficulties that are encountered when exploring this area. It was not until the 20th century that surgeons ventured to explore the third ventricle, when Dandy 11 described a transcortical—transventricular approach to the third ventricle, partially resecting the frontal lobe to remove a colloid cyst. Later, many neurosurgeons used this approach, with the addition of a cortical incision, particularly in those patients presenting with ventriculomegaly. 1, 6, 7, 10, 17