Surgical management of thyroid gland swellings in 22 May Hospital, Aden, Yemen

Thyroid gland swellings are common clinical presentation of thyroid disorders of various etiologies, to which thyroidectomy is often carried out. The study aimed at analyzing demographic, clinical and pathologic features of patients with thyroid gland swellings, presented to 22 May Hospital and operated during the study period.as well as studying the types of operation used and their complications. This is a retrospective study. All patients who presented to 22 May Hospital from 1 March 2018 to 28 February 2020 and operated were included in the study. Patients with cervical lymphadenopathy, retrosternal goiter, and extrathyroidal tumor invasion were excluded from the study. Relevant data were collected and processed. For statistical analysis, SPSS software vs.17 was used. The Freeman and Halton extension of Fischer exact test was completed using Vassarstat. P-value of ≤0.05 was considered statistically significant. The study included 117 patients. Female preponderance was noted (91.5%). The average age group was 39.4 yrs, with SD ±13.8. Patients had an average duration of complain 50.3 months with SD ± 67.8. Most patients were euthyroid (88.1%) and had no previous thyroid operation (94%). The overall cancer detection rate on histopathology exam was 12% and papillary thyroid cancer was the most frequent histopathologiccancer type (92.8%). Statistically significant difference was found in the cancer detection rate in the different forms of thyroid swellings, the highest rate was found in solitary thyroid nodule (33.3%). Incidental thyroid cancer was found in 2.5% of the research population, but the histopathologic examination of their completed thyroidectomy specimen showed no cancer remnant. The total thyroidectomy was the most frequently practiced thyroidectomy procedure (45.8% of operations). No statistically significant difference was found in the major complications of thyroidectomy procedures of different resection extent. It could be concluded from this study that cancer detection rate in solitary thyroid nodule is significant, therefore, it needs to be carefully identified and investigated thoroughly.

Post operative bleeding may occur and prone to develop tension hematoma which cause airway compression and may lead to asphyxia unless is evacuated [3].
There are several factors, apart from surgeons experience, that have been identified as risk factors for surgical complications, like operating on cancer, toxic hyperthyroidism, retrosternal goiter, lymph node dissection, and weight of the thyroid gland [5]. As well as completed thyroidectomy (revision thyroidectomy, redo thyroidectomy) is thought to carry a high risk of complications, including recurrent laryngeal nerve palsy and hypoparathyroidism. Previous thyroid surgery causes inflammation, edema and scarring which lead to loss of anatomical landmarks during the second operation [28].
There are several indications for thyroidectomy which include malignancy or clinical suspicion for malignancy, obstructive symptoms of goiter, hyperthyroidism and cosmetic issue [32].
Although thyroidectomy has been reported to be a well established surgical procedure, the approach and extent of tissue resection remain controversy. The extent and radicality of any surgical procedure should be weighed against its potential complications [13].
There are several surgical options for thyroidectomy, like total thyroidectomy, subtotal thyroidectomy, and hemithyroidectomy. During total thyroidectomy, both lobes and isthmus are completely removed leaving behind only viable parathyroid glands. whereas in subtotal thyroidectomy, most surgeons leave 2-3 grams of thyroid tissue on either side of the neck. Hemithyroidectomy refers to the complete removal of one lobe with the isthmus [15,27].
In the recent years, there is a trend to shift function preserving surgery towards ablative surgery in, the surgical treatment of nonmalignant thyroid disease. Opponents towards this tendency argue that higher recurrence rate of goiter and increased risk of operative complications in reoperations after incomplete resection [25]. However, many surgeons avoid total thyroidectomy due to the high incidence of complications, such as permanent recurrent laryngeal nerve palsy, and permanent hypoparathyroidism, and subtotal thyroidectomy has been the preferred operation for benign thyroid disease [28].
Thyroid cancer is the most common endocrine malignancy and there has been steady increase in its incidence over the past 15-20 years [39]. Incidental thyroid cancer is a malignancy undetected by preoperative imaging studies, but is identified by pathological examination of surgical specimen in patients treated for benign thyroid disease [24,29].
Fine needle aspiration cytology is an inexpensive, minimally invasive outpatient procedure that determines the malignancy risk in thyroid nodule. The mean false positive and false negative rates of FNAC are reported as less than 5% [38].
This study aimed at describing the demographic, clinical and pathologic features of patients with thyroid gland swelling, presented to 22 May Hospital and operated during the study period (described below). As well as studying the types of operation used and their complications.

Method:
This is a hospital based retrospective study. The study duration was 2 years. All patients who were presented with thyroid gland swelling (benign or malignant) and underwent thyroidectomy in 22 May Hospital-Aden from 1 st March 2018to 28 th February 2020, were included in the study. Patients with cervical lymphadenopathy, retrosternal goiter, and extrathyroidal tumor invasion were excluded from the study. Patients medical records, histopathology reports were revised, as well as the results of blood investigations, ultrasound findings and ENT consultation notes and anesthesiologist notes were checked. Demographic properties, preoperative clinical findings, and post operative findings and complications were evaluated and recorded to a prestructured questionnaire. After data were extracted, they was revised, coded and fed to statistical software IBM SPSS version 17. Categorical variables were expressed as counts and percentages, whereas continuous variables were expressed as means and standard deviation. The results were compared with other relevant studies in the literature. Also, univariate relations between form of neck swelling and other clinical variables (like gender, duration of symptoms, mean age, histopathology results) were looked up. Also, relations between types of operation and complications were studied. For this purpose, Fischer's exact test was used to study univariate relations of categorical variables. For contingency tables 2×3 and 2×4 the Freeman and Halton extension of Fischer's exact test was used. (Calculated on Vassarstats statistical computation web site, http://vassarstats.net). P-value of ≤0.05 was considered statistically significant. For continuous variables, the one way ANOVA test was used to compare means, and, if found statistically significant, it was further tested by post hoc tests (Turkey's HSD) for multiple comparisons.

Results:
A total of 117 patients were included in this study comprising of 107 female (91.5%) and 10 males (8.5%). The females to males ratio was 10.7:1. The mean arithmetic age was 39.4, with standard deviation of 13.8. 75% of the patients were 50 years old or younger. The minimum age was 9 years and the maximum age was 100 years. Most patients came from upcountry, particularly from Lahej Governorate (37.6%). All the presented patients (117 cases) in the study had a chief complain of neck swelling and had an average duration of 50.3 months with a standard deviation of 67.8 month. The shortest duration of complain was one month and the longest 360 months.Most of the patients were euthyroid (103 cases 88.1%), 8 patients (6.8%) were hyperthyroid, and 6 patients (5.1%) were hypothyroid.(Further details illustrated in Table 1) The majority of the patients in the study (110 patients, 94%) had no previous thyroid operation, while 7 patients (6%) had previous thyroid surgery. In 3 patients (2.5%) who had no previous thyroidectomy; incidental thyroid cancer was detected after the primary operation and they had a second operation (completion thyroidectomy) during the research period. Therefore, the total number of the thyroid operations in the study became 120. On local physical examination of the neck, different forms of thyroid gland swelling were found, being the bilateral nodular enlargement which was the most frequently detected form in 50 patients (42.7%). The study revealed a statistically significant difference in cancer detection among the different physical forms of thyroid swellings who had not operated before (p-value = 0.012). Also, there was a statistically significant variance in the mean age of presentation of the different physical forms of thyroid swellings who had not operated before (p-value = 0.011 ) and on multiple comparison of the mean age of difference found only between diffuse form of neck swelling and multinodular form of neck swelling (p-value = 0.041). The total thyroidectomy was the most frequently carried out operation (55 operation, 45.8% of total thyroidectomies). Further details are illustrated in Table 3.   Completion thyroidectomy was carried out in 10 patients. Seven patients of those had past history of nontotal thyroidectomy for benign thyroid swellings. They were presented with recurrent neck swelling. The new excision biopsy results revealed follicular carcinoma in one case and follicular adenoma in another case, and the remainder 5 cases had MNG. Another 3 patients, during the study period ,have underwent nontotal thyroidectomy (hemithyroidectomy) for benign thyroid lesion based on fine needle aspiration cytology and incidental cancer detected on histopathology examination (false negative FNAC rate was 2.56%). Revision operation has been done for them and the reexcised specimens were free from cancer on histopathology examination (Table 5).
No statistically significant difference was found in the major complications (wound hematoma, postoperative hypocalcemia and recurrent laryngeal nerve injury) of thyroidectomy procedures of different resection extent. Also, no statistically significant difference was found in the major complicationsbetween primary thyroidectomy and completion thyroidectomy (Table 7 and 8).

Discussion:
The study revealed a distinct female preponderance over males with a ratio of 10.7:1. This observation shows similarity with previous studies that in Yemen by Alhuraibi K. et al [4], Al-Sharafi B et al [6], and Al-wageeh S et al [9], who described , in their studies, that females to males ratios were of 11.6:1, 10.2:1 and 9:1 respectively. However, other research papers recognize female preponderance of thyroid disease to a much lesser extent: 1.85:1-2.31:1 [18,34]. The mean age of the current study was 39.4, with standard deviation, of 13.8. This value is compared well with studies from Yemen, Tanzania, KSA, and Sudan (mean age of 35.2, 40, 38.4, 43.7, and 43.9 respectively) [4,9,14,2,18]. whereas other studies showed higher figures (47.1, 48.4, 58.5) [31,34,36]. Most of the patients in this study came from rural areas located at a considerable distance from the hospital. This may explain the late presentation of many patients in the study. Similar findings were described by Al-wageeh S. et al [9], Alhuraibi K. et al [4], Chalya P.et al [14], and AfolabiA et al [2].
The majoriy of the patients in the study were euthyroid (88.1%) and this is similar to what mentioned by Al-SharafiB. et al [6] in their studies (87.6%). However, in the work of Al-HuraibiK.et al [4], euthyroid patients were slightly less frequent 80%. Hypothyroidism was found in 5.1% of cases. In comparison to other studies, the percentage of preoperative hypothyroidism showed similar proportions. For example, Afolabi A. et al [2] mentioned 4.3% hypothyroidism in their study population. Similarly Al-huraibi et al [4] as well as Sultan et al [35] found 5% of the patients hypothyroid, however, Olow M et al [28] from Magadishu reported hypothyroidism in 24% of the patients. In this study, hyperthyroidism constitutes only 6.8% of the operated patients. In some centers, hyperthyroidism were operatedmuch frequently. For example, PrabhakaranA. et al [31] from India, Al-huraibi K. et al [4] from Yemen,Guraya S et al from KSA [17], Sultan H. et al [15] from Egypt mentioned 11.2%, 15%,17.6%, and 25% respectively.
Regarding the clinical description of thyroid gland swellings, the bilateral nodular form was most frequently identified (39.3%) in this study, followed by the unilateral swelling in 35.9%, solitary nodule 17.9% and diffuse swelling in 3.4%. This is in consistency with the clinical description of thyroid gland swellings by Al-Huraibi K et al [4], particularly the incidence of solitary thyroid nodule (17.4%), however, diffuse goiter represented 15.6% of their study sample.
Because of the primary goal in the management of thyroid, gland swellings is to differentiate malignant lesions from benign condition. The physical differentiation of thyroid swelling into different forms may have clinical significance. In this study, for example, the cancer detection rate was different among the different forms of thyroid swellings. In solitary thyroid nodule, the cancer detection rate was the highest and reached 33.3%, followed by recurrent thyroid swelling, unilateral swelling, and bilateral nodular swellings, and diffuse swelling (14.2%, 9.5%, 4.3% and 0% respectively). Similarly, Keh S et al [20] found cancer in 34% of the solitary thyroid nodules. Anitha S and Ravimohan TR [11] found the mean age of the incidence of solitary thyroid nodule 35 years. Their findings are in consistence with the present study (mean age of STN, 36.2 yrs) The proportion of disease diagnosed after histopathology examination of the thyroidectomy specimens has shown similarities in many aspects with what published in some local and regional papers. Multinodular goiter was the most common thyroid pathology seen in this study. This finding is in agreement with many published papers found in the literature. The rate of follicular adenoma (11.9%) and thyroiditis (5.1%) detected in this study is close to the rate mention by Al-Huraibi K. et al [4] and Al-Wageeh S. et al [9] (follicular adenoma 11.8 % and 8.5%, thyroiditis 4%, 4.6% respectively). However, they found thyroid cancer more frequently (17.7%,and 21.1% respectively) than the current study (12%) [4,9]. Altaf S et al [8] in Karachi, Pakistan, found malignancy proven goiter in 23.2% of cases. Interestingly, Chayla P et al [14], in Tanzania, found the histopathologically proven thyroid malignancy, only in 7.9% of patients.
In the present study, papillary carcinoma was the most common histopathological type of carcinoma (92.8%), followed by follicular carcinoma (7.2%). In a previous study by Abdulhamid G et al [1], utilizing the Abroad Treatment registry of Aden Health Office, found that thyroid cancer was the second most common malignancy in female and 57.8% of those who had thyroid cancer were papillary histopathological type, followed by follicular cancer 24.56%, anaplastic cancer in 10.5% and medullar cancer in 7%. Although many published studies in the world state that papillary cancer is the most common histopathological type of thyroid cancer, followed by follicular carcinoma, different trend may be noted in some areas. Chalya P et al [14] in northwest Tanzania, noticed that follicular carcinoma was the most common type. The reason behind this is probably the existence of long standing goiter in that region [14]. whereas Altaf S from Karachi [8], found medullary carcinoma in 9.9% of the cases, the second most common variant, preceded by papillary carcinoma in 83.1% and follicular carcinoma dropped to the third variant (in 6.9%). In the current study, incidental thyroid carcinoma was found in 3 patients (2.56%), and all of them were of papillary carcinoma type. Similarly, the incidence of incidental thyroid cancer found by Matoro et al [23] was 4.62% of total patients, 21.9% of the total number of cancer patients, and the histological type in all cases were papillary cancer.
In the current study, the total thyroidectomy was the most frequently practiced thyroidectomy (45.8%), whereas subtotal thyroidectomy used less often (10%). Contrary to what mentioned in a previous study in Yemen, where subtotal thyroidectomy was accounted for 51% of the thyroidectomies, whereas total thyroidectomy together, with near total thyroidectomy, reached only 8.6% [4].This represents a shift in the management preference of local surgeons from less aggressive to more radical resection technique. This tendency is in consistency with many recent published papers [2,28,29]. The total thyroidectomy helps avoid reoperation and associated complications and nontotal thyroidectomy does not ensure the preservation of thyroid hormone function [22].
In the current study, no statistically significant difference was found in the rate of major complications ( namely recurrent laryngeal nerve injury, post operativehypocalcemia and wound hematoma) associated with total thyroidectomy and that associated with nontotal thyroidectomy (subtotal thyroidectomy and hemithyroidectomy). Post operative hypocalcaemia is a common and most often transient event after extensive thyroid surgery [18,30,33], whereas other authors found that the rate of complications of the total thyroidectomy (namely RLN palsy, hypocalcaemia, hematoma) did not differ statistically significantly from that associated with subtotal thyroidectomy [16,21]. However, Lin et al [22] found that the total thyroidectomy had significantly higher transient complication rate except for RLN palsy, however, statistically significant difference were not observed for permanent complications.
Recurrent goiter was found in 7 patients (5.9%) which is slightly higher than what was described by Altaf S et al [8] in Karachi (3.43%).
The subject of completion thyroidectomy had generated a considerable debate and controversy over many decades. The recurrence rate after nontotal thyroidectomy for benign goiters had varied from 5% to 40% among published series [22,37]. The surgical management of recurrent goiter is challenging, and the complication rate is increased, compared to initial surgery. There is an increased risk of RLN injury in recurrent goiter surgery [8]. The considerable higher complication rate of completion thyroidectomy is due to tissue scarring and fibrous adhesion [22]. In the current study, no statistically significant differences were found between primary and completion thyroidectomy, in the association with RLN palsy, hypocalcaemia and hematoma formation. This might be explained by that completion thyroidectomy was carried out preferentially by senior surgeons with long experience in thyroid surgery.