Computer-assisted resection of benign sinonasal tumors with skull base and orbital extension.

OBJECTIVE

To use freehand, real-time, intraoperative, 3-dimensional computed tomography (3-D CT) localization to assist with resection of sinonasal lesions with skull-base and/or orbital extension.

DESIGN

The 3-D CT is computer-assisted technology using the preoperative CT scan as a road map for resection of lesions. Previous technology, while resulting in little intraoperative error, required use of a somewhat cumbersome rigid articulated arm and attached probe, limiting mobility and requiring rigid fixation of the head to maintain system reference. A new freehand version of this technology, eliminating these limitations, has been used for resection of benign sinonasal lesions with skull-base and/or orbital extension.

SETTING

Tertiary care, university-based practice.

PATIENTS: Seven patients prospectively selected with benign lesions involving the sinonasal cavity and orbit and/or skull base.

INTERVENTION: All patients underwent surgical resection of their tumors using endoscopic, open, or combined procedures with the assistance of freehand 3-D CT localization. MAIN OUTCOME ASSESSMENTS: Surgeon assessment of usefulness.

RESULTS

In several cases, the device assisted the operator in determining the exact location of a displaced optic nerve, ensuring vision preservation, while in other cases, the location and depth of skull-base penetration was clearly determined, allowing resection via a transnasal endoscopic approach. In addition, the device was useful for determining the depth of necessary resection for optimal cosmetic result. In all cases, system accuracy was within less than 2 mm at the operative site. System limitations included need for an additional preoperative CT and time required at the beginning of the case for system setup and registration.

CONCLUSIONS

Freehand 3-D CT, while still with limitations, offers the advantage of increased surgical safety, aiding anatomic understanding in distorted surgical fields for resection of benign sinonasal tumors with orbital and skull-base extension.