Evolution of a Microsurgical to Endoscopic Practice for Treatment of Pituitary Tumors and Skull Base Lesions: Importance of Multidisciplinary Team Approach and Learning Curve

Introduction: Transnasal surgery for parasellar lesions has existed for nearly a century. With the introduction of the microscope in 1967, Hardy revolutionized microsurgical transsphenoidal surgery, which became standard practice over the next 30 years. More recently, the endoscope has been used to treat pituitary tumors and other skull base pathologies. The advancement of endoscopic skull base surgery has allowed surgeons to gain access to lesions beyond the confines of the sella. In this report, we describe the evolution of our endonasal transsphenoidal practice from primarily a microsurgical to an endoscopic practice over the course of 4 years.

Methods: We retrospectively reviewed a prospective database of endonasal cases performed by the senior author from July 2007 to September 2011. In total, 171 patients were divided into two groups. Group A patients (n = 73) were operated on prior to July 2009; Group B patients (n = 98) were operated on after July 2009. We evaluated the type of technique used (microscope vs. endoscope), types of pathology treated, and CSF leak rates.

Results: Over the 4-year course, there was a significant shift from using a microsurgical technique to primarily a fully endoscopic technique (fourfold increase). Microsurgical technique was used in 76.7% in Group A and 6.1% in Group B (P < 0.05). A purely endoscopic technique was used in 23.3% in Group A and 93.9% in Group B (P < 0.05). There were significantly more pituitary tumors treated in Group A (75.3%) than Group B (40.8%, P < 0.05). However, in Group B, there was a significant increase in the number of extrasellar pathologies treated (59.2% vs. 24.7%, P < 0.05), including craniopharyngiomas, meningiomas, and sinonasal tumors. There were no significant differences in postoperative CSF leaks between Groups A and B (2.7% vs. 2.0%, respectively).

Conclusion: This data represents a significant change in practice patterns from a microsurgical to an endoscopic approach. This is largely due to the senior author's adoption of the endoscopic technique because of its advantages of better illumination, panoramic visualization, and increased access to pathologies beyond the sella. There appears to be a learning curve with endoscopic skull base surgery. With increased experience and using a multidisciplinary team approach, more complex extrasellar lesions can be readily removed with low complication rates.