title: Incidence, Risk Factors, and Clinical Outcomes of Incidental Parathyroidectomy During Thyroid Surgery.
abstract: The reported rate of incidental parathyroidectomy (IP) during thyroid surgery is between 5.2 and 21.6 %. Current literature reports wide discrepancy in incidence, risk factors, and outcomes. Thus study was designed to address definitively the topic of IP and identify associated risk factors and clinical outcomes with this multi-institutional study.
  
  
  
  This retrospective cohort study included 1767 total thyroidectomies that occurred between 1995 and 2014 at two academic centers. Pathologic reports were reviewed for the presence of unintentionally removed parathyroid glands. Demographics, potential risk factors, and postoperative calcium levels were compared with matched control group. Logistic regression, t tests, and Chi squared tests were used when appropriate.
  
  
  
  IP occurred in 286 (16.2 %) of thyroidectomies. Risk factors for IP were: malignancy, neck dissection, and lymph node metastases (p = 0.005, <0.001, and <0.001). Fifty-three (19.2 %) of IPs were intrathyroidal. Those with IP were more likely to have postoperative biochemical (65.6 vs. 42.0 %; p < 0.001) and symptomatic (13.4 vs. 8.1 %; p = 0.044) hypocalcemia than controls. The number of parathyroids identified intraoperatively was inversely correlated with the number of parathyroid glands in the specimen (p < 0.001).
  
  
  
  Our findings indicate that malignancy, lymph node dissection, and metastatic nodal disease are risk factors for IP. Patients with IP were more likely to have postoperative biochemical and symptomatic hypocalcemia than controls, showing that there is a physiologic consequence to IP. Additionally, intraoperative surgeon identification of parathyroid glands results in a lower incidence of IP, highlighting the importance of awareness of parathyroid anatomy during thyroid surgery.
authors.affiliation: Albany Medical College, Albany, NY, USA.
authors.forename: Megan K
authors.initials: MK
authors.lastname: Applewhite
authors.affiliation: Section of General Surgery, Endocrine Surgery Group, The University of Chicago Medicine & Biological Sciences, Chicago, IL, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: White
authors.affiliation: University of California, San Francisco, CA, USA.
authors.forename: Maggie
authors.initials: M
authors.lastname: Xiong
authors.affiliation: University Health Network, Toronto, Canada.
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Pasternak
authors.affiliation: Section of General Surgery, Endocrine Surgery Group, The University of Chicago Medicine & Biological Sciences, Chicago, IL, USA.
authors.forename: Layth
authors.initials: L
authors.lastname: Abdulrasool
authors.affiliation: University of California, San Francisco, CA, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Ogawa
authors.affiliation: University of California, San Francisco, CA, USA.
authors.forename: Insoo
authors.initials: I
authors.lastname: Suh
authors.affiliation: University of California, San Francisco, CA, USA.
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Gosnell
authors.affiliation: Section of General Surgery, Endocrine Surgery Group, The University of Chicago Medicine & Biological Sciences, Chicago, IL, USA.
authors.forename: Edwin L
authors.initials: EL
authors.lastname: Kaplan
authors.affiliation: University of California, San Francisco, CA, USA.
authors.forename: Quan-Yang
authors.initials: QY
authors.lastname: Duh
authors.affiliation: Section of General Surgery, Endocrine Surgery Group, The University of Chicago Medicine & Biological Sciences, Chicago, IL, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Angelos
authors.affiliation: University of California, San Francisco, CA, USA.
authors.forename: Wen T
authors.initials: WT
authors.lastname: Shen
authors.affiliation: Section of General Surgery, Endocrine Surgery Group, The University of Chicago Medicine & Biological Sciences, Chicago, IL, USA. rgrogan@surgery.bsd.uchicago.edu.
authors.forename: Raymon H
authors.initials: RH
authors.lastname: Grogan
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000209:etiology*; D015994:Incidence; D008207:Lymphatic Metastasis; D008297:Male; D019300:Medical Errors / Q000009:adverse effects* / Q000706:statistics & numerical data*; D008875:Middle Aged; D037981:Neck Dissection / Q000009:adverse effects; D016105:Parathyroidectomy / Q000009:adverse effects* / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy / Q000009:adverse effects
chemical_list: D002118:Calcium