The evolution of peri-operative care in the safe management of pheochromocytoma

Background: The use of pre- and intra-operative vasoactive agents for improved blood pressure control has transformed the outcomes following pheochromocytoma (PC) resection. The first agent utilized was phenoxybenzamine, but selective alpha-1 antagonists (SAA) and calcium channel antagonists (CCA) have also been used with success. We sought to define the relationship between pre-operative treatment and intra-operative hemodynamics associated with each of these agents in patients with PC. Methods: A retrospective, single-institution review of patients >18 years with resected PC from 1996-2020 was performed. Pre-operative blockade was at the discretion of the treating providers. Adequacy of pre-operative blockade was determined by the attending surgeon prior to proceeding with PC resection. To determine the effectiveness of pre-operative blockade during surgery, vital signs throughout the operation were examined. Results: The final dataset included 166 patients. Phenoxybenzamine (55%) and SAA (24%) were the most commonly used pre-operative medications but phenoxybenzamine use decreased over time. Patients who experienced a hypertensive crisis had a higher initial systolic blood pressure and were older. There was no predilection for developing a hypertensive crisis based on race, sex, tumor size or type of pre-operative medication used. Patients in the early group (2010-2015) were found to have more pronounced hemodynamic instability when compared to patients in the late group (2016-2020). Conclusion: Although there are no demonstrated differences between antihypertensives, the prescription pattern has evolved away from phenoxybenzamine. However, as this is transition happening, patients exhibit better hemodynamic control. We hypothesize that this is due to greater experience by the intra-operative team.