Parathyroidectomy via bilateral cervical exploration: a retrospective review of 866 cases.

INTRODUCTION: Parathyroidectomy via cervical exploration is an effective primary-modality treatment for hyperparathyroidism, with cure rates of greater than 95%. We retrospectively reviewed 866 consecutive parathyroidectomies performed by a single surgeon between 1960 and 1997. We attempted to describe the polymorphic variation in multiglandular disease, the anatomic locations of pathologic glands, and the operative strategy and techniques which we believed were important to minimizing morbidity and maximizing curative success.
METHODS: The cases of 329 males and 537 females (age, 1-88 years) were reviewed. There were 766 operations performed: primary hyperparathyroidism (713), tertiary hyperparathyroidism (100), reoperations (53). The strategy for primary exploration includes a bilateral neck exploration, early recurrent laryngeal nerve skeletonization, and identification of at least four glands.
RESULTS: Normocalcemia was achieved in 98.2% of cases after initial cervical exploration. Persistent hypercalcemia occurred in 7 patients (<1%). Nine patients (1%) suffered persistent postoperative hypocalcemia. Unilateral recurrent laryngeal nerve injury occurred in two patients (<1%). Other perioperative complications included: reoperation for hematoma, repaired carotid artery injury, unexplained dysphagia, pneumothorax, deep venous thrombosis, and aspiration pneumonia. There were two mortalities (<1%) attributable to severe, comorbid disease. Ectopic glands were found in 120 cases. The frequency of glands at these sites were as follows: mediastinal (4.9%), intrathymic (8.4%), intrathyroid (6.7%), and retroesophageal/retrotracheal (3.5%). Thyroid resections provided diagnosis of concomitant thyroid carcinoma in 8.0% of resected patients. The pathology of patients with primary hyperparathyroidism (PHPT) consisted of single adenomas (77.2%), hyperplasia (21.0%), normal glands (1%), double adenomas (<1%), and parathyroid carcinoma (<1%). The distribution of adenomas was as follows: left upper, 25.3%; left lower, 27.3%; right upper, 26.8%; right lower, 20.6%. Hyperplastic glands were found in ectopic positions as follows: intrathymic (7.5%), intrathyroid (11.3%), mediastinal (2.5%), and retroesophageal/retrotracheal (0%). The average volume difference between the largest and smallest hyperplastic gland of each case was 1.80 + 4.40 cm3. Reoperations were performed upon 53 referred patients and 7 patients after failed exploration. Normocalcemia was attained in 98.3% of cases. Glandular pathology was identified in the previous operative field in 52 patients (86.7%). Adenomas were identified in 56.0% (n = 23) and hyperplasia in 39.0% (n = 16).
CONCLUSIONS: In our series, we were able to attain normocalcemia in 98.2% of cases after initial cervical exploration. We believe that identification of four glands, an exhaustive search of ectopic sites, bilateral exploration, and liberal use of biopsy and intraoperative frozen section were essential to curative success. The pathologist should identify parathyroid tissue in the specimen and differentiate the "abnormal" from "normal" gland. Morphologic criteria alone cannot be used because of polymorphic variation in hyperplasia in which pathologic glands may appear normal. Early identification of the recurrent laryngeal nerve allows for a safer neck exploration by alerting the surgeon to the location and course of the nerve. A bilateral approach does not contribute increased morbidity from recurrent laryngeal nerve injury.