Anatomical distribution and number of parathyroid glands, and parathyroid function, after total parathyroidectomy and bilateral cervical thymectomy

Abstract

The normal distribution of parathyroid glands is well documented. However, this study aims to evaluate the efficacy of total parathyroidectomy (TPTx) and bilateral cervical thymectomy (BCTx) for the treatment of secondary hyperparathyroidism (SHPT) through identifying the location of parathyroid glands with attention to the pattern and frequency of orthotopic and ectopic glands. Between 2013 and 2018, sixty chronic hemodialysis patients with medically refractory SHPT underwent TPTx & BCTx. The adequacy of the operation was defined by the pathological confirmation of at least 4 parathyroid glands, accompanied by an intact parathormone (iPTH) value of <60 pg/mL on postoperative day 1(POD1). Based on their anatomical localizations, four distinct sites were identified for both the upper (Zone I–IV) and lower parathyroid glands (Zone V–VIII). The mean follow-up was 15.2 ± 14.6 months. The mean iPTH values on POD1 were normal in 50 patients, with an average of 11.7 ± 14.4 pg/mL. Ten patients (16.6%) had persistent HPT after the operation, three of whom underwent complementary parathyroidectomy. The surgical success rates after first and second operations were both 83.3%. A total of 235 parathyroid glands were detected. Ninety-two percent of the upper parathyroids were located in Zones I and II. However, almost 28% of the lower parathyroids were ectopic and located in Zones VII and VIII. At least one fourth of the lower parathyroids are ectopic; for this reason, Zones VII and VIII require careful investigation during surgery. For upper parathyroids not found in Zone I–III, total thyroidectomy on the same side is recommended.

Diagnostic Accuracy of Intraoperative Intact Parathyroid Hormone Monitoring for Surgical Outcomes of Secondary Hyperparathyroidism

“…Previous studies have shown that an iPTH level <60 pg/ml (as a normal upper value) on the first postoperative day is a good predictor of surgical success [ 9 , 10 ]. We extended the observation period to 1 week after the operation, and we then used iPTH d1 and iPTH d7 levels as predictors associated with successful PTX.…”

Risk Factor Analysis and Prediction of Severe Hypocalcemia after Total Parathyroidectomy without Auto-Transplantation in Patients with Secondary Hyperparathyroidism

“…All surgical procedures were performed by Dr. Guangming Cheng and his surgical team. A successful operation was defined as previously described [ 23 ].…”

Parathyroid glands: variation in number, size and location

“…When superior PTGs did not lie in zones I-III, total thyroidectomy on the same side was recommended. 9 A hyperactive parathyroid adenoma, located in middle mediastinum, could not be approached via cervical subtotal parathyroidectomy with bilateral thymectomy, but through a successful thoracoscopic technique. 10 It has been also mentioned that thyroidectomy may be associated with incidental parathyroidectomy often due to intrathyroidal location of the PTGs.…”