Successful repeat transcatheter ablation of a mediastinal parathyroid adenoma 6 years after alcohol embolization

Recurrent hyperparathyroidism is rare following transcatheter ablation of mediastinal parathyroid adenomas. When it occurs it is usually early and resistant to further attempts at ablation. We present a patient with primary hyperparathyroidism in whom two surgical attempts at cure had been unsuccessful. Subsequently, a mediastinal adenoma was demonstrated angiographically and embolized with absolute alcohol. Hyperparathyroidism recurred 6 years later and the mediastinal adenoma was subsequently successfully ablated a second time by angiographic embolization with ionic contrast medium.     

Computed tomography for parathyroid localization

Computed tomography (CT) of the neck and mediastinum was performed in 10 patients with primary hyperparathyroidism. Nine had undergone previous surgery and were considered localization problems. Of four subsequently proven cervical adenomas, only one unusually large 19-g adenoma was visualized by CT. However, of two subsequently proven anterior mediastinal adenomas, CT scanning was positive in both; a single posterior mediastinal adenoma was not demonstrated. Of the remaining three patients, one was not operated on; in two others no adenoma was found at surgery. CT scanning is recommended prior to neck surgery in all patients with primary hyperparathyroidism to identify adenomas in the anterior mediastinum.     

Embolization of Bronchial Artery–supplied Ectopic Parathyroid Adenomas Located in the Aortopulmonary Window

Ectopic parathyroid adenomas in the aortopulmonary window (APW) are extremely rare, constituting only 1% of ectopic mediastinal adenomas and 0.24% of all parathyroid adenomas. The authors have encountered three patients with ectopic adenomas in the APW. In each case, the primary arterial supply to the APW adenoma arose from the bronchial artery. In addition, there was a small anastomotic arterial channel connecting the bronchial artery supplying the adenoma to the left inferior thyroid. All three adenomas were treated with transcatheter embolization, with control of hyperparathyroidism in two of three patients. One patient required thoracoscopic removal of the adenoma. It is critical that the interventionalist be aware of this arterial supply pattern to allow successful embolization of an APW ectopic adenoma.     

Localization of parathyroid adenomas using 11C-methionine positron emission tomography

BACKGROUND AND AIM: In symptomatic hyperparathyroidism, pre-surgical localization of the suspected site of adenoma is desirable. All widely available techniques may have difficulty in localizing the site. The aim of this study was to determine whether 11C-methionine positron emission tomography (PET) could accurately localize parathyroid adenomas in patients in whom conventional imaging had failed. PATIENTS AND METHODS: Fifty-one patients presenting with hyperparathyroidism, and in whom other imaging techniques had failed to definitely identify the site of adenoma, were reviewed retrospectively after 11C-methionine PET scanning. Patients were followed up by surgical histology, or clinically if surgery was not performed. RESULTS: 11C-Methionine PET scanning was found to have a sensitivity of 83%, a specificity of 100% and an accuracy of 88% in successfully locating parathyroid adenomas. Most false negatives were due to adenomas in the lower mediastinum that was outside the area of scanning. CONCLUSIONS: 11C-Methionine PET is a reliable and highly accurate technique for localizing parathyroid adenomas in patients in whom conventional imaging techniques have failed. It is necessary to image to the level of the lower mediastinum.     

The need for intraoperative parathyroid hormone monitoring during radioguided parathyroidectomy by video-assisted thoracoscopy (VATS)

PURPOSE: We report on a patient with primary hyperparathyroidism (1HPT) who had a preoperative Tc-99m sestamibi scan localizing a single parathyroid adenoma in the mediastinum. METHODS: On removal of this hyperfunctioning adenoma by radioguided video-assisted thoracoscopic surgery (VATS), intraoperative PTH levels failed to decline in the appropriate manner consistent with curative resection. This prompted the surgical team to investigate further for a second adenoma, which revealed a 2 x 1-cm mass near the inferior border of the thyroid gland on the right lateral aspect of the trachea. RESULTS: In the absence of intraoperative PTH monitoring, the operation would have been terminated after the removal of the mediastinal adenoma, leading to an incomplete surgical resection and persistent 1HPT. CONCLUSION: In our patient, curative resection was obtained and a second operation was avoided because of the use of intraoperative PTH monitoring. This case also emphasizes that although VATS was planned, in treating patients with 1HPT, one must also be prepared to perform a neck exploration.     

Unusual location of a parathyroid adenoma: the carotid sheath

We report the imaging features of an occult parathyroid adenoma with unusual location in the carotid sheath. Our patient presented with primary hyperparathyroidism. Following negative neck ultrasound and scintigraphy, exploratory neck dissection with partial thyroidectomy was performed twice over a 2 day period without biological response. Cervical and mediastinal CT and MRI were performed with no result. Digital angiography showed a tumoral blush supplied by the left inferior thyroid artery and located in close contact with the carotid artery. Venous sampling of the neck confirmed the left location of the adenoma and a third surgical intervention found the adenoma embedded in the left carotid sheath. This is an unusual case of parathyroid adenoma that necessitated the use of several imaging techniques.     

Diagnosis of recurrent hyperparathyroidism: comparison of MR imaging and other imaging techniques

Several reports have indicated good results with MR imaging of hyperparathyroidism. However, its use in recurrent hyperparathyroidism has not been assessed separately. Thirty patients with recurrent hyperparathyroidism were evaluated by MR with both T1- and T2-weighted images. Twenty-six and 23 of these patients, respectively, also had thallium-201 scintigraphy and high-resolution sonography. For the 28 patients who eventually had surgical exploration and histologic evidence of adenoma (21 cases) or hypoplasia (seven cases), MR accurately located abnormal parathyroid glands in 75% evaluated prospectively and 89% evaluated retrospectively. Scintigraphy located 68% prospectively and 76% retrospectively. Sonography detected 57% prospectively and 67% retrospectively. For patients undergoing three studies, the prospective and retrospective detection rate was significantly better (p less than .05) for MR compared with sonography but was not significantly different for MR and scintigraphy. MR detected three of four mediastinal adenomas evaluated prospectively and retrospectively. One false-positive case was seen with MR, one with scintigraphy, and one with sonography. Thus, MR can be used to locate abnormal parathyroid tissue at a rate equal to or better than scintigraphy or sonography.     

Pre-operative Localization of Parathyroid Adenomas: A Comparison of Power and Colour Doppler Ultrasonography with Nuclear Medicine Scintigraphy

AIM: To compare power and colour Doppler ultrasonography (US) with nuclear medicine scintigraphy (NM) in the preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). MATERIALS AND METHODS: Thirty-one patients with biochemical evidence of PHPT underwent pre-operative US and NM for parathyroid adenoma localization. Both studies were interpreted independently without prior knowledge of the other study's findings. All patients had surgical removal of the parathyroid adenoma utilizing standard neck exploration or minimally invasive unilateral surgical techniques with rapid serum assay of circulating parathyroid hormone levels. RESULTS: All patients had single parathyroid adenomas at surgery. Prospective sensitivities for US, NM and both studies combined were 65%, 68%, and 74%, respectively, with a positive predictive value of 100% each. The adenoma was localized by only one imaging modality in 16% of cases. CONCLUSIONS: US and NM provide complementary roles in the pre-operative localization of parathyroid adenomas in patients with PHPT.     

Minimally invasive surgery for solitary parathyroid adenomas in patients with primary hyperparathyroidism: role of US with supplemental CT

PURPOSE: To determine the role of ultrasonography (US) with supplemental computed tomography (CT) in patients with primary hyperparathyroidism who undergo minimally invasive surgery instead of conventional neck exploration. MATERIALS AND METHODS: US and CT were performed in 61 consecutive patients with primary hyperparathyroidism (part 1) to identify and localize solitary adenomas for resection by means of minimally invasive surgery and to provide a surgical road map. In part 2, involving 33 consecutive patients, CT was performed only when no solitary adenoma was identified with US or for road map information. Minimally invasive surgery was considered successful when serum calcium levels normalized and remained stable. RESULTS: In part 1, 46 definite solitary adenomas were found with US and two additional ones with CT. Minimally invasive surgery was successful in 45 patients and failed once. In part 2, US helped identify 23 solitary adenomas, and CT helped to find one. Minimally invasive surgery was successful in 22 patients and failed in two. Combined results in 94 patients demonstrated successful minimally invasive surgery in 67 (71%), with 64 of them selected with US alone (95% CI: 61, 80). The sensitivity of US in the diagnosis of solitary adenoma was 78% (95% CI: 67%, 86%), with a positive predictive value of 96% (95% CI: 88%, 99%). CONCLUSION: US examination of patients with primary hyperparathyroidism allowed successful selection for minimally invasive surgery in more than two-thirds of the cases, with additional CT useful chiefly for surgical road mapping.     

Resection of a mediastinal parathyroid adenoma by video-assisted thoracoscopy radio-guided by a gamma probe. A case report

We present a case of primary hyperparathyroidism in a 47 year old woman. The pre-operative 99mTc-sestaMIBI scan detected a single parathyroid adenoma located in the anterior or medium mediastinum. Surgery was carried out following 99mTc-sestaMIBI administration and using gamma probe radio-guided video-assisted thoracoscopy. The aim of this case report is to present this technique that allows adenoma resection with minimally invasive surgery. A reduction of surgical complications and an increase in the probability of surgical success could be obtained.     

Radioguided reoperative parathyroidectomy for persistent primary hyperparathyroidism

We report a case of reoperative radioguided parathyroidectomy in a patient with primary hyperparathyroidism. A 58-year-old man presented to our center with persistent hypercalcemia and hyperparathyroidism after 2 previous parathyroid explorations at an outside facility. Despite the use of preoperative and intraoperative localization, identification of the hyperfunctioning gland was unsuccessful during the initial operations. Because of the continued presence of symptoms, the patient was referred to our center for reoperation. Repeat Tc-99m sestamibi parathyroid scan showed an inferior right parathyroid adenoma. With the intraoperative guidance of a hand-held gamma probe, an enlarged parathyroid gland was localized on the spine behind the esophagus on the right, and successfully removed. Intraoperative parathyroid hormone testing confirmed a surgical cure. The use of radioguidance and intraoperative parathyroid hormone testing were essential to the successful resection. The patient remained disease-free at follow-up.     

Enhanced scintigraphic protocol required for optimal preoperative localization before targeted minimally invasive parathyroidectomy

At our tertiary care institution, a targeted minimally invasive parathyroidectomy (MIP) is the preferred surgical procedure for primary hyperparathyroidism. Similar to unilateral neck exploration (UNE), preoperative scintigraphic localization of the adenoma in relation to the midline is required. However, in contrast to the abbreviated standard incision for UNE, 2 distinct incision sites, 1 medial and 1 lateral, are available on each side with MIP. The incision site is ultimately chosen based on scintigraphic determination of the adenoma's vascular origin to facilitate ligation and removal. Unfortunately, the scintigraphic location of a parathyroid adenoma does not necessarily reflect the site of its vascular origin. We reviewed our database to identify factors that accurately predict the site of vascular origin of parathyroid adenomas. A retrospective chart review was performed on 125 patients who underwent Tc-99m sestamibi scintigraphy and parathyroidectomy. Scintigraphic localization, surgical findings, and histopathology were recorded. Preoperative image interpretations that were discordant with operative findings were independently reviewed. Scintigraphy identified the presence of an adenoma in 105 of 118 patients (89%) with primary hyperparathyroidism. In 17 of the 105 cases (16%), the scintigraphic interpretation did not accurately reflect the site of superior or inferior vascular origin seen at surgery. In many discordant cases, anterior images were insufficient for determining the vascular origin. The posterior displacement of an adenoma in relation to the thyroid on early lateral images was often critical in determining the superior or inferior vascular origin. Scintigraphic determination of the superior or inferior vascular origin of a parathyroid adenoma directs incision placement for MIP. Imaging protocols should include early lateral images when localizing parathyroid adenomas before minimally invasive parathyroidectomy.     

Percutaneous radiofrequency ablation of renal tumors: technique, complications, and outcomes

PURPOSE: To report the safety, technical success, and effectiveness of percutaneous radiofrequency (RF) ablation for renal tumors. MATERIALS AND METHODS: The authors retrospectively reviewed the medical records and imaging studies of 29 consecutive patients (18 men, 11 women; mean age, 65 +/- 2.62 years) with 30 renal tumors (mean diameter, 3.5 +/- 0.24 cm) who underwent percutaneous RF ablation at their institution from September 2001 to March 2004. All procedures were performed with computed tomography guidance with general anesthesia, and all patients were admitted to the hospital for overnight observation. Technical success, complications, and their management were recorded. Technique effectiveness was assessed by imaging and clinical follow up. RESULTS: Overall, 88 overlapping ablations were performed (mean, 2.6 +/- 0.16 ablations per tumor per session) in 34 sessions. There were four major complications (12%). Three patients had gross hematuria and urinary obstruction, all were successfully treated. One patient had persistent anterior abdominal wall weakness. There were also two minor complications (6%) without significant clinical sequelae. One patient had gross hematuria which resolved spontaneously, another patient had transient paresthesia of the anterior abdominal wall. There were no significant changes in renal function after RF ablation. The intent of RF ablation was eradication of the primary tumor in 27 patients and treatment of gross hematuria in the other two. Technical success was achieved in all cases. Follow-up images were available for 26 patients. The primary tumor was completely ablated in 23 of 24 patients (96%) in whom eradication of the primary tumor was attempted (follow up period: mean, 10 months, median 7 months). The two patients treated for hematuria remained asymptomatic for 6 and 27 months each. CONCLUSION: Percutaneous RF ablation for renal tumors is safe and well tolerated. High technical success rates are expected. Early reports of the technique's effectiveness are promising.     

Diagnosis of hyperparathyroidism

AIM: To preoperatively localize enlarged parathyroid glands in patients with hyperparathyroidism (HPT). METHODS: Besides clinical and biochemical workup, high-resolution ultrasonography (US) is the most commonly used imaging method.Additionally,Tc-99m-MIBI scintigraphy in subtraction or biphasic technique, computed tomography (CT) and magnetic resonance imaging (MRI) are used. RESULTS: US fails to detect a minimum of 10% of enlarged parathyroid glands,most commonly due to ectopic location, or difficult examination conditions, such as nodular goiter or previous surgery. If attempted US localization is unsuccessful, multiphase scintigraphy, using Tc-99m-sestamibi, can help to locate ectopic adenomas in the mediastinum. With SPECT, ademomas can be found which escape detection on planar scans due to their small size.With combined use of US and scintigraphy, a correct localization of parathyroid adenomas is possible in up to 90%. CT and MRI are of limited value due to their low specificity. CONCLUSION: For newly diagnosed hyperparathyroidism, high-resolution US is the method of choice for localizing parathyroid adenomas.If ultrasound fails to detect a lesion, Tc-99m-MIBI scintigraphy is recommended. In patients scheduled for re-operation for recurrent or persistent HPT, a preoperative detection of a parathyroid adenoma should be attempted whenever possible, in order to minimize the extent of surgery. The role of CT or MRI is mainly to help to better anatomically localize a suspected adenoma previously detected with scintigraphy.     

Frequency of extrathoracic metastases from bronchogenic carcinoma in patients with normal-sized hilar and mediastinal lymph nodes on CT

The only cure for bronchogenic carcinoma is complete surgical resection; the most common reason for not attempting surgical resection is mediastinal adenopathy. However, we have found that even when the lymph nodes are normal in size, the presence of extrathoracic metastases may preclude successful resection. In a series of 263 patients with pathologically proved non-small cell bronchogenic carcinoma who were seen over a 2-year period, we identified 95 patients in whom a preoperative CT scan showed only a solitary lung mass without evidence of hilar or mediastinal metastases, pleural effusion, or definite chest-wall involvement. The medical records and preoperative imaging studies were evaluated in this group. Twenty-four (25%) of these patients who had potentially resectable masses proved to have extrathoracic metastases; thus they were not candidates for surgery. Occurring in 16 (67%) of these 24 patients, adenocarcinoma was the most common cell type; squamous cell carcinoma was present in five patients (21%), and large cell carcinoma was present in three patients (13%). These findings suggest that extrathoracic metastases from bronchogenic carcinoma may occur without CT evidence of enlarged hilar or mediastinal lymph nodes. Such metastases may preclude successful surgical resection.     

Percutaneous transluminal angioplasty of the iliac arteries: 66 experiences

Sixty-six iliac arteries in 45 patients, 25 male and 20 female, were treated with percutaneous transluminal angioplasty (PTA) for atherosclerotic occlusive disease. Of 103 lesions dilated, 51 were in common iliac and 51 in external iliac arteries. While iliac artery disease was the primary lesion in 18 patients, eight of whom had total occlusion, 27 patients had additional femoropopliteal disease. An overall primary success rate of 84% in dilatation of the stenotic lesions, and 33% in recanalization of totally occluded iliac arteries was achieved. In 12 patients, a prescheduled aortic bifurcation graft was cancelled. In one patient, in addition to recanalization of the occluded common iliac artery, the stenotic distal aorta was also successfully dilated. Angioplasty was unsuccessful in 12 patients. There were only three severe complications requiring surgical assistance. To date, less than 2 years, there has been a patency rate of 100%. Transluminal angioplasty is the treatment of choice for single stenotic lesions of the iliac arteries. Lack of calcification is not an absolute guarantee of success, but a favorable factor.     

Hyperparathyroidism: comparison of MR imaging with radionuclide scanning

Twenty-three patients with hyperparathyroidism were evaluated preoperatively with magnetic resonance (MR) imaging. Twenty patients also underwent thallium-201/technetium-99m scintigraphy. Of 22 patients with primary hyperparathyroidism, 12 had persistent or recurrent disease. One had secondary hyperparathyroidism due to end-stage renal disease. MR imaging allowed accurate localization of abnormal parathyroid glands in 64% evaluated prospectively and 82% evaluated retrospectively. Scintigraphy allowed localization of 60% evaluated prospectively and 70% retrospectively. The two imaging modalities together allowed detection of 68% evaluated prospectively and 91% retrospectively. MR imaging allowed detection of two of five mediastinal adenomas evaluated prospectively and four of five retrospectively. In patients who underwent both imaging studies, MR was more successful in those with previous neck surgery (73% evaluated prospectively and 91% retrospectively) than in those with no prior surgery (57% prospectively and 71% retrospectively). Scintigraphy allowed accurate localization in 64% evaluated prospectively and 64% retrospectively in patients with previous surgery versus 57% prospectively and 86% retrospectively in patients with no prior neck surgery. Four false-positive results were obtained with MR imaging and three with scintigraphy. MR imaging was useful for parathyroid localization in patients with hyperparathyroidism, particularly in patients requiring additional surgery.     

Parathyroid imaging: Its current status and future role

The management of autonomous (primary or tertiary) hyperparathyroidism is controversial for two important reasons: (1) Diagnosis of primary or tertiary hyperparathyroidism (as distinct from reactive or secondary hyperparathyroidism) has been revolutionized in the past 20 years as a result of routine inclusion of serum calcium concentration assays in serum multiautomated analysis, now obtained routinely for both hospitalized as well as ambulatory patients. The prevalence of primary hyperparathyroidism in the general population has appeared to rise as a consequence of this assay and the enhanced detection of this disease. This situation has confused the management of hyperparathyroidism since most patients now present with asymptomatic disease, and the need for surgical treatment is controversial in asymptomatic individuals. (2) Primary hyperparathyroidism usually is caused by hypersecretion of parathyroid hormone by an autonomously functioning parathyroid adenoma. In a small percentage of cases, multigland hyperplasia is present. In experienced hands, surgical removal of an adenoma within the thyroid bed cures the hyperparathyroidism 90% to 95% of the time, without performance of a preoperative procedure to localize the adenoma. Approximately 10% of parathyroid tissue is ectopic in location, however. Furthermore, approximately two thirds of "missed" adenomas are within the thyroid bed. Reexploration in the event of a failed operation therefore is not an uncommon occurrence. Parathyroid localization procedures clearly are indicated in patients with primary hyperparathyroidism who have evidence of persistent disease after a failed attempt at surgical cure. In patients first presenting with primary hyperparathyroidism, the need for a localization procedure is less clear, since surgery appears to be successful much of the time without it. Regardless of the nature of the above controversies, surgery for autonomous hyperparathyroidism continues, and localization procedures become more popular. Preoperative localization procedures such as angiography and venography with venous sampling for parathormone are cumbersome and invasive. Noninvasive tests to localize the parathyroid glands have emerged in the past 10 years, including dual tracer radionuclide scintigraphy with 201-thallous chloride and 99m-technetium pertechnetate, high-resolution computer tomography, and fine parts ultrasonography. Dual tracer scintigraphy with thallium and technetium is reported to have a localization sensitivity of 70%-90%. False-negative studies occur primarily in patients with small adenomatous or hyperplastic glands.(ABSTRACT TRUNCATED AT 400 WORDS)     

原发性甲状旁腺机能亢进的外科治疗

总结了30例原发性甲状旁腺机能亢进患者的手术治疗经验。颈丛或全身麻醉下低领位切口，术中快速病理结果证实28例为甲状旁腺腺瘤，均单发性，其中2例异位于甲状腺内，1例异位于前上纵隔，单纯切除；增生1例，但仅1个旁腺受累，全切除；腺癌1例，侵及食管、气管，肿瘤及受累部分食管气管切除并气管切开。无手术并发症。25例随访8个月至19年，包括增生1例，症状改善无复发。腺癌患者带气管套管生存已4年。提示手术治疗原发性甲状旁腺机能亢进疗效确实，应首先；明确为腺瘤者可行单侧探查，即使腺癌也不要轻易放弃。     

Thallium-technetium-subtraction scintigraphy in secondary hyperparathyroidism

Between 1983 and 1992 thallium-technetium subtraction scintigraphy (TTS) was performed on 74 patients with clinical and biochemical evidence of hyperparathyroidism. Twenty-five of the 53 investigations since 1988 were conducted on patients with renal failure with a suspicion of secondary hyperparathyroidism. In a retrospective study we have evaluated radioisotope scintigraphy for patients with adenoma and for renal failure patients with possible parathyroid hyperplasia. Thirty of 74 patients underwent neck exploration. Scintigraphy detected 17 of 24 parathyroid adenomas (sensitivity 71%). In contrast, in six renal patients who came to operation, scintigraphy localised only 5 of 20 hyperplastic parathyroid glands (sensitivity 25%) and in one renal patient we localised a parathyroid adenoma. A review of the literature shows low detection rates for hyperplasia by TTS to be a common observation. Based on these findings a rational approach is offered for parathyroid localisation in renal patients prior to neck exploration. Correspondence to: T. Hawkins