Cinacalcet effects on the perioperative course of patients with secondary hyperparathyroidism

Variable practice patterns in the surgical management of renal hyperparathyroidism

BACKGROUND

Hyperparathyroidism is common among patients with chronic kidney disease, end-stage kidney disease, and kidney transplant. The American Association for Endocrine Surgery published clinical practice guidelines that address the surgical treatment of secondary and tertiary hyperparathyroidism. The purpose of this study is to determine practice patterns for the surgical management of secondary and tertiary hyperparathyroidism prior to guideline publication.

METHODS

With the approval of the American Association for Endocrine Surgery, a Qualtrics email survey was sent to the Association's membership in 2022 about current clinical decision making for surgical treatment of secondary and tertiary hyperparathyroidism. Respondents were divided into groups based on surgical subspecialty (endocrine surgery versus non-endocrine surgery), yearly parathyroidectomy volume, and yearly parathyroidectomy volume for surgical treatment of secondary and tertiary hyperparathyroidism. Descriptive statistics were performed; the role of volume was evaluated.

RESULTS

There were 142 responses from 795 solicited email addresses (18% response rate); 114 (84%) identified as endocrine surgeons. The majority (62%) perform >50 parathyroidectomies yearly, but most perform <10 parathyroidectomies for surgical treatment of secondary and tertiary hyperparathyroidism per year (<10/y, 53.7%; 10-30/y, 41.9%; >30/y, 4.4%). Subtotal parathyroidectomy is most commonly performed for surgical treatment of secondary (83%) and tertiary (52%) hyperparathyroidism, but transcervical thymectomy variably performed for both. There was no consensus regarding starting calcitriol preoperatively (always 43%, never 25%, depends on vitamin D levels 24%) or stopping cinacalcet (2 weeks prior 28%, day of surgery 29%, postoperatively 20%). Surgeons who perform >10 parathyroidectomies per year for surgical treatment of secondary and tertiary hyperparathyroidism were less likely to consider the patient's preoperative vitamin D levels to inform their decision to start calcitriol before surgery (<10 cases/year, 34%; ≥10 cases/year 15%; P = .023), were more likely to have a postoperative hypocalcemia protocol managed by the surgical team (<10 cases/year, 49%; ≥10 cases/year, 58%; P = .029), and were more likely to use intraoperative parathyroid hormone monitoring for tertiary hyperparathyroidism (<10 cases/year, 70%; ≥10 cases/year, 87%; P = .046).

CONCLUSION

The majority of respondents perform <10 parathyroidectomies yearly for surgical treatment of secondary and tertiary hyperparathyroidism. Subtotal parathyroidectomy was most commonly performed, but there was little other consensus regarding preoperative management, intraoperative decision-making, and postoperative care. Opportunity exists through guideline dissemination to improve heterogeneity of care provided to surgical treatment of secondary and tertiary hyperparathyroidism patients.

Pre-operative Cinacalcet Administration Reduces Immediate Post-operative Hypocalcemia Following Total Parathyroidectomy in Severe Renal Hyperparathyroidism

BACKGROUND

In severe renal hyperparathyroidism (RHPT), whether administrating Cinacalcet before total parathyroidectomy can reduce post-operative hypocalcemia remains unclear. We compared post-operative calcium kinetics between those who took Cinacalcet before surgery (Group I) and those who did not (Group II).

METHODS

Patients with severe RHPT (defined by PTH ≥ 100 pmol/L) who underwent total parathyroidectomy between 2012 and 2022 were analyzed. Standardized peri-operative protocol of calcium and vitamin D supplementation was followed. Blood tests were performed twice daily in the immediate post-operative period. Severe hypocalcemia was defined as serum albumin-adjusted calcium < 2.00 mmol/L.

RESULTS

Among 159 patients who underwent parathyroidectomy, 82 patients were eligible for analysis (Group I, n = 27; Group II, n = 55). Demographics and PTH levels before Cinacalcet administration were comparable (Group I: 169 ± 49 pmol/L vs Group II: 154 ± 45, p = 0.209). Group I had significantly lower pre-operative PTH (77 ± 60 pmol/L vs 154 ± 45, p < 0.001), higher post-operative calcium (p < 0.05), and lower rate of severe hypocalcemia (33.3% vs 60.0%, p = 0.023). Longer duration of Cinacalcet use correlated with higher post-operative calcium levels (p < 0.05). Cinacalcet use for > 1 year resulted in fewer severe post-operative hypocalcemia than non-users (p = 0.022, OR 0.242, 95% CI 0.068-0.859). Higher pre-operative ALP independently correlated with severe post-operative hypocalcemia (OR 3.01, 95% CI 1.17-7.77, p = 0.022).

CONCLUSION

In severe RHPT, Cinacalcet led to significant drop in pre-operative PTH, higher post-operative calcium levels, and less frequent severe hypocalcemia. Longer duration of Cinacalcet use correlated with higher post-operative calcium levels, and the use of Cinacalcet for > 1 year reduced severe post-operative hypocalcemia.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Secondary and Tertiary Renal Hyperparathyroidism

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate treatment of secondary (SHPT) and tertiary (THPT) renal hyperparathyroidism.

BACKGROUND

Hyperparathyroidism is common among patients with chronic kidney disease, end-stage kidney disease, and kidney transplant. The surgical management of SHPT and THPT is nuanced and requires a multidisciplinary approach. There are currently no clinical practice guidelines that address the surgical treatment of SHPT and THPT.

METHODS

Medical literature was reviewed from January 1, 1985 to present January 1, 2021 by a panel of 10 experts in SHPT and THPT. Recommendations using the best available evidence was constructed. The American College of Physicians grading system was used to determine levels of evidence. Recommendations were discussed to consensus. The American Association of Endocrine Surgeons membership reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines present the epidemiology and pathophysiology of SHPT and THPT and provide recommendations for work-up and management of SHPT and THPT for all involved clinicians. It outlines the preoperative, intraoperative, and postoperative management of SHPT and THPT, as well as related definitions, operative techniques, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Preoperative and Perioperative Care, Surgical Planning and Parathyroidectomy, Adjuncts and Approaches, Outcomes, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal management of secondary and tertiary renal hyperparathyroidism.

Surgery for Renal Hyperparathyroidism in the Era of Cinacalcet: A Single-Center Experience

BACKGROUND AND AIMS

There are only few data on the influence of cinacalcet on the outcome of parathyroidectomy in patients with renal hyperparathyroidism. Indication and timing of surgery have changed since its introduction, especially with regard to kidney transplantation. Therefore, we retrospectively analyzed patients undergoing parathyroidectomy for renal hyperparathyroidism in our institution.

MATERIAL AND METHODS

Between 2008 and 2015, 196 consecutive operations in 191 patients were analyzed. About 80 operations (41%) were performed in patients receiving cinacalcet compared with 116 operations (59%) in patients without cinacalcet. Clinical data, preoperative medication, pre- and postoperative laboratory values, type and details of surgery including complications, as well as cardiovascular complications and kidney transplantation with graft function were recorded.

RESULTS

Demographical data were similar in patients with or without cinacalcet treatment. A total of 54% of patients received a kidney graft before or after parathyroidectomy. Pre- and postoperative parathormone levels were similar in both groups (preoperatively 755 vs 742 ng/L, postoperatively 50 vs 46 ng/L, p > 0.10), whereas patients with cinacalcet showed significantly lower calcium levels preoperatively (2.28 vs 2.41 mmol/L, p = 0.0002). There was no difference in recurrence or persistence of hyperparathyroidism, duration of surgery, hospital stay, or complication rate. Creatinine levels in patients with tertiary hyperparathyroidism were similar after 1-year follow-up.

CONCLUSION

Cinacalcet did not influence outcome of patients with parathyroidectomy for renal hyperparathyroidism and can be safely offered to patients not responding to medical treatment.

Risk factors of developing the hungry bone syndrome after parathyroidectomy for primary hyperparathyroidism

Background.

Around 13% of patients undergoing parathyroidectomy for primary hyperparathyroidism (PHPT) postoperatively develop a condition known as the hungry bone syndrome (HBS). Although the condition is quite prevalent, the research in this field is very limited. The aim of our study was to determine possible risk factors of developing HBS after parathyroidectomy for PHPT.

Materials and methods.

In this study we enrolled patients who underwent parathyroidectomy for PHPT from January 2005 to December 2016 and performed a retrospective analysis. We used the definition of HBS as hypocalcaemia with normal or elevated PTH values. Patients were divided into two groups by the postoperative HBS prevalence: patients with postoperative HBS and those without postoperative HBS.

Results.

In all, 94 patients were included into the final analysis. We found that patients who developed HBS more often underwent parathyroidectomies simultaneously with a thyroid surgery, underwent longer operations (73.9 ± 41.7 vs. 102.4 ± 44.8 minutes; p = 0.001), and had heavier parathyroid glands removed (0.6 (0.3–8.0) vs. 0.8 (0.15–14.0) g; p = 0.041). Also, these patients had higher preoperative PTH values (15.3 (6.1–63.7) vs. 22.4 (9.2–47.8) pmol/l; p = 0.003). From the ROC curve of the preoperative PTH values and the development of the hungry bone syndrome (AUC = 0.721 (95% CI 0.59–0.85); p = 0.003) we found a 45 pmol/l PTH cut-off value that shows a 90% tendency to develop postoperative HBS.

Conclusions.

Patients undergoing longer parathyroidectomies and those with heavier removed parathyroid glands tend to develop HBS. A preoperative PTH value higher than 45 pmol/l determines an over 90% risk of developing HBS.