Defining the "edge of the envelope": patient selection in treating complex sellar-based neoplasms via transsphenoidal...

Endonasal approaches have become the gold standard intervention for many anterior and middle skull base tumors. The authors aimed to define some of the existing limitations of these approaches by reviewing their experience with complex sellar region tumors that were initially considered for both transsphenoidal and open skull base approaches and were thus deemed tumors at "the edge of the envelope."

Between April 2008 and April 2010, 250 transsphenoidal operations were performed at Brigham and Women's Hospital. All cases were retrospectively reviewed to identify patients with complex sellar region tumors that were initially considered for, or soon thereafter required, an open craniotomy as the definitive treatment. The anatomical tumor characteristics that posed limitations to performing safe and effective endonasal skull base operations were reviewed.

Thirteen cases exemplifying some of the existing limitations to achieving optimal surgical outcomes via transsphenoidal-based approaches are presented. The following 8 factors are separately discussed that repeatedly limited the extent of resection, increased the risk of the operation, and contributed to perioperative complications: significant suprasellar extension, lateral extension, retrosellar extension, brain invasion with edema, firm tumor consistency, involvement or vasospasm of the arteries of the circle of Willis, and encasement of the optic apparatus or invasion of the optic foramina.

Although the ability to approach and resect complex tumors using endonasal skull base techniques has evolved dramatically in recent years, several inherent tumor characteristics mandate extensive preoperative consideration. In selected cases these characteristics may lend support to selecting an open craniotomy as the initial operation.