The experimental induction of parathyroid hyperplasia in rats,and the use of toluidine blue O forin vivo identification of parathyroid tissue

An experiment was designed to compare the degree of parathyroid hyperplasia induced in rats by subtotal nephrectomy and by oral phosphate administration singly or in combination. The greatest degree of parathyroid hyperplasia was×4.49 and was seen in the rats with both subtotal nephrectomy and oral phosphate administration. Over the 77-day period of the experiment, subtotal nephrectomy alone did not produce a significant increase in the size of the glands, whereas phosphate fed to otherwise normal rats did produce a significant increase.Toluidine blue was given intravenously before killing the rats and was found to stain the hyperplastic glands in the same way that it stains normal and adenomatous glands. Staining was found to be satisfactory for identification purposes in both the normal and in the hyperplastic glands with 5 mg/kg body weight. A greater depth of staining was given by 10 mg/kg body weight.

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Zusammenfassung Es wurde ein Experiment an Ratten durchgeführt, um den Grad der Parathyreoidea-Hyperplasie anhand folgender Punkte zu vergleichen: subtotale Nephrektomie, orale Phosphatverabreichung oder eine Kombination von beiden. Die maximale Parathyreoidea-Hyperplasie war 4,49mal größer als bei den Kontrollen und wurde bei Ratten mit subtotaler Nephrektomie und mit oraler Phosphatverabreichung festgestellt.Während der 77 Tage des Experimentes erzeugte subtotale Nephrektomie allein keine bedeutende Zunahme der Drüsengröße; Phosphat hingegen, welches im übrigen normalen Ratten verfüttert wurde, bewirkte eine bedeutende Zunahme.Toluidinblau wurde den Ratten intravenös injiziert, bevor sie getötet wurden; es färbte die hyperplastischen Drüsen ebenso befriedigend wie normale und adenomatöse Drüsen. Die Färbung war mit 5 mg/kg Körpergewicht befriedigend zur Identifizierung der normalen wie der hyperplastischen Drüsen. Eine tiefere Färbung wurde mit 10 mg/kg Körpergewicht erreicht.

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Résumé Le degré d'hyperplasie parathyroidïenne a été étudié chez le Rat après néphrectomie subtotale, après administration buccale de phosphate ou par combinaison des deux. Le degré le plus élevé d'hyperplasie parathyroidïenne est de ×4.49 et a été observé chez le rat après néphrectomie sub-totale et administration buccale de phosphate.Au cours des77 jours d'expérience, la néphrectomie sub-totale ne produit pas une augmentation significative de la taille des glandes, alors que le phosphate, mélangé à l'alimentation de rats normaux, produit une augmentation significative.Le bleu de toluidine, administré par voie intra-veineuse avant le sacrifice des rats, colore les glandes hyperplasiques de la même façon qu'il colore les glandes normales et adénomateuses. La coloration s'avère intéressante pour l'identification des glandes normales et hyperplasiques à la concentration de 5 mg/kg de poids corporel. Une coloration plus intense est obtenue avec 10 mg/kg de poids corporel.

     

The role of dual radionuclide scintigraphy in the preoperative localization of abnormal parathyroid glands

Success rates for neck exploration in patients with hyperparathyroidism should exceed 90 per cent in the hands of experienced surgeons. The ability to localize abnormal parathyroid glands preoperatively should maintain or increase the rate of success. Dual isotope subtraction scintigraphy using thallium-201 and technetium-99m pertechnetate offers a noninvasive means of localization. The usefulness of this procedure was studied in thirteen patients with suspected hyperparathyroidism. The scan accurately localized the site of abnormal parathyroid glands (nine adenomas and eight hyperplastic glands) in 91 per cent of the patients. Localization was most successful in adenomas weighing more than 500 mg. We conclude that dual radionuclide scintigraphy is useful in the preoperative location of enlarged parathyroid glands.     

Rapid intraoperative localization of parathyroid glands utilizing methylene blue infusion.

OBJECTIVE: To review a single surgeon's experience utilizing an intraoperative methylene blue infusion (IMBI) to identify parathyroid glands during neck exploration for primary hyperparathyroidism. STUDY DESIGN AND SETTING: Retrospective review of 35 patients who underwent bilateral neck exploration utilizing an IMBI at a dose of 7.5 mg/kg following the induction of general anesthesia. RESULTS: All patients reverted to normocalcemia with a mean follow-up of 17 months. IMBI facilitated the identification of abnormal parathyroid tissue in 34/35 patients (97%). A dark blue-purple staining was observed in 33/37 stained adenomas (89%). Four adenomas and four hyperplastic glands stained a lighter shade of blue-green. Among 89 normal glands, 41(46%) stained a pale green-grey color. CONCLUSIONS: IMBI is a safe, readily available, cost-effective, and underutilized technique that facilitates rapid identification of parathyroid adenomas, helps distinguish normal glands from hyperplastic glands, and helps to locate ectopic glands. An overall reduction in operative time, especially for bilateral neck exploration, can be anticipated.     

Diagnostic usefulness of201T1-chloride scintigraphy for preoperative localization of parathyroid tumors

²⁰¹T1-chloride scintigraphy was performed in 10 patients with hyperparathyroidism to assess the localization of abnormal parathyroid glands. This approach proved to be useful in 8 of 10 patients. In particular, an intramediastinal ectopic gland was clearly demonstrated in one patient. Several disadvantages were noted, however,²⁰¹Tl-chloride scintigraphy could be the first choice for preoperative localization of abnormal parathyroid glands. If a negative image is obtained, further examinations such as arteriography or parathyroid hormone assay by selective venous blood sampling should be done.     

Detection of parathyroid adenoma in patients with primary hyperparathyroidism: the use of office-based ultrasound in preoperative localization

BACKGROUND: The purpose of this investigation is to show that preoperative localization of the parathyroid gland using office-based ultrasound (US) and Tc-99m sestamibi scan is superior to all other approaches in detecting a parathyroid adenoma. METHODS: We performed a retrospective analysis of 43 patients who underwent parathyroidectomy for primary hyperparathyroidism. All patients underwent office-based US and sestamibi scintigraphy. Upon completion of the localization studies, a plan for focused or full operation was determined. RESULTS: In 42 of 43 patients, office-based US performed by a surgeon and sestamibi scintigraphy successfully detected the location of a parathyroid abnormality (42/43 cases, sensitivity = 98%, P < .05 =.0001). Office-based US localized the abnormal gland to the specific side (right/left) in 36 of 43 cases (84%). Sestamibi alone localized to the specific side in 29 of 43 cases (67%) for a statistically significant difference (P = .03). US localized the abnormal gland to the specific quadrant (34/43 cases [79%] sensitivity versus 23/43 cases [53%] sensitivity using sestamibi scan alone to localize to the specific quadrant, P = .03). CONCLUSION: It is clear that the combined modalities of office-based US and sestamibi scintigraphy in preoperative localization have a high success rate and should be considered in parathyroid surgery.     

Reassessment of parathyroid hormone monitoring during parathyroidectomy for primary hyperparathyroidism after 2 preoperative localization studies

HYPOTHESIS: For patients with primary hyperparathyroidism and patients with 2 localization studies showing the same single location of parathyroid disease, use of intraoperative parathyroid hormone (IOPTH) measurement does not significantly increase the success of minimally invasive parathyroidectomy. DESIGN: Retrospective cohort study. SETTING: Experience of 2 academic centers over 5 years (at Brigham and Women's Hospital, Boston, Mass) and almost 4 years (at Rhode Island Hospital, Providence). PATIENTS: A total of 569 patients with primary hyperparathyroidism who underwent technetium Tc 99m sestamibi (MIBI) parathyroid imaging and neck ultrasonography (US). MAIN OUTCOME MEASURES: Incidence of correct prediction of location and extent of disease. RESULTS: In 322 patients (57%), MIBI and US imaging identified the same single site of disease. In 319 (99%) of these 322 patients, surgical exploration confirmed a parathyroid adenoma at that site, and the IOPTH levels normalized on removal. In 3 (1%) of the 322 patients, IOPTH measurement identified unsuspected additional disease. In 3 (1%) of the remaining 319 patients, IOPTH-guided removal of a single adenoma failed to correct hypercalcemia. Therefore, the failure rate of surgery in patients with positive MIBI and positive US imaging was 1% with IOPTH measurement and 2% without IOPTH measurement (P = .50). In 201 (35%) of the 569 patients, only 1 of the 2 studies recognized an abnormality or the studies disagreed on location. In these cases, either MIBI imaging or US imaging (if MIBI imaging was negative) failed to predict the correct site or extent of disease in 76 (38%) of the 201 patients (P<.001 vs concordant studies). CONCLUSIONS: In primary hyperparathyroidism, concordant preoperative localization with MIBI and US imaging is highly accurate. Use of IOPTH measurement in these cases adds only marginal benefit. When only 1 of the 2 studies identifies disease or the studies conflict, however, IOPTH measurement remains essential during minimally invasive parathyroidectomy.     

Mid-mediastinal parathyroid lesions: preoperative localization and surgical approach in two cases

Although hyperfunctioning mediastinal parathyroid lesions that require median sternotomy or thoracotomy for removal are occasionally present, the majority are located in the anterior mediastinum closely associated with the thymus. Only eight cases of ectopic hyperfunctioning parathyroid tumors in the middle mediastinum have been reported. We experienced two cases of either persistent or recurrent hyperparathyroidism in which abnormal parathyroid tissue was located in the aorticopulmonary window. One of the patients had a parathyroid adenoma and the other had metastatic lesions of parathyroid carcinoma. In both cases, thallium scanning proved useful in identifying the lesions while computed tomography scan was effective for mediastinal three-dimensional localization. In one case, single photon emission computed tomography imaging with thallium proved beneficial for both identification and localization of the middle mediastinal lesion. The surgical approach used in both cases was different. In one case, left thoracotomy was performed, after which the ligamentum arteriosum was divided, and an adenoma anterior to the left main bronchus and posterior to the left pulmonary artery removed. In the other case, two metastatic tumors of parathyroid carcinoma anterior to the right main bronchus and posterior to the right pulmonary artery were resected through a median sternotomy and opening of the pericardium.     

The efficacy of technetium-99m-MIBI scan and intraoperative methylene blue staining for the localization of abnormal parathyroid glands

(Received for publication on Jan. 21, 1998; accepted on July 7, 1998)     

Combined use of preoperative methylene blue dye and microcoil localization facilitates thoracoscopic wedge resection of indeterminate pulmonary nodules in children

The ability to biopsy indeterminate pulmonary lesions in children has evolved with advances in minimal access surgery. Recent advances in preoperative localization including image-guided dye injection or wire implantation have expanded the types of lesions that are accessible via minimal access surgery. We present a case of a 13-year-old boy who underwent preoperative localization using both methylene blue dye and microcoil labeling, and a subsequent thoracoscopic pulmonary wedge resection under the same anesthesia. The combined use of both dye and microcoil localization provides the advantage of superior intraoperative visualization of the lesion and the ability to use fluoroscopy to confirm the presence of the nodule in the surgical specimen. We recommend this technique for the biopsy of indeterminate pulmonary lesions that would not otherwise be accessible via a minimally invasive approach.     

Impact on surgery of preoperative localization of parathyroid lesions with dual radionuclide subtraction scanning

In an effort to localize parathyroid lesions preoperatively, scanning with radioactive thallium and technetium was performed in 20 patients considered clinically to have hyperparathyroidism. In the 11 found at surgery to have single parathyroid adenomas, scanning correctly localized the lesion in 10; in the other patient the lesion was in the unscanned mediastinum. Preoperative scanning was not as rewarding in the seven patients with parathyroid hyperplasia. A thyroid lesion was the source of an abnormality seen on the parathyroid scan in one patient, while neck scanning and surgical exploration were negative in another. Comparison of the patients who had parathyroid adenomas localized in the neck with a control group of similar patients who did not undergo preoperative scanning showed that the average surgical time was reduced by 50% with preoperative localization and there was a decrease in the number of nonparathyroid tissue biopsies.