Endocrine Abstracts

Background: Bilateral total adrenalectomy (TA), despite causing persistent adrenal insufficiency with lifetime replacement of corticosteroids, is the method of choice in patients with bilateral pheochromocytoma. Partial adrenalectomy (PA) is an alternative approach that aims to balance tumor removal while maintaining adrenal function, although the oncological completeness of the procedure is questionable.

Objective: The aim of this systematic review and meta-analysis was to compare bilateral total adrenalectomy and partial (cortical-sparing) adrenalectomy.

Methods: A bibliographical search of databases (MEDLINE, EMBASE, Scopus, Web of Science, CENTRAL) as well as registers of clinical trials (ClinicalTrials.gov, European Trials Register, WHO International Trials Registry Platform) was conducted in order to identify eligible studies. The databases and registries were searched from inception until August 14, 2021, and no language restrictions or dates were imposed. Both randomised controlled trials and observational studies comparing TA with PA in adults with bilateral pheochromocytoma were considered for inclusion in this study. The primary outcomes were the risk of pheochromocytoma recurrence and steroid dependence. The secondary outcomes of interest were: time to recurrence after surgery, development of metastatic pheochromocytoma, incidence of adrenal crisis, morbidity, overall mortality and pheochromocytoma-specific mortality.

Results: Twenty five retrospective observational studies including 1444 patients were eligible. During follow-up, every third patient after PA required steroid supplementation: RR 0.32, 95% CI: 0.26–0.38, P < 0.00001, I²=21%. Patients undergoing partial adrenalectomy had lower risk of developing Addisonian-like crisis: OR 0.3, 95% CI: 0.1–0.91, P=0.03, I²=0%. On the contrary, PA was associated with higher risk of reccurence than TA: OR 3.72, 95% CI: 1.54-8.96, P=0.003, I²=28%. We found no difference between PA and TA groups in the development of metastatic pheochromocytoma: OR 1.47, 95%CI: 0.48-4.44), P=0.5, I² =0%, overall mortality: OR 1.04, 95% CI: 0.47-2.33, P=0.92, I² =0%, as well as pheochromocytoma-specific mortality: OR 0.54, 95% CI: 0.08–3.72, P=0.53.

Conclusions: Patients undergoing partial adrenalectomy had a three-fold lower risk of developing steroid dependence and developing an adrenal crisis, but had a higher risk of recurrence. Thus, partial adrenalectomy may be worth considering in some patients with bilateral pheochromocytoma only with careful lifelong follow-up. Our findings are based on limited certainty evidence, and further well-designed, multi-center studies are required to confirm the benefits and drawbacks of both approaches.