Association of Peritumoral Brain Edema with Operative Time and Short-term Outcome in Dogs

Abstract: Background - Peritumoral brain edema (PTBE) is commonly identified on preoperative magnetic resonance imaging (MRI) in dogs with intracranial tumors, however its clinical relevance in veterinary neurosurgical planning is poorly defined. Hypothesis/Objectives - To determine whether preoperative PTBE severity is associated with operative time and short-term outcome in dogs undergoing intracranial tumor surgery. Animals - Forty-five client-owned dogs undergoing surgical treatment for intracranial tumors at a referral hospital. Methods - Retrospective review; PTBE graded mild, moderate, or severe by extent of T2-weighted and FLAIR hyperintensity beyond the tumor margin; operative time, transfusion, intraoperative complications, and 30-day survival recorded; all surgeries performed by a single surgeon. Results - PTBE was mild (n = 10), moderate (n = 18), or severe (n = 17). In frontal-lobe meningiomas, mean operative time increased from 205 minutes in mild–moderate PTBE cases to 231 minutes in severe PTBE cases. In intra-axial tumors, operative time increased with PTBE severity (236, 253, and 270 minutes for mild, moderate, and severe PTBE, respectively). Transfusion was required in 13 dogs and was more frequent with severe PTBE than with mild–moderate PTBE (8/17 vs 5/28; odds ratio, 4.09; 95% confidence interval, 1.05–15.89; p = 0.048). Six intraoperative complications occurred, all in severe PTBE. Forty of 45 dogs survived to 30 days. Conclusions and Clinical Importance - Greater PTBE severity was associated with prolonged operative time and increased transfusion and complication rates, supporting PTBE as a clinically relevant indicator of operative difficulty in dogs undergoing intracranial tumor surgery.