Layer change concept for extracapsular removal of functional pituitary neuroendocrine tumors: technical note.

OBJECTIVE: Surgery for moderately large pituitary neuroendocrine tumors often identifies the normal pituitary gland on either the left or right side, whereas the layer of the normal pituitary gland becomes thinned or disappears on the opposite side (cavernous sinus side). Conventional extracapsular resection dissects the extra-pseudocapsular layer circumferentially to remove the tumor. However, a more reliable and easier approach is to dissect between the outer pituitary capsule and the medial wall of the cavernous sinus on the cavernous sinus side than the extra-pseudocapsular layer (the layer change technique). METHODS: We retrospectively reviewed 24 consecutive functional pituitary tumors, divided into cases treated with the layer-change procedure (LCP) and other procedures. RESULTS: Extracapsular removal with LCP was used mostly for growth hormone-, thyroid-stimulating hormone-, and prolactin-producing tumors, and medium 10-30 mm size tumors. There were no differences in surgical remission or complications. Postoperative hormone replacement was needed mainly in other procedure group, including patients with Cushing's disease after surgical remission. CONCLUSION: The LCP is a conceptual framework for extracapsular removal. This concept has the potential to improve the accuracy and safety of extracapsular removal for pituitary tumors.