Mediastinal Parathyroid Research Articles

Partial Median Sternotomy: An Attractive Approach to Mediastinal Parathyroid Disease

Parathyroid exploration through a standard cervical approach is adequate for the resection of most mediastinal parathyroid glands. A subset of mediastinal parathyroid glands causing hyperparathyroidism, however, cannot be removed in this manner. We reviewed our experience with the use of partial median sternotomy in the treatment of these patients. Over a 14-year period, all but 10 of 937 (1.1%) consecutive patients explored for hyperparathyroidism by a single endocrine surgeon were treated by a cervical approach. Partial median sternotomy was performed in 10 cases and was successful in seven cases (70%), with conversion to a complete sternotomy being required in three cases. Six of these seven patients had failed a previous parathyroid exploration (86%), including one patient who had a previous complete sternotomy. Cure of hyperparathyroidism was achieved in all seven patients undergoing partial median sternotomy. In five patients a mediastinal parathyroid gland was removed (71%), and in one patient a parathyroid adenoma in the carotid sheath was eventually found, and the location of the hyperfunctioning parathyroid gland in one patient was never determined although the patient was cured. The mean length of hospital stay after a partial median sternotomy was 2.6 days. One patient sustained a recurrent laryngeal nerve injury at the time of a repeat cervical exploration and partial median sternotomy. Rarely, mediastinal parathyroid glands cannot be resected through a cervical approach. In these cases the use of partial median sternotomy is an attractive technique in achieving cure of hyperparathyroidism and is associated with minimal morbidity and a short length of hospital stay.

Nueva técnica quirúrgica para glándulas paratiroides intratorácicas: la videotoracoscopia con detección de Tc-MIBI intraoperatoria

Ectopic mediastinal parathyroid glands are uncommon (1-11% of all cases of hyperparathyroidism). Median sternotomy used to be performed to resect them, with large and painful incisions that prolonged the length of hospital stay. Current imaging techniques (thoracic computed tomography and Tc-mibi scan) can accurately locate the ectopic glands, allowing minimally invasive exploration. We report a new surgical technique: video-assisted thoracoscopic resection associated with intraoperative Tc-mibi scintigraphy for ectopic mediastinal parathyroid glands. This technique allows minimally invasive access and reduces complications and length of hospital stay. Therefore we believe that video-assisted thoracoscopy could become the technique of choice in patients with high surgical risk and a fifth ectopic parathyroid gland. We report the case of a 49-year-old man in whom surgery was successful.

Radioguided Thoracoscopic Mediastinal Parathyroidectomy With Intraoperative Parathyroid Hormone Testing

Primary hyperparathyroidism is the leading cause of hypercalcemia in the United States. The goal of this study was to evaluate the feasibility of radioguided thoracoscopic mediastinal parathyroidectomy and intraoperative immunoreactive parathyroid hormone (iPTH) level testing to guide completeness of resection. Mediastinal parathyroidectomy was performed thoracoscopically with intraoperative radioguidance using a hand-held gamma probe after injection of 10 mci of TC-99m sestamibi. Parathyroid excision was confirmed by ex vivo measurement of specimen radioactivity greater than 20% of background. Complete resection was confirmed by a greater than 50% decrease in serum iPTH level at 5 minutes postresection. Four patients had mediastinal parathyroid glands successfully localized and resected thoracoscopically. Mean weight of the excised parathyroid adenoma was 1,714 mg (range, 425 to 4,400 mg). Baseline iPTH levels decreased from a mean of 202 to 39 pg/dL 5 minutes postresection. One patient underwent radioguided resection of a second enlarged cervical parathyroid adenoma at the same setting when his intraoperative iPTH levels failed to fall below 50% of baseline, despite resection of a 440 mg mediastinal parathyroid gland. Median hospital stay was one day. All mediastinal parathyroid glands resected were confirmed adenomas on final histologic examination. All patients were normocalcemic at follow-up (mean, 25 months), indicating cure. Thoracoscopic mediastinal parathyroidectomy with intraoperative iPTH level monitoring is safe and effective. Radioguidance facilitates parathyroid localization. Ex vivo specimen radioactivity of greater than 20% of background confirms parathyroid resection and obviates the need for costly, time-consuming frozen section analysis. A 50% decrease in baseline iPTH level 5 minutes postresection confirms complete resection of parathyroid adenomas.

A Case of Thoracic Hemorrhage due to Ectopic Parathyroid Hyperplasia With Chronic Renal Failure

We report a case of secondary hyperparathyroidism in a 53-year-old man who had thoracic hemorrhage originating from an ectopic thymic parathyroid gland tumor. He was on long-term hemodialysis treatment and had persistent secondary hyperparathyroidism caused by 3 swollen parathyroid glands around the thyroid gland and a mediastinal ectopic parathyroid gland tumor. Parathyroidectomy and removal of the mediastinal tumor were planned. Preoperative chest x-ray and a computed tomographic scan obtained just before surgery showed left pleural effusion. Furthermore, diagnostic thoracentesis yielded hemorrhagic exudative fluid. Thoracoscopy confirmed the presence of a mediastinal tumor lesion that was bleeding into the thoracic cavity. The tumor was resected using thoracoscopic surgery, and ectopic thymic parathyroid gland hyperplasia associated with hemorrhage was pathologically diagnosed. A postoperative diagnostic chest computed tomographic scan and technetium 99m 2-methoxyisobutyl isonitrile scintigraphy showed successful removal of the ectopic parathyroid gland tumor. Subsequently, the secondary hyperparathyroidism could be clinically controlled by medical treatment, and total parathyroidectomy has been postponed indefinitely. We consider that hemorrhage from the ectopic parathyroid gland tumor resulted in thoracic bleeding. To our knowledge, this is the first case report of secondary hyperparathyroidism with thoracic hemorrhage originating from an ectopic mediastinal parathyroid gland.

Cervical excision using superior sternum lifting method for large mediastinal parathyroid gland

Cervical excision using superior sternum lifting method for large mediastinal parathyroid gland

Near-total parathyroidectomy is beneficial for patients with secondary and tertiary hyperparathyroidism

Despite several options for the extent of parathyroidectomy in secondary and tertiary hyperparathyroidism, <5% of patients are referred for surgical procedures. The purpose of this study was to identify beneficial outcomes of near-total parathyroidectomy (NTPTX) in this population. NTPTX (a vascularized parathyroid remnant is left in situ, and cryopreservation is performed) was completed in 142 patients with secondary (n = 93 patients) and tertiary (n = 49 patients) hyperparathyroidism, and was guided by intraoperative intact PTH (IOPTH). One hundred thirty-six of 142 patients (96%) remain cured at a mean follow-up time of 23 +/- 26 months. Six patients had missed mediastinal (n = 4 patients) or cervical (n = 2 patients) parathyroid glands. No patient required re-resection of a cervical parathyroid remnant. One patient had hypoparathyroidism and underwent autografting with cryopreserved tissue. NTPTX reduced parathyroid mass (4526 +/- 4515 mg to 77 +/- 56 mg) and IOPTH (1171 +/- 1252 pg/mL to 101 +/- 127 pg/mL). Fatigue and musculoskeletal pain resolved promptly after operation. Patients with tertiary hyperparathyroidism experienced an improvement in bone density of 3.6% per year. NTPTX achieved full healing of extremity ulcers without amputations or perioperative death in 22 patients with calciphylaxis. NTPTX effectively treats secondary and tertiary hyperparathyroidism in >95% patients. IOPTH monitoring and cryopreservation are valuable procedural adjuncts. Limb salvage in calciphylaxis, symptomatic relief, and improved bone density are substantial benefits to recommend this procedure to patients with renal hyperparathyroidism.

Infarction of mediastinal parathyroid gland causing spontaneous remission of secondary hyperparathyroidism

Secondary hyperparathyroidism is a serious complication in long-term hemodialysis patients. The authors report on 2 patients on long-term hemodialysis who suffered from persistent secondary hyperparathyroidism due to missed mediastinal parathyroid gland after total parathyroidectomy with forearm autograft. Reoperation was planned. In both cases, severe hypocalcemia suddenly developed; serum parathyroid hormone (PTH) level decreased markedly after this episode. The serum calcium level increased gradually in response to administration of vitamin D and calcium carbonate, but serum PTH level remained low. A follow-up computed tomography scan showed that the formerly enlarged mediastinal parathyroid gland was markedly reduced in size. Moreover, a hot spot formerly detected by technetium 99m-MIBI (methoxy-isobutyl-isonitrile) scintigraphy in the mediastinum disappeared after this episode. The authors considered that necrosis of the enlarged ectopic parathyroid gland, probably due to infarction, resulted in hypocalcemia. To the authors' knowledge, this is the first case report of spontaneous mediastinal parathyroid autoinfarction after parathyroidectomy in hemodialysis patients.

Infarction of mediastinal parathyroid gland causing spontaneous remission of secondary hyperparathyroidism

Secondary hyperparathyroidism is a serious complication in long-term hemodialysis patients. The authors report on 2 patients on long-term hemodialysis who suffered from persistent secondary hyperparathyroidism due to missed mediastinal parathyroid gland after total parathyroidectomy with forearm autograft. Reoperation was planned. In both cases, severe hypocalcemia suddenly developed; serum parathyroid hormone (PTH) level decreased markedly after this episode. The serum calcium level increased gradually in response to administration of vitamin D and calcium carbonate, but serum PTH level remained low. A follow-up computed tomography scan showed that the formerly enlarged mediastinal parathyroid gland was markedly reduced in size. Moreover, a hot spot formerly detected by technetium 99m-MIBI (methoxy-isobutyl-isonitrile) scintigraphy in the mediastinum disappeared after this episode. The authors considered that necrosis of the enlarged ectopic parathyroid gland, probably due to infarction, resulted in hypocalcemia. To the authors' knowledge, this is the first case report of spontaneous mediastinal parathyroid autoinfarction after parathyroidectomy in hemodialysis patients.

Partial median sternotomy: An attractive approach to mediastinal parathyroid disease

Background Parathyroid exploration through a standard cervical approach is adequate for the resection of most mediastinal parathyroid glands. A subset of mediastinal parathyroid glands causing hyperparathyroidism, however, cannot be removed in this manner.

Combined transmission and 99mTc-sestamibi emission tomography for localization of mediastinal parathyroid glands

Although parathyroid scintigraphy using (99m) Tc-sestamibi is considered the best preoperative localization method for hyperfunctioning parathyroid tissue it lacks the anatomical details required for successful, minimal invasive surgery of ectopic parathyroid lesions. This study presents the role of combined SPECT/X-ray-CT imaging in a single device for localization of mediastinal parathyroid glands. (99m) Tc-sestamibi SPECT/X-ray-CT was performed by gamma camera-mounted anatomical X-ray tomography (GMAXT; GE Medical systems, Millenium VG with Hawkeye) in four patients with ectopic parathyroid glands (two patients with primary, two with persistent secondary hyperparathyroidism). The device contains an X-ray tube and a set of detectors that rotate around the patient combined with a gamma camera. For comparison with GMAXT addition-ally high resolution computed tomography images of the neck and mediastinum were performed. Correct preoperative localization was achieved. The parathyroid glands were located in the anterior mediastinum. High resolution computed tomography could not provide further details. Three patients were operated by a minimal invasive open and one patient by a transsternal approach because of concomitant aortic valve replacement. (99m)Tc-sestamibi/X-ray-CT fusion imaging in a single device can accurately localise ectopic or supernumerary mediastinal parathyroid tumours in primary and secondary hyperparathyroidism. Morbidity,radiation exposure, time, and costs are reduced by avoiding multiple diagnostic examinations and minimal invasive parathyroid surgery becomes possible.

Intraoperative radioguided thoracoscopic removal of ectopic parathyroid adenoma

Twenty-five percent of primary hyperparathyroidism is caused by ectopic mediastinal parathyroid glands, with 2% of these not accessible to standard cervical surgical approaches. Advancement in video-assisted thoracoscopic surgical techniques has decreased the need for sternotomy to successfully remove these ectopic glands. The thoracoscopic approach, however, is limited by the surgeon’s inability to always accurately visualize ectopic glands. Intraoperative radionuclide-guided dissection, using a thoracoscopic approach, provides a novel adjunct to the removal of occult ectopic parathyroid glands. We report a case of an occult ectopic parathyroid adenoma removed thoracoscopically using an intraoperative handheld gamma probe.

Thoracoscopic resection of ectopic parathyroid glands

Background. The vast majority of parathyroid glands in hyperparathyroidism can be resected through a cervical approach. In approximately 2% of the cases, the ectopic gland is in the mediastinum in a location that requires a thoracic approach.Methods. We report 7 such cases that were resected using video-assisted thoracic surgery to avoid the need for an open surgical procedure.Results. All glands were successfully identified preoperatively and subsequently resected. Hospital stay averaged less than 3 days with only one minor complication.Conclusions. Ectopic mediastinal parathyroid glands may be safely and accurately resected using video-assisted thoracic surgery to avoid open approaches.

Retrospective analysis of sequential changes in serum intact parathyroid hormone levels during conventional parathyroid exploration.

The purpose of this study was to assess sequential changes in serum parathyroid hormone (PTH) levels during conventional parathyroidectomy. Sera were collected before and 10 minutes after resection of each parathyroid tumor from 112 consecutive patients and assayed postoperatively within 48 hours for PTH. PTH reductions corroborated cures for 94 of 112 cases (84%), including 70 of 71 patients with solitary adenomas (SAs). However, there were 15 false positives (13%), in which PTH decreased more than 50% within 10 minutes of resection of 1 parathyroid tumor while additional parathyroid tumors remained in situ (1 of 71 SAs, 4 of 6 double adenomas, 7 of 15 primary hyperplasias, and 3 of 17 tertiary hyperplasias). There were 3 false negatives (3%), with PTH unchanged, even though postoperative PTH and calcium values confirmed cure (1 SA, 1 primary hyperplasia, and 1 tertiary hyperplasia). There were only 2 of 112 failed explorations (1.8%), which would not have been avoided by PTH monitoring because both subsequently were found to have mediastinal parathyroid adenomas. We conclude that intraoperative PTH changes corroborated outcome in SA but may under-estimate the extent of resection required in parathyroid hyperplasia.

Mediastinoscopic Extirpation of Mediastinal Ectopic Parathyroid Gland

We report a case of a 50-year-old man with hyperparathyroidism secondary to chronic renal failure who underwent extirpation of a mediastinal ectopic parathyroid gland by a transcervical approach under mediastinoscopy. This procedure provides an excellent approach to the mediastinal ectopic parathyroid gland, and is less invasive than median sternotomy or thoracotomy.

Mediastinal Parathyroid Cysts

To present our experience with mediastinal parathyroid cysts and summarize previously reported cases. We retrospectively reviewed medical records and reviewed the pertinent literature. The clinical, operative, and pathologic findings in 7 cases of mediastinal parathyroid cysts encountered at one institution and 31 cases previously reported in the literature are described. Rarely, cysts may arise from an aberrant mediastinal parathyroid gland. Such cysts may manifest as a symptomatic mass, as an asymptomatic finding on roentgenography, or during the assessment of a patient with hyperparathyroidism. The diagnosis may be made by fine-needle aspiration or by excision and pathologic examination. Functioning parathyroid cysts represent degeneration of a hyperfunctioning gland, such as an adenoma, and are usually removed through a cervical approach. Nonfunctioning cysts in asymptomatic patients with normal serum calcium levels are considered indeterminate and should be managed accordingly. Excision is usually recommended.

Detection of mediastinal parathyroid glands by nonselective digital arteriography.

Six patients with failed previous operations and anterior mediastinal parathyroid glands were evaluated with selective angiography and nonselective arterial digital arteriography. Selective angiography depicted two of nine mediastinal glands; nonselective arterial digital arteriography depicted only one of nine mediastinal glands and missed a sizable (4.5 cm) gland demonstrated by routine arteriography. Nonselective arterial digital arteriography did not demonstrate any additional mediastinal glands. From this preliminary experience, it was concluded that nonselective arterial digital arteriography is not a sensitive method for detecting mediastinal glands.

The detection of mediastinal parathyroid glands by computed tomography, selective arteriography, and venous sampling: an analysis of 17 cases.

Computed tomography (CT) scans were reviewed in 19 cases of proved mediastinal parathyroid glands. Glands were detected in five of 17 cases (29%) with adequate scans; four of six (67%) anterior mediastinal glands larger than 2 cm were visible. The smallest lesion demonstrated by CT ws 1.6 cm. In the same series, selective arteriography was positive in 10 of 15 cases (67%), with the smallest lesion measuring 0.5 cm. Venous sampling was performed in 15 patients, and a thymic sample obtained in 10; a twofold step-up of parathyroid hormone in thymic veins was noted in eight of 15 cases (53%), but was not localizing, as samples in other veins were elevated in all but one case. Angiography appears more sensitive than second-generation CT for detecting mediastinal glands. However, CT is very useful in patients with previous failed explorations. Scanning must include contiguous sections extending several centimeters below the carina, in order to encompass low-lying mediastinal glands.

The localization of abnormal mediastinal parathyroid glands.

The venous drainage of parathyroid glands ectopically located in the mediastinum is generally caraniad into the inferior thyroid veins. Parathyroid glands in the neck can cause elevated concentrations of parathyroid hormone in mediastinal veins because of thyroidalthymic anastomoses. Therefore venous sampling alone cannot distinguish cervical from mediastinal adenomas. Arteriography can localize mediastinal parathyroids and should be perfomred before any repeat exploration.