Comparison Study between Conventional and 3-Dimensional Nasal Endoscopy for Resection of Skull Base Tumors

Objective: The endoscopic approach to the skull base is a well-established method for removal of skull base tumors and for reconstruction of cranial base defects. However, the main drawback of conventional endoscopes is their 2-dimensional view, which limits depth of perception and hence the surgeon's ability to detect anatomical structures at the skull base. Our goal was to evaluate the utility of a novel 3-dimensional (3D) endoscopic system for excision of skull base tumors.

Methods and Patients: Of 65 cases operated on via the 3D endoscopic approach (3DEA), 12 were operated on via a combined subfrontal-endoscopic approach. Eleven patients (17%) were operated on for excision of malignant tumors and 48 (74%) for benign lesions. In six patients (9%), the 3DEA was used for skull base reconstruction and in one for osteomyelitis. Sixteen patients (25%) had undergone previous surgery. Tumors involved the anterior skull base (n = 15), sphenoid and planum (n = 29), clivus (n = 10), sella (n = 23), and cervical spine (n = 3) regions. Reconstruction was performed with nasal septal flap, bone flap, or fascia lata for defects with high-flow leaks (n = 21) and with fat for low-flow leaks (n = 18).

Results: Complete macroscopic tumor resection was accomplished in 55/58 tumor cases. One patient had perioperative complication that included gram-negative meningitis (1.5%). There were no postoperative cerebrospinal fluid (CSF) leaks, pneumocephalus, intracranial bleeding, or mortality. We evaluated the surgeon's ability to promptly recognize anatomical structures at the skull base using 0° and 30° 3D and conventional endoscopes. The 3DEA technique was superior to the conventional technique for identification of the sellar region, carotid prominence, optic prominence, cribriform plate, and fovea ethmoidalis (P < 0.0001), but not for detection of the turbinates, clivus, sphenoid, maxillary, ethmoidal, and frontal sinuses.

Conclusion: Use of 3D endoscopic skull base surgery is feasible for resection of tumors and reconstruction. Stereoscopic view via endoscopes allows easier recognition of anatomical landmarks at the skull base, but do not offer significant advantage in the paranasal sinuses and nasal cavity.