Impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy

ObjectivesTo determine the impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy.Material and methodsA single-center retrospective study was conducted for a 5-year period in a university hospital center, including 605 patients undergoing total thyroidectomy, 52 of whom had mediastinal-recurrent cellular and lymph-node dissection.EndpointsThe main endpoint was intraoperative number of parathyroid glands as predictor of parathyroid hormone (PTH) level and postoperative hypocalcemia. The secondary endpoint was the correlation between associated mediastinal-recurrent cellular and lymph-node dissection and incidental parathyroidectomy and its impact on PTH level and calcemia in the immediate postoperative period and at 1 month.Results161 patients (26.61%) showed hypocalcemia in the immediate postoperative period and 12 (1.98%) at 1 month. Mediastinal-recurrent cellular and lymph-node dissection increased incidental parathyroidectomy risk 4.6-fold. Mediastinal-recurrent cellular and lymph-node dissection was associated with a statistically “suggestive” decrease in day-1 calcemia (P = 0.03), and no significant decrease at 1 month (P = 0.52). Incidental parathyroidectomy (6.7% of cases with parathyroidectomy versus 1.3% without) did not significantly increase the rate of early hypocalcemia (P = 0.28), but was associated with a “suggestive” worsening at 1 month (P = 0.02).ConclusionHypocalcemia after total thyroidectomy is a complex, probably multifactorial issue. Systematic parathyroid gland identification is not recommended due to the increased risk of gland lesion, mainly by devascularization. Incidental parathyroidectomy may induce hypocalcemia at 1 month postoperatively (statistically “suggestive” association).     

甲状旁腺切除术用于难治性肾性继发性甲状旁腺功能亢进的安全性及近远疗效

背景与目的:甲状旁腺切除术(PTX)是治疗药物不能控制的难治性肾性继发性甲状旁腺功能亢进症(SHPT)的重要手段,但PTX术后仍有可能发生永久性甲状旁腺功能减退,无动力性骨病或难治性骨软化症,且国内尚缺乏对PTX术后远期的疗效观察的研究。本研究进一步评价PTX治疗难治性肾性SHPT的安全性与近远期疗效。方法:纳入2011年1月—2014年12月在安徽医科大学第二附属医院行PTX治疗的139例伴有难治性肾性SHPT的维持性透析患者。收集患者术前及术后3 d、6个月及1、2、3年的临床资料、血全段甲状旁腺激素(iPTH)、血钙、血磷、血红蛋白(Hb)及红细胞压积(Hct)等,观察并记录术后症状缓解情况、术后并发症和随访情况。结果:139例患者的PTX手术成功率为95.7%(133/139),术中共计切除甲状旁腺腺体537枚,平均切除3.86枚/例。12例(8.6%)术后发生一过性喉返神经损伤,其中声音嘶哑9例(6.5%),饮水呛咳3例(2.2%),未予处理术后3个月内均自行好转。术后低钙血症或缺乏维生素D者120例(86.3%),给予西那卡塞、补钙及补充活性维生素D治疗后得到有效控制。全组未发生切口感染、出血、窒息及甲状腺功能减退等外科并发症。患者的贫血状况均有不同程度地改善,Hb和Hct术后6个月明显升高并在随访期间保持稳定;术后iPTH明显降低,术后3 d的血钙、磷、钙磷乘积水平最低,随访3年仍低于手术前,所有变化与术前均有统计学差异(均P0.05)。随访期间无死亡病例。患者术前的骨痛、顽固性皮肤瘙痒、失眠、异位钙化、肌无力伴萎缩症状在术后1 d即明显缓解;身高缩短、骨骼畸形患者随访期间无进行性加重;纳差、全身营养状况及自理能力术后3个月内不同程度地改善。11例(7.9%)持续性SHPT,包括4例(2.9%)术中未完全切除甲状旁腺腺体,1例(0.7%)术中1枚腺体较小而未切除完全,6例(4.3%)术后检查存在纵隔异位甲状旁腺。随访期间,5例(3.5%)腺体未切除完全者的iPTH均800 pg/mL,肌无力及顽固性皮肤瘙痒临床症状明显,再次行PTX;6例(4.3%)存在异位甲状旁腺腺体者,因手术风险较大患者拒绝再次手术,予以药物治疗;8例(5.8%)术后复发,其中6例(4.3%)系前臂移植物复发所致,均在局麻下行前臂皮下移植物切除;2例(1.4%)系颈部原位残留腺体过度增生,予以二次手术,术后症状缓解。所有进行二次手术的患者在随访结束时无明显的临床症状,均未复发。结论:PTX可改善难治性肾性SHPT患者临床症状、贫血及钙磷代谢,且近远期疗效均较好,是治疗难治性SHPT的安全有效方法。     

Detectability and surgical outcomes in parathyroid surgery – a single-centre experience

The incidence of primary hyperparathyroidismand referrals for the removal of parathyroid adenomas are increasing. Factors that improve the detectability, and ultimately the surgical outcome, are the focus of this retrospective study. We included 117 patients who had parathyroid operations with intraoperative monitoring of parathyroid hormone (PTH). Sestamibi, ultrasound and, in selected cases, fusion with computed tomograms (CT), were done to locate the lesion preoperatively. Concentrations of calcium and PTH before and after operation, specimen weight, and preoperative vitamin D concentrations, were assessed. The sensitivity of sestamibi and ultrasound for the preoperative location of adenomas was 92% and 80%, respectively. Sestamibi located them more accurately in patients with low preoperative concentrations of vitamin D (p = 0.037) and with heavier adenomas (p < 0.001). We found no significant association between the preoperative concentrations of PTH and detectability on preoperative scans (p = 0.058). Postoperative follow up showed that 97% of the 117 patients were biochemically cured. Accurate location helps to lower morbidity as it facilitates a targeted approach. Further studies are needed to explore the role of vitamin D in the location of parathyroid adenomas before parathyroidectomy.     

Identificación de adenomas ocultos en hiperparatiroidismo primario con PET-TC 18F-fluorocolina

IntroductionSingle parathyroid adenomas are the most common cause of primary hyperparathyroidism (PHP) in our population. Parathyroidectomy is still the only potentially curative treatment and requires preoperative localization imaging studies to perform selective surgery. In patients with negative results on conventional tests, PET/CT has demonstrated higher sensitivity rates.MethodsA prospective cohort study was designed, including 34 patients diagnosed with PHP between 2017 and 2019, candidates for surgery with negative preoperative localization tests with scintigraphy and MIBI SPECT/CT. All patients underwent PET/CT with 18F-Fluorocholine. The clinical, biochemical and postoperative outcome results were compared with a control group of 30 patients with positive standard tests.ResultsHyperfunctional parathyroid tissue was detected in 85% of the patients that had undergone choline PET/CT. The selective resection of the adenoma identified in these patients achieved curative criteria in 87% of the cases without undergoing bilateral cervical surgical exploration. The preoperative levels of PTH, calcemia and gland weight were significantly lower in this group compared to the control group. No differences were identified in cure criteria or approach between the 2 groups.ConclusionIn our study, choline PET/CT showed higher detection rates compared to the gold standard. The increase provides the opportunity to perform unilateral selected adenoma resection, especially in patients with smaller adenomas associated with lower calcemia and PTH levels and patients with previous cervical surgery.     

Parathyroid cancer: An update

Parathyroid cancer (PC) is a rare malignant tumor which comprises 0.5–5% of patients with primary hyperparathyroidism (PHPT). Most of these cancers are sporadic, although it may also occur as a feature of various genetic syndromes including hyperparathyroidism-jaw tumor syndrome (HPT-JT) and multiple endocrine neoplasia (MEN) types 1 and 2A. Although PC is characterized by high levels of serum ionized calcium (Ca) and parathyroid hormone (PTH), the challenge to the clinician is to distinguish PC from the far more common entities of parathyroid adenoma (PA) or hyperplasia, as there are no specific clinical, biochemical, or radiological characteristic of PC. Complete surgical resection is the only known curative treatment for PC with the surgical approach during initial surgery strongly influencing the outcome. In order to avoid local recurrence, the lesion must be removed en-bloc with clear margins. PC has high recurrence rates of up to 50% but with favorable long-term survival rates (10-year overall survival of 60–70%) due to its slow-growing nature. Most patients die not from tumor burden directly but from uncontrolled severe hypercalcemia. In this article we have updated the information on PC by reviewing the literature over the past 10 years and summarizing the findings of the largest series published in this period.     

甲状旁腺激素对大鼠牵张成骨过程中O NC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因表达的影响

目的：探讨甲状旁腺激素（PTH）对大鼠牵张成骨（DO）过程中ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因表达的影响。方法30只雄性大鼠制备大鼠下颌骨DO模型。随机分5组，每组6只。第1组（只有牵张无PTH），术后8周取材，应用HE染色及微CT检测，以确定成骨情况。第2组（有牵张无PTH），第3组（有牵张有PTH），第4组（无牵张有PTH），第5组（对照组：无牵张无PTH）。2、3、4组及对照组术后1周取材，RT-PCR测定ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因的表达。结果第1组，新骨形成，骨质充满牵张区，骨质连续，大鼠建模成功。RT-PCR检测结果显示，2、3、4组与对照组比较，OPN、COL1、RUNX2、ALP基因表达有明显提高（P＜0．05），其中第3组最为明显。ONC、C-FOS、VEGF基因2、3、4组与对照组比较差异无统计学意义（P＞0．05）。结论 PTH在 DO 过程中，间歇性给以 PTH的作用只有在牵张期发挥作用，其对 OPN、COL1、RUNX2、ALP基因表达能够获得理想的协同作用。