Transcranial echo-guided transsphenoidal surgical approach for the removal of large macroadenomas.

Abstract

Transsphenoidal surgery for the removal of macroadenomas has some disadvantages, including the risk of performing procedures without adequate visualization, difficulties in estimating the amount of residual tumor, and the risk of injuring major vessels. To overcome these disadvantages, the authors have developed transcranial echo-guided transsphenoidal surgery. Three patients with large macroadenomas and two patients with irregularly shaped macroadenomas were selected for this operation. In addition to standard preparations for transsphenoidal surgery, in each case the right frontal bone was trephined and an echo probe was inserted transdurally through the trephination hole. During tumor removal, brightness-mode echo images and Doppler color flow images were obtained. The echo images allowed for real-time visualization of the tumor and surrounding brain structures including major arteries and the cisterns; histological heterogeneities of the tumor could also be appreciated. The tumors were removed safely and maximal tumor removal was achieved. Transcranial echo-guided transsphenoidal surgery provides real-time visualization of tumor removal. The method enhances the safety of this surgery, maximizes the removal of the tumor, and is inexpensive.