Disturbances in fluid and electrolyte balance can complicate surgery for pituitary and sellar lesions. Our previous study (Kelly et al, 1995) in patients with the standard microscopic transsphenoidal approach revealed an incidence of postoperative symptomatic hyponatremia of 5% in 99 patients.

     We sought to determine whether the endoscopic approach provided any benefit with regard to this complication.

     This retrospective review included 316 consecutive endoscopic pituitary/anterior skull base procedures done during a 34 month period ending March 2011 by a single surgeon. Pathology included 230 pituitary adenomas, 48 craniopharyngiomas/RCCs, 9 arachnoid cysts, 10 CSF leaks and 19 miscellaneous lesions.

     This retrospective review included 316 consecutive endoscopic pituitary/anterior skull base procedures

     Symptomatic hyponatremia (Na below 130) developed in 16 patients (5%). Symptoms included nausea/vomiting (73%), dizziness/lethargy (60%), Headache (40%), abdominal pain (30%), anorexia (20%), and seizures (6%). The major risk factor was the presence of a macroadenoma. Another 5.6% of our patients developed asymptomatic hyponatremia. Permanent Diabetes insipidus developed in 2.5%, and transient DI was seen in 7.6%. Among the patients with symptomatic hyponatremia, the nadir sodium was 122.8, and the nadir occurred most frequently on postop day 7.

     This is a retrospective study.

     The incidence of symptomatic hyponatremia in patients undergoing the endoscopic procedure was identical to that found in the prior study of microscopic pituitary surgery.

     This implies that the endoscopic approach offers no specific advantages with regard to fluid and electrolyte complications.