The Duration of Preoperative Administration of Single -Receptor Blocker Phenoxybenzamine before Adrenalectomy for Pheochromocytoma: 18 Years of Clinical Experience from Nationwide High-Volume Center.

Purpose: There is no consensus for the optimum duration of preoperative administration of phenoxybenzamine (PXB) before adrenalectomy for pheochromocytoma. The aim of this study is to investigate whether perioperative hemodynamics and postoperative outcomes are related to the duration of PXB administration.

Methods: In total, 102 patients managed preoperatively with single -receptor blocker phenoxybenzamine were enrolled from 469 consecutive patients diagnosed histologically with pheochromocytoma. The patients received surgical treatment in the Department of Urology, Peking University First Hospital, between January 2001 and July 2018. All patients were divided into three groups: Group A (<14 d), Group B (14-30 d), and Group C (>30 d). Patient and tumor characteristics, intraoperative hemodynamics, and postoperative outcomes were recorded and compared among the three groups.

Results: These patients included 47 men and 55 women, with an average age of 43 years at the time of surgery. Clinical characteristics, except the status of preoperative biochemical tests (24 hr urine fractioned catecholamine or plasma-fractioned catecholamine) (=0.020), preoperative hemodynamics, and medicine management and surgical approaches, in the three groups were comparable. Multivariate analyses demonstrated that the size of the tumor (=0.034) was an independent risk factor for intraoperative hemodynamic instability. Among the three groups, we found no significant difference in intraoperative hemodynamics and postoperative outcomes.

Conclusion: The data from the current study indicated that the preoperative management of pheochromocytoma with single -receptor blocker PXB for more than 2 weeks, after the final dose adjustment, could not further reduce the risk of intraoperative hemodynamic instability or postoperative complications. Thus, our study supports that 14 days would be enough for the duration of preoperative management of pheochromocytoma with single -receptor blocker PXB in final dose.