Preoperative localization of parathyroid adenomas

Patients with primary hyperparathyroidism have a parathyroid adenoma approximately 80% of the time. Preoperative localization of parathyroid adenomas has been significantly improved by the utilization of high resolution (high frequency) real-time ultrasound. This technique was accurate in 14 (78%) of the 18 cases in our series. There were four false negatives and no false positives. This imaging technique can routinely identify lesions less than 1 cm. High resolution real-time ultrasound is fast, safe, and cost effective. It is an ideal screening test for the preoperative localization of parathyroid adenomas.     

Preoperative parathyroid localization: correlating false-negative technetium 99m sestamibi scans with parathyroid disease

OBJECTIVE/HYPOTHESIS: The recent trend toward minimally invasive directed parathyroid surgery has increased the surgeon's reliance on preoperative parathyroid localization. Technetium Tc 99m sestamibi scanning is generally viewed as the gold standard for preoperative localization, with reported sensitivities of 75% to 100% and specificities of 75% to 90%. However, in each reported series there exists a group of patients in whom preoperative localization is either equivocal or negative. STUDY DESIGN: We focused on a subset of patients from our parathyroid database with false-negative sestamibi (MIBI) scans, in an attempt to elucidate features that could affect these studies. We identified 20 patients with negative preoperative scans and confirmed parathyroid disease. We compared them with 22 consecutive patients with positive scans, correlating the following variables: patient age, gender, concomitant thyroid disease (Hashimoto's thyroiditis, papillary thyroid carcinoma, thyroid adenoma), preoperative parathyroid hormone values, location and number of enlarged parathyroid glands, parathyroid weight, and the relative proportion of chief cells, clear cells, oxyphil cells, and adipose tissue. METHODS: Retrospective chart review of clinicopathological and radiological findings. RESULTS: We found that patients with false-negative scans were more likely to have an enlarged parathyroid containing a high proportion of clear cells (P =.01). A trend was seen (P =.1) correlating increased parathyroid fat content and false-negative scans. Conversely, positive preoperative scans were more likely to be associated with a higher percentage of oxyphil cells (P =.02). Univariate analysis for other variables, as well as logistic regression analysis, did not achieve statistical significance. CONCLUSIONS: To date, the present study is the largest clinicopathological review of patients with false-negative sestamibi scans. Technetium Tc 99m uptake correlates with parathyroid oxyphil cell content, and false-negative scans can occur with parathyroid glands containing predominantly clear cells.     

Preoperative parathyroid adenoma localization by the technetium-thallium subtraction scan

The technetium-thallium subtraction scintigram was utilized preoperatively in 14 consecutive patients explored for primary hyperparathyroidism. The scintigram accurately identified the site of a parathyroid adenoma in 12 of 13 patients.     

Ultrasonography for preoperative localization of enlarged parathyroid glands in secondary hyperparathyroidism

Objective

Parathyroidectomy (PTx) is sometimes performed to treat secondary hyperparathyroidism (2HPT) related to long-term dialysis. In this procedure, all four parathyroid glands should be resected. However, in patients with 2HPT, the four glands are not uniformly enlarged; therefore, preoperative diagnosis is difficult in comparison with primary hyperparathyroidism. We compared glands detected on preoperative ultrasonography (US) with those resected during PTx to examine the usefulness and limitations of US.

Methods

The subjects were 44 patients with 2HPT who underwent PTx between December 2003 and November 2007. Surgery was indicated for patients meeting the following three conditions: a serum intact PTH (iPTH) level of 500 pg/ml or more; a maximum glandular volume of 500 mm³ or more; and increased bone metabolism. Before surgery, we detected the parathyroid glands using US, and three-dimensionally measured their sizes. PTx was performed based on US diagnosis, and resected glands were weighed.

Results

Assuming that four parathyroid glands are present in each patient, the total number of glands in the 44 patients was 176. Of the 176 glands, 139 were detected on preoperative US. However, 27 could not be resected. Therefore, the detection rate on US was 63.6% (112/176). Of 37 glands that could not be detected on preoperative US, 30 were detected during surgery, and resected. There was a positive correlation between the glandular volume measured on US and isolated gland weight. However, there was no correlation between the preoperative serum iPTH level and the sum of the four isolated gland weights.

Conclusion

On preoperative US, approximately 80% of the glands were detected. However, the misdiagnosis rate was approximately 20%. The rate of accurate diagnosis was 63.6%. Even when glands were misdiagnosed or could not be confirmed on preoperative US, approximately 80% of them could be detected and resected during surgery. It may be impossible to estimate the glandular volume based on the preoperative serum iPTH level.     

Techniques for parathyroid localization with ultrasound

Four-gland parathyroid exploration has been the gold standard for parathyroid surgery until recently. Emphasis is now placed on minimally invasive and focused parathyroidectomy. In conjunction with functional sestamibi scanning, ultrasonography permits accurate localization of enlarged parathyroid glands in the vast majority of patients with hyperparathyroidism. Consequently, ultrasound technology applied to parathyroid pathology facilitates directed surgical therapy and minimally invasive applications. As such, ultrasonography holds great promise as a tool that enables cost-effective and advanced patient care.     

磁共振成像在继发性甲状旁腺功能亢进症术前定位的诊断价值

目的　研究磁共振成像（magnetic resonance imaging,MRI）在继发性甲状旁腺功能亢进症（secondary hyperparathyroidism,SHPT）患者术前定位诊断价值。方法　回顾性分析2010～2016年在我院首次行甲状旁腺切除+自体移植术,均通过MRI、99m锝-甲氧基异丁基异腈（99mTc-MIBI）核素显像及彩色多普勒超声等3种影像学对 病变甲状旁腺进行术前定位的51例SHPT患者。以术后病理诊断所报甲状旁腺枚数为“金标准”,分别统计3种影像学检查所诊断常位及纵隔异位甲状旁腺的确诊数、漏诊数,并计算出各自的敏感度,采用率的卡方检验将MRI敏感度同其他两种影像学检查的敏感度加以对比分析。结果　术后病理回报甲状旁腺共197枚,其中常位甲状旁腺180枚,纵隔异位甲状旁腺17枚,MRI、99mTc-MIBI核素显像及彩色多普勒超声对常位甲状旁腺的敏感度分别为76.67%、51.11%、44.44%;对纵隔异位甲状旁腺的敏感度分别为29.41%、0、0;常位及纵隔异位甲状旁腺的敏感度：MRI检查高于99mTc-MIBI核素显像和彩色多普勒超声,差异均有统计学意义（P 均<0.05）。结论　MRI是SHPT术前定位的一种有效的辅助检查,可作为SHPT术前定位的首选辅助检查。     

Ultrasound examination of the parathyroid glands

High-resolution sonography is a significant imaging tool available for evaluation of the parathyroid glands. It works particularly well in concert with nuclear imaging, especially in assisting preoperative localization of parathyroid lesions and in guiding interventional parathyroid procedures. Its limitations relate to anatomic areas not accessible to insonation. In the hands of an experienced examiner, it is a cost-efficient and important adjunct for the endocrine surgeon.     

亚甲蓝在继发性甲旁亢手术中对甲状旁腺的定位作用

目的 探讨亚甲蓝正显影染色法在甲状旁腺全切术中对甲状旁腺的定位作用。 方法 将49 例行甲状旁腺全切术的继发性甲状旁腺功能亢进(SHPT)患者分为两组,术中静滴亚甲蓝染色定位甲状旁腺25例作为试验组,无任何显影方法辅助24例作为对照组。比较两组手术时间、手术成功率、不良反应发生率、甲状旁腺的检出率及阳性预测值。 结果 两组比较手术时间、手术成功率差异均有统计学意义(P<0.01,P=0.05);术后发生亚甲蓝相关不良反应分别为1例、0例,差异无统计学意义(P=1.00);检出率分别为99.00%、92.86%,差异有统计学意义(P=0.03);阳性预测值分别为97.06%、91.92%,差异无统计学意义(P=0.11)。 结论 在继发性甲状旁腺功能亢进症患者行甲状旁腺全切术中,亚甲蓝正显影染色法是快速、安全而有效的定位方法。     

Combined use of a nanocarbon suspension and 99mTc-MIBI for the intra-operative localization of the parathyroid glands

Objective

To investigate the combined use of a nanocarbon (NC) suspension and low-dose ^99mTc-MIBI for parathyroid localization during surgery in patients with secondary hyperparathyroidism (sHPT).

Pathology of the thyroid and parathyroid glands

Open communication between surgeon and pathologist is key in the area of thyroid and parathyroid pathology. Gross and microscopic examination provides valuable data, including important prognostic information, to guide further clinical management. A number of new techniques are being developed. These will not only enable us to learn more about the pathogenesis of lesions in these organs but may provide additional prognostic data.     

Implementation of a 4-dimensional computed tomography protocol for parathyroid adenoma localization

PurposeTo present the results of our implementation of a four-dimensional computed tomography- (4DCT) based parathyroid localization protocol for primary hyperparathyroidism at a safety net hospital.MethodsWe performed a retrospective review of all patients who underwent parathyroidectomy for primary hyperparathyroidism at Elmhurst Hospital Center from June 2016 – September 2019. Patients treated prior to the implementation of 4DCT during October 2018 served as historical controls for comparison. Imaging-related costs and hospital charges were obtained from the Radiology Department for each patient.ResultsForty-two patients underwent parathyroid surgery during the study period. Twenty patients had undergone 4DCT while 22 had nuclear medicine studies with or without ultrasonography. The sensitivity and specificity of 4DCT was 90.4% and 100% respectively, compared to 63% and 93.7% for nuclear imaging studies and 41% and 95% for ultrasound. The mean number of glands explored was significantly less in the 4DCT group, 1.8 ± 1.19 versus 2.77 ± 1.26 (p = 0.01). There was no increase in infrastructure or personnel costs associated with 4DCT implementation.Conclusions4DCT represents an increasingly common imaging modality for pre-operative parathyroid localization. Here we demonstrate that 4DCT is associated with a reduction in the number of glands explored and enables minimally invasive parathyroid surgery. 4DCT is a cost-effective and clinically sound localization study for parathyroid localization in an urban safety-net hospital.     

经静脉低剂量亚甲蓝甲状旁腺定位在甲状腺手术中的初步应用

目的　探讨低剂量亚甲蓝在甲状腺癌手术过程中对于甲状旁腺功能保护的有效性及其安全性。方法　回顾性分析我科室2014年8月～2015年1月甲状腺乳头状癌患者41 例,其中男9例,女32例,中位年龄46岁,初次手术38例,二次手术3例。均行甲状腺手术,并在术中应用3～4 mg/kg亚甲蓝静脉快速滴注。结果　蓝染甲状旁腺84枚,39例染色患者平均染色时间（31.27±9.41）min。3 mg/kg组和4 mg/kg组染色率及染色时间差异均无统计学意义（t =0.24、0.20,P 均>0.05）。术后各组患者均未出现口周麻木、肌肉酸胀、疼痛、肌痉挛等甲状旁腺功能减退症状。术后监测甲状旁腺激素水平,所有患者均未出现持续性功能减退。无患者出现神经中毒症状及其他严重不良反应。结论　甲状腺手术中经静脉低剂量亚甲蓝甲状旁腺定位是一种安全、有效、易于实施的技术。     

Surgical anatomy of the thyroid and parathyroid glands

From a surgical viewpoint there are several critical anatomic structures that lie in close proximity to the thyroid gland. These critical structures include the recurrent laryngeal nerves, the superior laryngeal nerves, and the parathyroid glands. Successful thyroid surgery depends on the technical skill of the surgeon to identify and preserve these vital structures.     

Preoperative ultrasound is worthwhile for reoperative parathyroid surgery

OBJECTIVES/HYPOTHESIS: High-resolution ultrasound and sestamibi scanning are regarded as the first-line methods for preoperative localization of parathyroid adenomas. The utility of ultrasound in reoperative cases has been questioned because of concern that scarring will obscure normal tissue planes and vascularity that are critical to identification of an adenoma using this imaging modality. The purposes of the study were to evaluate the ability of high-resolution ultrasound to accurately localize parathyroid adenomas in the reoperative exploration and to identify any factors that influence its accuracy STUDY DESIGN: Retrospective chart review at a tertiary care academic medical center. METHODS: All patients seen in referral for parathyroid surgery between May 1994 and September 2002 underwent high-resolution ultrasound as their initial diagnostic test. Patients who subsequently underwent exploration were included in the study. Intraoperative and ultrasound findings were compared. RESULTS: One hundred forty-two patients were included, 116 without and 26 with prior exploration. The sensitivity and positive predictive value of ultrasound were 86.9% and 89.1%, respectively. These data were not significantly different in patients without (88.2% and 90%) and in patients with (80% and 84.2%) prior thyroid or parathyroid surgery. The overall accuracy was 79% with a false-negative rate of 11.3%. Thyroid nodularity was significantly more common (81.8%) in patients who had a false-positive or false-negative finding on ultrasound than in the total population (61.3%). CONCLUSION: High-resolution ultrasound is an accurate method for localizing parathyroid adenomas even in patients who have previously undergone parathyroid exploration. However, the presence of thyroid nodules can interfere with its accuracy.     

Intraoperative gamma probe localization of parathyroid adenomas

OBJECTIVES/HYPOTHESIS: In an effort to reduce operative time, improve diagnostic accuracy, and decrease perioperative morbidity, we combined preoperative technetium Tc 99m-sestamibi localization with the use of the gamma probe intraoperatively. This report examines our experience with the gamma probe for rapid intraoperative localization of parathyroid adenomas. STUDY DESIGN: A retrospective chart review was performed to identify all patients who underwent parathyroid exploration with the aid of the gamma probe at Lenox Hill Hospital (New York, NY). METHODS: Charts were reviewed for operative details, radiological findings, and pathological diagnoses. RESULTS: Between November 1, 1998, and June 30, 2000, 35 parathyroid explorations were performed with the aid of the gamma probe. The preoperative localization study was accurate in 34 of 35 cases. The gamma probe successfully identified the parathyroid adenoma in 33 of 35 cases. There were two false-positive cases in which the gamma probe mistakenly identified a thyroid adenoma rather than a parathyroid adenoma. In 11 of 35 cases, the gamma probe was judged essential for rapid localization of the parathyroid adenoma. These cases included patients with multiple or ectopic adenomas and patients who had previous parathyroid surgery. Average operative time to remove parathyroid disease was 80 minutes (range, 45-140 min), which included 20 to 40 minutes waiting for frozen-section results. All patients became normocalcemic, and there were no major complications in this series. CONCLUSION: The gamma probe is a useful tool that complements a well-performed localization study. It is most useful in patients who have multiple or ectopic adenomas or have had prior parathyroid surgery.     

Methylene blue infusion for intraoperative identification of the parathyroid glands

Identifying the parathyroid glands is of fundamental importance in thyroid and parathyroid surgery. We found that intravenous infusion of methylene blue was beneficial in intraoperative identification of the parathyroid glands in patients undergoing surgery for hyperparathyroidism as well as total and bilateral subtotal thyroidectomy. The technique is safe and easy to use, and it clearly reduces the operative time. We suggest that it be used routinely in thyroid and parathyroid surgery.     

甲状腺全切除术中甲状旁腺及其功能的保护

目的 探讨甲状腺全切除术中甲状旁腺的显露定位及其血供的保护方法.方法 回顾性分析辽宁省肿瘤医院头颈外科1990年2月至2009年12月期间296例甲状腺全切手术患者资料,术中显露并保护甲状旁腺及其血供,检测并对比术前、术后血清钙离子和甲状旁腺激素(parathyroid hormone,PTH)水平,对术后出现低钙症状和甲状旁腺功能低下者行支持治疗.结果 296例甲状腺全切手术中见上甲状旁腺共542枚,其中444枚(81.9%)位置恒定于甲状腺背面甲状软骨下缘水平;确切显露104枚上甲状旁腺的血管,其中71枚(68.3%)由甲状腺下动脉上行支供血.下甲状旁腺共467枚,位置变异较大,231枚(49.5%)位于甲状腺背面下1/3部分,116枚(24.8%)位于甲状腺侧叶最下端近甲状腺下动脉入腺体处;确切显露142枚下甲状旁腺的血管,其中114枚(80.3%)的血供来自甲状腺下动脉或最下动脉的分支.术后发生低钙血症13例,无一例发生永久性甲状旁腺功能低下.结论 甲状旁腺血供来源与其位置有密切关系.甲状腺全切除及近全切除术中辨认和保护甲状旁腺及其血液供应,可有效防止术后甲状旁腺功能低下的发生.