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Comparison of the exposure obtained by endoscope and microscope in the extended trans-sphenoidal approach.

OBJECTIVE
Trans-sphenoidal surgery is often combined with other approaches for the treatment of middle cranial base tumors. By combining a maxillotomy with trans-sphenoidal approach, significantly wider exposure to these regions is gained. However, endoscope-assisted techniques have also been used for sellar and parasellar and upper clival regions.


METHODS
An extended trans-sphenoidal approach was performed on 10 cadaver heads using the operating microscope and was repeated with a 0-degree endoscope. The mean horizontal and vertical distances were measured and pictured for each technique, and both distances were compared using a parametric paired Student's t-test.


RESULTS
The mean horizontal distances in the 10 specimens were 19.5 +/- 1.8 mm by microscope and 27.5 +/- 2.2 mm by endoscope, and the mean vertical distances were 25.8 +/- 1.9 mm by the microscope and 34.5 +/- 3.5 mm by the endoscope.


CONCLUSION
The aim of this study was to quantify the amount of exposure obtained with an extended trans-sphenoidal approach and to compare both endoscopic and microscopic techniques. Using the endoscope in conjunction with the operating microscope may provide additional exposure and better access in skull base surgery.