Post-Parathyroidectomy Peripheral Edema in 914 Patients: Incidence, Independent Predictors, and a Calcium-Shift Mechanism

Objective Post-parathyroidectomy (PP) peripheral edema is an under-recognized postoperative phenomenon. This study defines its incidence, identifies independent predictors, and proposes a pathophysiological mechanism. Methods Retrospective cohort analysis of 914 patients undergoing curative parathyroidectomy (July 2011–January 2026); pre-existing cardiac, renal, hepatic, or nutritional comorbidities were excluded. Independent predictors were identified by binary logistic regression with prespecified sensitivity models. Results PP edema occurred in 173 patients (18.9%), resolving spontaneously within a mean of 18±6.2 days. Compared with patients without edema, those with PP edema had significantly higher preoperative calcium, PTH, ALP, and tumor weight (all p<0.001). They also demonstrated a steeper postoperative calcium fall (4.40±1.46 vs. 3.60±1.71 mg/dL; p<0.001). On multivariate analysis (n=914), fall in calcium (OR 2.048, 95% CI 1.514–2.771), PTH (OR 1.290 per 100 pg/mL, 95% CI 1.200–1.387), ALP (OR 1.232 per 50 IU/L, 95% CI 1.149–1.320), and tumor weight (OR 1.728 per 500 mg, 95% CI 1.462–2.043) were independent predictors (all p<0.001). Conclusion PP peripheral edema occurs in approximately 1 in 5 patients with severe symptomatic PHPT, is benign and self-limiting, and shows a strong dose-dependent association with the postoperative calcium fall (r s =0.780), consistent with a proposed hypocalcemia-driven vasodilatory mechanism. Findings should not be extrapolated to mild or asymptomatic disease. Recognition prevents unnecessary investigations in patients without pre-existing cardiac or renal disease; empiric loop diuretic use is unlikely to be physiologically rational.