Pietro Giorgio Calò

Hypocalcemia following thyroid surgery: incidence and risk factors. A longitudinal multicenter study comprising 2,631 patients

Postoperative hypocalcemia is the most frequent complication of total thyroidectomy. It may have a delayed onset, and therefore delays the discharge from the hospital, requiring calcium replacement therapy to alleviate clinical symptoms. During a 7-month period, 2,631 consecutive patients undergoing primary or completion thyroidectomy were prospectively followed up and underwent analysis regarding postoperative hypoparathyroidism. Data were prospectively collected by questionnaires from 39 Italian endocrine surgery units affiliated to the Italian Endocrine Surgery Units Association (Club delle Unità di EndocrinoChirurgia—UEC), where thyroid surgery is routinely performed. The incidence of hypoparathyroidism was 28.8xa0% (757 patients), including transient hypocalcemia (27.9xa0%—734 patients) and permanent hypocalcemia (0.9xa0%—23 patients). The rate of asymptomatic hypocalcemia was 70.80xa0%. The incidence of permanent hypocalcemia was higher in the symptomatic hypocalcemia group (7.5xa0%) than in asymptomatic one (1.5xa0%). Female patients experienced a transient postoperative hypocalcemia more frequently than male patients (29.7 and 21.2xa0%, respectively; pxa0<xa00.0001). The percentage developing hypocalcemia in patients in which parathyroid glands were intraoperatively identified and preserved was higher than in the patients in which the identification of parathyroid glands was not achieved (29.2 vs. 18.7xa0%, pxa0<xa00.01). This prospective study confirmed the main risk factors for postoperative hypocalcemia: thyroid cancer, nodal dissection, and female gender. It farther showed that identifying parathyroids has an important role to prevent permanent hypocalcemia though with a higher risk of transient hypocalcemia. A suitable informed consent should especially emphasize the importance of some primary factors in increasing the risk of hypocalcemia after thyroid surgery.

Impact of prophylactic central compartment neck dissection on locoregional recurrence of differentiated thyroid cancer in clinically node-negative patients: A retrospective study of a large clinical series

BACKGROUNDnIn clinically node-negative patients with differentiated thyroid cancer (DTC), indications for routine central lymph node dissection (RCLD) are the subject of intensive research, and surgeons are divided between the pros and cons of this surgery. To better define the role of neck dissection in the treatment of DTC, we analyzed retrospectively the results in three centers in Italy.nnnMETHODSnThe clinical records of 752 clinically node-negative patients with DTC who underwent operative treatment between January 1998 and December 2005 in three endocrine surgery referral units were evaluated retrospectively. The complications and medium- and long-term outcomes of total thyroidectomy (TT) alone (performed in 390 patients: group A) and TT combined with bilateral RCLD (362 patients: group B) were analyzed and compared.nnnRESULTSnThe incidence of permanent hypoparathyroidism and permanent unilateral vocal folds was 1% and 0.8% in group A and 3.6% and 1.7% in the group B, respectively. Bilateral temporary recurrent nerve palsy was observed in one of the 362 patients in group B. After a follow-up of 9.5 ± 3.5 years (mean ± SD), the locoregional recurrence rate with positive cervical lymph nodes was not substantially significantly different between the two groups.nnnCONCLUSIONnIn our series, TT combined with bilateral RCLD was associated with a greater rate of transient and permanent complications. Similar incidences of locoregional recurrence were reported in the two groups of patients. Considering the recent trend toward routine central lymphadenectomy, further studies are needed to evaluate the benefits of these different approaches.

Thyroid diseases cause mismatch between MIBI scan and neck ultrasound in the diagnosis of hyperfunctioning parathyroids: usefulness of FNA–PTH assay

DESIGNnTo evaluate the efficacy of the main tools in the diagnostic localization of hyperfunctioning parathyroids (HP) in primary hyperparathyroidism (pHPT) with concomitant thyroid diseases.nnnMETHODSnForty-three patients with pHPT associated with nodular goiter (NG, n=32) and/or autoimmune thyroid diseases (AITDs, n=11) for a total of 63 neck lesions were considered. Sixteen patients displaying HP (16 lesions), unequivocally localized by sestaMIBI scintigraphy (MIBI) and neck ultrasound (US) (group I), were compared with 27 patients (47 neck lesions) displaying equivocal parathyroid localization (group II). In all cases, neck US, MIBI scan, cytology, and parathyroid hormone assay in fine-needle aspiration washout fluid (FNA-PTH) were performed. All patients finally underwent surgery.nnnRESULTSnAccording to histological examination, high FNA-PTH values (>103u200apg/ml) correctly identified all HP in both groups of patients (100% of sensitivity and specificity). Both MIBI and US correctly identified all HP only in group I patients; in contrast, four patterns of mismatch between these techniques were observed in group II patients, leading to low diagnostic performances of neck US (71.4% sensitivity and 78.9% specificity) and of MIBI scan (35.7% sensitivity and 42.1% specificity). The latter was due to both false-negative (mainly in AITD) and false-positive (mainly in NG) scan images.nnnCONCLUSIONSnCoexistent thyroid diseases are responsible for mismatch between MIBI and US images resulting in equivocal HP localization. In these cases, FNA-PTH resulted in the most accurate tool to identify HP. However, although safe, it should be advised only to patients with uncertain HP localization.

Intraoperative recurrent laryngeal nerve monitoring in thyroid surgery: is it really useful?

AIMnThe aim of this study was to evaluate the ability of intraoperative recurrent laryngeal nerve monitoring to predict the postoperative functional outcome and the potential role of this technique in reducing the postoperative nerve palsy rate.nnnMATERIALS AND METHODSnBetween June 2007 and December 2011, 1693 consecutive patients who underwent thyroidectomy by a single surgical team were evaluated. We compared patients who have had a neuromonitoring and patients who have undergone surgery with the only visualization. Patients in which NIM was not utilized (Group A) were 942 against the others 751 (group B).nnnRESULTSnIn group A there were 28 recurrent laryngeal nerve injuries (2.97%) of which 21 were transients (2.22%) and 7 were permanents (0.74%). In group B there were 20 recurrent laryngeal nerve injuries (2.66%) of which 14 (1.86%) transients and 6 (0.8%) permanents. Differences between the two groups were not statistically significative.nnnCONCLUSIONSnThe technique of intraoperative neuromonitoring in thyroid surgery is safe and reliable in excluding postoperative recurrent laryngeal nerve palsy; it has high accuracy, specificity, sensitivity and negative predictive value. Neuromonitoring is useful to identify the recurrent laryngeal nerve and it can be a useful adjunctive technique for reassuring surgeons of the functional integrity of the nerve but it does not decrease the incidence of injuries compared with visualization alone. Its application can be particularly recommended for high-risk thyroidectomies.

Identification alone versus intraoperative neuromonitoring of the recurrent laryngeal nerve during thyroid surgery: experience of 2034 consecutive patients

BackgroundThe aim of this study was to evaluate the ability of intraoperative neuromonitoring in reducing the postoperative recurrent laryngeal nerve palsy rate by a comparison between patients submitted to thyroidectomy with intraoperative neuromonitoring and with routine identification alone.MethodsBetween June 2007 and December 2012, 2034 consecutive patients underwent thyroidectomy by a single surgical team. We compared patients who have had neuromonitoring and patients who have undergone surgery with nerve visualization alone. Patients in which neuromonitoring was not utilized (Group A) were 993, patients in which was utilized (group B) were 1041.ResultsIn group A 28 recurrent laryngeal nerve injuries were observed (2.82%), 21 (2.11%) transient and 7 (0.7%) permanent. In group B 23 recurrent laryngeal nerve injuries were observed (2.21%), in 17 cases (1.63%) transient and in 6 (0.58%) permanent. Differences were not statistically significative.ConclusionsVisual nerve identification remains the gold standard of recurrent laryngeal nerve management in thyroid surgery. Neuromonitoring helps to identify the nerve, in particular in difficult cases, but it did not decrease nerve injuries compared with visualization alone. Future studies are warranted to evaluate the benefit of intraoperative neuromonitoring in thyroidectomy, especially in conditions in which the recurrent nerve is at high risk of injury.

Total thyroidectomy without prophylactic central neck dissection in clinically node-negative papillary thyroid cancer: is it an adequate treatment?

BackgroundCervical lymph node metastases in papillary thyroid cancer are common. Although central neck dissection is indicated in clinically nodal-positive disease, it remains controversial in patients with no clinical evidence of nodal metastasis. The aim of this retrospective study was to determine the outcomes of clinically lymph node-negative patients with papillary thyroid cancer who underwent total thyroidectomy without a central neck dissection, in order to determine the rates of recurrence and reoperation in these patients compared with a group of patients submitted to total thyroidectomy with central neck dissection.MethodsTwo-hundred and eighty-five patients undergoing total thyroidectomy with preoperative diagnosis of papillary thyroid cancer, in the absence of suspicious nodes, were divided in two groups: those who underwent a thyroidectomy only (group A; nu2009=u2009220) and those who also received a central neck dissection (group B; nu2009=u200965).ResultsSix cases (2.1%) of nodal recurrence were observed: 4 in group A and 2 in group B. Tumor histology was associated with risk of recurrence: Hürthle cell-variant and tall cell-variant carcinomas were associated with a high risk of recurrence. Multifocality and extrathyroidal invasion also presented a higher risk, while smaller tumors were at lower risk.ConclusionsThe role of prophylactic central lymph node dissection in the management of papillary thyroid cancer remains controversial. Total thyroidectomy appears to be an adequate treatment for clinically node-negative papillary thyroid cancer. Prophylactic central neck dissection could be considered for the more appropriate selection of patients for radioiodine treatment and should be reserved for high-risk patients only. No clinical or pathological factors are able to predict with any certainty the presence of nodal metastasis. In our experience, tumor size, some histological types, multifocality, and locoregional infiltration are related to an increased risk of recurrence. The potential use of molecular markers will hopefully offer a further strategy to stratify the risk of recurrence in patients with papillary thyroid cancer and allow a more tailored approach to offer prophylactic central neck dissection to patients with the greatest benefit. Multi-institutional larger studies with longer follow-up periods are necessary to draw definitive conclusions.

Differentiated Thyroid Cancer: Indications and Extent of Central Neck Dissection—Our Experience

The aim of this retrospective study was to determine the rate of metastases in the central neck compartment and examine the morbidity and rate of recurrence in patients with differentiated thyroid cancer treated with or without a central neck dissection. Two hundred and fifteen patients undergoing total thyroidectomy with preoperative diagnosis of differentiated thyroid cancer, in the absence of suspicious nodes, were divided in two groups: those who underwent a thyroidectomy only (group A; n = 169) and those who also received a central neck dissection (group B; n = 46). Five cases (2.32%) of nodal recurrence were observed: 3 in group A and 2 in group B. Tumor histology was associated with a risk of recurrence: Hürthle cell-variant and tall cell-variant carcinomas were associated with a high risk of recurrence. Multifocality and extrathyroidal invasion also presented a higher risk, while smaller tumors were at lower risk. The results of this study suggest that prophylactic central neck dissection should be reserved for high-risk patients only. A wider use of immunocytochemical and genetic markers to improve preoperative diagnosis and the development of methods for the intraoperative identification of metastatic lymph nodes will be useful in the future for the improved selection of patients for central neck dissections.

Intraoperative neuromonitoring in thyroid surgery: a point prevalence survey on utilization, management, and documentation in Italy

The frequency of neuromonitoring during thyroid surgery is underreported in Italy. The present survey depicts and describes the patterns of use, management, documentation for IONM devices of IONM during thyroid surgery by surgeons in Italy. A point prevalence survey was undertaken. Source data were mixed from Italian surgeons attending the 2014 International Neuromonitoring Study Group (INMSG) meeting, four IONM manufacturers available in Italy and surgical units were identified from Company sales data. Qualitative and quantitative data were used to analyze. Questions probed IONM prevalence, surgeon background, hospital geographic practice locations, type of hospital, rationale for IONM use, sources of initial capital investment for IONM acquisition, type of equipment, use of continuous IONM, monitoring management, use of distinctive standards, and IONM documentation. IONM is currently delivered through 48 units in Italy. In 2013, the distribution of IONM by specialties included: general (50xa0%), ENT (46xa0%), and thoracic surgery (4xa0%). Overall, 12.853 IONM procedures were performed in the period from 2006 to 2013: 253 were performed in 2007 and about 5,100 in 2013. Distribution according to the type of hospital is: public 48xa0%, academic setting 37xa0%, and private maintenance 15xa0%. The use category of high volume thyroid hospitals represented 33xa0%. Initial capital investment for the acquisition of the monitoring equipment was 67xa0% public and 33xa0% with charitable/private funding. Audio plus graphic and EMG electrodes surface endotracheal tube-based monitoring systems accounted for the majority. Continuous IONM was introduced in 5 Academic Centers. Overall motivations expressed are legal (30xa0%), RLN confirmation (20xa0%), RLN identification (20xa0%), prognosis (10xa0%), helpful in difficult cases (10xa0%), decrease surgical time (5xa0%), and educational (5xa0%). The survey revealed that participants had few experience with the standardized approach of IONM technique (28xa0%). General IONM information to patients and/or subsequent specific IONM informed consent was initiated in 8xa0% of centers. EMG determinations were included in medical chart in 20xa0%. There were no significant associations found between all parameters considered. The present study describes an increased utilization of IONM in Italy. We highlighted areas for improvement in the management and documentation of IONM.

Renal cell carcinoma metastasis to thyroid tumor: a case report and review of the literature

IntroductionMetastatic neoplasms to the thyroid gland are rare in clinical practice. Clear cell renal carcinoma is the most frequent site of origin of thyroid metastases and represents 12 to 34% of all secondary thyroid tumors. Tumor-to-tumor metastases, in which a thyroid neoplasm is the recipient of a metastasis, are exceedingly rare. We report a case of clear cell renal carcinoma metastatic to a follicular adenoma. This is the tenth case of renal cell carcinoma metastasis to thyroid tumor reported in the literature.Case presentationA 62-year-old Caucasian woman with a history of clear cell renal carcinoma was admitted to our institution for multinodular goiter. A histological examination after total thyroidectomy revealed clear cell renal carcinoma metastasis to a thyroid follicular adenoma.ConclusionsPreoperative diagnosis of secondary thyroid neoplasm is difficult to achieve. The diagnosis of metastatic disease should be taken into account if patients have a history of clear cell renal carcinoma or if there is a multifocal growth pattern and clear cell appearance of the cytoplasm.

Intraoperative parathyroid hormone assay during focused parathyroidectomy: the importance of 20 minutes measurement

BackgroundParathyroid hormone (PTH) monitoring during the surgical procedure can confirm the removal of all hyperfunctioning parathyroid tissue, as the half-life of PTH is approximately 5 min. The commonly applied Irvin criterion is reported to correctly predict post-operative calcium levels in 96-98% of patients. However, the PTH baseline reference concentration is markedly influenced by surgical manipulations during preparation of the affected glands, interindividual variability of the PTH half-life and modifications in the physiological state of the patient during surgery. The aim of this study was to evaluate the possible impact of the measurement of intraoperative PTH 20 minutes after surgery.MethodsBetween 2003 and 2012, 188 patients underwent a focused parathyroidectomy associated to rapid intraoperative PTH assay monitoring. Blood samples were collected: 1) at pre-incision time, 2) at 10 min after gland excision and 3) at 20 min after excision, if a sufficient reduction of PTH value was not observed. On the bases of the Irvin criterion, an intra-operative PTH drop>50% from the highest either pre-incision or pre-excision level after parathyroid excision was considered a surgical success.ResultsA >50% decrease of PTH after gland excision compared to the highest pre-excision value occurred in 156/188 patients (83%) within 10 min and in further 12/188 after 20 minutes (6.4%). In the remaining 20 patients (10.6%) values of PTH remained substantially unchanged or decreased less than 50% and for this reason bilateral neck exploration was performed. An additional pathologic parathyroid was removed in 9 cases, a third in one. In the other 10 cases further neck exploration by a standard cervical approach was negative and in four of these persistent postoperative hypercalcemia was demonstrated. The overall operative success was 97.3%. Intraoperative PTH monitoring was accurate in predicting operative success or failure in 96.3% of patients.ConclusionsThe 20 minutes PTH measurement appears very useful, avoiding unnecessary bilateral exploration and the related risk of complications with only a slight increase of the duration of surgery and of the costs. PTH values decreasing appeared to be influenced by surgical manipulations during minimally invasive parathyroidectomy.