Endocrine Abstracts

Introduction: Transsphenoidal surgery (TS) is used for pituitary and suprasellar tumors. It has a risk of damaging the pituitary axis and developing hypocortisolism, a potential life threating risk.

Objetive: Incidence of hypocortisolism after TS, postsurgery cortisol (PSC) levels that predict hypocortisolism and potential risk factors for hypocortisolism after TS.

Methods: Prospective study in patients who underwent TS in 2016. Glucocorticoid replacement (GR) began in surgery with hydrocortisone (HC) 100 mg tid. We defined hypocortisolism as PSC<10 mcg/dl (discharged with HC 20 mg/day), possible hypocortisolism as PSC 10–20 mg/dl (discharged with HC 10 mg/day) and eucortisolism as PSC >20 mcg/dl 3 days after TS. Definitive eucortisolism was defined as Cortisol >18 mcg/dl after 100 mcg ACTH stimulation or basal cortisol >20 mcg/dl 5 weeks after TS.

Results: Twenty-three (12 females) patients underwent TS, mean age 52 years (22–85): 56%nonfunctioning adenomas, 20%GH adenomas, 4%arachnoid cyst and 8%craniopharyngioma. Preoperative features: tumor’s mean diameter: 25 mm (5–65), involvement of cavernous sinuses (KNOSP grade≥2) 60%. Five patients present preoperative hypocortisolism. Pituitary-adrenal axis (PAA) assessment: After TS 9 patients were diagnosed of hypocortisolism, 13 of possible hypoC and 1 of eucortisolism. Five week after TS: 8 were diagnosis of definitive hypocortisolism and 15 of definitive eucortisolism. Mean PSC was 13.5 mcg/dl (2.28–22.5) in definitive eucortisolism patients and 8.75 mcg/dl (1.2–14.35) in definitive hypocortisolism. 75% with definitive hypocortisolism patients had PSC <12 mcg/dl. In patients with definitive hypocortisolism: 60% presented preoperative hypocortisolism, 30% preoperatory GH deficit, 60% cavernous sinuses involvement, with KNOSP grade >2 and 50% were >30 mm.

Conclusions: Hypocortisolism after TS is a mayor complication; large and invasive tumors have more risk to develop postsurgery pituitary hypofunction. Three days PSC can predict development of definitive hypocortisolism, PSC ≥15 mcg/dl may be use to diagnose eucortisolism and avoid unnecessary replacement HC treatment in this patients.