Could the Less-Than Subtotal Parathyroidectomy Be an Option for Treating Young Patients With Multiple Endocrine Neoplasia Type 1-Related Hyperparathyroidism?

Abstract

Background: The surgical treatment of primary hyperparathyroidism (HPT) in patients with multiple endocrine neoplasia type 1 (MEN1) has evolved due the concern of permanent hypoparathyroidism. As the diagnosis has increased, the extent of operation has decreased. Most MEN1 patients requiring parathyroidectomy are younger than 50 years and they pose a difficult balance to achieve between persistent HPT and life-long hypoparathyroidism. The aim of the present study is to review our experience with a large series of patients with MEN1-related HPT (HPT/MEN1) treated at a single institution in order to find clues to a better treatment decision in these younger cases.Method: Retrospective analysis of consecutive HPT/MEN1 cases treated at a single institution with different operations: total parathyroidectomy and immediate forearm autograft (TPTX-AG), subtotal (STPTX), unintentional less than subtotal (U-LSTPTX) and intentional less than subtotal parathyroidectomy (I-LSTPTX).Results: Considering 84 initial cases operated on since 2011 (TPTX-AG, 39; STPTX, 22, U-LSTPTX, 13, and I-LSTPTX, 10), the rates of hypoparathyroidism were 30.8% (U-LSTPTX), 28.2% (TPTX-AG), 13.6% (STPTX), and 0% (I-LSTPTX). Two-thirds of them (68%; 57/84) were young (<50 years) or asdolescents. MIBI scan was more sensitive to show parathyroid glands and bilateral disease. Considering the concordance of MIBI and ultrasound for the possibility of unilateral clearance, it would be suitable to 22.6% of the cases. Intra-operative parathormone showed a significant decay even after unilateral exploration, but longer follow up is necessary. Overall, there were seven (4%) adolescents in 161 cases treated from 1987 to 2018, three underwent TPTX-AG and four had U-LSTPTX. Five are euparathyroid, one had mild recurrence, and one required a reoperation after 8 years due to the residual gland.Conclusions: Young patients are the most frequent candidates to parathyroidectomy. Less extensive procedures may be planned only if carefully reviewed preoperative imaging studies suggest a localized disease. Patients and their relatives should be fully informed of the risks and benefits during consent process. Future research with larger cohorts and long-term results are necessary to clarify if less than I-LSPTX or unilateral clearance are really adequate in selected groups of patients with HPT/MEN1 presenting lower volume of disease detected by preoperative imaging studies.

Less-than-subtotal parathyroidectomy as treatment for primary hyperparathyroidism in multiple endocrine neoplasia- type 1: a good option?

“…This study showed coincidental sample between the intentional (LTSPTxI) and unintentional (LTSPTxNI) groups analyzed. Most of the study sample was composed of females and the mean age of the analyzed patients was 40 years, corroborating the data reported in other studies in the literature 4,6,7 . The reason for the larger number of female patients submitted to surgery is not clear, considering that disease penetrance is not associated with gender.…”

“…single side, either for one or two ipsilateral hyperplasic glands, are eligible to be submitted to this technique. This type of surgery has presented results similar to those of SxPT, but with no persistent PHT/MEN1; however, some studies have shown that surgeries using restrictive approaches present higher recurrence rates 4,7 . The great advantage of unilateral clearance is that, despite the risk of reoperation, it enables PHT/MEN1 recurrence correction through reoperation on a cervical bed that has not been previously manipulated, as in a first cervical approach.…”

“…It is a major frustration for the surgeon, because there is preoccupation with the possibility of being a non-resolving approach with probable persistence. However, the opposite was also observed: almost one-third of these patients remained with hypoparathyroidism and only approximately 15% of them presented persistence or recurrence 4 .…”

“…It is caused by mutations in the MEN1 tumor suppressor gene locus on chromosome 11q13, which codifies a protein named MENIN, of mainly nuclear expression [1][2][3] . It has full penetrance, and in 80-100% of the cases, the first clinical manifestation occurs through primary hyperparathyroidism (PHT/MEN1) [4][5][6] .…”

Single gland excision for MEN1‐associated primary hyperparathyroidism

“…However, in the last years few authors have favoured a unilateral approach to avoid permanent postoperative hypoparathyroidism. 3,[9][10][11][12][13] A unilateral approach or even focused single gland excision is considered justified, if preoperative diagnostic procedures (ultrasonography and/or 99mTc-MIBI scintigraphy) reveal unilateral or single enlarged parathyroid glands. In these cases, a targeted resection of one or two glands might be performed, if the intraoperative quick PTH measurement (IOPTH) reveals a drop of the intact serum parathyroid hormone level in the normal range after excision of hyperplastic gland(s).…”