Recovery of parathyroid function after total thyroidectomy: long-term follow-up study

BACKGROUND: To prevent postoperative hypoparathyroidism following total thyroidectomy, the parathyroid glands are preserved in situ and/or resected or devascularized parathyroid glands are autotransplanted. A retrospective investigation was conducted utilizing biochemical and specific endocrine assessments to evaluate the difference in recovery of parathyroid function in the long term. METHODS: A total of 103 patients underwent total thyroidectomy at Second Department of Surgery, School of Medicine, Kagawa University between 1990 and 1998. These patients were divided into a preservation group (n = 17), with only preserved glands in situ; a combination group (n = 72), consisting of patients with one or more parathyroid glands preserved in situ and one or more autotransplanted parathyroid glands; and an autotransplantation group (n = 14), with only transplanted glands. RESULTS: The overall incidence of permanent hypoparathyroidism in the preservation group, the combination group, and the autotransplantation group was 0%, 1.4%, and 21.4%, respectively. The mean levels of intact parathyroid hormone in the preservation group, the combination group, and the autotransplantation group recovered to 102%, 107%, and 50% of the preoperative levels at 5-year follow up. CONCLUSION: The results of the present study suggest that parathyroid glands should be preserved in situ whenever possible, to promote better recovery of postoperative function, and that only autotransplantation produces inadequate recovery of long-term function.     

Outcomes of Parathyroid Autotransplantation During Total Thyroidectomy: A Comparison with Age- and Sex-Matched Controls

Purpose: To determine the effect of parathyroid autotransplantation (PA) on postoperative hypocalcemia in cases of total thyroidectomy. Materials and Methods: Cases undergoing total thyroidectomy and PA were compared with age and sex-matched controls who had not undergone PA. The postoperative percentage changes (PC) of parathyroid hormone (PTH) and calcium (Ca+2) in the first 12–24 hours (12–24hr→preop), between the 1st-3rd weeks (1-3wk→preop) and at the 6th month (6mo→preop), the rates of hypocalcemia (Ca+2< 8mg/dL) and low PTH level (PTH< 15 pg/mL), permanent hypocalcemia, inadvertent parathyroidectomy in both groups were compared. Results: The number of patients with PTH12-24hr<15 pg/mL was significantly higher (n:34,(55.7%)) than the number of patients in the control group (n:16(26.2%)), (p=0.001). The rate of decrease in the blood Ca+2 median PC (6mo→preop) was significantly higher in the PA group (4.2%) than the control group (1.1%), (p=0.008). There was no significant difference between the 2 groups in terms of the postoperative frequency of hypocalcemia (p>0.05). In the PA&age≤50 group, the rate of inadvertent parathyroidectomy was higher than that of cases over age 50 (p=0.029). Conclusion: In spite of the presence of an increased postoperative hypocalcemia trend in cases requiring PA during total thyroidectomy, the rates of transient and permanent hypocalcemia were not different to the control cases. But the frequency of cases with low PTH level in cases undergoing PA was higher than that of the control cases. In cases of 50 years of age and under, who had undergone PA, the possibility of inadvertent parathyroidectomy increased.     

Parathyroid autotransplantation during thyroidectomy

Permanent hypoparathyroidism is a debilitating morbidity following thyroidectomy, with a reported incidence of up to 43%. Apart from meticulous dissection to preserve parathyroid glands and their blood supply, parathyroid autotransplantation (PA) has been increasingly employed to preserve parathyroid function. The adoption of PA during thyroidectomy has been reported to be associated with a low incidence of permanent hypoparathyroidism. Biochemical function of parathyroid autografts can be demonstrated objectively by forearm reimplantation or during long-term follow up. The clearest indication for PA is for inadvertently removed or devascularized parathyroid glands during thyroid surgery. Other strategies, including routine autotransplantation of at least one parathyroid gland, can be considered, but is associated with a high incidence of transient hypocalcaemia. Apart from refinement in technique to facilitate graft success, a reliable way to assess overall parathyroid function or viability of individual parathyroid gland may assist in monitoring parathyroid function and selecting patients requiring this procedure to prevent permanent hypoparathyroidism.     

甲状旁腺的术中观察及术后甲状旁腺功能减退的探讨

目的在甲状腺手术中认识甲状旁腺的局部解剖及甲状腺手术切除范围和甲状旁腺功能减退的关系,探讨术后甲状旁腺功能减退的原因及预防治疗措施。方法回顾2582例甲状腺手术患者的临床资料并术后随访。结果其中对721例双侧甲状腺侧叶全切者行术中探察,发现甲状腺病理状态下甲状旁腺的局部解剖位置及数量变异大,探察到的每种情况术后暂时性甲状旁腺功能减退发生率各不相同,其中上下甲状旁腺双侧均不明显组永久性甲状旁腺功能减退发生1例。2453例手术中行甲状腺部分切除、单侧叶次全切除、单侧叶全切除、双侧叶全切除、双侧叶全切及颈淋巴结清扫者（即甲状腺癌根治）暂时性甲状旁腺功能减退发生率依次增高,其中以双侧叶次全切除暂时性甲状旁腺功能减退发生率最高。且又因甲状腺疾病病种各不相同,甲状旁腺功能减退发生率亦各不相同。结论术后甲状旁腺功能减退的发生与手术操作、甲状旁腺的局部解剖及其变异、甲状腺手术切除范围、巨大甲状腺及其内巨大包块对双侧甲状腺后被膜深面组织的压迫,甲状腺疾病病种不同而手术难度各异等皆有关系。     

Parathyroid hormone assay predicts hypocalcaemia after total thyroidectomy

BACKGROUND: Postoperative parathyroid gland function after total thyroidectomy (TT) has traditionally been monitored by the measurement of serum calcium concentrations. The purpose of this study is to determine whether measurement of parathyroid hormone (PTH) concentrations in the early postoperative period accurately predicts patients at risk of developing hypocalcaemia. METHODS: A prospective cohort study of patients undergoing TT was carried out. PTH concentrations were measured preoperatively and at 4 and 23 h postoperatively. Serum calcium concentration was measured preoperatively and twice daily for 48 h after surgery. RESULTS: One hundred patients undergoing TT were recruited into the study in the period June 2004 to July 2005. Benign multinodular goitre was the most common indication for surgery (77%). The incidence of temporary hypocalcaemia (Ca < 2.0 mmol/L) was 18%. The mean PTH concentration at 4 h after surgery was 22.3 ng/L and was not significantly different from the 23-h concentration of 23.2 ng/L (P = 0.18). A PTH concentration of < or = 3 ng/L measured at 4 h after surgery had a sensitivity, specificity and likelihood ratio of 0.71, 0.94 and 11.3, respectively, for predicting postoperative hypocalcaemia. The accuracy of a single PTH concentration at 4 h was good for predicting hypocalcaemia (area under receiver-operator characteristic curve 0.90; confidence interval 0.81-0.96). There was no significant difference in accuracy between the 4- and 24-h PTH concentrations (P = 0.14). CONCLUSIONS: A single measurement of PTH concentration in the early postoperative period after TT reliably predicts patients who are likely to develop hypocalcaemia. This approach facilitates early discharge and may decrease the need for multiple postoperative blood tests.     

Assessment of parathyroid autotransplantation for preservation of parathyroid function after total thyroidectomy

BACKGROUND: Hypoparathyroidism with permanent hypocalcemia is a well-recognized complication after thyroid surgery. AIM: This study was conducted to assess the role of immediate parathyroid autotransplantation in the preservation of parathyroid function after total thyroidectomy. PATIENTS AND METHODS: Twenty-eight patients had autotransplantation of parathyroid glands resected or devascularized during total thyroidectomy. Data were collected prospectively regarding demographics, indication for surgery, operative procedure, pathologic diagnosis, number of glands transplanted, and subsequent course. Thyroid nodules were evaluated by ultrasonography, radionuclide scanning, and/or fine-needle aspiration cytology. All patients had serum ionized calcium, phosphorus, and intact parathyroid hormone (PTH) levels measured preoperatively and monitored regularly postoperatively for a period of 14 weeks and again at 6 months after operation. Patients were categorized into three groups according to the number of glands transplanted: one (group 1, n = 6), two (group 2, n = 14), or three glands (group 3, n = 8). In three other volunteers, one parathyroid gland was transplanted in the brachioradialis and subjected to electron microscopy 1, 2, and 4 weeks after transplantation. RESULTS: Total thyroidectomy was performed for malignant disease in 16 patients (57.1%) and for benign disease in 12 (42.9%) patients. All patients reverted to asymptomatic normocalcemia without the need for any medications within 4 to 14 weeks. Normal levels of serum markers were regained slower when one gland was transplanted compared with two or three glands (P <.01). Electron microscopic examination showed evidence of ischemic degeneration in the transplanted tissues 1 week postoperatively. Regeneration started by the second week and coincided with normalization of PTH levels. Optimum resting and nearly normal status of parathyroid tissue was achieved by the fourth week. CONCLUSIONS: This study showed that active PTH production coincides with regeneration of parathyroid cells and that autotransplantation of at least two resected or devascularized glands during total thyroidectomy nearly eliminates permanent postoperative hypoparathyroidism, thus improving the safety of total thyroidectomy performed for malignant or benign disease.     

ROUTINE AUTOTRANSPLANTATION OF AT LEAST ONE PARATHYROID GLAND DURING TOTAL THYROIDECTOMY MAY REDUCE PERMANENT HYPOPARATHYROIDISM TO ZERO

Background : Permanent hypoparathyroidism, although a recognized complication of total thyroidectomy, is an outcome that all endocrine surgeons try to avoid. Methods : To minimize the risk of postoperative hypoparathyroidism a strategy was developed of routine autotransplantation of at least one parathyroid gland into the ipsilateral sternomastoid muscle during every total thyroidectomy. One hundred consecutive patients undergoing total thyroidectomy were included in the study. Serum calcium and albumin levels were measured pre-operatively, on the first 2 postoperative days, and after 2 weeks, or until return to normal serum calcium levels without calcium supplementation. If patients developed biochemical evidence or symptoms of hypocalcaemia postoperatively, a calcium replacement was administered according to defined protocol. Results : In 74 cases one parathyroid gland was autotransplanted: 44 for inadvertent removal or anatomical reasons, 19 because of devascularization (assessed by a cut through the gland’s capsule and evaluation of the capillary bleeding pattern), and 11 by protocol. In 25 cases, two or more glands were autotransplanted. Fourteen patients developed symptoms of hypocalcaemia and received calcium supplementation, as did another 13 asymptomatic patients with only biochemical evidence of hypocalcaemia. At follow-up 3 months postoperatively the incidence of permanent hypoparathyroidism was zero, with all patients being normocalcaemic without calcium supplementation. Conclusions : This strategy, easily adopted by any experienced surgeon, has the potential to eliminate permanent hypoparathyroidism following total thyroidectomy.     

Secretion of Parathyroid Hormone After Surgical Trauma

Parathyroid hormone was measured in nine patients subjected to surgery under general anaesthesia not involving operative bone trauma. Total calcium concentration, ionized serum calcium and serum albumin was also analyzed pre- and postoperatively. An increase in serum parathyroid hormone was registered postoperatively without any acompanying decrease in ionized serum calcium. the measured changes are at present unexplained, but can be caused by other mechanisms than bone trauma.     

Serum intact parathyroid hormone as a predictor of hypocalcaemia after total thyroidectomy

BACKGROUND: Hypocalcaemia from hypoparathyroidism is a complication of total thyroidectomy. The aim of the present study was to determine whether an early postoperative level of serum parathyroid hormone (PTH) after total thyroidectomy predicts the development of significant hypocalcaemia and the need for treatment. METHODS: Patients undergoing total thyroidectomy had their serum level of intact PTH checked 1 h after removal of the thyroid gland. Serum calcium level was checked on the following morning. Oral calcium and/or calcitriol was commenced if the patient developed hypocalcaemic symptoms, or if the corrected serum calcium level was <2.0 mmol/L. RESULTS: Seventy-nine patients were included in the present study. Thirteen patients had symptoms of hypocalcaemia on postoperative days 1 or 2 and 66 patients remained asymptomatic. The postoperative intact PTH, day 1 calcium and day 2 calcium was 0.32 +/- 0.60 pmol/L, 2.01 +/- 0.11 mmol/L, and 2.02 +/- 0.16 mmol/L, respectively, for the symptomatic group and 1.98 +/- 1.25, 2.21 +/- 0.13, and 2.19 +/- 0.14, respectively, for the asymptomatic group. Calcium support was given to 25 patients, of whom 14 also required calcitriol. CONCLUSION: Serum PTH 1-h after total thyroidectomy is a reliable predictor of hypocalcaemia and can allow safe early discharge of patients from hospital.     

In Vitro Parathyroid Hormone Release in Patients with Secondary Hyperparathyroidism

Background: The purpose of this study was to determine the precise endocrim. characteristics of parathyroid function in secondary hyperparathyroidism (sHPT).
Methods: We examined the effects of extracellular ionized calcium (Ca²⁺) varying from 0.5 to 2.0 mM on parathyroid hormone (PTH) release in parathyroid cell suspensions using a mid-regional PTH assay. Cells were obtained from 26 patients with sHPT who were divided into two groups according to the type of hyperplasia they exhibited, either nodular (n=16) or diffuse [n= 10). For compdrison, we also analyzed data from nine patients with primary hyperparathyroidism (pHPT; adenomas).
Results: Significant in vitro suppression of PTH release by Ca²⁺ was observed in the majority of subjects, regardless of the histologic abnormality. The pHPT group exhibited no significant relationship between clinical and in vitro data. In contrast, in the sHPT group (taken as a whole), suppression of PTH release by Ca²⁺ exhibited a plateau at a total serum calcium concentration of 2.5 mmol/L, and a parathyroid gland weight of 2 g.
Conclusions: These findings suggest that there is a curvilinear relationship in sHPT, but not pHPT, between the in vitro calcium sensitivity of parathyroid cells and total serum calcium, as well as gland weight. The in vitro calcium sensitivity in sHPT remains constant when the total serum calcium concentration exceeds 2.5 mmol/L, or when the gland weight exceeds 2 g.     

甲状腺全切除术后测定甲状旁腺激素对预测低血钙发生的价值

目的 探讨甲状腺全切除术后甲状旁腺激素(PTH)测定在预测有症状低血钙方面的意义.方法 前瞻性地选择2010年6月至2011年12月期间在首都医科大学宣武医院普通外科甲状腺乳腺专业组同一个主诊医师小组接受甲状腺全切除术的连续45例患者,分别于术后1h测定PTH与血钙,并在住院期间每天监测PTH与血钙,记录出现低血钙的症状.利用受试者工作曲线分析预测低血钙的临界值.结果 共45例患者,有9例(20.0％)术后血钙正常;17例(37.8％)术后出现无症状低血钙;19例(42.2％)出现有症状低血钙,需要补充钙剂治疗.血钙正常者、无症状低血钙者及有症状低血钙者术后1 h PTH值分别为(40.5±23.7) ng/L、(18.3±9.1)ng/L及(7.6±4.2)ng/L,方差分析显示,P＜0.001.术后1 h PTH值≤13.4 ng/L可以预测患者将发生低血钙的相关症状,敏感性为94.7％,特异性为76.9％.结论 甲状腺术后1 h PTH值≤13.4 ng/L的患者发生低血钙相关症状的可能性较大,需要补充钙剂治疗以减少患者的不适症状.     

Parathyroid Hormone Secretion After Operative Bone Trauma

Skeletal trauma in man (operations for scolioses and femoral shortening) results in a significant increase in parathyroid hormone secretion beginning the day after the operation and lasting for more than 1 week. A concurrent decrease in serum calcium, dependent on the postoperative lowering of serum albumin, was also observed.     

甲状旁腺全切术后低iPTH与骨代谢指标及钙化防御相关性研究

目的探讨甲状旁腺全切术后低甲状旁腺素水平与骨代谢标志物及钙化防御相关性研究,关注术后iPTH合理的控制范围。方法选取我院240例行甲状旁腺全切术的透析患者,根据iPTH水平分为:0～49、50～149、150～300pg/mL三组,统计分析相关生化指标,骨代谢标志物及钙化防御发病情况。结果 PTX术后三个月患者Hb、Cr水平较术前无显著改变(P0.05),患者Ca、P、iPTH、TRACP-5b、CTX较治疗前显著下降,B-ALP及钙化防御发生较治疗前明显升高(P0.05);随着iPTH逐渐降低,三组患者β-CTX及RACP-5b改变无统计学意义(P0.05),iPTH 50～149pg/mL组与iPTH 150～300pg/mL相比,BALP改变及钙化防御发生比例差异无统计学意义(P0.05),iPTH 0～49pg/mL组B-ALP及钙化防御比例明显高于上述两组,差异具有统计学意义(P0.05)。结论术后患者短期内成骨细胞功能上调,破骨细胞活性降低,临床症状缓解确切,iPTH进一步降低,过低iPTH患者B-ALP显著升高,游离血钙大量参与骨骼钙化及异位矿化,成骨-破骨细胞耦联活化机制破坏,导致钙化防御例数短期明显升高,因此甲状旁腺全切+前臂移植亦或甲状旁腺次全切,可避免术后iPTH水平剧烈波动,是应该推荐的合理手术方案。     

Hypoparathyroidism After Total Thyroidectomy: Importance of the Intraoperative Management of the Parathyroid Glands

World Journal of Surgery - Total thyroidectomy is the most common surgical procedure for the treatment of thyroid diseases. Postoperative hypocalcemia/hypoparathyroidism is the most frequent...     

甲状腺手术中甲状旁腺辨识方法进展

目的总结甲状腺手术中甲状旁腺辨识方法的最新进展,以期为提高临床疗效提供一定的参考。方法复习国内外有关甲状腺手术中甲状旁腺辨识方法的文献,并且作一综述。结果甲状腺手术中辨识甲状旁腺的方法良多,如肉眼识别法、术中快速病理检查、术中染色识别法、术中光学识别法、术中甲状旁腺激素监测、γ-探测仪、组织学鉴定等,每种方法均存在着自身的优点与不足。结论对甲状旁腺的辨识不可单纯依赖于某种方法,还需要外科医师增强自身辨别甲状旁腺的能力。