Timing of parathyroidectomy in kidney transplant candidates: a systematic review and a proposed clinical algorithm.

Objective: Parathyroidectomy (PTx) is widely used for severe secondary hyperparathyroidism (SHPT) in kidney transplant candidates, but the optimal timing (pre-transplant versus post-transplant) remains controversial. This systematic review aimed to compare the outcomes of pre-transplant PTx and post-transplant PTx on graft loss, tertiary hyperparathyroidism (THPT), renal function, and complications, and to propose a clinical algorithm for PTx timing. Methods: We systematically searched PubMed, Embase, Web of Science, and Cochrane Library from inception to July 2024, with an update in April 2026. Studies directly comparing pre-transplant and post-transplant PTx in adult kidney transplant candidates were included. Notably, all eligible studies were observational, and no relevant interventional studies have been published to date. Due to heterogeneity in outcome definitions and measurement methods, no meta-analysis was performed; results were synthesized narratively and summarized in tables. Risk of bias was assessed using the Newcastle-Ottawa Scale. Results: Eight studies (4355 patients) were included. Graft loss events were low in both groups, with most studies indicating a potential trend toward lower graft loss in the pre-transplant PTx group; one study reported a significant adjusted odds ratio favoring pre-transplant PTx (0.547, 95% CI: 0.327-0.913). Pre-transplant PTx was associated with lower 1-month eGFR in one study, but this difference was absent at 36 months, and no long-term differences in eGFR or serum creatinine were observed across studies. THPT definitions varied, with no consistent between-group difference. Postoperative hypocalcemia rates were inconsistent. A large database study reported that pre-transplant PTx was associated with significantly higher 30-day composite morbidity, major adverse cardiovascular events, and readmission, with no difference in mortality. Based on the synthesized evidence, we propose a risk-stratified algorithm incorporating waitlist time, PTH level, dialysis vintage, and a validated nomogram to guide PTx timing. Conclusion: Pre-transplant PTx may be associated with lower graft loss and comparable long-term renal function compared with post-transplant PTx. Given the limitations of the current evidence, a personalized approach using the proposed algorithm may optimize clinical decision-making. Prospective studies are needed to validate this framework. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024556524, identifier CRD42024556524.