Thyroidectomy in high body mass index patients: A single center experience

Risk Factors for Recurrent Laryngeal Nerve Palsy in Thyroid Surgery: A Single Center Experience of 1147 Procedures with Intermittent Intraoperative Neuromonitoring

BACKGROUND

Recurrent laryngeal nerve (RLN) palsy is one possible complication during thyroid surgery. Intraoperative neuromonitoring and visualization of the nerve during surgery are standard procedures to reduce the risk of RLN palsy. This study aims to investigate new factors for RLN palsy and review ones that are already known in the literature to help surgeons prepare for the procedure.

METHODS

A retrospective study design was used to analyze the data of 1147 patients from a certified center for thyroid surgery. All patients underwent either total thyroidectomy or hemithyroidectomy from 2016 to 2020. The acquired information was analyzed descriptively. A logistic regression was used to analyze the independent variables of interest with the binary variable RLN palsy (yes/no). For the second aim of this study, a multiple logistic regression was applied to analyze the combined significant known and new risk factors.

RESULTS

Surgery indication for Graves' disease (OR 14.34, p < 0.001), thyroid cancer (OR 2.39, p = 0.012), and recurrent goiter (OR 5.57, p < 0.001) increased the risk for RLN palsy significantly compared to nodular goiter in hemithyroidectomy. The duration of surgery correlated positively with a higher risk for RLN palsy (OR 1.009, p = 0.005). For gender, BMI, resection weight, left or right nerve at risk, and surgeon experience, no significant differences were found.

CONCLUSION

Operations for Graves' disease, thyroid cancer, and recurrent goiter have the highest risk for RLN palsy and surgeons should be alerted. The longer the operation, the higher the risk of RLN palsy. The correlation between surgery method (hemithyroidectomy vs. thyroidectomy) and RLN palsy should be carefully considered due to possible bias.

The impact of body mass index on operative time in transoral endoscopic thyroidectomy vestibular approach for thyroid cancer

BACKGROUND

The impact of body mass index (BMI) on operative time in transoral endoscopic thyroidectomy vestibular approach (TOETVA) for thyroid cancer is still a subject of debate. This study assessed the impact of BMI on operative time and postoperative complications in patients undergoing TOETVA.

METHODS

The study has been conducted to compare the outcomes of TOETVA in patients with high BMI (≥25) and those with normal BMI (<25). Postoperative outcomes, including operative time, blood lost, recurrent laryngeal nerve (RLN) palsy, hypocalcemia and postoperative pain score, were evaluated.

RESULTS

A total of 62 patients who underwent TOETVA were included in the study. The high BMI group consisted of 39 patients, while the normal BMI group included 23 patients. No significant differences were observed between the two groups regarding operative time, blood loss, postoperative pain score, and postoperative complications such as recurrent laryngeal nerve (RLN) palsy and hypocalcemia.

CONCLUSIONS

BMI was not significantly associated with operative time and postoperative complications in patients undergoing TOETVA, indicating its safety and feasibility for elevated BMI patients.

Thyroidectomy Outcomes in Obese Patients

INTRODUCTION

Obese patients often have higher complication rates after elective general surgeries; however, few studies have examined the outcomes after thyroidectomy. This study examines whether increased body mass index (BMI) is associated with poor postoperative outcomes after thyroid surgery.

METHODS

A retrospective review of patients who underwent thyroidectomy from 2015 to 2018 was performed. Demographics, comorbidities, pathology, and extent of resection (total versus hemithyroidectomy) were examined. Patients were classified into BMI groups according to the WHO definitions, and the incidence of surgical outcomes was determined in each group. Surgical outcomes of interest included readmission rates (RRs), length of stay, average operating room time, return to the operating room, hypocalcemia, postop infections, hematomas, and recurrent laryngeal nerve injury. Between-subjects statistics including independent samples t-test, ANOVA, and chi-square analyses were performed.

RESULTS

There were n = 465 patients included with a mean BMI 32.35 (standard deviation = 8.55) and median BMI 30.78 (Q1 = 26.26, Q3 = 36.73). There were no differences between BMI groups in age, gender, smoking, heart disease. There was a positive association between increased BMI and postoperative infection (P < 0.001), pneumonia (P = 0.018), and surgical site infection (P = 0.04), which were highest for BMI > 40. Increased BMI was associated with a higher 30-d RR (P = 0.008), particularly for BMI >40 versus BMI <40 (6.2% versus 1.05%; P = 0.003). There were no significant differences between surgical outcomes for patients with increased BMI who underwent total thyroidectomy or hemithyroidectomy.

CONCLUSIONS

Excellent postoperative outcomes were observed in all BMI categories. Higher postoperative infection and 30-d RRs were observed in the morbidly obese. Contrary to previous studies, operating room times were similar regardless of BMI.

Association between body mass index and outcomes after autologous breast reconstruction: a nationwide inpatient database study in Japan

BACKGROUND

Although autologous reconstruction following breast cancer surgery is common, little is known about the association between preoperative body mass index (BMI) and short-term surgical outcomes. This study investigated the association between BMI and short-term surgical outcomes in autologous breast reconstruction using a nationwide Japanese inpatient database.

METHODS

We retrospectively identified female patients with breast cancer who underwent breast reconstruction using a pedicled flap or free flap from July 2010 to March 2020. Multivariable regression analyses and restricted cubic spline analyses were conducted to investigate the associations between BMI and short-term outcomes with adjustment for demographic and clinical backgrounds.

RESULTS

Of the 13,734 eligible patients, 7.1% and 22.2% had a BMI of < 18.5 kg/m2 and > 25 kg/m2, respectively. Compared with BMI of 18.5-21.9 kg/m2, overweight (25.0-29.9 kg/m2) and obese (≥ 30.0 kg/m2) were significantly associated with higher occurrences of takebacks (odds ratio, 1.74 [95% confidence interval, 1.28-2.38] and 2.89 [1.88-4.43], respectively) and overall complications (1.37 [1.20-1.57] and 1.77 [1.42-2.20], respectively). In the restricted cubic spline analyses, BMI showed J-shaped associations with takebacks, overall complications, local complications, and wound dehiscence. BMI also demonstrated linear associations with postoperative surgical site infection, duration of anesthesia, duration of drainage, length of stay, and hospitalization costs.

CONCLUSION

In autologous breast reconstruction following breast cancer surgery, a higher BMI was associated with takebacks, morbidity, a longer hospital stay, and higher total costs, whereas a lower BMI was associated with fewer surgical site infections, a shorter hospital stay, and lower total costs.

The impact of obesity on thyroidectomy outcomes: a case-matched study

Obesity is a well-known public health concern in Western World. Accordingly, an elevated number of obese patients undergo thyroidectomy every year. We aim to assess the impact of obesity on intraoperative and postoperative outcomes of patients who undergo thyroidectomy. 1228 patients underwent thyroidectomy at our department between January 2021 and September 2021. We divided patients into two groups according to body mass index (BMI): non-obese (BMI < 30 kg/m2) and obese (BMI ≥ 30 kg/m2). A propensity score approach was performed to create 1:1 matched pairs (matching according to age, gender, diagnosis, nodule size and type of operation). After matching, the final population included 522 patients, equally divided between each group: non-obese group (Group A; n = 261) and obese group (Group B; n = 261). The primary endpoint of the study was the overall rate of postoperative complications; secondary endpoints of the study were operative time, use of energy device and length of hospital stay. The duration of hospital stay resulted longer in Group B (p = 0.002). No statistically significant differences were documented in terms of operative time (p = 0.206), use of energy devices (p = 0.855) and surgical complications (p = 0.429). Moreover, no statistically significant differences were documented considering each specific complication: transient and permanent hypocalcemia (p = 0.336; p = 0.813, respectively), transient and permanent recurrent laryngeal nerve palsy (p = 0.483; p = 0.523, respectively), hematoma (p = 0.779), bleeding (p = 0.178), wound infection (p = 0.313) and cheloid formation (p = 0.412). Thyroidectomy can safely be performed in obese patients. Outcomes resulted comparable; nonetheless, obesity correlates to longer hospital stay.

Impact of Obesity on Risk of Hypocalcemia After Total Thyroidectomy: Targeted National Surgical Quality Improvement Program Analysis of 16,277 Patients

INTRODUCTION

Hypocalcemia following total thyroidectomy (TT) is common due to postoperative parathyroid dysfunction and vitamin D deficiency. Given the association between obesity and vitamin D deficiency, we sought to correlate body mass index (BMI) with hypocalcemia after TT.

METHODS

Patients undergoing TT between 2016 and 2020 were identified from the American College of Surgeons National Surgical Quality Improvement Program thyroidectomy-targeted database. Univariable and multivariable regressions, stratified by BMI category (normal, overweight, obese), identified factors associated with hypocalcemia prior to discharge, within 30 d, and severe hypocalcemic events (emergent evaluation, intravenous calcium supplementation, or readmission).

RESULTS

Sixteen thousand two hundred seventy seven TT were performed with available BMI data. Three thousand five hundred thirty one (21.7%) patients had normal BMI, 4823 (29.6%) were overweight, and 7772 (47.7%) were obese. Patients with BMI ≥ 25 had decreased risk of hypocalcemia before discharge (9.8% versus 13%, odds ratio [OR] 0.73, P < 0.001), 30 d (8.1% versus 10.4%, OR 0.76, P < 0.001), and severe hypocalcemic events (5.5% versus 6.4%, OR 0.84, P = 0.029) compared to normal BMI patients. On multivariable analysis for normal BMI patients, age < 45 y was a risk factor for hypocalcemia before discharge, 30 d, and severe hypocalcemic events (P < 0.05 for all). Additional risk factors in this group for 30-d hypocalcemia included parathyroid autotransplant and central neck dissection (P < 0.05) and recurrent laryngeal nerve injury for severe hypocalcemic events (P = 0.01).

CONCLUSIONS

Younger patients with BMI < 25 are at an increased risk for hypocalcemia and severe hypocalcemic events after TT. These patients may benefit from preoperative counseling and increased calcium/vitamin D supplementation to reduce prolonged hospitalization and mitigate morbidity.

Effect of body habitus on surgical outcomes following bilateral axillo-breast approach robotic thyroidectomy: a retrospective cohort study

INTRODUCTION

BMI has been shown to predict perioperative outcomes in patients undergoing surgery. Most studies assessing the role of body habitus in thyroid surgery have focused on open surgery, with few studies assessing patients undergoing robotic surgery. The present study evaluated the effects of BMI on surgical outcomes in patients undergoing bilateral axillo-breast approach (BABA) robotic thyroidectomy.

MATERIALS AND METHODS

This study included patients who underwent BABA robotic thyroidectomy between January 2013 and September 2021 at Seoul National University Bundang Hospital. Patients were categorized into six groups based on the WHO classification of overweight and obesity. Clinicopathological characteristics, postoperative complications, and surgical outcomes were evaluated.

RESULTS

A total of 1921 patients were included. Comparisons of the six BMI groups showed no statistically significant differences in postoperative stay, resection margin involvement, postoperative complications, and recurrence. Subgroup analysis showed that hypocalcemia rates differed among BMI groups in patients who underwent lobectomy, with underweight and class II obese patients being at the highest risk ( P =0.006). However, the actual number of complications was relatively small and similar among the groups. In patients who underwent total thyroidectomy and isthmectomy, BMI was not correlated with postoperative complications, including hypocalcemia, recurrent laryngeal nerve palsy, postoperative bleeding, and chyle leakage.

CONCLUSION

Body habitus was not significantly associated with operative time and postoperative complications in patients undergoing BABA robotic thyroidectomy, indicating that this approach is safe and feasible in obese patients.

Analysis of preoperative influential factors and construction of a predictive nomogram of difficult thyroidectomy

OBJECTIVE

To explore the preoperative influential factors of difficult thyroidectomy and establish a preoperative nomogram for predicting the difficulty of thyroidectomy.

METHODS

A total of 753 patients who underwent total thyroidectomy with central lymph node dissection between January 2018 and December 2021 were retrospectively enrolled in this study and randomly divided into training and validation groups at a ratio of 8:2. In both subgroups, the patients were divided into difficult thyroidectomy and nondifficult thyroidectomy groups based on the operation time. Patient age, sex, body mass index (BMI), thyroid ultrasound, thyroid function, preoperative fine needle aspiration (FNA), postoperative complications and other data were collected. Logistic regression analysis was performed to identify the predictors of difficult thyroidectomy, and a nomogram predicting surgical difficulty was created.

RESULTS

Multivariate logistic regression analysis demonstrated that male sex (OR = 2.138, 95% CI 1.055-4.336, p = 0.035), age (OR = 0.954, 95% CI 0.932-0.976, p < 0.001), BMI (OR = 1.233, 95% CI 1.106-1.375, p < 0.001), thyroid volume (OR = 1.177, 95% CI 1.104-1.254, p < 0.001) and TPO-Ab (OR = 1.001, 95% CI 1.001-1.002, p = 0.001) were independent risk factors for difficult thyroidectomy. The nomogram model incorporating the above predictors performed well in both the training and validation sets. A higher postoperative complication rate was found in the difficult thyroidectomy group than in the nondifficult thyroidectomy group.

CONCLUSION

This study identified independent risk factors for difficult thyroidectomy and created a predictive nomogram for difficult thyroidectomy. This nomogram may help to objectively and individually predict surgical difficulty before surgery and provide optimal treatment.

Transient Hypocalcemia After Total Thyroidectomy: The Obesity Paradox at Work?

INTRODUCTION

With increasing rates of obesity worldwide, a correlation between high body mass index (BMI) and postoperative morbidity after thyroid surgery remains unclear. Postoperative transient hypocalcemia is common after total thyroidectomy due to interruption of parathyroid function. This study examines the relationship between BMI and hypocalcemia after total thyroidectomy.

MATERIALS AND METHODS

A retrospective review of prospectively collected data for 1135 patients who underwent total thyroidectomy for cancer, multinodular goiter (MNG), or Graves' disease between June 2009 and November 2020 at a single institution was performed. BMI groups followed the World Health Organization classification. Hypocalcemia was defined as serum calcium ≤8 mg/dL. Calcium levels measured on postoperative day 0 and the following morning were compared between the BMI groups.

RESULTS

Of 1135 total thyroidectomy patients, 85% were women. The mean age and standard deviation of patients was 49 (± 13) y, with most of Hispanic origin (64%). Overall, 41.5% of patients had cancer, 45% nontoxic MNG, 5.8% toxic MNG, and 12% Graves' disease. Stratified by BMI, 27% of patients were normal, 34% overweight, and 39% obese. Overall, overweight and obese patients experienced less transient hypocalcemia at both time points compared to normal patients postoperatively (P = 0.01 and P = 0.009). Furthermore, overweight and obese patients with Graves' disease experienced less transient hypocalcemia at both time points (P = 0.04 and P = 0.05). There was no statistical difference in other groups.

CONCLUSIONS

A protective role of higher BMI or "obesity paradox" for postoperative hypocalcemia may exist in those obese patients after total thyroidectomy.

Impact of body mass index on short-term outcomes after differentiated thyroid cancer surgery: a nationwide inpatient database study in Japan

INTRODUCTION

Recent studies have shown worse post-operative outcomes following several surgeries in underweight or obese patients. However, the association between body mass index (BMI) and short-term outcomes following thyroid cancer surgery remains unclear because of the small number of patients, deficits in background data known as risk factors (e.g. cancer stage, operative procedure, intraoperative device use and hospital volume) and categorisation of BMI.

METHODS

We identified patients who underwent thyroidectomy for differentiated thyroid cancer from July 2010 to March 2017 using a Japanese nationwide inpatient database. We used restricted cubic spline (RCS) analyses to investigate potential non-linear associations between BMI (without categorisation) and outcomes: post-operative complications (local and general), duration of anaesthesia, post-operative length of hospital stay and hospitalisation costs. The analyses were adjusted for demographic and clinical backgrounds including the above-stated factors. We also performed multivariable regression analyses for the outcomes with categorisation of BMI.

RESULTS

Among 59,671 eligible patients, the median BMI was 22.9 kg/m2 (interquartile range (IQR), 20.7-25.6 kg/m2). In total, 3860 patients (6.5%) had local complications and 787 patients (1.3%) had general complications. Although there were no significant associations with local complications, such as bleeding, recurrent laryngeal nerve paralysis and surgical site infection, the occurrence of general complications was significantly associated with higher BMI. BMI showed a linear association with the duration of anaesthesia and U-shaped associations with post-operative length of stay and hospitalisation costs. The lowest points of the U-shaped curves occurred at a BMI of approximately 24 kg/m2. The multivariate regression analyses showed consistent results with the RCS analyses.

DISCUSSION/CONCLUSION

Whereas RCS analyses revealed no significant associations between BMI and post-operative local complications, obesity was significantly associated with the occurrence of general complications. The linear association between BMI and duration of anaesthesia corresponds to previous studies. Although post-operative length of stay and total hospitalisation costs demonstrated U-shaped associations, the slight differences would not be clinically important. Even if surgeons must pay attention to general complications in obese patients undergoing thyroid cancer surgery as well as other surgeries, underweight and overweight patients can undergo thyroidectomy as safely as patients with normal BMI.

Varied Recurrent Laryngeal Nerve Course Is Associated with Increased Risk of Nerve Dysfunction During Thyroidectomy: Results of the Surgical Anatomy of the Recurrent Laryngeal Nerve in Thyroid Surgery Study, an International Multicenter Prospective Anatomic and Electrophysiologic Study of 1000 Monitored Nerves at Risk from the International Neural Monitoring Study Group

Background: The recurrent laryngeal nerve (RLN) can be injured during thyroid surgery, which can negatively affect a patient's quality of life. The impact of intraoperative anatomic variations of the RLN on nerve injury remains unclear. Objectives of this study were to (1) better understand the detailed surgical anatomic variability of the RLN with a worldwide perspective; (2) establish potential correlates between intraoperative RLN anatomy and electrophysiologic responses; and (3) use the information to minimize complications and assure accurate and safe intraoperative neuromonitoring (IONM). Methods: A large international registry database study with prospectively collected data was conducted through the International Neural Monitoring Study Group (INMSG) evaluating 1000 RLNs at risk during thyroid surgery using a specially designed online data repository. Monitored thyroid surgeries following standardized IONM guidelines were included. Cases with bulky lymphadenopathy, IONM failure, and failed RLN visualization were excluded. Systematic evaluation of the surgical anatomy of the RLN was performed using the International RLN Anatomic Classification System. In cases of loss of signal (LOS), the mechanism of neural injury was identified, and functional evaluation of the vocal cord was performed. Results: A total of 1000 nerves at risk (NARs) were evaluated from 574 patients undergoing thyroid surgery at 17 centers from 12 countries and 5 continents. A higher than expected percentage of nerves followed an abnormal intraoperative trajectory (23%). LOS was identified in 3.5% of NARs, with 34% of LOS nerves following an abnormal intraoperative trajectory. LOS was more likely in cases of abnormal nerve trajectory, fixed splayed or entrapped nerves (including at the ligament of Berry), extensive neural dissection, cases of cancer invasion, or when lateral lymph node dissection was needed. Traction injury was found to be the most common form of RLN injury and to be less recoverable than previous reports. Conclusions: Multicenter international studies enrolling diverse patient populations can help reshape our understanding of surgical anatomy during thyroid surgery. There can be significant variability in the anatomic and intraoperative characteristics of the RLN, which can impact the risk of neural injury.

Is there a relationship between different types of prior bariatric surgery and post-thyroidectomy hypocalcemia?

Background

Hypocalcemia is a common complication after total thyroidectomy (TT). A history of bariatric surgery has been identified as a risk factor for this complication. This study aimed to assess the risk of hypocalcemia post TT in patients with a history of obesity procedures: laparoscopic sleeve gastrectomy (LSG), Roux-en-Y gastric bypass (RYGB), and laparoscopic gastric banding (LAGB).

Methods

We compared the risk of hypocalcemia post TT (serum calcium levels <8 mg/dL) between patients with restrictive (LSG and LAGB), malabsorptive (RYGB), and patients without a history of obesity surgery. Hypoparathyroidism was considered permanent if the plasma parathyroid hormone (PTH) levels at 6 months were less than 15 pg/mL (normal range: 15-65 pg/mL) and the patient still required oral calcium (calcium carbonate) and vitamin D supplementation, in addition to the supplements that were taken routinely before thyroidectomy.

Results

From the 13,242 patients who underwent TT from 2006 to 2018, 90 patients (0.7%) had a history of bariatric surgery: 35 LAGB, 29 LSG, and 26 RYGB. The risk of hypocalcemia was higher in RYGB patients (50%, n=13) than in LAGB (17.1%, n=6) or LSG patients (20.6%, n=6) (P=0.003). Furthermore, hypocalcemia risk was similar between patients with a history of restrictive procedures (18.8%, 12/64) and patients with no history of bariatric surgery (17.2%, 2,268/13,152) (P=0.4). Permanent hypoparathyroidism was observed in one and 6 patients from the LAGB and RYGB groups, respectively; however, it was not observed in any patient from the LSG group.

Conclusions

RYGB is a risk factor for hypocalcemia post TT, while restrictive bariatric procedures are not.

Can thyroidectomy be considered safe in obese patients? A retrospective cohort study

BACKGROUND

Obesity is a growing public health concern in most western countries. More and more patients with high body mass index (BMI) are undergoing surgical procedures of all kinds and, in this context, obese patients are undergoing thyroid surgery more than ever before. The aim of the present study was to evaluate whether thyroidectomy can be considered safe in obese patients.

METHODS

Patients undergoing thyroidectomy in our Unit between January 2014 and December 2018 were retrospectively analysed. Patients were divided into two groups: those with BMI < 30 kg/m² were included in Group A, while those with BMI ≥ 30 kg/m² in Group B. Univariate analysis was performed to compare these two groups. Moreover, multivariate analyses were performed to evaluate whether the BMI value (considered in this case as a continuous variable) had a significant role in the development of each individual postoperative complication.

RESULTS

A total of 813 patients were included in this study: 31 (3.81%) were underweight, 361 (44.40%) normal-weight, 286 (35.18%) overweight, 94 (11.57%) obese and 41 (5.04%) morbidly obese. Six hundred and seventy-eight patients were included in Group A and 135 in Group B. At univariate analysis, the comparison between the two groups, in terms of operative time and thyroid weight resulted in statistically significant results (P = 0.001, P = 0.008; respectively). These features were significantly higher in Group B than in Group A. About postoperative stay and complications, no statistically significant difference was found between the two groups. At multivariate analyses, only the development of cervical haematoma was statistically significantly correlated to the BMI value. Patients with high BMI had a lower risk of cervical haematoma (P = 0.045, OR 0.797, 95% CI 0.638-0.995).

CONCLUSIONS

This study showed that obesity, in the field of thyroid surgery, is not associated with any increase of postoperative complications. Thus, it is possible to conclude that thyroidectomy can be performed safely in obese patients. Our result about operative times had no clinical significance.

The relationship between thyroidectomy complications and body mass index

INTRODUCTION

Obesity is a growing public health problem associated with many comorbid diseases. The aim of this study was to evaluate the relationship between body mass index and complications of thyroidectomy.

METHODS

Patients who underwent total thyroidectomy between January 2015 and December 2018 were enrolled. Patients were divided into two groups, i.e., BMI <25 (group A) and BMI≥ 25 (group B). Demographics, operative time, and complications were retrospectively reviewed.

RESULTS

The study included 145 patients (66 in Group A and 79 in Group B). There was no significant difference between the two groups in terms of age (p=0.330) and gender (p=0.055). No surgical site infection and bleeding complications were observed in any patients. The mean operative time was 148.4 minutes (90-235) in Group A and 153.4 minutes (85-285) in Group B (p=0.399). Transient hypocalcemia was observed in 25 (37.9%) patients in group A, and 23 (29.1%) patients in Group B (p = 0.291). Permanent hypocalcemia was not observed in any patient in group A, and in 2 patients in Group B (2.5%) (p = 0.501). Transient recurrent nerve palsy was observed in 1 (1.5%) patient in Group A and in 3 (3.8%) patients in Group B (p=0.626). None of the patients had permanent recurrent nerve palsy. Parathyroid autotransplantation was performed on 1 patient (1.5%) in group A and on 7 (8.9%) patients in Group B (p=0.055).

CONCLUSION

We think there is no relationship between a high BMI and thyroidectomy complications, and surgery can also be performed safely in this patient group.

Voice change after thyroidectomy without vocal cord paralysis: Analysis of 2,297 thyroidectomy patients

BACKGROUND

Some patients experience long-term voice change after thyroidectomy. One of the most common symptoms of voice change is pitch lowering, which is closely related to unfavorable voice quality. Here we observed voice outcomes for 6 months of follow-up after thyroidectomy to identify factors closely related to low-pitched voice.

METHODS

We retrospectively reviewed the records of 2,297 patients who underwent thyroidectomy between January 2014 and December 2017. All the patients had their vocal status examined using videostroboscopy, acoustic voice analyses, aerodynamic study, and Thyroidectomy-Related Voice Questionnaire scores. We stratified patients into 2 groups (low-pitched voice versus favorable voice) according to pitch lowering (reduction in speaking fundamental frequency ≥12 Hz 1 month after thyroidectomy compared to the preoperative value). We compared preoperative data with postoperative data collected 1, 3, and 6 months after thyroidectomy to identify factors contributing to low-pitched voice.

RESULTS

Univariate logistic regression analyses showed that factors related to low-pitched voice were female sex, older age, low body weight, short stature, and a high positive lymph node ratio. Multivariate analyses showed that female sex and older age were significantly associated with a negative prognosis for low-pitched voice 1 month after thyroidectomy (odds ratios 0.41 and 1.04, respectively; P < .001). Receiver operating characteristic curves for predicting sustained low-pitched voice during 6 months showed that speaking fundamental frequency ≥12.48 Hz 1 month after thyroidectomy was the optimal cutoff value, with 87.9% sensitivity and 95.8% specificity (P < .001).

CONCLUSION

Female sex and older age are strongly associated with increased risk for low-pitched voice after thyroidectomy. Speaking fundamental frequency ≥12.48 Hz 1 month after thyroidectomy can be used to predict sustained low-pitched voice after thyroidectomy.

Investigation of recurrent laryngeal palsy rates for potential associations during thyroidectomy

BACKGROUND

There are many clinical associations and potential mechanisms of injury resulting in recurrent laryngeal nerve palsy (RLNP) after thyroidectomy. One possible cause of RLNP is focal intralaryngeal compression of the recurrent laryngeal nerve (RLN), which may be associated with the tracheal tube (TT). Therefore, we examined current RLNP rates to investigate potential associations, including intralaryngeal, airway, anaesthetic and anthropometric factors.

METHODS

We analysed 1003 patients undergoing thyroid surgery at The Alfred from 2010 to 2017, who had anatomically intact RLNs at the conclusion of thyroidectomy. All included patients underwent pre- and post-operative flexible nasendoscopy. The primary outcome was RLNP rate. We analysed potential associated factors including age, sex, operative time, surgical indication, pathology, American Society of Anaesthesiologists Physical Status, Mallampati scores, body mass index, intubation grade, TT size and specimen weight. The independent risk factors were identified by logistic regression analysis.

RESULTS

Overall, RLNP occurred in 83 patients (8.3%) of which one was permanent (0.1%). On univariate analysis, RLNP was associated with male sex (P = 0.02), and duration of surgery (P = 0.002). On multivariate analysis, both male sex (P = 0.047) and duration of surgery (P = 0.04) remained significant. Further, factors postulated to cause intralaryngeal compression of the RLN, including TT size, body mass index, intubation grade and Mallampati score, were not significantly associated with RLNP.

CONCLUSION

Our study showed a RLNP rate of 8.3%, and associations with longer operative duration, and male sex. Potential intralaryngeal factors were not identified.

Thyroid surgery in obese patients: A review of the literature

The incidence of obesity in the general population has tripled in the past four decades. The number of bariatric surgeries performed annually has quadrupled in the past ten years due to this obesity epidemic. Concomitantly, the number of patients who are obese or who have undergone bariatric surgery and have become candidates for thyroid surgery has also increased considerably. Among patients undergoing thyroidectomy in the French population, the proportion of obese patients currently represents 10 to 20%. In addition, the frequency of benign and malignant thyroid pathologies seems to be increased by obesity, with a Hazard Ratio of around 1.8 for thyroid cancers in obese women. While obesity does not seem to influence the specific post-operative morbidity of thyroidectomy, a history of malabsorptive bariatric surgery should encourage the greatest caution in patients who need to undergo thyroid surgery since it is associated with a significant risk of severe hypocalcemia (>60% in some studies) requiring intravenous calcium supplementation in about 20% of cases. In the latter situation, peri-operative vitamin D-calcium supplementation is essential. In addition, the replacement dose of Levothyroxine (T4) intended for replacement must also be adapted in obese patients, calculated not from the actual weight but from the ideal weight. The objective of this review is to discuss the influence of obesity on the evolution of nodular and neoplastic thyroid pathologies, on the morbidity of thyroid surgery as well as on post-operative drug treatments. The impact of bariatric surgery on these different aspects is also discussed.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

Risk factors and effects of hypocalcemia prior to discharge following thyroidectomy

PURPOSE

To find patient and surgical characteristics associated with hypocalcemia prior to discharge (HPTD) in thyroidectomy patients.

MATERIALS AND METHODS

In a retrospective analysis of the 2016-2017 National Surgical Quality Improvement Program, eligible total thyroidectomy patients were stratified into cohorts based on development of HPTD. We identified demographic and surgical risk factors for the development of hypocalcemia via binary logistic regression and identified the negative sequelae of HPTD utilizing univariate and multivariate methods.

RESULTS

We identified a total of 6519 patients who underwent total thyroidectomy, of which 450 (6.9%) had HPTD. Predictors associated with an increased incidence of HPTD included female sex (OR: 1.737 [95% CI: 1.319-2.288]; p < .001), increased operative time (OR: 1.003 [1.002-1.004]; p < .001), and central neck dissection (OR: 1.484 [1.190-1.850]; p < .001). However, factors that decreased incidence of HPTD included increased age, obesity (OR: 0.648 [0.501-0.837]; p = .001), and the use of vessel sealant devices (VSD) (OR: 0.650 [0.527-0.803]; p < .001). Multivariate analysis further revealed that HPTD independently led to an increased hospitalization length after surgery (B: 0.708 [0.607-0.809]; p < .001) and an increased 30-day readmission rate (OR: 2.429 [1.594-3.704]; p < .001).

CONCLUSION

Obesity, increased age, and intra-operative VSD use were significantly associated with decreased rates of HPTD after total thyroidectomy. Female sex, longer operations, and central neck dissections were associated with HPTD. Delineating risk factors and protective factors for HPTD in total thyroidectomy patients is important as patients with HPTD were found to be at a significantly higher risk for longer post-operative stays, increased odds of 30-day readmission, and increased hypocalcemia-related event.

Postthyroidectomy obesity in a Korean population: does the extent of surgery matter?

Purpose

The purpose of this study was to investigate the prevalence of postthyroidectomy obesity, and the relationship between the extent of thyroidectomy and obesity.

Methods

A survey conducted at an outpatient clinic from June to October 2014 and retrospective charts for patients undergoing thyroidectomy at Konkuk University Medical Centers from June 2009 to December 2013 were reviewed. We compared clinical characteristics and pre- and postoperative obesity-related factors in 227 patients who underwent total thyroidectomy or lobectomy.

Results

Patients included 39 males and 188 females with a mean age of 46.0 ± 11.0 years; the mean follow-up period was 23.9 ± 16.7 months, and 90 of the 227 patients showed postthyroidectomy obesity. In effect of operative extent on postoperative obesity, patients who underwent TT (48.2 years) than those who underwent lobectomy (43.4 years). TT group had longer follow-up and the frequency of menopause was higher than in the lobectomy group. No differences in postthyroidectomy obesity, body weight change, or body mass index (BMI), change among 2 groups. The predictors of postthyroidectomy obesity were older age, female, heavy alcohol consumption (P = 0.029), higher preoperative BMI (P < 0.001), larger postoperative weight gain (P = 0.024), and larger BMI change. However, the extent of thyroidectomy did not affect postthyroidectomy obesity. Preoperative BMI (P < 0.001) and heavy alcohol consumption (P = 0.03) were independent factors of postthyroidectomy obesity.

Conclusion

The extent of thyroidectomy does not affect postthyroidectomy obesity. Preoperative BMI and heavy alcohol consumption are risk factors for postthyroidectomy obesity. Studies are needed to suggest preoperative life style modification to prevent postthyroidectomy obesity.

Obesity May Not Affect Outcomes of Transoral Robotic Thyroidectomy: Subset Analysis of 304 Patients

OBJECTIVES/HYPOTHESIS

Obesity is an increasing health concern worldwide. It has been associated with perioperative complications that could affect patient outcomes. Our aim was to compare surgical outcomes in obese and nonobese patients after transoral robotic thyroid (TORT) surgery.

STUDY DESIGN

Retrospective cohort study.

METHODS

A total of 304 consecutive patients who underwent TORT between January 2012 to December 2017 were included in the study. Patients were divided into two groups according to their body mass index (BMI): BMI < 30 kg/m² and BMI ≥30 kg/m² . Patient demographics, operative extent, pathological data, surgical outcomes, and postoperative complications were included and analyzed. A χ² test was used to compare categorical variables, and a Student t test was used to compare changes of continuous variables between groups. Statistical significance was conferred by a two-tailed P value of ≤.05.

RESULTS

There were 290 patients in the non-obese group and 14 patients in the obese group. There was no statistically significant difference between the two groups in terms of patient demographics, operative procedure, or pathological characteristics. The only statistically significant difference was for lymph node dissection (P = .012); however, for both groups, unilateral central node dissection was the most common procedure. There was also no statistically significant difference found for operative time, length of stay, pain score, or postoperative complications including TORT-specific complications such as oral commissure tear and general complications such as recurrent nerve injury.

CONCLUSIONS

This initial experience shows that TORT appears to be a safe and feasible option for obese patients pursuing scarless thyroid surgery.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:1343-1348, 2020.

Impact of body mass index on robotic transaxillary thyroidectomy

Obesity is associated with increased operating times and higher complication rates in many types of surgery. Its impact on robotic thyroidectomy however, is not well documented. The aim of this study was to investigate the relationship between body mass index (BMI) and robotic transaxillary thyroidectomy (RTAT). A retrospective review of prospectively collected data of all patients who underwent RTAT at Yonsei University Health System from October 2007 to December 2014 was performed. Patients were divided into three groups based on BMI (Group 1: BMI < 25, Group 2: BMI 25-29.99, Group 3: BMI ≥ 30), and compared. A total of 3697 patients were analyzed. No differences between the three groups were observed in clinicopathological factors, extent of surgery or length of stay. After multivariate analysis, only seroma and transient voice hoarseness were related to increasing BMI. Total operative time was significantly longer for Group 3 patients with less-than-bilateral total thyroidectomy (BTT), but was not significantly different for patients with BTT. Although obese patients undergoing RTAT have a slightly higher risk of seroma, transient voice hoarseness, and longer operative times, BMI did not influence the other important surgical outcomes of thyroidectomy. Therefore, obesity should not be a contraindication for performing RTAT.