CANDIDATE'S THESIS Minimally Invasive Pituitary Surgery

Objectives/Hypothesis: Surgical approaches to the pituitary have undergone numerous refinements over the last 100 years. The introduction of the endoscope and the advent of minimally invasive pituitary surgery (MIPS) have revolutionized pituitary surgery. This study aims to compile and evaluate outcomes of all of the MIPS performed at our institution. Study Design: Retrospective, cases series of 176 consecutive patients undergoing MIPS. Methods: Patient demographics, tumor characteristics, and intraoperative or postoperative complications for of 176 consecutive patients undergoing MIPS were complied. Statistical analysis for categorical variables and incidence across series were conducted using Pearson's chi(2) test and Fisher's exact tests. Odd ratios were calculated to relate the discrete variables to outcomes and designing clinical prediction of risk. Results: One hundred seventy-six patients who underwent 193 procedures. Pathologic evaluation revealed 147 of the tumors to be pituitary adenomas. Only one death occurred (mortality rate of 0.5%). The rate of diabetes insipidus occurred in 20.2% of the procedures. Vascular complications occurred in 5.2% of the procedures. Intraoperative cerebrospinal fluid (CSF) leaks were identified in 19.7% whereas postoperative CSF leak was noted in 10.3%. Resection of Ratlike's cleft cyst correlated higher risk of both intraoperative and postoperative CSF leak (OR = 2.6, P <.001). Resection of tumors other than adenomata correlated with significantly higher risk of CSF leak (OR = 9.0, P = <.001). Sinusitis occurred after eleven resections (5.7%). Meningitis occurred in 2 of 193 resections (1.0%) in our series. Two neurologic complications occurred in our series, pneumocephalus and cranial neuropathy (1.0%). No other complications occurred. Conclusions: MIPS is a safe and efficacious marriage of the endoscope to the transsphenoidal approach. Thus, a brightness and clarity of vision is combined with the unique ability to explore the tumor bed with angled views and hydroscopy. Outcomes and complication rates comparable to traditional transsphenoidal approaches have resulted but with less dissection and tissue manipulation, reduced need for packing, and greater patient comfort and acceptance.