New devices for direct transnasal surgery on pituitary adenomas.

A micro-pressure-suction-irrigation system (MPSIS) is a surgical device that cleans the operative field of blood and tumor tissues with one-hand manipulation, dissects tumor tissue with its rapid flow, and removes debris by suction without injury to the normal tissue structures. Since 1997, good transnasal surgical results for pituitary adenomas have been achieved in Japan using this system. However, the surgical results for large, fibrous pituitary adenomas were unfavorable. Ultrasonic surgical aspirators with needle-type probes and an electromagnetic field system, all recently developed in Japan, are improving the results of direct transnasal surgery on pituitary adenomas. The MPSIS effectively dissects typical adenoma tissue with rapid irrigation and removes it by suction. A tumor in the cavernous sinus was removed by this system under direct vision in combination with pituitary mirrors. Fibrous adenomas were resected using ultrasonic surgical aspirators with needle-type probes. Thick mucosa and a firm tumor were vaporized with an electromagnetic field system. The sellar floor was reconstructed with combined ceramics, used in cases requiring additional surgery or drainage of cerebrospinal fluid leakage during surgery. Direct transnasal surgery with these devices was performed to remove 143 pituitary adenomas. Most of these pituitary adenomas could be selectively removed except for those lesions with extensive cavernous sinus invasion. There was no surgical morbidity or mortality. With the advancement of surgical technique and the development of surgical devices, most pituitary adenomas, even those that are fibrous or firm, can be removed via the transnasal route.