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

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.

Retrospective cohort study.

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.

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.

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.