Clinical characteristics and outcome in 15 dogs treated with transsphenoidal hypophysectomy for nonfunctional sellar masses.

OBJECTIVE: To characterize the clinical features, neurological examination findings, diagnostic imaging results, histopathological findings, and outcome following transsphenoidal hypophysectomy (TSH) in dogs with nonfunctional sellar masses (NFSM). STUDY DESIGN: Multi-institutional retrospective study. METHODS: Medical records of dogs that underwent TSH for a NFSM were reviewed for clinical signs, physical and neurological examination findings, diagnostic imaging results, endocrine testing, surgery reports, and outcome. Magnetic resonance (MR) imaging was rereviewed, and tumors were classified using the previously described system according to pituitary tumor extension and vascular involvement. Owners of dogs that survived to discharge were contacted. RESULTS: The majority of dogs presented for mentation change (12/15). The mean pituitary to brain ratio (P/B ratio) was 1.05 (0.6-1.4). Eight dogs had a tumor imaging classification of 5B. Eleven dogs were diagnosed with a nonfunctional pituitary adenoma (NFPA). Perioperative mortality was 33% (5/15). The median survival for all dogs was 232 days (0-1658). When dogs that did not survive to discharge were excluded, the median survival time was 708 days. Seven of 10 dogs that survived the perioperative period received adjunctive therapy. Owner assessment of outcome was excellent (6/7) to good (1/7). CONCLUSION: The common presenting complaint for dogs with large NFSM causing mass effect was mentation changes. Dogs with NFPA that survived to discharge and received adjunctive therapy had good to excellent outcomes. CLINICAL SIGNIFICANCE: Transsphenoidal debulking with adjunctive therapy can be considered for the treatment of NFSM causing clinical signs of mass effect in dogs. Successful long-term outcomes are possible.