Hemodynamic instability during resection of pheochromocytoma in MEN versus non-MEN patients.

OBJECTIVE: Hemodynamic (HD) instability still underlies difficulties during pheochromocytoma resection. Little is known about HD instability in patients with multiple endocrine neoplasia (MEN) type 2-related pheochromocytoma. Our aim was to assess differences in HD during pheochromocytoma resection between MEN2 and non-MEN patients. In addition, we sought to identify risk factors for intraoperative HD instability.

DESIGN: Retrospective cohort study.

METHODS: A total of 22 MEN2 and 34 non-MEN patients underwent 61 pheochromocytoma resections at the University Medical Center Utrecht between 2000 and 2010. All MEN2-related pheochromocytomas were diagnosed by annual screening. HD instability was assessed by measuring the frequency of hypotensive (mean arterial blood pressure (MABP) <60  mmHg) and/or hypertensive (systolic arterial blood pressure (SABP) >200  mmHg) episodes.

RESULTS: Compared with non-MEN patients, MEN2 patients were younger at diagnosis, had less symptoms, lower hormone levels, and smaller tumors. Intraoperatively, MEN2 patients had a similar frequency of hypertensive episodes (1.3 vs 1.9, P=0.162, 95% confidence interval (CI): -6.7 to 35.4) and a similar maximum SABP (200 vs 220  mmHg, P=0.180, 95% CI: -9.7 to 50.5). However, MEN2 patients experienced less frequent (1.04 vs 2.6, P=0.003, 95% CI: 0.57 to 2.6) and less severe hypotensive episodes after tumor resection (lowest MABP: 52.5 vs 45.6  mmHg, P=0.015, 95% CI: -12.6 to 1.16). Tumor size was an independent risk factor for HD instability for the total group after multivariate analysis.

CONCLUSION: MEN2 patients with pheochromocytoma, despite their smaller tumors, do not distinguish themselves from non-MEN patients in terms of hypertensive episodes during pheochromocytoma resection. Therefore, pretreatment with α- and β-blockade remains the standard of care in MEN2-related as well as in non-MEN-related pheochromocytomas.