The supracondylar approach to the jugular tubercle and hypoglossal canal

BACKGROUND Circumscribed lesions of the hypoglossal canal and of the jugular tubercle still remain a surgical challenge. So far, transpetrosal, transcondylar sub occipital, and extreme lateral approaches have been used to access this reg ion. These surgical procedures beau a high risk for neurological deficits. Therefore, we introduce a new minimally invasive extradural approach to the hypoglossal canal that also allows access to the lateral aspects of the ju gular tubercle. METHODS After a paramedian retromastoid skin incision, a basal suboccipital craniec tomy lateral to the foramen magnum toward the jugular tubercle is performed . With this approach the occipital condyle and the lateral osseous circumfe rence of the foramen magnum are preserved. Drilling extradurally, the dorsa l parts of the jugular tubercle are removed. The exposure is extended downw ard to the posterior margins of the hypoglossal canal and laterally to the jugular bulb, enabling a minimally invasive exposure of the hypoglossal can al, the lateral aspects of the jugular tubercle, and medial aspects of the jugular bulb. RESULTS Using this supracondylar approach, surgical interventions were performed in three patients suffering from a hypoglossal neurinoma, a cholesterol granu loma extending into the jugular tubercle, and a cyst of the hypoglossal can al, respectively No additional postoperative neurological deficits were see n. CONCLUSIONS The supracondylar approach seems to be useful to gain access to benign lesi ons of the hypoglossal canal and of the jugular tubercle to decompress tumo rs or cysts. In contrast to previously reported techniques this approach ha s a low risk of morbidity. The surgical field, however, is restricted later ally by the jugular bulb, medially and basally by the residual occipital co ndyle and dorsally by the dura. Therefore, this approach is useful to remov e small lesions or to perform extended biopsies. Radical removal of large t umors seems to be problematic using this approach. (C) 1998 by Elsevier Sci ence Inc.