The Zygomatic Osteotomy in Middle Cranial Fossa Surgery: A Retrospective Cohort Review

Background The zygomatic osteotomy, an adjunct to middle cranial fossa (MCF) surgical approaches, improves the superior–inferior angle of approach and minimizes temporal lobe retraction. However, the impact of the zygomatic osteotomy on approach-related complications has not been well documented. In this study, we evaluated complications associated with a zygomatic osteotomy as well as analyzed the factors predictive of a zygomatic osteotomy for middle fossa approaches.

Methods Retrospective review of all patients operated on via a MCF approach between 2005 and 2016 at our academic tertiary referral center. Demographic variables, tumor characteristics, surgical details, and postoperative complications were extracted from the medical record. For each case, the anticipated trajectory of approach was determined by the senior author independent of the data collected by the research team. Variables were analyzed as either continuous or nominal variables using SAS and SPSS. We utilized univariate and multivariate analyses to determine correlations between the zygomatic osteotomy and surgical complications while at the same time adjusting for confounding variables.

Results Use of zygomatic osteotomy: A total of 82 patients were analyzed. Fifty-three presented with a tumor, 11 with a basilar tip aneurysm, and 16 with other lesions, primarily cerebrospinal fluid leaks. Out of 82 patients, 19 (23%) received a zygomatic osteotomy, 47 (57%) were conducted using an anterolateral to posterior (A-P) trajectory, 33 (40%) straight lateral, and 2 (2.4%) posterolateral to anterior (P-A). In 15 out of 47 A-P trajectories, a zygomatic osteotomy was used compared with 4 of 29 in straight lateral, and 0 of 2 in P-A. Surgical trajectory was significantly correlated to use of the zygomatic osteotomy (p < 0.05). Among the 47 patients operated on with an A-P approach, we found (ROC curve) that the cutoff tumor size that best predicted a zygomatic osteotomy was 37 mm (sensitivity = 0.846 and specificity = 0.794). Complications of zygomatic osteotomy: Of the 82 cases, 18 patients had a complication (approach related = 10, systemic = 9 × sum over 100% due to a patient suffering both). The multivariate logistic regression model failed to reveal any significant correlation between complications and zygomatic osteotomies (p = 0.6299).

Discussion Our study demonstrated that the most important determinant in the decision to remove a patient’s zygomatic arch is the anticipated trajectory; specifically an A-P angle of approach was the most highly correlated with removal of the zygomatic arch. Within the category of patients operated on with an A-P approach, the size cutoff of 37 mm was a significant determinant in the decision of whether to perform a zygomatic osteotomy. At the same time, our findings indicated that the odds of suffering a surgical complication were not significantly different between the groups of patients who underwent zygomatic osteotomy versus those who did not.

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