Abstract
Introduction
Aging is a normal process that the human body naturally goes through. As the physiological function is irreversibly declining, it leads to age-related diseases and other comorbidities. 1 According to the World Health Organization (WHO), it is projected that the population aged 60 years and over is expected to increase from 1 billion in 2020 to 2.1 billion by the year 2050. 2 Saudi Arabia follows the global increase in aging population. The life expectancy in Saudi Arabia has improved from 64.4 years in the 1980s to 74.3 years in the 2000s. 3 The elderly population of those aged 60 and above is expected to rise from 3% in 2010 to 18.4% in 2050. 4
One of the most common head and neck operations performed worldwide is thyroidectomy. It has various indications including suspicion of malignancy, gland enlargement, compression, and resistant hyperthyroidism. 5 The prevalence of benign and malignant thyroid disease is higher in older people, and nodular thyroid diseases account for approximately 70% of women over 70 and 60% of men over 80, which necessitates the operation this age group.6,7 Although thyroidectomy has its own complications, understanding the link between aging and postoperative complications is critical because it may influence how the condition is managed and the type of therapy used primarily. There is a discrepancy in literature regarding the safety and the risk of developing postoperative complications in the older population in comparison to the younger population.
An aged population undergoing thyroidectomy has a greater incidence of complications, according to a population-based study done in the United States involving 22,848 patients. 8 In addition, a 2019 retrospective analysis using a nationwide database also in the United States with 414,079 cases provided additional evidence for that conclusion, albeit for certain complications such as recurrent laryngeal never (RLN) injury. 7 On the other hand, according to 2 other studies, thyroidectomy in individuals over 65 is safe and does not have a greater rate of complications.9,10 Furthermore, most studies in literature showed that increased length of hospitalization correlated with advanced age.6-8
Given the discrepancy in literature and the fact that no studies were conducted previously in Saudi Arabia or in the Middle East describing the relationship between age-related complications after thyroidectomy, this study aimed to analyze the clinical trends of patients undergoing thyroidectomy of different age groups.
Methodology
Study Setting and Participants
A multicenter retrospective record review was conducted at 3 tertiary care centers in Jeddah, Saudi Arabia. The 3 centers are King Abdulaziz University Hospital (KAUH), Dr. Soliman Fakeeh Hospital, and King Abdulaziz Medical City. Ethical approval was obtained from the institutional review board of KAUH (Reference number 71-23). As the study was conducted retrospectively, informed consent was waived. Data from KAUH included operations from January 2010 to December 2020. Data from Dr. Soliman Fakeeh included records from January 2018 to December 2021. Records from King Abdulaziz Medical City were evaluated for the period from January 2012 to December 2022. Our inclusion criteria consisted patients of all ages of both sexes who underwent thyroidectomy. We excluded patients with incomplete medical records. The number of patients who fulfilled the inclusion criteria was 798. Figure 1 demonstrates the number of thyroidectomies evaluated from each center, as well as the number of cases included and excluded.
Flowchart of medical records reviewed.
Evaluated Data
Data extracted from the electronic medical records systems included age, gender, type of thyroidectomy (total thyroidectomy, hemithyroidectomy, completion thyroidectomy), histopathological diagnosis, operative time in minutes, postoperative length of hospitalization in days, and postoperative complications within 6 months.
Statistical Analysis
Data entry was performed by using Microsoft Excel 2016 (Microsoft Corporation) Statistical package for the social sciences (SPSS) for Windows (version 21; IBM Corp) was used for statistical analysis. Patients were divided into 2 groups based on age: <60 years age group and ≥60 years age group. The 2 age groups were compared with regard to various variables. Mean and standard deviation (SD) were calculated to describe continuous variables while numbers and percentages were used for categorical variables. Normal distribution was tested using the Shapiro-Wilk test. All continuous variables were normally distributed. Chi-square and independent t tests were used to evaluate the differences between qualitative and continuous variables. Pearson’s correlation test was used to evaluate relationships between continuous variables. Logistic regression analysis was performed with postoperative complications as the dependent variables. A P value <.05 was considered significant.
Results
A total of 961 medical records from 3 tertiary care centers were reviewed, of which 163 records were excluded due to missing data. This study included 798 patients (Figure 1).
Baseline Characteristics
Demographic characteristics of the patients included in this study are summarized in Table 1. Female patients constituted the majority of the study population (n = 625, 78.3%), while the remaining 173 (21.7%) patients were males. The <60 years age group was comprised of 81% female patients and 19% male patients, compared to 63.4% female patients and 36.6% male patients in the ≥60 years age group (P < .001). The mean age of the patients was 44.00 ± 14.38. When classified by age, most of the patients were <60 years of age (n = 675, 84.6%), while the remaining patients were 60 years of age and older (n = 123, 15.4%). The most common type of thyroidectomy done was total thyroidectomy (n = 563, 70.6%). Most histopathological results were benign (n = 425, 53.3%), while the other 373 (46.7%) were malignant. Of the 425 benign thyroids, 237 (55.76%) had the final pathology recorded, the other 188 (44.24%) results were not available. Of the 237 available results, the majority (n = 118, 49.79%) were diagnosed as multinodular goiter, followed by Hashimoto’s thyroiditis (n = 38, 4.8%). Of the 373 malignant thyroids, the most common histopathology was papillary thyroid carcinoma (n = 320, 85.80%). Table 1 compares between the characteristics of the patients.
Demographic and Other Characteristics of Patients Who Underwent Thyroidectomy.
Statistically significant, P < 0.05.
Length of Stay and Operative Time
The mean postoperative length of hospitalization was 3.64 ± 4.87 days. The ≥60 years age group had a statistically significant longer mean postoperative length of hospitalization (5.37 ± 7.21 days) compared to the <60 years age group (3.33 ± 4.24 days; P = .003; Figure 2). There was a weak positive correlation between age and length of hospitalization (r = .128) with a statistically significant relationship (P < .001). The mean operative time was 176.55 ± 72.17 minutes (Table 1). Age and operative time were weakly negatively correlated (r = −.009) with an insignificant statistical relationship (P = .857). This finding was further verified by multivariate logistic regression after adjustment for gender, type of procedure, and type of diagnosis (P = .001)
Mean length of hospitalization after thyroidectomy.
Postoperative Complications
Of the 798 thyroidectomies reviewed, 679 (85.1%) occurred without any recorded complications, while 119 (14.9%) developed at least one complication postoperatively. A total of 14.4% of the patients in the <60 years age group developed at least one postoperative complication compared to 17.9% of the patients in the ≥60 years age group (P = .385; Figure 3). The most common postoperative complication was hypocalcemia (n = 67, 8.4%) followed by hypoparathyroidism (n = 43, 5.4%; Figure 4). Seroma and recurrent laryngeal nerve injury occurred more commonly in the ≥60 years age group compared to the <60 years age group with a statistically significant difference (P = .005 and P = .003, respectively). In contrast, hypocalcemia occurred more commonly in patients of the <60 years age group with a statistically significant difference (P = .039). Furthermore, there was no statistically significant difference in the occurrence of hypoparathyroidism between the 2 age groups. Table 2 demonstrates a comparison between the age groups in relation to different postoperative complications. These findings were further verified by multivariate logistic regression after adjustment for gender, type of procedure, and type of diagnosis (Table 3).
Rate of postoperative complications of thyroidectomy.
Postoperative complications of patients who underwent thyroidectomy.
Postoperative Complications of Patients Who Underwent Thyroidectomy.
Statistically significant, P < 0.05.
Multivariate Logistic Regression for Odds of Postoperative Complications Among Patients Undergoing Thyroidectomy: ≥60 Versus <60 Age Groups a .
Adjusted for gender, type of procedure, and type of diagnosis.
Statistically significant, P < 0.05.
Discussion
This study aimed to assess the clinical trends of patients who underwent thyroidectomy in the older age group as compared to younger patients. We discovered a notable difference in the gender distribution among the 2 age groups. Among individuals below 60, there was a significantly higher proportion of female patients, accounting for 81%, while male patients constituted only 19% in this age group. However, in the ≥60 age category, female patients still made up the majority at 63.4%, but the percentage of male patients increased to 36.6%. These data can point to an early disease in females or a delayed diagnosis in males. This is also consistent with the fact that thyroid cancer is more common in women and is considered the second most common cancer in women after breast cancer, and recent literature indicates an increase in male thyroid cancer incidence as well. 11 This increase in incidence of thyroid cancer among males is especially apparent in the elderly population. 12
According to the histological findings, more than half of our patients had benign nodules, and the majority of both age groups were given the diagnosis of multinodular goiter, which was followed by Hashimoto’s thyroiditis. A study done in Riyadh found that up to 60% of the patients had nodular goiter or Hashimoto’s thyroiditis. 13 Surprisingly, our study revealed that almost half of our patients were diagnosed with malignant thyroid neoplasms across both age groups. In comparison, Echanique et al reported in their nationwide study in the United States that the majority of their patients (65.8%) were diagnosed with benign thyroid neoplasms, while the rest (34.2%) were diagnosed with malignant disease. 7 A majority, up to 90%, were diagnosed with papillary thyroid cancer (PTC), followed by other histological types. This finding emphasizes the high prevalence of PTC among thyroid cancer cases in Saudi Arabia. Moreover, it highlights the importance of early diagnosis and intervention in managing thyroid cancer effectively.
There is no consensus in literature on the safety of thyroidectomy in the older age groups.7-10 In our study, we compared between the younger (<60 years) and the older (>60 years) age groups with regard to the risk of developing certain postoperative complications. Multiple previous studies showed a higher incidence of RLN injury in older patients undergoing thyroidectomy compared to younger patients. However, not all the findings were statistically significant. Schwartz et al 14 reported in their retrospective cohort study a higher incidence of permanent and temporary RLN paralysis in the older age group compared to the younger age group; however, the difference was not statistically significant. Likewise, Canonico et al 15 reported similar findings. In contrast, Sosa et al 8 and Echanique et al 7 found a statistically significant increase in RLN injury with increasing age in their large population-based analysis. In our study, we found that the risk of developing RLN injury postoperatively was higher in the older age group in bivariate analysis as well as in multivariate analysis after adjusting for the gender, type of disease, and type of procedure. One of the theories to explain this finding is that in elderly, the peripheral nervous system’s response to injury is reduced and self-repair process occurs more slowly and incompletely in older people, making older people more vulnerable to injury.
Temporary hypocalcemia and hypoparathyroidism are common possible complications following thyroidectomy. Hypocalcemia is significant as it can lead to clinical implications including seizures, tetany, and arrythmias which can be fatal, usually appearing at 24 to 72 hours postoperatively, and thus increasing lengths of hospitalization.7,16 To help decrease the burden and incidence of symptomatic hypoparathyroidism and hypocalcemia, protocols have been developed for prophylactic calcium supplementation following total or completion thyroidectomy. 16 Although we found that younger age group were more likely to develop postoperative hypocalcemia in our study compared to patients in the older age group. However, there was no significant difference in the odds of developing hypoparathyroidism. A possible explanation is the stricter administration of prophylactic calcium, especially in elderly patients.7,14
Notably, there was no difference in the odds of developing hematoma in our study. A similar finding was reported by Schwartz et al 14 In contrast, other studies in literature found a higher rate of hematoma formation in older patients.17,18
In our study, we found that the older age group had a longer mean length of hospitalization postoperatively compared to the younger age group with a statistically significant difference. This finding is consistent with previous findings in literature. In a large population-based study conducted in the United States, Echanique et al 7 reported that length of stay increased linearly with increasing age. In addition, another population-based study conducted in the United States by Sosa et al 8 found that patients of the older age groups had a mean length of stay 60% longer than younger patients. This finding is likely attributable to multiple factors such as the increasing number of comorbidities that predispose the older patients to increased complications and therefore prolonged length of hospital stays.7,8,19
Even though this study assessed various clinical trends in older patients undergoing thyroidectomy compared to younger patients, it was not without limitations. This study was limited by its retrospective study design. Likewise, comorbidities were not assessed, which may have played a role in affecting complications as well as postoperative length of hospitalization. Furthermore, data on mortality were not included. Nevertheless, our relatively large cohort of patients supports the validity of our findings and contributes to answering an important question in the field of surgery.
Our recommendations for future researchers are to establish a national-based study including more complications that were limited or missing in our study as well as readmission rates and mortality rates among thyroidectomy patients.
Conclusion
In our region, the overall risk of developing postoperative complications was not different between the younger and older age groups. However, certain complications, including RLN injury, were more likely to develop in the older age group, which requires vigilance from surgeons performing thyroidectomy. Likewise, the length of hospitalization was significantly longer in the older population. Awareness of complications and challenges of thyroidectomy in the older age group is crucial to improve care.
Footnotes
Data Availability
The data used in the current study are available from the corresponding author on reasonable request.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Ethics Approval
Ethical approval was obtained from the institutional review board of KAUH (Reference number 71-23).
Informed Consent
As the study was conducted retrospectively, informed consent was waived.
