|Year : 2020 | Volume
| Issue : 2 | Page : 78-81
Incidence and risk factors of inadvertent parathyroidectomy during thyroid surgery: A single-center retrospective study
Abdulaziz Rajeh Alanzi1, Abdullah Ghafouri2, Wael Khalifa3, Hassan Hawsawi1, Suzan Alzaidi2
1 Department of Otorhinolaryngology - Head and Neck Surgery, King Abdulaziz Medical City, Jeddah, Saudi Arabia
2 Department of Otorhinolaryngology - Head and Neck Surgery, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
3 Department of Otorhinolaryngology - Head and Neck Surgery, King Abdulaziz University, Rabigh, Saudi Arabia
|Date of Submission||10-May-2020|
|Date of Decision||10-Jun-2020|
|Date of Acceptance||21-Jun-2020|
|Date of Web Publication||30-Dec-2020|
Dr. Abdulaziz Rajeh Alanzi
Department of Otorhinolaryngology - - Head and Neck Surgery, King Abdulaziz Medical City, Jeddah
Source of Support: None, Conflict of Interest: None
Context: Thyroidectomy is considered a relatively safe surgery with morbidity of <5% when undertaken by experienced surgeons. Inadvertent parathyroidectomy (IP) means pathology report has found parathyroid tissue in the thyroid specimen, and it was reported to range from 2.9% to 31%. Aims: The aim of this study is to measure the incidence rate and to evaluate the significant relationship between risk factors and IP during thyroid surgery. Settings and Design: A retrospective chart review study was carried out in King Fahad Armed Forces Hospital, Jeddah, between June 2015 and December 2019. Subjects and Methods: All consecutive patients undergoing unilateral or bilateral thyroidectomy were enrolled in this study. Histopathology reports were reviewed to identify the specimens that included parathyroid tissue and underlying thyroid disease, and these were compared to patients with no parathyroidectomy in terms of gender, pathological features, re-operation, Hashimoto thyroiditis, extrathyroidal extension, and central neck dissection. Statistical Analysis Used: Statistical analysis was carried out using the Statistical Package for the Social Sciences. Results: Retrospective analysis of 181 consecutive thyroidectomy cases reveals that 34 (18.7%) patients had IP. Significant risk factors for IP included extra-thyroid extension (P = 0.008), total thyroidectomy (P = 0.017), and Hashimoto thyroiditis (P = 0.021). Other risk factors, including gender, malignancy, central neck dissection, and re-operation, were not statistically significant in this study. Conclusions: IP during thyroid surgery is not uncommon (18.7%). Total thyroidectomy, hashimoto thyroiditis, and extrathyroidal extension of the tumor were found to be significant risk factors. We recommend more meticulous intra-operative identification of parathyroid glands, particularly for patients with these risk factors.
Keywords: Central neck dissection, completion thyroidectomy, during, extrathyroidal extension, Hashimoto thyroiditis, hemithyroidectomy, inadvertent, incidental, malignancy, parathyroidectomy, thyroidectomy, total thyroidectomy
|How to cite this article:|
Alanzi AR, Ghafouri A, Khalifa W, Hawsawi H, Alzaidi S. Incidence and risk factors of inadvertent parathyroidectomy during thyroid surgery: A single-center retrospective study. Saudi J Otorhinolaryngol Head Neck Surg 2020;22:78-81
|How to cite this URL:|
Alanzi AR, Ghafouri A, Khalifa W, Hawsawi H, Alzaidi S. Incidence and risk factors of inadvertent parathyroidectomy during thyroid surgery: A single-center retrospective study. Saudi J Otorhinolaryngol Head Neck Surg [serial online] 2020 [cited 2021 Apr 23];22:78-81. Available from: https://www.sjohns.org/text.asp?2020/22/2/78/305460
| Introduction|| |
Thyroidectomy is a widely performed surgery by otolaryngologists and general surgeons. It is considered a relatively safe surgery with morbidity of <5% when undertaken by experienced surgeons. Major postoperative complications include permanent hypoparathyroidism (1.7%) and recurrent laryngeal nerve injury (1%).
Inadvertent parathyroidectomy (IP) means pathology report has found parathyroid tissue in the thyroid specimen, and it was reported to range from 2.9% to 31%. In the literature, studies aimed to determine the risk factors of IP, including type of surgery, central lymph node dissection, reoperation, malignancy, Hashimoto thyroiditis, and extrathyroidal extension. However, studies have shown variation in the significant relationship between these risk factors and IP. Therefore, identifying the parathyroid glands, preserving the blood supply, and autotransplantation are very important for avoiding postoperative permanent hypocalcemia. The aim of our study is to measure the incidence rate and to evaluate the significant relationship between risk factors and IP during thyroid surgery.
| Subjects and Methods|| |
After Institutional Ethics Committee approval, a retrospective chart review study was carried out in King Fahad Armed Forces Hospital, Jeddah, between June 2015 and December 2019. All consecutive patients in this 4-year period with benign and malignant thyroid diseases undergoing unilateral or bilateral thyroidectomy performed by a single surgeon were enrolled in this study. The patient records were reviewed, and data on age, gender, history of previous surgery, and details of operative and postoperative reports were recorded on data sheets. Thyroid surgery was classified into hemithyroidectomy, total thyroidectomy, and completion thyroidectomy. Simultaneous central neck dissection was included in the analysis. Pathology reports were reviewed for histological diagnosis and specifically for the presence of inadvertent parathyroid tissue. Statistical analysis was carried out using the Statistical Package for the Social Sciences SPSS software (Chicago, IL, USA). The Chi-square test was used to analyze the association between the categorical study variables and IP in terms of gender, pathological features, re-operation, Hashimoto thyroiditis, extrathyroidal extension, and central neck dissection. P ≤ 0.05 was considered statistically significant.
| Results|| |
Retrospective analysis of consecutive 181 patients reveals that 34 (18.7%) patients had inadvertently removed parathyroid glands. Patient is between the age group of 13 and 87 years. Mean and standard deviation were 46.3 and 14.4, retrospectively. The majority of patients were females 161 (89%). Indication of surgery was benign in 120 (66.3%) and malignant in 61 (33.7%) patients. However, gender (P = 0.4) and malignancy (P = 0.3) were not significant risk factors for IP.
The thyroid operations carried out were hemithyroidectomy in 37 (20.4%), total thyroidectomy in 136 (75.1%), and completion thyroidectomy in 8 (4.4%) patients. IP was common in total thyroidectomy compared with other operations (P = 0.017). Central neck dissection was done in 15 patients and was not found to be significant risk factor for IP (P = 0.15) [Table 1].
Papillary thyroid cancer was found to be the most common malignancy, whereas multinodular goiter was the most common benign thyroid disease [Table 2].
Of the 34 patients with IP, 7 patients have extrathyroidal extension (20.5%), and 18 patients (52.9%) have Hashimoto thyroiditis background in histopathology. Using the Chi-square test for the analysis, extrathyroidal extension (P = 0.008) and Hashimoto thyroiditis (P = 0.021) were found to be significant risk factors for IP [Table 1].
| Discussion|| |
In 2018, Bai et al. published the first systematic review and meta-analysis study about the risk factors and outcomes of incidental parathyroidectomy in thyroidectomy. This systematic review includes 35 reliable similar studies. Only one of them was a local study done in Saudi Arabia.
As far as we know; the current study is the second local study in Saudi Arabia to determine the incidence of IP during thyroid surgery. We found that the incidence rate was 18.7% and this compares favorably with the rates reported in the previous studies (2.9%–31.0%). Understanding thyroid anatomy and parathyroid glands variation with strict adherence to surgical principles is vital for an operating surgeon in any thyroid surgery. There is also variability in the number of parathyroid glands, but in most patients, there are four glands located extracapsularly, posterior to the thyroid gland. Superior parathyroid glands are usually constant in their location behind the superior pole of thyroid gland, whereas inferior parathyroid glands are more variable in its location. However, intraoperative dissection for the identification of all parathyroid glands during thyroid surgery is not necessary and sometimes could be hazardous.,
In our study, risk factors for IP included extra-thyroid extension (P = 0.008), total thyroidectomy (P = 0.017), and Hashimoto thyroiditis (P = 0.021) [Table 1]. Bilateral dissection in total thyroidectomy puts all parathyroid glands at risk. Hashimoto thyroiditis causes the formation of scar tissue secondary to inflammation, both of which can cause dissection difficulties, leading to increased risk of IP. Extra-thyroidal extension, which occurs in malignancy, and Hashimoto thyroiditis were not found to be a risk factor in some studies., However, in our study, we found them to be strong predictors for IP.
In previous studies, female gender, male gender, younger age,, completion thyroidectomy,,,, central neck dissection,,,,,,, and malignancy,,,, were found to be risk factors for IP. However, in our study, these factors were not found to be significant risks for IP.
Incidence of IP can be affected with different operating surgeons. In our study, all thyroid surgeries were performed primarily by a single surgeon or directly under his supervision.
Statement of ethics
The study has been approved by the regional Institutional Review Board. All participants have given their consent.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]