Risk factors influencing death prior to discharge in 302 dogs undergoing unilateral adrenalectomy for treatment of primary adrenal gland tumours

Abstract

Adrenalectomies for canine adrenal tumours are associated with peri‐operative morbidity and mortality. Objectives of this study included assessing the prognostic value of tumour‐ or surgery‐related variables in predicting peri‐operative mortality and overall survival in dogs undergoing adrenalectomies for primary adrenal tumours as well as pre‐treatment with phenoxybenzamine on survival to discharge with pheochromocytomas specifically. A multi‐institutional retrospective cohort study was performed across nine institutions. Electronic medical record searches identified 302 dogs which met the inclusion criteria. Data collected included dog‐related, tumour‐related, treatment‐related, surgery‐related, and outcome variables. Univariate and multivariable logistic regression and cox proportional hazards models were used to identify variables associated with death prior to discharge and tumour‐related survival. Overall, 87% of dogs survived to discharge with a tumour‐related survival time of 3.96 years. Post‐operative complications were reported in 25%. Increased surgical time (p = 0.002) and pre‐surgical medical treatment other than phenoxybenzamine (p = 0.024) were significantly associated with increased peri‐operative mortality while ureteronephrectomy (p = 0.021), post‐operative pancreatitis (p = 0.025), and post‐operative aspiration pneumonia (p < 0.001) were significantly associated with decreased overall survival. Phenoxybenzamine pretreatment had no effect on peri‐operative mortality. Thirty‐seven of 45 (82%) dogs with pheochromocytomas not pretreated survived to discharge, and 50 of 59 (85%) dogs with pheochromocytomas pretreated with phenoxybenzamine survived to discharge (p = 0.730). This study provides information on risk factors for death prior to discharge and tumour‐related survival that may help guide clinical management and owner expectations. In addition, the study findings challenge the previously reported benefit of phenoxybenzamine for pretreatment of dogs undergoing adrenalectomies for pheochromocytomas.

Anaesthetic management of a dog undergoing unilateral adrenalectomy for phaeochromocytoma excision using a partial intravenous anaesthetic protocol

“…Importantly, in this study, the authors also found no effect on intraoperative cardiovascular stabilization. Moreover, more recent literature did not support the preoperative phenoxybenzamine administration in dogs undergoing phaeochromocytoma excision, since no reduced mortality was found ( Appelgrein et al ., 2020 ; Enright et al ., 2022 ; Piegols et al ., 2023 ). These three studies question the Herrera et al .…”

“…Even though a 2-week treatment was generally recommended to achieve complete α-blockade preoperatively ( Herrera et al ., 2008 ), it was administered for 1 week only in the present case. This was not considered a major concern, as recent literature generally does not support their use ( Appelgrein et al ., 2020 ; Enright et al ., 2022 ; Piegols et al ., 2023 ). Nevertheless, normotension was never achieved preoperatively, despite the concomitant administration of prazosin and amlodipine, a calcium channel blocker.…”