Respective indications for orbital rim, zygomatic arch and orbito-zygomatic osteotomies in the surgical approach to central skull base lesions. Critical, retrospective review in 146 cases

Background Orbital Rim (ORo) Zygomatic Arch (ZAo) and Orbito-Zygomatic (OZo ) osteotomies can be useful adjuncts to the classical Fronto-Pteriono-Tempo ral craniotomy in facilitating the exposure of deep seated skull base lesio ns, sparing brain retraction injuries. Based on a review of 146 "operated" cases, the authors suggest their guidelines for patient selection for each of these osteotomies. Method. 146 lesions (100 central skull base tumors, 29 deep vascular lesion s and 17 mesial temporal epileptogenic foci) were surgically treated by the senior author between 1988-1999 using ORo (59 cases), ZAo (12 cases) and O Zo (75 cases). The lesion were radically cured in 85% of the cases. A retrospective critical analysis of patients' records by an independent ob server evaluated: 1) - the usefulness and the appropriateness of the perfor med osteotomy for obtaining an optimal approach to the lesion and 2) - morb idity related to the osteotomy and to brain retraction. Findings. In only one case, the osteotomy (ORo) was found not to be useful. An other 17 patients who underwent OZo would have benefited from a reduced osteotomy (ORo in 15 cases, ZAo in 2 cases). In another case an ORo was fo und insufficient for an effective exposure of the lesion. Osteotomy-related morbidity rate was 10.2% (15 patients), mostly due to tra nsient Temporo Mandibular Joint dysfunction. In spite of an appropriate approach, 12 patients (8.2%) showed neurological deficits (temporary) and/or CT manifestations attributable to brain retrac tion. Interpretation. The additional osteotomies were found useful and relatively safe in facilitating the exposure of most of the lesions in this series. A target (rather than pathology) and surgical axis oriented list of indicati ons for ORo, ZAo and OZo is given.