Endoscopic Endonasal Surgery for Recurrent Pituitary Tumors: Technical Challenges to the Surgical Approach

Pituitary adenoma resection is achieved from various approaches, the most common being microscopic, speculum-based transnasal or sublabial transsphenoidal resection. Rates of tumor recurrence following this technique range from 30%–40%.

Two-surgeon, purely endoscopic endonasal techniques, with the option of expanded exposure, offer the potential advantage of increased visibility of the supra- and parasellar regions, allowing more complete tumor resection, even for cases of recurrent pituitary tumors. However, the scarring and altered anatomy that result from the previous dissection make revision surgery a technically challenging endeavor. We review our experience in a series of patients who underwent revision endoscopic pituitary surgery following previous microscopic, speculum-based transnasal or sublabial approaches.

Records were reviewed of 151 patients who underwent endoscopic endonasal pituitary surgery between February 2008 and August 2010. Of these, 26 patients had previous microscopic-speculum-based approaches. Speculum-based approaches are nearly always done through the right nostril. As a result, there was increased scarring and loss of anatomical landmarks in the right posterior nasal cavity and sphenoid region. Our most frequent form of skull base reconstruction is the nasoseptal flap, elevated from the right septum. However, in one patient a septal perforation did not allow a nasoseptal flap elevation. In another patient, the pedicle of the right-sided flap became detached due to the previous dissection of the right anterior clival wall. Because of the right-sided posterior nasal scarring encountered, a left-sided nasoseptal flap was successfully utilized in six patients. Image guidance was used in 22 patients. There were 13 intraoperative CSF leaks, which were repaired using a combination of techniques. There was only one delayed CSF leak on postoperative day 23, requiring operative repair with an abdominal fat graft.

In conclusion, revision endoscopic pituitary surgery following microscopic, speculum-based approaches is technically challenging. Because the previous approach was likely through the right nostril, we have found it advantageous to elevate the nasoseptal flap from the left side. Intraoperative CSF leaks are frequent and should be addressed with appropriate reconstructive techniques. The use of image guidance should be considered because of the altered anatomic landmarks.