Predictive Value of Postoperative Plasma Concentrations of ACTH, Α-MSH and Cortisol for Recurrence of Cushing's Disease After Transsphenoidal Hypophysectomy in Dogs
Transsphenoidal hypophysectomy is an effective treatment for Cushing's disease or pituitary-dependent hypercortisolism (PDH) in the dog. However, recurrences occur after initial remission. The aim of this study was to analyze the predictive value of immediate postoperative plasma concentrations of ACTH, α-MSH, and cortisol for recurrence after transsphenoidal hypophysectomy in dogs with PDH.
Transsphenoidal hypophysectomy was performed in 55 dogs with PDH. Plasma concentrations of ACTH, α-MSH, and cortisol were measured before surgery and 1, 2, 3, 4, 5 and 24 to 48 hours after removal of the pituitary gland. The prognostic value of the hormone concentrations for recurrences (disease-free period) was analyzed with univariate Cox proportional-hazard analysis followed by stepwise multivariate analysis.
Forty-eight of the 55 dogs went into remission. Median disease-free period was 569 days. Hypercortisolism recurred in 12 dogs after median 255 days. Postoperative plasma ACTH, cortisol and α-MSH concentrations at 4 and 5 hours after removal of the pituitary gland were significantly associated with recurrence. In multivariate analysis the plasma ACTH concentration remained significant.
It is concluded that immediate postoperative measurement of plasma concentrations of ACTH, α-MSH and cortisol is a valuable tool for evaluation of long-term outcome after transsphenoidal hypophysectomy in dogs with Cushing's disease.
Originally presented at the European College of Veterinary Internal Medicine--Companion Animals Congress, September, 2007.