Long-term follow up after adrenalectomy for primary hyperaldosteronism

Abstract

Purpose: Primary hyperaldosteronism sub-types have a radically different management: adrenalectomy for adrenal aldosterone unilateral secretion and medical therapy for bilateral secretion. Our aim was to prove higher long term postoperative blood pressure (BP) in patients with histological defined hyperplasia compared to patients with histological adenoma. Methods: We retrospectively included patients with biological primary hyperaldosteronism, an unilateral nodule on computed tomography (CT) and who underwent adrenalectomy between 2005 to 2009. This was the period before using routinely adrenal venous sampling in our institution. We compared long-term postoperative BP between pre-operative suspected patients of unilateral secretion but with final histological diagnosis of adenoma (group 1) and those with hyperplasia (group 2). Results: 41 patients underwent adrenalectomy (mean age 53.9±12.2). Mean peripheral aldosterone/renin ratio was 229.4. 6 patients (15%) had adrenal hyperplasia as post-operative histological diagnosis (group 2). No difference was observed pre-operatively between the two groups in term of clinical and biological characteristics (mean BP group 1: 136.7±15.8 / 81.8±12.1 mmHg vs group 2: 137.5±9.6 / 85±5.8 mmHg; mean kalemia group 1: 2.9±0.5 mmol/l vs group 2: 3.0±0.5 mmol/l; p=NS). Nodule size on CT was higher in group 1 (18.9mm ±8.7; n=35) than in group 2 (11.7mm ±1.5; n=6) (p=0.05). Post-operative mean follow-up was 4.6 years. Long-term postoperative mean BP was higher in group 2 (137.0±14.8 / 87.0±17.2 mmHg) than in group 1 (127.2±7.4 / 76.1±7.8 mmHg) (p=0.03). Postoperative mean antihypertensive drug score was 0.6±0.7 in group 1 and 2.2±2.4 in group 2 (p=0.002). Long-term mean kalemia was similar in the two groups (group 1: 4.4±0.4 mmol/l vs group 2: 4.0±0.4 mmol/l; p=NS). Conclusions: Long term follow-up after adrenalectomy shows higher BP and antihypertensive drug score in patients with hyperplasia than patients with adenoma. This data confirm that nowadays adrenal venous sampling is essential before adrenal surgery whatever nodule size on CT to prove unilateral secretion.