title: Cryopreservation of parathyroid tissue after parathyroid surgery for renal hyperparathyroidism: does it really make sense?
abstract: BACKGROUND
  Metachronous autotransplantation of cryopreserved parathyroid tissue is a technique for treating postoperative hypoparathyroidism after parathyroid surgery for renal hyperparathyroidism (rHPT). The aim of the present study was to evaluate our institution's experience with metachronous autotransplantation to analyze the role of cryopreservation in the treatment of rHPT and to determine for whom and when cryopreservation of parathyroid tissue should be deemed necessary.
  
  
  METHODS
  A prospective database of patients with rHPT who underwent surgery between 1976 and 2011 was screened for patients with hypoparathyroidism who received a metachronous autotransplantation. Data were analyzed regarding clinical data, histopathological findings of the cryopreserved parathyroid tissues, and patient outcome after metachronous replantation of parathyroid tissue.
  
  
  RESULTS
  Fifteen of 883 patients with rHPT underwent a metachronous autotransplantation under local anesthesia at a mean time of 23 months following the last cervical surgery. Histopathology of the parathyroid tissue chosen for transplantation revealed a necrosis rate of 0 % in 14 and 70 % in one patient. Mean preoperative serum calcium and parathyroid hormone (PTH) levels were 2.0 mmol/l and 3.7 pg/ml, respectively. Autotransplantation raised mean serum calcium and PTH levels to 2.2 mmol/l and 97.5 pg/ml, respectively, after a mean follow-up of 78 months.
  
  
  CONCLUSIONS
  Metachronous autotransplantation following parathyroid surgery in patients with rHPT effectively normalizes PTH and calcium levels. The success rate is high if an adequate cryopreservation procedure is applied. However, it is rarely necessary, and therefore the cryopreservation of parathyroid tissue in all patients has to be questioned, at least from an economic point of view.
authors.affiliation: Department of Visceral, Thoracic and Vascular Surgery, Philipps University Marburg, Baldingerstrasse, 35043 Marburg, Germany. ralph.schneider@med.uni-marburg.de
authors.forename: Ralph
authors.initials: R
authors.lastname: Schneider
authors.forename: Annette
authors.initials: A
authors.lastname: Ramaswamy
authors.forename: Emily P
authors.initials: EP
authors.lastname: Slater
authors.forename: Detlef K
authors.initials: DK
authors.lastname: Bartsch
authors.forename: Katja
authors.initials: K
authors.lastname: Schlosser
mesh_terms: D015925:Cryopreservation; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000209:etiology / Q000601:surgery*; D007674:Kidney Diseases / Q000150:complications; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000637:transplantation*; D016105:Parathyroidectomy; D011446:Prospective Studies