Robot-Assisted Thoracoscopic Mediastinal Parathyroidectomy: A Single Surgeon Case Series

A case report of mediastinal parathyroid carcinoma in a chronic kidney disease patient: Addressing management conundrum

Parathyroid carcinoma is a rare malignancy; and it is rarer to find one located in an ectopic location. Ectopic parathyroid glands are a reported cause of failed primary surgery for hyperparathyroidism. We report here a 73-year-old male who previously had parathyroidectomy for primary hyperparathyroidism but then had recurrence of his symptoms with a diagnosis of a mediastinal parathyroid carcinoma on further evaluation. This presentation of complicated mediastinal parathyroid carcinoma posed significant diagnostic and management challenges due to comorbid stage IV chronic kidney disease (CKD). Secondly, due to the same comorbid condition, a more aggressive calcimimetic regimen could not be undertaken due to the risk of renal dysfunction with potential progression to dialysis status. Thirdly, he was a high-risk surgical candidate due to significant cardiovascular risks. Ideally, open surgical intervention would be recommended but due to the associated risks, he was managed with robotic-assisted thoracoscopic surgery. He subsequently developed hypocalcemia which normalized with supplemental calcium at follow-up.

Robot-Assisted Thoracoscopic Resection of Ectopic Parathyroid Tissue in Mediastinum: A Scoping Review

Ectopic parathyroid tissue in the mediastinum represents a rare and potentially serious clinical entity with challenging diagnostic and surgical management. The main surgical approach for this issue is open thoracotomy, which is a safe technique but carries risks and complications associated with such as extensive surgery. The purpose of this study is to demonstrate robotic thoracic surgery as an alternative and potentially advantageous method to treat patients with ectopic parathyroid adenomas compared with open and video-assisted thoracoscopic surgery approaches. A total of 13 reports in the literature were identified that provided details in terms of complications, surgical approach, and results of minimally invasive surgical resection of mediastinal ectopic parathyroid tissue.

Localization and surgical approach to mediastinal parathyroid glands

BACKGROUND

Hyperactive parathyroid glands (PTGs) are in the mediastinum 4.3% of the time. Historically, localization and resection of these glands can be challenging.

METHODS

We searched all operative notes involving a thoracic surgeon and a preoperative diagnosis of hyperparathyroidism from 2001 to 2019.

RESULTS

Eighty-five cases were reviewed, of which 63 were included. Only 14 patients (22%) had de novo hyperparathyroid operations. Seventeen patients (27%) had single-photon emission computed tomography with computed tomography fusion (SPECT-CT) as the only preoperative localization test (excluding chest radiography and ultrasound), and all were resected successfully. The initial surgical approach was transcervical for 16 (27%) patients, however only 7 remained transcervical. 4 (6%) patients had an exploration in which the target lesion was resected but it was not parathyroid tissue.

CONCLUSION

Most patients presenting with mediastinal PTG have had prior HPT surgery. The trend toward more focused HPT surgery may mean more de novo mediastinal PTG resections. An unambiguous functional and anatomic localization test, such as a spect-ct scan, is the best predictor of a successful resection. Ambiguous or discordant scans should be approached cautiously, and additional confirmatory tests are recommended. For suspected PTG located in the thymus, the thoracic surgeon should choose the most familiar approach to achieve complete thymectomy.

Robotic resection of ectopic mediastinal parathyroid adenoma with intraoperative parathyroid hormone monitoring: a case report

Background

Primary hyperparathyroidism is a disease caused by the secretion of excess parathyroid hormone (PTH) owing to the enlargement of the parathyroid gland. Ectopic parathyroid glands exist in the mediastinum in approximately 1–2% of cases, which is relatively rare. Intraoperative monitoring of serum PTH level is important to assess whether the source of hyperparathyroidism has been eliminated.

Case presentation

A 53-year-old asymptomatic woman was diagnosed with ectopic mediastinal parathyroid adenoma. A three-port robotic partial resection of the thymus containing the tumor was attempted, but bleeding from a swollen pericardial diaphragmatic vein led to the addition of an assist port along the way. The PTH level was measured intraoperatively. After confirming that the 15-min PTH level after removal of the tumor was less than 50% of the baseline value, the operation was completed. The tumor was positive for PTH and was diagnosed as an ectopic mediastinal parathyroid adenoma. Some small ectopic parathyroid gland tissues were observed in other parts of the thymic tissue. Serum calcium and PTH levels decreased and normalized.

Conclusions

We report the usefulness of robotic resection for ectopic mediastinal parathyroid adenoma with PTH monitoring. However, histopathologically, small parathyroid gland tissues may remain in the surrounding thymus. Hence, we believe that a strict follow-up is required for parathyroid function in the future.

Surgical Treatment of Ectopic Mediastinal Parathyroid Tumors: A 23-Year Clinical Data Study in a Single Center

Background. Ectopic mediastinal parathyroid glands are parathyroid glands located completely below the clavicle. At present, most literature reports on ectopic mediastinal parathyroid tumors (EMPT) are case reports or small case sequences.Methods. This study conducted a retrospective analysis of ectopic mediastinal parathyroid tumors cases treated over the past 23 years, summarizing and analyzing general conditions, preoperative positioning, postoperative pathology, intraoperative conditions, and long-term follow-up results.Results. This study enrolled 28 patients. Among them, 27 patients underwent preoperative localization diagnosis using 99mTc-sestamibi scan (MIBI) in conjunction with chest computed tomography (CT), including 26 cases of the anterior superior mediastinum and 2 cases of middle mediastinum. Postoperative pathology revealed 23 cases of parathyroid adenoma, 4 cases of parathyroid hyperplasia, and 1 case of parathyroid cyst. In this study, 12 patients underwent video-assisted thoracoscopic surgery (VATS) and thoracotomy approaches. Using Mann-Whitney U test, we discovered that VATS approach group is significantly superior in surgical time (P = 0.039) and intraoperative bleeding (P < 0.001). Within one week of surgery, 26 patients with primary hyperparathyroidism (PHPT) experienced a significant decrease in blood parathyroid hormone (PTH) (P < 0.001) and blood calcium (P < 0.001), and all achieved long-term remission.Conclusions. EMPT is most frequently performed in the anterior superior mediastinum. EMPT is predominantly parathyroid tumors, and most of them are associated with PHPT. MIBI and chest CT combination can be used for preoperative lesion localization (positive rate 96.15%). VATS can be used as a better surgical approach. PHPT patients before surgery can achieve long-term symptom relief with surgical treatment.

Mediastinal parathyroidectomy: Utilization of a multidisciplinary, robotic-assisted transthoracic approach in challenging cases

BACKGROUND

The majority of ectopic mediastinal parathyroid adenomas are accessible transcervically and those not amenable to this approach pose a significant clinical and technical challenge.

METHODS

Retrospective review of transthoracic robot-assisted mediastinal parathyroidectomy (TTRMP) for primary hyperparathyroidism between 2012 and 2019 at a single institution.

RESULTS

16 patients underwent TTRMP, 63% were female with a mean age of 64 ± 2.0 years. Nine of 16 had prior parathyroidectomy; 80% had persistent disease and a mean 2.8-year delay from index operation until TTRMP. Locations included: intrathymic (8), AP window (4), carina (3), and retroesophageal (1). Two patients underwent parathyroid reimplantation. Mean post-operative calcium and PTH were 9.2 ± 0.2 mg/dL and 20.2 ± 5.6 pg/mL, respectively. Complications included: temporary hypocalcemia (4), permanent hypocalcemia (1), DVT (1), hoarseness (1), and subcostal neuralgia (1).

CONCLUSION

In experienced hands, TTRMP is a safe and effective approach to mediastinal parathyroids not accessible transcervically. A multidisciplinary approach should be used in reoperative cases.