Speculating suitability of partial adrenalectomy for lateralized primary aldosteronism: With emphasis on partial and complete success as optimistic outcomes.

Primary aldosteronism (PA) is the most common secondary hypertension. The best treatment for a lateralized PA is unilateral adrenalectomy. Recent studies explored partial adrenalectomy (pAdx) to reduce the risk of adrenal insufficiency. However, in cases involving multiple aldosterone-producing micronodules/nodules (mAPM/mAPN), pAdx cannot completely remove all origins of excess aldosterone and might not resolve hypertension. CYP11B2 immunohistochemical staining helps HISTALDO (Histopathology of PA) diagnosis, and adrenal specimens were categorized into various groups accordingly. To determine whether pAdx should be considered for lateralized PA, we focused on the success rate of classical (black + grey group) versus non-classical (white group) lateralized PA, and the percentage of co-existing mAPM/mAPN in lateralized PA. The visible tumor in imaging could be either non-functional (incidentaloma; white group), or with concurrent surrounding mAPM/mAPN (grey group) causing hypertension. Among 445 patients who underwent unilateral adrenalectomy, 390 were diagnosed with lateralized PA. There were 63 (30.73%) in the black, 79 (38.54%) in the grey, 63 (30.73%) in the white group. The overall complete clinical success rate was 51.28% in our lateralized PA patients; with 65.08% in the black, 50.63% in the grey, and 26.98% in the white group. The overall partial clinical success rate was 38.54%; with 28.57% in the black, 34.18% in the grey, and 53.97% in the white group. Were pAdx performed, significantly lower success rates would be achieved, especially for lateralized PA patients of the grey and white groups. We speculate that unilateral pAdx is not an appropriate option for the majority of lateralized PA patients. Our results show that unilateral partial adrenalectomy is not a good surgical option for the majority of lateralized PA patients. In clinically lateralized PA patients, no matter which group they are in the HISTALDO classification, they would benefit from unilateral total adrenalectomy.