Endoscopic Transnasal Surgical Technique
for Pituitary Tumors

Since the 1970s, the standard surgical approach for resection of most pituitary tumors has been the transsphenoidal technique. In the mid 1990s, Mayo Clinic surgeons began using the nasal endoscope in a modification of the standard surgical approach. This new endoscopic transnasal technique decreased operative time, length of hospital stay, and patient discomfort, without compromising surgical success.

Sublabial Transseptal Approach

John Atkinson, M.D., of the Department of Neurosurgery at Mayo Clinic in Minnesota, says, "The sublabial transseptal approach had been the standard procedure for resection of pituitary tumors at Mayo Clinic since the 1970s. This approach to the sphenoid sinus involves making a sublabial incision for access to the nasal cavity and then removing the nasal septum. The sphenoid sinus is entered, allowing access to the sella turcica. After resection of the tumor, the nasal septum is replaced, requiring nasal packing postoperatively."

Sublabial transseptal surgical approach

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Endoscopic Transnasal Approach

Dr. Atkinson explains, "The endoscopic transnasal technique requires no external incision. The nasal endoscope is advanced through a nostril to the anterior wall of the sphenoid sinus. The sphenoid sinus ostium is enlarged, and the posterior portion of the vomer is removed, allowing access to the sphenoid sinus. After placement of a self-retaining nasal speculum, the sella turcica is entered, and the neurosurgical portion of the procedure is undertaken as with the sublabial transseptal approach. After resection of the tumor, the nasal speculum is withdrawn, the nasal septum is adjusted to midline if necessary, and a mustache nasal dressing is applied."

Endoscopic Transnasal Approach vs. Sublabial Transseptal Approach

The similarities and differences between the two techniques are summarized in Table 1. Dr. Atkinson notes, "The main difference from the surgeon's standpoint is that with the endoscopic transnasal approach the surgical field is smaller and is angled approximately 10° off center. The disadvantages that these factors present for the surgeon can be overcome with experience. For the patient, the absence of the sublabial incision eliminates the possibility of postoperative lip numbness. Also, leaving the nasal septum intact decreases postoperative discomfort from nasal packs and reduces the chance of complications related to manipulation of the nasal septum."

A retrospective case-controlled analysis of the initial experience at Mayo Clinic with the endoscopic transnasal technique for resection of nonfunctioning pituitary macroadenomas was published in 1999. This study compared the operative outcomes of patients who had the standard sublabial transseptal procedure with the outcomes of patients who had the endoscopic procedure during the first three years after it was introduced. The results showed no differences in completeness of tumor resection, change in visual field defects, or alterations in pituitary function between the two groups. Operative time, anesthesia time, and length of hospital stay were less in the endoscopic transnasal group.

A subsequent case-controlled analysis of the experience at Mayo Clinic with the endoscopic transnasal technique for resection of corticotropin-secreting pituitary microadenomas was published in 2008. This study compared the operative outcomes of patients who had the standard sublabial transseptal procedure with the outcomes of patients who had the endoscopic procedure. The results showed no differences in Cushing's syndrome cure rates or in complications between the twp groups. Anesthesia time, blood loss, and length of hospital stay were less in the endoscopic transnasal group.

Surgical field for endoscopic transnasal surgery

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Perioperative Management

Charles Abboud, M.D., of the Division of Endocrinology, Diabetes, Metabolism, and Nutrition at Mayo Clinic in Minnesota says: "The endoscopic transnasal approach has now become the standard procedure for removal of functioning and nonfunctioning pituitary adenomas and other sellar masses. Currently, Mayo Clinic neurosurgeons perform approximately 120 transsphenoidal procedures per year. Patients without medical or surgical complications (about 90 percent) are typically dismissed the morning of the day after surgery and are seen as outpatients by the endocrinologist that afternoon. Any immediate postoperative hormonal deficiencies are treated, and a plan to assess for late postoperative hormonal and surgical complications is developed."