Value of Prophylactic Cervical Thymectomy in Parathyroid Hyperplasia

Role of thymectomy in surgical treatment of renal hyperparathyroidism

INTRODUCTION

The role for routine thymectomy in patients with secondary or tertiary hyperparathyroidism (SHPT, THPT) is unclear. We aim to compare rates of recurrence and complications in patients who underwent subtotal parathyroidectomy with and without thymectomy.

METHODS

Patients who underwent surgery for renal HPT at a tertiary endocrine surgery center between 2010 and 2022 were reviewed. Presence of parathyroid tissue in resected tissue was identified through pathology reports. A multivariate logistic regression was used to compare baseline characteristics, recurrence rates and complications between those who did and did not undergo thymectomy.

RESULTS

Of 107 patients who underwent subtotal parathyroidectomy, 29 (27.1 ​%) underwent concomitant thymectomy. Recurrence occurred in 15 patients (14 ​%). Thymectomy did not affect recurrence (OR: 0.33, 95%CI: 0.06-1.28, p ​= ​0.14), but was associated with permanent hypoparathyroidism (OR: 4.62, 95%CI: 1.67-13.18, p ​= ​0.003). Fewer parathyroid specimens increased the odds of thymectomy (p ​= ​0.04). Parathyroid glands were found in 6 thymectomy samples (20.7 ​%).

CONCLUSION

Thymectomy at the time of subtotal parathyroidectomy for renal HPT was not associated with disease recurrence, but increased likelihood of permanent hypoparathyroidism.

Is thymectomy necessary during parathyroidectomy for secondary hyperparathyroidism in patients with end-stage kidney disease?

BACKGROUND

Guidelines recommend thymectomy at the time of parathyroidectomy for secondary hyperparathyroidism to reduce the likelihood of persistent or recurrent disease. We sought to determine the frequency of thymectomy and explore its impact on recurrence of secondary hyperparathyroidism.

METHODS

Using TriNetX, a multi-institutional electronic health record and insurance claims network, we conducted a retrospective cohort study of adults with secondary hyperparathyroidism who underwent parathyroidectomy with or without thymectomy from 2005 to 2023. Rates of thymectomy, repeat parathyroidectomy, and calcimimetic use were compared between cohorts. Recurrence was defined by parathyroid hormone ≥600 pg/mL, reoperation, or calcimimetic use. Current Procedural Terminology and SNOMED codes for parathyroidectomy did not distinguish between subtotal compared with total parathyroidectomy.

RESULTS

Among 2,564 patients underwent surgery for secondary hyperparathyroidism, 2,272 (88.8%) underwent parathyroidectomy and 287 (11.2%) underwent parathyroidectomy + thymectomy. Rates of parathyroidectomy + thymectomydecreased over time, from 25.5% in 2005 to 10.1% in 2023. Preoperatively, there was no difference in mean preoperative parathyroid hormone levels, serum calcium or calcidiol, or cinacalcet use. Postoperatively, there was no difference in the mean parathyroid hormone level (183 pg/mL vs 180 pg/mL, P = .88), odds of calcimimetic use (odds ratio, 0.94, 95% confidence interval, 0.64-1.39), reoperation within 5 years postoperatively (odds ratio 0.72, 95% confidence interval 0.39-1.36), or rates of kidney transplantation (odds ratio 1.03, 95% confidence interval 0.67-1.60) between parathyroidectomy and parathyroidectomy + thymectomy groups.

CONCLUSION

Thymectomy is infrequently performed during parathyroidectomy for secondary hyperparathyroidism, and rates continue to decline. Although thymectomy at time of parathyroidectomy did not appear to decrease recurrence, future studies should include extent of parathyroidectomy to determine impact of thymectomy on recurrence in secondary hyperparathyroidism.

[Special features of the diagnostics and treatment of hereditary primary hyperparathyroidism]

Between 2% and 10% of patients with primary hyperparathyroidism (pHPT) are diagnosed with hereditary forms of primary hyperparathyroidism (hpHPT). They are more prevalent in younger patients before the age of 40 years, in patients with persistence or recurrence of pHPT and pHPT patients with multi-glandular disease (MGD). The various forms of hpHPT diseases can be classified into four syndromes, i.e., hpHPT associated with diseases of other organ systems, and four diseases that are confined to the parathyroid glands. Approximately 40% of patients with hpHPT suffer from multiple endocrine neoplasia type 1 (MEN-1) or show germline mutations of the MEN‑1 gene. Currently, germline mutations that lead to a specific diagnosis in patients with hpHPT have currently been described in 13 different genes, which enables a clear diagnosis of the disease; however, a clear genotype-phenotype correlation does not exist, even though the complete loss of a coded protein (e.g. due to frame-shift mutations in the calcium sensing receptor, CASR) often leads to more severe clinical consequences than merely a reduced function of the protein (e.g. due to point mutation). As the various hpHPT diseases require different treatment approaches, which do not correspond to that of sporadic pHPT, a clear definition of the specific form of hpHPT must always be strived for. Therefore, before surgery of a pHPT with clinical, imaging or biochemical suspicion of hpHPT, genetic proof or exclusion of hpHPT is necessary. The differentiated treatment approach for hpHTP can only be defined by taking the clinical and diagnostic results of all the abovenamed findings into account.

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.

Application of carbon nanoparticles in localization of parathyroid glands during total parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

Intraoperative imaging is used to address the challenges of parathyroidectomy, but no standard modality has been established. This study aimed to assess whether carbon nanoparticle injection is useful in localizing parathyroid glands (PGs) during parathyroidectomy.

METHODS

Patients who underwent total parathyroidectomy (TPTX) between September 2015 and November 2018 were included. The operative duration and intact parathyroid hormones (iPTH) were analyzed.

RESULTS

A total of 61 patients were included; of these, 32 with carbon nanoparticle injection (TPTX + CN group) and 29 without (TPTX group). The operative duration in the TPTX + CN group was significantly shorter (90.6 ± 21.2 vs 101.4 ± 19.4 min, P = 0.042), which is more apparent in those with normal sized PGs. For those with four enlarged PGs, iPTH levels on 1 day and 1 year postoperatively were significantly lower in the TPTX + CN group (P = 0.032 and P = 0.036, respectively).

CONCLUSION

Carbon nanoparticles are useful in the identification normal sized PGs and complete resection of enlarged PGs.

Unusual recurrent renal secondary hyperparathyroidism caused by hyperplastic autograft with supernumerary parathyroid adenoma: A case report

RATIONALE

Secondary hyperparathyroidism (SHPT) is often complicated with chronic renal failure. Though the total parathyroidectomy (TPTX) with forearm autotransplantation (FAT) has been commonly used to treatment refractory renal SHPT, the recurrence of SHPT is not infrequent, resulting from hyperplastic autograft, remnant parathyroid tissues, and supernumerary parathyroid gland (SPG).

PATIENT CONCERNS

A 67-year-old man undergoing TPTX+FAT 4 years previously for renal SHPT, who received regular hemodialysis with active vitamin D supplements of Rocaltrol treatment postoperatively, was admitted to our hospital with progressively elevated serum intact parathyroid hormone (iPTH) from 176 to 1266 pg/mL for 8 months and bilateral ankle joints pain for 1 month. Tc-sestamibi dual-phase imaging with single positron emission tomography (SPECT)/computed tomography (CT) revealed a nodule in suprasternal fossa, besides a nodule in autografted site, accompanied with intense radioactivity.

DIAGNOSIS

Recurrent SHPT was easily diagnosed based on previous medical history, painful joints, increased serum iPTH level and positive findings of Tc-sestamibi imaging. Routine postoperative pathology showed that the nodules were consistent with an adenomatoid hyperplasic autograft and a supernumerary parathyroid adenoma in suprasternal fossa, respectively.

INTERVENTIONS

Reoperation for removing nodules in suprasternal fossa and autografted site was performed 1 month later. Then regular hemodialysis 3 times a week with Rocaltrol was continued.

OUTCOMES

During 12 months of follow-up, the joints pain improved obviously and the serum iPTH level ranged from 30.1 to 442 pg/mL.

LESSONS

Although rare, recurrent renal SHPT may be caused by a coexistence of both hyperfunctional autograft and SPG after TPTX+FAT. The Tc-sestamibi parathyroid imaging with SPECT/CT is helpful to locate the culprits of recurrent renal SHPT before reoperation. To prevent recurrence of renal SHPT, the present initial surgical procedures should be further optimized in patient on permanent hemodialysis.