PSUN11 Outcomes of Nonselective or Selective Alpha-Adrenergic Antagonist for Preoperative Management of Intra-adrenal Pheochromocytoma

BACKGROUND: Pheochromocytoma is a rare neoplasm of the adrenal medulla that leads to catecholamine excess. Adrenalectomy is the standard management for operative candidates. Preoperative alpha-adrenergic antagonism has been traditionally performed with the non-selective irreversible agent phenoxybenzamine. Recently, use of this agent has been limited due to availability and cost. We sought to determine whether type of preoperative antihypertensive management with nonselective alpha-adrenergic antagonist or selective alpha-1 antagonist was associated with differences in patient outcomes for those undergoing adrenalectomy. METHODS: We performed a retrospective review of adult patients at a single institution undergoing index adrenalectomy for initial diagnosis of intra-adrenal pheochromocytoma from 2012 through 2021. Exclusion criteria were prior adrenalectomy and extra-adrenal pheochromocytoma or paraganglioma. Clinical and demographic factors were assessed. Our primary outcome was intraoperative hemodynamic stability, secondary outcomes were postoperative hemodynamic instability, and surgical complications. Data were analyzed using Chi-squared, Fisher's exact and Mann Whitney U tests. RESULTS: During the study period, 38 patients underwent index adrenalectomy for initial diagnosis of intra-adrenal pheochromocytoma. Patient age was a mean of 57.8 years (SD 13.6) with 14 male (37%) and 34 (90%) white. On preoperative cross-sectional imaging, the mean tumor size was 3.9cm (IQR 2.5–5.2) with 15 (40%) left sided, 21 (58%) right sided and 1 (3%) bilateral with 32 (87%) undergoing minimally invasive laparoscopic or robotic assisted adrenalectomy. The mean pre-contrast density on computed tomography imaging was 35.4 Hounsfield units (SD 15). Preoperative plasma metanephrines were mean 0.65 (SD 6.7), plasma normetanephrines 11.1 (SD 14.3). For preoperative pharmacologic therapy, 16 (42%) were on phenoxybenzamine, 21 (55%) selective alpha-1 antagonist, and 1 (3%) patient on both who was excluded from comparative analysis. Nine patients overall (24%) had preoperative hypertensive crisis with no difference between the groups. There was no difference between the groups for intraoperative hemodynamic instability with 6 (38%) in the phenoxybenzamine group and 10 (48%) in the selective alpha blockade group (p = 0.74) or postoperative hemodynamic instability with 5 (31%) compared with 9 (45%) respectively (p = 0.50). Groups were also similar with regard to age, sex, body mass index, comorbidities, preoperative catecholamine levels, American Society of Anesthesiologists Physical Status classification, minimally invasive or open surgery, tumor size, estimated surgical blood loss, and postoperative complications. Follow up duration was longer for the phenoxybenzamine group at 55 months (SD 35) compared with 21 months (SD 25) for the selective alpha blockade group (p = 0.003). CONCLUSIONS: Use of preoperative alpha adrenergic antagonism selective alpha-1 antagonists showed similar outcomes intraoperative and postoperatively compared with irreversible nonselective alpha-adrenergic antagonists in this cohort. Use of selective alpha-1 antagonists should be considered when nonselective agents are not accessible. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.