As previously mentioned, there exists no definitive evidence regarding the impact of parathyroidectomy on graft function, and clear guidelines are lacking regarding the necessity of parathyroidectomy in recipients with persistent hyperparathyroidism post-renal transplantation. The objective of this meta-analysis was to scrutinize the interplay between graft function and parathyroidectomy across various studies, aiming to ascertain its safety profile. Within this meta-analysis, we scrutinized the repercussions of parathyroidectomy on graft renal function post-renal transplantation. Despite its longstanding practice, the impact of parathyroidectomy on graft renal function remains a topic of debate, and this study serves as a pivotal reference in the domain. Our meta-analysis, encompassing 12 studies meeting the inclusion criteria, revealed notable effects of parathyroidectomy on parathyroid hormone and serum calcium levels. However, concerning graft renal function, we observed varying degrees of deterioration one year post-surgery, indicating that parathyroidectomy may compromise graft function within the initial year post-surgery. The potential etiologies of this impairment may encompass electrolyte imbalances; acute hypocalcemia post-parathyroidectomy, stemming from the removal of PTH-secreting parathyroid glands, could impact cardiac and muscular function, including smooth muscle function, thereby influencing the vascular system and the urinary excretion dynamics of the transplanted kidney. [24]. Surgical interventions can induce alterations in blood pressure and hemodynamics, potentially influencing the perfusion of the transplanted kidney[25–29] Drug metabolism: Following parathyroidectomy, adjustments in the dosage of immunosuppressive medications may be necessary to uphold the transplanted kidney's function, given the potential impact on drug metabolism. Surgical stress: Every surgical intervention elicits a physiological stress response, which might transiently impact the performance of the transplanted kidney. Risk of infection: Post-surgery, there is an escalated susceptibility to infections, potentially jeopardizing the health of the transplanted kidney. Long-term PTH level changes: Parathyroidectomy may lead to sustained reductions in PTH levels over time, potentially influencing calcium and phosphorus metabolism within the transplanted kidney..[30, 31] Renal impairment: Inadequate management during or post-surgery may result in direct or indirect harm to the transplanted kidney. The distinctive outcomes we derived in contrast to other analyses of similar nature may stem from the comprehensive and current nature of our meta-analysis, encompassing the most recent and extensive literature available to date.
While certain studies suggest that parathyroidectomy within the first year following renal transplantation poses an independent risk for impaired graft function, with postoperative impairment likely to be partially reversible, our study also indicates that patients undergoing parathyroidectomy after the initial year post-transplantation tend to exhibit a recovery trend in graft function, approaching preoperative levels post-parathyroidectomy[32].In patients who underwent parathyroidectomy one year post-transplantation, the graft function directly affected by post-transplantation parathyroidectomy exhibited a tendency to return to the preoperative level of parathyroid function.
Other studies have demonstrated that renal transplantation following parathyroidectomy leads to a persistent reduction in serum calcium and parathyroid hormone levels without a substantial risk of graft failure. Additionally, this study indicated a tendency toward elevated serum creatinine levels during the early postoperative phase after parathyroidectomy. Despite eventual graft loss observed in three recipients, the study concluded that such loss was not attributable to parathyroidectomy.[27] .
Although this meta-analysis encompassed a total of 12 studies, several limitations are evident: (1) Absence of a consensus regarding the definition of tHPT within the literature, coupled with a lack of definitive guidelines proposing specific diagnostic criteria for tHPT. This situation can result in variations in the patient populations included across different studies. (2) Absence of a consensus concerning parathyroidectomy surgical approaches, which currently revolve around two primary modalities: subtotal parathyroidectomy and total parathyroidectomy with autotransplantation. However, while some studies focused on delineating the impact of distinct surgical methods on outcomes, a significant portion did not explore this aspect. (3) Lack of data pertaining to the control group (i.e., untreated tHPT). Most of the studies included in this analysis lacked a control group, possibly due to various treatments received by this patient cohort or a high rate of patient intervention preferences. Consequently, the clinical data acquired may lack adequate comparative value. (4) Our study indicates that parathyroidectomy is associated with a risk of graft function impairment in the year following surgery. Nonetheless, the long-term trajectory of such impairment remains unclear, necessitating extended data analysis to derive conclusive insights. These factors may elucidate the discordant findings observed in certain published articles and contribute to the source of heterogeneity in specific results.
To summarize, one year post-parathyroidectomy following renal transplantation, patients exhibited normalized calcium and parathyroid hormone levels. However, there was impaired graft function and a heightened risk of graft loss. As a clinician, it is imperative to assess the safety of parathyroidectomy for patients. Based on this study's findings, prudent evaluation of its safety is warranted when considering parathyroidectomy for individuals with secondary hyperparathyroidism post-renal transplantation.