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

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.

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.

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 Risk Factors for Phonation Disorders after Thyroid Surgery

Phonation disorders after thyroidectomy are among the most common complications and occur as a result of recurrent laryngeal nerve (RLN) injury. The multivariate analysis of risk factors for phonation disorders after thyroidectomy was assessed. A group of 830 patients with 1500 RLNs at risk of injury during thyroidectomy were analyzed retrospectively. The impact of the method of RLN identification, age, sex, BMI, kind of thyroid surgery, pathology, surgeon’s experience and thyroid volume on vocal cord paralysis was analyzed. We found that the retrosternal goiter and the volume above 100 mL were the most important risk factors for both transient and permanent paralysis. Thyroid cancer had a statistically significant impact on the increase in permanent paralysis, while this indication had practically no impact on transient paralysis. Among patients over 65 years with obesity, the probability of transient complications approximately doubled, with no effect on the permanent paralysis. Men were approximately 1.7 times more likely to develop any type of phonation disorder. Secondary operations more than doubled the risk of transient and permanent vocal cord paralysis. Thyroidectomy with only visual RLN identification was associated with a risk of both transient and permanent vocal cord paralysis almost two times higher, compared to neuromonitoring.

Transaxillary gasless endoscopic hemithyroidectomy versus conventional open hemithyroidectomy: early single-centre experience

Conventional open thyroidectomy is defined as a gold standard in thyroid gland disease treatment. However, progressive surgery methods such as endoscopic technique provide better structure visualisation and improved cosmetic effect. Our study aim is to compare conventional open (COH) and endoscopic transaxillary hemithyroidectomy (TAH) and define the learning curve for TAH procedure. We retrospectively analysed 107 COH and 65 TAH cases. Patients' demographic data and surgery results were compared. Also, surgeon learning curve analysis using cumulative sum (CUSUM) was performed for the duration of the surgery. TAH was applied to younger female patients with lower thyroid gland volume. COH group patients were hospitalised for longer in comparison with TAH (p < 0.05). Mean TAH surgery time was longer (78.1 min, SD = 22.6) compared with COH (66.7 min, 15.3) (p < 0.05). Overall complication rate was comparable between groups. There was a tendency towards a lower unintentional parathyroidectomy rate in TAH group. TAH group results showed significantly longer surgery time for patients whose body mass index (BMI) was over 30 (kg/m²), compared to whose BMI was below 30 (kg/m²) (p = 0.004). Shortest endoscopic surgery time (64.9 ± 12.45 min) was achieved between 41 and 50 cases. CUSUM analysis showed that surgery time decreased after the 30th TAH case. TAH approach compared to COH results in longer surgery time, shorter hospital stay and comparable rate of postoperative complications. However matched pair studies are necessary to clarify the results. After thirty cases, the surgeon became proficient in transaxillary endoscopic thyroid surgery.

The association of obesity with thyroid carcinoma risk

Background

The prevalence of obesity and an increased incidence of thyroid carcinoma (TC) threaten public health in parallel on a global scale. Sufficient evidence supports excess body fatness in thyroid carcinogenesis, and the role and anthropometric markers of obesity have been causally associated with the rising risk of TC.

Methods

A literature search was conducted in PubMed. Studies focused on the effect of obesity in TC.

Results

This review mainly discusses the global incidence and prevalence of obesity‐related TC. We also review the role of obesity in TC and potential clinical strategies for obesity‐related TC.

Conclusions

Excess body fatness in early life and TC survival initiate adverse effects later in life.

The incidence of thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more sensitive diagnostic procedures. Obesity has increased with sufficient rapidity in the same time frame and may as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this review was to focus on the relationship between obesity and the risk of thyroid cancer. Obesity seems to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. The possible underlying mechanism is involved chronic inflammation mediated by cytokines, leptin, and adiponectins.

Partial Versus Total Thyroidectomy: What Influences Most Surgeons' Decision? Analysis of a Nationwide Cohort of 375,810 Patients Over 10 Years

National and international guidelines about thyroid surgery seem to be moving more and more towards less radical surgical procedures but everyday practice does not seem to always align with them. We describe for the first time the role of non-surgical parameters in the surgeon's choice for thyroid surgery.

OBJECTIVE

To describe thyroid surgery and to identify the factors leading to either a total or a partial thyroidectomy regardless of the severity of the thyroid disease.

SUMMARY BACKGROUND DATA

National and international guidelines about thyroid surgery seem to be moving more and more towards less radical surgical procedures but everyday practice does not seem to always align with them.

METHODS

We based this nationwide retrospective cohort study on a national database that compiles discharge abstracts for every admission for thyroidectomy to French acute healthcare facilities (PMSI database 2010 to 2019).

RESULTS

In this study, 375,810 patients (male: 23%; age = 53 ± 15 y) had a thyroidectomy (partial: 28%) for cancer (17%), hyperthyroidism (16%), non-functioning goiter (64%) or other (3%). We noticed a global trend toward more partial thyroidectomy (p < 0.001) with a significant increase in the proportion of lobectomy in the post-ATA recommendations' period (p < 0.001) as well as in the "French Levothyrox crisis" period, in which we saw an unexpected rise of adverse events notifications associated with the marketing of a new formula of Levothyrox (p < 0.001) amid widespread media coverage. In a multivariate analysis, we also identified that complete resection was more frequently performed in centers with a caseload > 40/y (p < 0.001, OR = 1.48), for obese patients (BMI> 30 kg/m2; p < 0.001, OR = 1.42), and according to the indication of surgery (OR benign = 1, OR cancer = 2.25, OR hyperthyroidism = 4.13).

CONCLUSION

We describe for the first time the role of non-surgical parameters in the surgeon's choice for thyroid surgery.

Morbid Obesity and Thyroid Cancer Rate. A Review of Literature

In the past three decades, several recent studies have analyzed the alarming increase of obesity worldwide, and it has been well established that the risk of many types of malignancies is increased in obese individuals; in the same period, thyroid cancer has become the fastest growing cancer of all malignancies. We investigated the current literature to underline the presence of a connection between excess body weight or Body Mass Index (BMI) and risk of thyroid cancer. Previous studies stated that the contraposition between adipocytes and adipose-resident immune cells enhances immune cell production of multiple pro-inflammatory factors with subsequent induction of hyperlipidemia and vascular injury; these factors are all associated with oxidative stress and cancer development and/or progression. Moreover, recent studies made clear the mitogenic and tumorigenic action of insulin, carried out through the stimulation of mitogen-activated protein kinase (MAPK) and phosphoinositide-3 kinase/AKT (PI3K/AKT) pathways, which is correlated to the hyperinsulinemia and hyperglycemia found in obese population. Our findings suggest that obesity and excess body weight are related to an increased risk of thyroid cancer and that the mechanisms that combine overweight with this cancer should be searched for in the adipokine pathways and chronic inflammation onset.