title: The role of intraoperative parathyroid hormone testing in patients with tertiary hyperparathyroidism after renal transplantation.
abstract: BACKGROUND
  Intraoperative parathyroid hormone (PTH) testing has been shown to accurately define adequacy of parathyroid resection in patients with primary hyperparathyroidism (HPT) and alters the operative management in 10% to 15% of cases. However, the benefit of this technique in patients with tertiary HPT after renal transplantation undergoing parathyroidectomy is unclear.
  
  
  METHODS
  Intraoperative PTH was measured in 32 consecutive patients undergoing parathyroidectomy for tertiary HPT after renal transplantation between March 2001 and November 2004 by using the Elecsys assay at baseline and, subsequently, 5, 10, and 15 minutes after curative resection. The outcomes of these patients were evaluated.
  
  
  RESULTS
  All patients were cured after surgery. Of the 32 patients, 29 were found to have parathyroid hyperplasia, while 1 had a single adenoma and 2 had double adenomas. The average drop in intraoperative PTH levels after curative resection was 69 +/- 3.5% at 5 min., 77 +/- 2.3% at 10 minutes, and 83 +/- 3.4% at 15 minutes. PTH testing changed the intraoperative management in 5 (16%) patients. One patient with a single adenoma and 2 patients with double adenomas had a >50% drop at 10 minutes. after excision; therefore, the operation was terminated without further resection. Two patients did not have a >50% drop at 10 minutes after 3.5 gland resection. These patients were explored further, and additional supernumerary parathyroid glands were identified and resected. After resection of these additional glands, the PTH fell by >50%, indicating cure.
  
  
  CONCLUSIONS
  In patients undergoing parathyroidectomy for tertiary HPT after renal transplantation, a decrease in intraoperative PTH levels >50% at 10 minutes after completion of the operation indicated adequate resection. Furthermore, intraoperative PTH testing altered the operative management in 16% of patients. Therefore, similar to its role in patients with primary HPT, intraoperative PTH testing appears to play an equally important role in the management of patients with tertiary HPT undergoing parathyroidectomy.
authors.affiliation: Section of Endocrine Surgery, Department of Surgery, University of Wisconsin Medical School, Madison, WI 53792, USA.
authors.forename: Silke V
authors.initials: SV
authors.lastname: Haustein
authors.forename: Eberhard
authors.initials: E
authors.lastname: Mack
authors.forename: James R
authors.initials: JR
authors.lastname: Starling
authors.forename: Herbert
authors.initials: H
authors.lastname: Chen
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood* / Q000209:etiology / Q000601:surgery*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010281:Parathyroid Hormone / Q000097:blood*; D016105:Parathyroidectomy; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D010281:Parathyroid Hormone