Stereotactic approach to skull-base lesions

Stereotactic biopsy approach to the upper clivus through the middle fossa floor that avoids pneumatised cavities and the intradural compartment

BACKGROUND

Biopsies of clival lesions are usually performed, under general anaesthesia, through an anterior endoscopic approach or, alternatively, through a trans-nasal or trans-oral stereotactic approach.

METHODS

A 57-year-old man with a symptomatic osteolytical lesion of the clivus, who refused general anaesthesia, underwent a sterotactically guided biopsy of the lesion by an antero-lateral approach through the temporal and sphenoid bones.

RESULTS

Biopsy was successfully performed and the resulting diagnosis was myeloma. The patient was comfortable during and after surgery and there were no complications.

CONCLUSIONS

The present stereotactic antero-lateral approach to the biopsy of the upper clivus can be considered an useful adjunct to the current trans-oral and transnasal approaches that often require general anaesthesia.

Transnasal access for sampling a skull base lesion

SUMMARY

Transnasal needle access for sampling was used in two patients with posterior nasopharyngeal lesions. The procedure was performed under CT guidance. This new technique is simple and appears suitable for selected cases. The two cases and the details of the procedure are described.

[Image guided stereotactic approach of central nervous system lesions: accuracy, morbidity, mortality]

We studied seventy-five patients with brain lesions biopsied by stereotaxis from March 1993 to December 1998 at Universidade Federal de São Paulo-Escola Paulista de Medicina. The three most frequent lesions were: metastasis, low grade astrocytomas and glioblastoma multiforme. The morbidity rate was 2.66% due to: one case of scalp infection in a patient with thalamic cyst; and a partial seizure during surgery in a patient with lymphoma. The mortality rate was 1.33% due to increasing of cerebral edema after biopsy and the patient died after one week. The diagnostic accuracy was 89.33%.

Modifications of transnasal and transoral stereotactic procedures--technical notes

Stereotactic transnasal and transoral procedures have been reported by different authors in the past. In this paper, several modifications of these methods are described. The modifications are: transnasal approach to the frontal skull base and suprasellar regions; and transoral approaches to the clivus, the petroclival junction, medial part of the cerebellopontine angle and the lateral mass of C-1. Eleven patients were operated on using these modifications. The procedures were for biopsy and brachytherapy. No complications resulted from the procedures.