Predictive value of postoperative day 1 parathyroid hormone levels for early and late hypocalcaemia after thyroidectomy.

PURPOSE: Early parathyroid hormone (PTH) levels after total thyroidectomy can predict patients at low risk of hypocalcaemia who can be discharged early without calcium supplementation. For centres without facility to perform early PTH levels, PTH levels sent on the first postoperative day (POD1) may be an alternative. However, there is less data regarding optimal cut-off PTH levels for POD1 discharge. METHODS: Retrospective review of prospective database of thyroid operations between September 2009 and February 2020 at tertiary referral centre. Main outcome measure was symptomatic hypocalcaemia. RESULTS: Five hundred seventy patients undergoing total (521) or completion thyroidectomy with POD1 PTH levels available were included. Among patients with POD1 PTH levels ≥ 20 pg/ml and POD1 calcium ≥ 2.0 mmol/l, the incidence of symptomatic hypocalcaemia was 1% (3/300), and need for intravenous calcium 0.3% (1/300). For POD1 PTH levels 15-19 pg/ml and POD1 calcium ≥ 2.0 mmol/l, the incidence of symptomatic hypocalcaemia and need for intravenous calcium was 5.4% (3/55). For PTH levels 10-14 pg/ml and calcium ≥ 2.0 mmol/l, the incidence of symptomatic hypocalcaemia and need for intravenous calcium was 11.7% (7/60). The risk of permanent hypoparathyroidism was < 1% for POD1 PTH levels ≥ 15 pg/ml; 5.4% for levels 10-14 pg/ml; and 19.8% for levels < 10 pg/ml. CONCLUSIONS: POD1 PTH levels ≥ 15 pg/ml along with calcium ≥ 2.0 mmol/l are associated with low risk of symptomatic hypocalcaemia, and represent a safe criterion for discharge of most patients without calcium supplementation. For certain patient groups, a higher threshold of 20 pg/ml could be considered.

Tissue sealant versus surgical drain following parotidectomy.

PURPOSE: Sialocele and salivary fistula are recognised complications of parotid surgery and have been reported to be more common with less extensive parotidectomy. We investigated the efficacy of tissue sealant(Cunniffe et al., 2019) 1 as an alternative to surgical drainage in terms of length of hospital stay (LOS), cost, and incidence of wound complications. METHODS: The study comprised a retrospective review of a prospectively maintained parotidectomy database at a single tertiary Head and Neck referral centre between 2009 and 2020. Cases undergoing concomitant neck dissection or major skin resection were excluded. Patients were divided into Group 1 (without tissue sealant), and Group 2 (with tissue sealant). Patients were also divided based on extent of surgery 1) Extracapsular dissection/Partial superficial parotidectomy 2) Superficial/total parotidectomy. RESULTS: Of 202 included patients, there were 146 in Group 1 (143 with drain), and 56 in Group 2 (7 with drain). Compared to Group 1, Group 2 had a significantly shorter LOS (mean 1.4 ± 0.98 versus 3.1 ± 1.29 days, p < 0.05) and estimated cost (€1386 versus €2736). There was no significant difference in the complication rates (15.8% Group 1 versus 10.7% Group 2, p = 0.50). Group 1 showed a higher incidence of complications in patients undergoing less extensive parotidectomy (19/70 versus 4/76, p = 0.02), whereas in Group 2, the difference was not significant (5/30 versus 1/26, p = 0.20). CONCLUSION: The use of tissue sealant as an alternative to surgical drains after parotidectomy facilitates reduced LOS and cost savings without increase in morbidity.

Use of intraoperative neural monitoring for prognostication of recovery of vocal mobility and reduction of permanent vocal paralysis after thyroidectomy.

INTRODUCTION: The benefits of intraoperative neural monitoring (IONM) of recurrent laryngeal nerve (RLN) on post-thyroidectomy vocal cord palsy (VCP) rates are contentious. We wished to study impact of IONM on permanent VCP after thyroidectomy. METHODS: Retrospective review of prospective series of 1011 (1539 nerves-at-risk) patients undergoing thyroidectomy without (418, group 1) and with (583, group 2) IONM. RESULTS: There were three recognized nerve injuries in group 1, vs one in group 2 (P = .3). There were no differences in overall VCP rates. However, patients in group 2 with immediate postoperative VCP had higher likelihood of full recovery than patients in group 1 (55 of 56 vs 23 of 29 patients, P = .01), and lower incidence of total permanent VCP (2 of 917 vs 9 of 647 patients, P = .01). CONCLUSION: Among patients with immediate postoperative VCP after thyroidectomy, IONM is associated with a higher likelihood of regaining normal vocal function. This may be related to better identification of RLN branching in IONM cases.

Perioperative magnesium levels in total thyroidectomy and relationship to hypocalcemia.

BACKGROUND: We have previously shown an association between hypomagnesemia and hypocalcemia after thyroidectomy. However, little is known regarding the trend in magnesium levels in the days after thyroidectomy. Our objective was to study this trend in magnesium levels after thyroidectomy. METHODS: Retrospective review of 173 thyroidectomies with analysis of calcium and magnesium levels on postoperative day 1 (POD1) and POD2. RESULTS: Across the whole group, there was a highly significant decline in magnesium levels between preoperative (0.87 ± 0.06 mmol/L), POD1 (0.80 ± 0.07 mmol/L), and POD2 (0.78 ± 0.08 mmol/L) (P < .0001). The magnitudes of the magnesium level declines were significantly higher, and the absolute magnesium levels on POD1 and POD2 significantly lower, in patients developing hypocalcemia (n = 69). CONCLUSION: Magnesium levels after total thyroidectomy demonstrate a downward trajectory which persists through POD2 and is highly correlated with hypocalcemia. Further study is required to determine if magnesium replacement can alter the course of hypocalcemia in hypocalcemic patients after total thyroidectomy.

Impact of Microcalcifications on Risk of Malignancy in Thyroid Nodules with Indeterminate or Benign Cytology.

OBJECTIVE: Adverse sonographic features such as microcalcification may predict increased likelihood of malignant cytology by fine-needle aspiration and, accordingly, increased risk of malignant histology. Our objective was to study the predictive value of microcalcifications and other sonographic features for malignancy among thyroid nodules with benign or indeterminate cytology. STUDY DESIGN: Case series with chart review. SETTING: Academic teaching hospital. SUBJECTS: Patients (N = 769) with 858 thyroid nodules undergoing 1142 ultrasound fine-needle aspirations; 411 cases had surgical correlation. METHODS: Sonographic features predictive of malignancy were correlated with malignancy as determined by histology. Incidental malignancies occurring outside the index nodule were discounted. RESULTS: Cytology was inadequate (87 cases), benign (518), indeterminate (210), and malignant (44). In 32 cases, initial benign cytology was upgraded to a higher-risk category after repeat ultrasound fine-needle aspiration. Microcalcification (P = .001) and irregular margins (P = .04) were significantly predictive of malignant cytology. Among surgical cases, microcalcification (P < .001) and irregular margins (P = .04) were significantly predictive of malignant histology; 170 patients with initial benign cytology and 161 with indeterminate cytology underwent surgery. Microcalcification was significantly associated with malignancy among cases with indeterminate cytology (P = .04) but not among cases with benign cytology (P = .23); however, only 13 of 33 cases with benign cytology and microcalcifications underwent surgery. CONCLUSION: Presence of microcalcification increases the risk of malignancy in thyroid nodules with indeterminate cytology and may thus aid in selection of cases for surgery.

Outcome of Subclassification of Indeterminate (Thy-3) Thyroid Cytology into Thy-3a and Thy-3f.

OBJECTIVES: The British Thy system is a widely used classification system for reporting thyroid fine-needle aspiration (FNA) cytology. The Royal College of Pathologists in 2009 recommended the subdivision of the Thy-3 (indeterminate) category into Thy-3a (atypia) and Thy-3f (follicular neoplasm). Our objective was to examine the malignancy rates of Thy-3a and Thy-3f cases at our institution and to investigate whether the risk of malignancy in Thy-3a cases is reduced by FNA on a different occasion showing benign cytology. METHODS: This is a retrospective study of 748 thyroid nodules undergoing 1,032 FNAs, with indeterminate (Thy-3) cytology subdivided into Thy-3a and Thy-3f. Cases were correlated with final histology in surgical cases. Incidental carcinomas occurring outside the biopsied nodule were discounted. RESULTS: A total of 109 nodules had a final cytological diagnosis of Thy-3a, of which 67 underwent surgery, with an incidence of malignancy of 13.4% (9/67); 90 nodules had a final cytological diagnosis of Thy-3f, of which 84 underwent surgery, with an incidence of malignancy of 17.9% (15/84). The difference in malignancy rates was not significant (p = 0.51). The incidence of malignancy in nodules with benign and Thy-3a cytology on separate occasions was not significantly different from cases with a single Thy-3a cytology. CONCLUSIONS: Thyroid nodules with Thy-3a cytology have a slightly lower risk of malignancy than Thy-3f cases. However, the difference is not significant and does not appear to be reduced by FNA on a separate occasion showing benign cytology. Management decisions for patients with Thy-3a cytology should be taken carefully to avoid missing cancers.