title: Safety and Prognostic Impact of Prophylactic Level VII Lymph Node Dissection for Papillary Thyroid Carcinoma.
abstract: OBJECTIVE
  To study the safety of prophylactic level VII nodal dissection regarding hypoparathyroidism (temporary and permanent) and vocal cord dysfunction (temporary and permanent) and its impact on disease free survival.
  
  
  METHODS
  This prospective study concerned 63 patients with papillary thyroid carcinoma with N0 neck node involvement (clinically and radiologically) in the period from December 2009 to May 2013. All patients underwent total thyroidectomy and prophylactic central neck dissection including levels VI and VII lymph nodes in group A (31 patients) and level VI only in group B (32 patients). The thyroid gland, level VI and level VII lymph nodes were each examined histopathologically separately for tumor size, multicentricity, bilaterality, extrathyroidal extension, number of dissected LNs and metastatic LNs. Follow-up of both groups, regarding hypoparathyroidism, vocal cord dysfunction and DFS, ranged from 6-61 months.
  
  
  RESULTS
  The mean age was 34.8 and 34.3, female predominance in both groups with F: M 24:7 and 27:5 in groups A and B, respectively. Mean tumor size was 12.6 and 14.7mm. No statistical differences were found between both groups regarding age, sex, bilaterality, multicentricity or extrathyroidal extension. The mean no. of dissected level VI LNs was 5.06 and 4.72 and mean no. of metastatic level VI was 1 and 0.84 in groups A and B, respectively. The mean no. of dissected level VII LNs was 2.16 and mean no. of metastatic LNs was 0.48. Postoperatively temporary hypoparathyroidism was detected in 10 and 7 patients and permanent hypoparathyroidism in 2 and 3 patients; temporary vocal cord dysfunction was detected in 4 patients and one patient, and permanent vocal cord dysfunction in one and 2 patients in groups A and B, respectively. No significant statistical differences were noted between the 2 groups regarding hypoparathyroidism (P=0.535) or vocal cord dysfunction (P=0.956). The number of dissected LNs at level VI only significantly affected the occurrence of hypoparathyroidism (<0.001) and vocal cord dysfunction (<0.001).The DFS was significantly affected by bilaterality, multicentricity and extrathyroidal extension.
  
  
  CONCLUSIONS
  Level VII nodal dissection is a safe procedure complementary to level VI nodal dissection with prophylactic central neck dissection for papillary thyroid carcinoma.
authors.affiliation: Department of Surgical Oncology, National Cancer Institute, Cairo University, Cairo, Egypt E-mail : drihab74@hotmail.com.
authors.forename: Ihab Samy
authors.initials: IS
authors.lastname: Fayek
authors.forename: Ahmed Ahmed
authors.initials: AA
authors.lastname: Kamel
authors.forename: Nevine Fh
authors.initials: NF
authors.lastname: Sidhom
mesh_terms: D000328:Adult; D002291:Carcinoma, Papillary / Q000473:pathology* / Q000601:surgery; D004534:Egypt / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007011:Hypoparathyroidism / Q000453:epidemiology*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012449:Safety; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D055815:Young Adult