Thoracoscopic excision of mediastinal parathyroid adenomas: a report of two cases

[Ectopic parathyroid adenoma: Scintigraphic detection and radioguided surgery]

AIM

The aim of this study was to evaluate the role of (99m)Tc-MIBI parathyroid scintigraphy and radioguided parathyroidectomy on the diagnosis and treatment of primary hyperparathyroidism (PHP) due to ectopic adenomas.

METHODS

We reviewed 105 consecutive patients who underwent radioguided parathyroidectomy due to adenomas between March 2004 and December 2008. Of this group we studied 20 patients (19%) with ectopic adenomas. All patients had biochemical evidence of PHP, a positive parathyroid scintigraphy, radioguided detection with histolopathological confirmation of adenoma and at least 1 year-follow up. The parathyroid scintigraphy consisted on dual-phase planar and tomographic images (SPECT or SPECT/CT). During the parathyroidectomy, intraoperative PTH determinations (0, 7, 15 and 30 min after the parathyroidectomy) were done. The follow up consisted on blood examinations of PTH, calcium, phosphorus and vitamin D and assessment of renal function.

RESULTS

Parathyroid scintigraphy detected all adenomas. Scintigraphic and surgical findings were coincident in 18 cases (90%). The final adenoma localization was paraesophagic in 9 patients, cervicothymic in 5, posterior cervicomediastinal in 4, anterior mediastinal in 1 and parathymic in 1. The parathyroidectomy consisted on 12 minimally invasive surgeries, 2 unilateral cervicotomies, 4 bilateral cervicotomies and 2 sternotomies. No case of persistent or recurrent PHP was observed during the follow up.

CONCLUSIONS

Parathyroid scintigraphy (SPECT/CT) and radioguided surgery are effective methods on the localization and treatment of PHP due to ectopic adenomas. In our study the radioguided parathyroidectomy was successful in all cases and there was no evidence of persistent or recurrent hyperparathyroidism on the follow up.

Surgical treatment of mediastinal parathyroid adenoma: rationale for intraoperative parathyroid hormone monitoring

BACKGROUND

Recent publications have recommended parathyroidectomy guided solely by preoperative imaging. However, when the parathyroid adenoma is located deep in the mediastinum, the surgeon often encounters difficulties to localize and completely remove all hyperfunctioning parathyroid tissues. Thus, we hypothesized that patients with mediastinal adenoma differ substantially from cervical cases and require a specific strategy. The aim of this study was to evaluate the efficacy of intraoperative serum parathyroid hormone monitoring (ioPTH) used to guide completeness of targeted mediastinal parathyroidectomy.

METHODS

In a 10-year period, 33 patients underwent targeted mediastinal parathyroidectomy with ioPTH for primary sporadic hyperparathyroidism. A greater than 50% drop in ioPTH was considered confirming successful resection. If ioPTH failed to decline adequately, the operation was extended to complete cervical exploration. We analyzed the impact of ioPTH on the final surgical outcome.

RESULTS

In 26 patients the adenoma was correctly identified and removed at targeted mediastinal parathyroidectomy. In 7 patients lack of adequate ioPTH drop after targeted mediastinal parathyroidectomy triggered continued exploration, providing success at complete cervical exploration in 6 patients. In 1 patient this strategy failed owing to an undiagnosed lesion in the posterior mediastinum. Use of ioPTH decreased the failure rate from a potential 21.2% without ioPTH to 3% in the actual series.

CONCLUSIONS

Mediastinal parathyroid adenoma represents a distinct subset of primary hyperparathyroidism and requires a specific diagnostic and therapeutic approach. In these cases ioPTH monitoring is a reliable and effective method to confirm curative resection. It is an important adjunct predictor of postoperative successful outcome, which allows a low failure rate and avoids unnecessary reoperations.

Thoracoscopic removal of mediastinal parathyroid glands: a critical appraisal of an emerging technique

OBJECTIVE

To retrospectively evaluate the feasibility of thoracoscopic removal of mediastinal parathyroids.

SUMMARY BACKGROUND DATA

Mediastinal exploration to resect ectopic parathyroid(s) is needed in approximately 2% of cases in hyperparathyroidism. Recent advances in thoracoscopic surgery allow for a minimally invasive treatment.

METHODS

From 1999 through 2007, 13 patients affected by primary hyperparathyroidism (11 females, mean age 60 years, range: 22-88) underwent thoracoscopic removal of mediastinal parathyroids. Scintigraphy produced positive results in 11 of 13 cases, computed tomography scan in 9 of 10, parathyroid hormone venous sampling in 10 of 10 patients, and magnetic resonance imaging in 5 of 7. Right thoracoscopic access was used in 9 patients, left in 4. Postoperative outcome was analyzed.

RESULTS

Thoracoscopy enabled retrieval of mediastinal parathyroids in 10 of 13 (78%) cases. Mean operating time was 92 minutes (range: 50-240). One procedure (8%) was converted. No perioperative deaths/major complications occurred. Mild complications occurred in 2 of 13 (15%) patients (pneumothorax/pneumonia, transient recurrent nerve palsy). Mean hospital stay was 4.7 days (range: 2-15). At a mean follow-up of 73 months (range: 16-105), parathyroid hormone and calcium venous concentrations were high in 3 patients. Unsuccessful procedures were related to doubtful or non-concordant preoperative localization.

CONCLUSIONS

The thoracoscopic approach for mediastinal parathyroidectomy is feasible and safe. An accurate preoperative work-up should be standardized to avoid useless procedures. In case of negative preoperative localization of the abnormal gland, thoracoscopy should not be adopted as a diagnostic tool.