Basic approaches to surgical treatment of thyroid diseases

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The most common thyroid pathology is macrofollicular and microfollicular colloid goiter, benign cysts, thyroiditis (autoimmune, fibrous and purulent), carcinomas (anaplastic, Hurthle cell, medullary, papillary, squamous cell and follicular), as well as benign thyroid neoplasms (adenoma, angioma, lymphoma) [1]. According to the results of histological and cytological examination of thyroid biopsy specimens, benign neoplasms are diagnosed in the following ratios: macro- and microfollicular colloid goiter - about 70% of cases, follicular adenoma - 15-25% of cases, autoimmune thyroiditis - 3-20% of cases [1-4]. The most common type of thyroid cancer is papillary carcinoma, diagnosed in approximately 80% of cases among all malignant neoplasms of this organ, followed by follicular cancer and medullary cancer, occurring in 10–22% and 4–6% of cases, respectively [1, 5–7]. Hürthle carcinoma (3–5% of cases), poorly differentiated carcinoma (about 4% of cases), and anaplastic cancer (1–2% of cases) are diagnosed much less frequently [8–10].

Objective. To study the main approaches to the surgical treatment of thyroid diseases.

Materials and methods: a review of data in PubMed, ScienceDirect, and eLIBRARY was performed using the keywords “endocrinology,” “thyroidectomy,” “hemithyroidectomy,” “thyroid gland,” “thyroid cancer,” and “intraoperative neuromonitoring.” Of the 56 sources initially identified, 15 were included in the review.

Treatment of focal thyroid pathology can be performed by conservative and surgical methods [11]. Total and subtotal thyroidectomy, hemithyroidectomy are the most common surgical interventions [1, 12]. It is important to note that extensive thyroid surgery in patients with cytologically indeterminate nodules or low-aggressive thyroid cancer demonstrates comparable results with total thyroidectomy with a lower risk of complications [13]. Current guidelines recognize hemithyroidectomy as an acceptable initial treatment for cytologically indeterminate nodules and papillary thyroid carcinoma, while the incidence of transient hypoparathyroidism is reduced during surgery [13, 14]. However, the choice between hemithyroidectomy and total thyroidectomy is often a complex issue requiring an individual approach [13]. Hemithyroidectomy involves the removal of the entire affected thyroid lobe and isthmus with possible removal or preservation of the central cervical lymph nodes, while total thyroidectomy involves the removal of the entire thyroid gland with the option of removing or preserving the lymph nodes [13]. During the consultation with the patient, a number of additional factors should be taken into account - his personal preferences, the possibility of preoperative diagnostics, the prospects for long-term follow-up and the need for thyroid hormone replacement therapy [13]. In addition, local symptoms, personal and family history of thyroid cancer and the presence of hereditary syndromes are taken into account [13].

According to the American Thyroid Association (ATA) and the National Comprehensive Cancer Network (NCCN) guidelines, if thyroid nodules smaller than 4 cm in size without associated features of malignancy are detected, it is advisable to consider hemithyroidectomy [13]. Recently, active surveillance of papillary thyroid microcarcinomas smaller than 4 cm in the absence of signs of malignancy and metastases to the lymph nodes has become an increasingly acceptable treatment method [13]. The ATA thyroid cancer guidelines suggest preferentially performing hemithyroidectomy when solitary nodules with indeterminate cytology according to the Bethesda classification III (follicular changes of undetermined significance) or IV (follicular neoplasia) are detected [13]. The undeniable advantages of hemithyroidectomy are minimization of the risk of developing temporary or persistent hypoparathyroidism, as well as a decrease in the likelihood of damage to the superior and recurrent laryngeal nerves [14]. If malignant nodes are detected in one lobe of the thyroid gland and benign nodes in the other, it is advisable to perform hemithyroidectomy of the lobe with the tumor and simultaneous intraoperative radiofrequency ablation (RFA) of the contralateral lobe [14].

The duration of thyroid surgery is on average 1-2 hours and depends on the size of the goiter-altered tissue, the nature of the disease (in the presence of a toxic form of goiter, the duration of the surgery increases due to the presence of severe bleeding of the parenchyma), localization, anatomical and technical features [15]. In the case of a small goiter, the duration of the surgery increases due to lesser stretching of the Berry ligament [15]. Despite the fact that ultrasound is the most frequently used method for diagnosing thyroid diseases, its capabilities are limited with significant tumor sizes [16]. In such cases, it is difficult to accurately assess the relationship of the tumor with neighboring organs, and sometimes even determine its origin [16]. The combination of single-photon emission computed tomography (SPECT) with X-ray computed tomography (X-ray computed tomography) is an advanced radioisotope X-ray study [16]. Such an integrated approach provides increased information content and optimized diagnostic capabilities [17]. This method allows to accurately determine the size and location of pathological formations, as well as to assess their relationship with adjacent anatomical structures [17]. According to the opinion of the authors of most national recommendations for the diagnosis of thyroid diseases, ultrasound examination is one of the leading diagnostic methods [17]. At the same time, the specific technical characteristics of ultrasound limit its use in mediastinal pathology [17]. In this regard, in the presence of a retrosternal goiter or a goiter of significant size, the use of additional methods of radiation diagnostics is recommended to obtain a complete clinical picture [17].

Conclusion

The most common pathology of the thyroid gland is macrofollicular and microfollicular colloid goiter, benign and malignant neoplasms, thyroiditis. Treatment of focal pathology of the thyroid gland can be carried out by conservative and surgical methods. Total and subtotal thyroidectomy, hemithyroidectomy are the most common surgical interventions. In the presence of non-toxic goiter of large sizes, toxic goiter that does not respond to conservative treatment, malignant neoplasms of the thyroid gland, thyroidectomy is recommended in most cases. Recently, active monitoring of papillary microcarcinomas of the thyroid gland less than in the absence of signs of a malignant process and metastases to the lymph nodes has become an increasingly acceptable method of treatment. According to the recommendations of the American Thyroid Association and the National Comprehensive Cancer Network, when thyroid nodules smaller than 4 cm in size are detected without concomitant signs of malignancy, it is advisable to consider hemithyroidectomy. Thus, the choice of surgical tactics depends on the nature of the thyroid disease, the prevalence of the pathological process and should take into account the capabilities of modern surgery and the wishes of the patient.

About the authors

Michail Remezov

Voronezh State Medical University named after N.N.Burdenko

Author for correspondence.
Email: docmikle@mail.ru
ORCID iD: 0000-0003-1598-6768
SPIN-code: 8853-9959

5th year student of the pediatric faculty

Russian Federation, 394036, Russia, Voronezh, Studencheskaya st. 10

Anastasia Yuryevna Laptieva

Voronezh State Medical University named after N.N.Burdenko

Email: alaptieva@vrngmu.com
ORCID iD: 0000-0002-3307-1425
SPIN-code: 7626-9016

Assistant at the Department of General and Outpatient Surgery

394036, Russia, Voronezh, Studencheskaya st. 10

Anton Petrovich Ostroushko

Voronezh State Medical University named after N.N.Burdenko

Email: oap@vrngmu.com
ORCID iD: 0000-0003-3656-5954
SPIN-code: 7626-9016

PhD, Associate Professor of the Department of General and Outpatient Surgery

394036, Russia, Voronezh, Studencheskaya st. 10

References