title: Factors affecting postoperative hypocalcemia after thyroid surgery: Importance of incidental parathyroidectomy.
abstract: OBJECTIVE
  The present study evaluated effects of incidental parathyroidectomy, surgical technique, and presence of thyroiditis or hyperthyroidism on occurrence of postoperative persistent or transient hypocalcemia.
  
  
  METHODS
  Patients who underwent thyroidectomy at İstanbul Medeniyet University between 2013 and 2015 were included in the study. Patient information, postoperative serum calcium levels, and pathology reports were investigated retrospectively. Group 1 was made up of patients who were found to have hypocalcemia (calcium ≤8.5 mg/dL) according to postoperative serum level and normocalcemic patients were placed in Group 2. Groups were compared statistically in terms of rate of incidental parathyroidectomy, surgical technique, and presence of thyroiditis or hyperthyroidism.
  
  
  RESULTS
  Mean age was 49.8±12.8 years (range: 20-88). A total of 417 patients were included in the study, 74 (17.7%) were male and 343 (82.3%) were female. Group 1 consisted of 205 (49.2%) patients who had hypocalcemia according to postoperative serum level, and remaining 212 (50.8%) patients were placed in Group 2. In Group 1, 38 (18.5%) patients had incidental parathyroidectomy, and with only 18 (8.5%) patients in Group 2, a statistically significant relationship was found between incidental parathyroidectomy and hypocalcemia (p=0.003). There was no statistically significant difference in terms of presence of thyroiditis or hyperthyroidism between groups. There was statistically significant decrease in postoperative hypocalcemia rate in patients with lobectomy compared to patients with bilateral total thyroidectomy or central neck dissection (p<0.01).
  
  
  CONCLUSIONS
  Risk of postoperative hypocalcemia may be reduced with lobectomy for selected patients. In addition, delicate dissection during thyroidectomy is important in order to protect parathyroid glands and prevent hypocalcemia.
authors.affiliation: Department of General Surgery, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey.
authors.forename: Ibrahim Ali
authors.initials: IA
authors.lastname: Ozemir
authors.affiliation: Department of General Surgery, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey.
authors.forename: Mehmet Zeki
authors.initials: MZ
authors.lastname: Buldanli
authors.affiliation: Department of General Surgery, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey.
authors.forename: Oktay
authors.initials: O
authors.lastname: Yener
authors.affiliation: Department of General Surgery, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey.
authors.forename: Metin
authors.initials: M
authors.lastname: Leblebici
authors.affiliation: Department of General Surgery, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey.
authors.forename: Tunc
authors.initials: T
authors.lastname: Eren
authors.affiliation: Department of General Surgery, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Baysal
authors.affiliation: Department of General Surgery, Istanbul Medeniyet University, Goztepe Training and Research Hospital, Istanbul, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Alimoglu
keywords: Hypocalcemia; incidental parathyroidectomy; thyroidectomy