Parathyroid conditions in childhood

This review of parathyroid surgery in children will briefly discuss parathyroid gland embryology and anatomy before focusing on the pathophysiology, clinical presentation, and treatment of hyperparathyroidism in children. Hyperparathyroidism (HPT) is the overproduction of PTH and it is rare in children, with an incidence of 2-5 per 100,000. This rarity means that the principles of caring for children with parathyroid disease are largely extrapolated from the richer adult experience; however, the unique pediatric aspects of parathyroid problems and their surgical treatment, including presentation, imaging, operative approach, and complications, will be considered.     

Hyperparathyroidism associated with thyroid pathology

BACKGROUND: The pathological association between thyroid and parathyroid gland disease is here discussed. The multiphase analyzer has revealed a new type of subclinical primary hyperparathyroidism (HPP) and the role of surgery in these cases is not clear. METHODS: This is a prospective study of all cases of thyroid disease in association with parathyroid disease treated surgically in our Institute from July 1999 to June 2001. RESULTS: Of the 221 thyroidectomies carried out, 29 patients had an elevated preoperative serum level of parathyroid hormone (PTH). An ultrasonography examination was performed on all patients and a preoperative scanning with 99Tc-MIBI on 11 of 29 patients. We examined intraoperatively 19 cases of HPP (14 parathyroid adenoma, 5 hyperplasia). In 10 cases we observed a normal size of the parathyroid gland and we did not perform a parathyroidectomy. CONCLUSIONS: All patients with elevated serum parathyroid hormone and serum calcium levels before thyroidectomy should be considered candidates also for surgery to the parathyroid glands. The pathological association between thyroid and parathyroid gland diseases is not rare. We must conduct an accurate neck exploration in all these cases.     

Sporadic primary hyperparathyroidism

Primary hyperparathyroidism (HPT1) is a common endocrine disorder, which is asymptomatic in 80% of cases. The diagnosis is ordinarily easily made, based on an inappropriately elevated parathormone level (PTH) in the face of hypercalcemia. In 85% of cases, HPT1 is due to hormone secretion from a single parathyroid gland (uniglandular disease) and the remaining patients have multiglandular disease. The best localization study is MIBI scintigraphy (methoxy isobutyl isonitrile) coupled with the results of a neck ultrasound exam (sensitivity >95%). Other investigations are reserved for patients with persistent or recurrent HPT1 post-surgery. Surgery is the only cure. The surgical approach may include a bilateral cervical exploration, a unilateral approach under local anesthesia, or focused minimally invasive (video-assisted or totally endoscopic) approaches. A decrease in PTH level measured intraoperatively of greater than 50% is predictive of cure in more than 97% of cases. Surgery is recommended even for moderate HPT1 and for very elderly patients because improvement in both the quality of life and bone density have been proven in these situations. The role of medical treatment is limited. Persistent or recurrent HPT1 requires a meticulous diagnostic approach and management in surgical centers with expertise. Persistent elevation of PTH postoperatively without hypercalcemia does not mandate further exploration. The prognosis of normocalcemic patients with elevated postoperative PTH levels remains uncertain.     

Feasibility of Rapid Parathormone Assay for Enabling Minimally Invasive Parathyroid Excision

There is no doubt that the success of minimally invasive parathyroidectomy (MIP) has changed the whole treatment of patients with primary hyperparathyroidism, especially the approach towards traditional bilateral neck exploration. A single adenoma is the most common cause of primary hyperparathyroidism and its removal results in cure. Hence, it is worth the effort to localise and excise the single adenoma using modern technologies such as high-quality sestamibi scans and to confirm complete excision using rapid intra operative parathormone (IOPTH) assays. The objective of the study was to evaluate the feasibility of rapid IOPTH assay in successfully facilitating minimally invasive parathyroid excision. This research involved the retrospective study of seven patients, who underwent MIP at Sagar Hospital in Bengaluru, India, for parathyroid adenoma. All patients with evidence of unifocal disease on sestamibi scanning and cervical ultrasonography, underwent MIP via 2–3 cm lateral incision. Blood samples for measurement of IOPTH were taken at the time of induction of anaesthesia and 10 min after the adenoma excision. Reduction of parathormone (PTH) levels of more than 50 % in the postexcision sample was taken as evidence for complete extirpation of parathyroid adenoma. A solitary adenoma was identified in all the seven patients. After MIP, IOPTH levels fell in six of the seven patients. Following the surgery, all the cases were followed up for a period of 1 month. During this time, except for one patient, six patients remained asymptomatic and blood tests revealed normal serum calcium levels. A histopathological examination confirmed the diagnosis of parathyroid adenoma in six of the seven patients. After accurate preoperative localisation of the adenoma in patients with primary hyperparathyroidism, MIP with IOPTH measurement offers a safe and successful outcome.     

61例尿毒症患者甲状旁腺全切加前臂移植术后低钙血症的发生与处理

目的针对内科治疗无效的继发性甲状旁腺功能亢进（sHPT）的尿毒症患者行甲状旁腺全切加前臂移植术,分析术后患者低钙血症的发生与处理。方法61例患者术后立即监测血钙浓度,并静脉补充葡萄糖酸钙,使血钙维持在1．8～2．2mmol／L之间,统计手术前、后患者的全段甲状旁腺激素（iPTH）、血清钙磷乘积和碱性磷酸酶（AKP）水平以及手术切除的总的腺体质量。结果56例患者（占91．7％）术后12-24h即出现血钙低于1．8mmol／L,静脉立即补充葡萄糖酸钙,约合元素钙（18±6）g,补钙剂量与术前血iPTH（r=0．621,P〈0．01）、钙磷乘积（r=0．719,P〈0．01）、AKP（r=0．606,P〈0．01）及总的切除腺体质量（r=0．716,P〈0．01）相关。结论低钙血症是患者甲状旁腺术后的常见表现,与SHPT的严重程度有关,术后及早监测血钙和静脉补钙可有效、安全预防严重低钙血症的发生。     

Parathyroidectomy: Overview of the Anatomic Basis and Surgical Strategies for Parathyroid Operations

It is imperative for the surgeon who performs parathyroidectomy to have a thorough understanding of the anatomy and embryology of the parathyroid glands in order to optimize the cure rate for patients with hyperparathyroidism (HPT). Furthermore, all clinicians caring for patients with hyperparathyroidism should be aware of the advancements in preoperative parathyroid localization, intraoperative PTH monitoring and surgical strategies for treatment of hyperparathyroidism. In this chapter, the anatomy and embryology of the parathyroid glands will be reviewed. The available surgical options for treatment of patients with hyperparathyroidism will be addressed, including “focused” parathyroidectomy, bilateral neck exploration, radioguided parathyroidectomy, and endoscopic and video-assisted parathyroidectomy. The unique challenge associated with reoperative parathyroidectomy for persistent or recurrent hyperparathyroidism will be outlined. Finally, insight into how to locate a qualified surgeon will be provided and recommendations will be made on what constitutes an appropriate choice of operation for specific patients with primary hyperparathyroidism.     

Impact of parathyroidectomy on cardiovascular risk in primary hyperparathyroidism: A narrative review

AimsPrimary hyperparathyroidism (PHPT), one of the most frequent endocrine disorders, is not only associated with bone and kidney disorders but also with increased cardiovascular risk. This cardiovascular risk is not part of the indication for surgery owing to discordant evidence of the effects of parathyroidectomy (PTX), especially in mild PHPT which is the most common presentation of PHPT. This literature review focuses on the effects of PTX on the cardiovascular risk in PHPT. The MEDLINE database was searched via the PubMed interface, selecting relevant articles published after 1990 in English.Data synthesisIn the most recent series, PTX appeared to have a positive impact on cardiovascular morbidity and mortality. Surgery improves arterial hypertension, markers of glucose homeostasis, vascular and cardiac remodeling and electrocardiographic impairments due to classical PHPT. However, the results of surgery on mild PHPT are conflicting.ConclusionsPTX seems to improve cardiovascular risk in patients presenting the classical form of PHPT. This improvement is correlated with preoperative serum calcium and/or PTH level, depending on the cardiovascular risk factor. However, many aspects of this improvement are not fully understood. Future studies should assess the effects of PTX on nocturnal hypertension, cardiac morphology and functions. The results for mild PHPT are conflicting owing to the limited size of the cohorts included in studies and the lack of randomized trials. Surgery is not currently recommended for patients presenting mild PHPT based on the cardiovascular risk and more studies are needed to better understand the interest of PTX on cardiovascular outcomes.     

Technetium-99m-sestamibi/pertechnetate subtraction scintigraphy vs ultrasonography for preoperative localization in primary hyperparathyroidism

A prospective study was performed to evaluate the efficacy of technetium-99m-sestamibi and technetium-99m-pertechnetate subtraction scanning and US for imaging parathyroid glands in primary hyperparathyroidism. Sixty-three patients were surgically treated for primary hyperparathyroidism (HPT). Preoperative scintigraphy and US were performed in all cases. Bilateral neck exploration was carried out on each patient. Results of radionuclide studies and US were compared with surgical and histological findings. In 57 patients with primary HPT the radionuclide scanning gave true-positive results. Four false-negative and two false-positive scintigrams were obtained. The sensitivity and the positive predictive value (PPV) of scintigraphy were 93 and 97%, respectively. Forty-one cases were correctly localized by the US. Seventeen US results were false negative and five were false positive. The sensitivity and the PPV for US were 71 and 89%, respectively. There was a statistically significant difference between the sensitivity of the scintigraphy compared with the US ( p=0.001). Sensitivities of radionuclide scans and US were higher for adenomas (100 and 83%) than for hyperplastic glands (75 and 40%). The sensitivity of technetium-99m-sestamibi and technetium-99m-pertechnetate subtraction scintigraphy was significantly higher compared with US. This sensitive method could help surgeons in performing a rapid and directed parathyroidectomy.     

Surgery did not improve the subjective neuropsychological symptoms of patients with incidentally detected mild primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is known to cause diverse subjective symptoms, in addition to those related to osteitis fibrosa cystica and kidney stones. The treatment of the disease ameliorates the subjective symptoms and improves the patients’ quality of life. In this prospective study, patients undergoing surgery for incidentally detected, mild, asymptomatic PHPT were assessed to determine whether subjective neuropsychological symptoms are improved even in patients with “asymptomatic” PHPT. From October 1995 to March 2004, 25 patients who had one or more neuropsychological symptoms preoperatively and were followed up 1 year after parathyroidectomy were enrolled. The subjective symptoms were identified using questionnaires distributed to patients; eight questions were used to determine the presence or absence of psychoneurological symptoms. Compared to their preoperative status, patients responded that their general health perceptions 1 year after surgery were improved (13 cases, 52%), unchanged (11 cases, 44%), or aggravated (1 case, 4%). There were no statistically significant differences in the patients’ responses before and after surgery with respect to individual neuropsychological symptoms, such as “tiring easily, “forgetfulness,” “decreased concentration,” “depression,” “irritability,” “uneasiness,” and “sleeplessness.” Therefore, subjective neuropsychological symptoms did not improve in otherwise asymptomatic PHPT patients following parathyroidectomy. However, patients’ questionnaire responses may not reflect their actual status as accurately as laboratory examination results. Overall, 52% of patients were subjectively satisfied with surgery; this may result from patients’ expectations of treatment.