Degree of catecholamine hypersecretion is the most important determinant of intra-operative hemodynamic outcomes in pheochromocytoma

Abstract

Pheochromocytoma resection is often complicated by intra-operative hypertension and post-resection hypotension. Factors associated with these hemodynamic alterations are not well defined. The aim of this study was to analyse the clinical-laboratory features associated with hemodynamic parameters during pheochromocytoma resection. Twenty-seven patients submitted to tumor resection - either open (no.=18) or video laparoscopic - between 1978-2007 were included. Nineteen received pre-operative alpha-blockers. Intra-operative hemodynamic data analysed were: maximum and minimum mean arterial blood pressure (MABP), no. of severe hypertensive (systolic BP >200 mmHg) and hypotensive episodes (MABP <60 mmHg), maximum and minimum heart rate (HR), no. of episodes of tachycardia and bradycardia, need to receive iv intra-operative treatment for hypertension and hypotension and the volume of fluids administered during surgery. Patients were 39.4+/-14.4-yr-old, 66% women. Intra-operative hemodynamic parameters were not different in patients submitted to open or video laparoscopic resection. Maximum intraoperative HR and the percentage of patients with HR>100 beats/min were higher in patients without pre-operative alpha- blocker treatment (no.=8). Pre-operative urinary vanylmandelic acid was positively associated with intra-operative maximum MABP (r=0.535, p=0.047) and with maximum transoperative systolic BP (r=0.805, p=0.016). Pre-operative urinary catecholamine (Pearson correlation r=0.575, p=0.03) and vanylmandelic acid (Pearson correlation r=0.605, p=0.04) levels were associated with maximum intra- operative MABP, adjusted for the presence of pheochromocytoma symptoms, surgical approach and pre-operative alpha-blockers. In conclusion, the degree of pre-operative catecholamine secretion was the most important aspect of transoperative BP control.