Local Ethanol Destruction in the Treatment of Thyroid Diseases

The dissertation focuses on the development and refinement of percutaneous local chemical destruction with ethanol in various thyroid diseases. It examines the use of ethanol sclerotherapy under ultrasound guidance for the treatment of nodular non-toxic and toxic goiter. The study analyzes the treatment of solid, cystic, and mixed nodules and proposes a differentiated approach to selecting the volume and frequency of sclerosant administration according to the structure and initial size of the nodules. Immediate and long-term outcomes, possible complications and their prevention, as well as the economic effectiveness of sclerotherapy in comparison with conventional surgery are evaluated. On the basis of the study, a diagnostic and therapeutic algorithm for the management of patients with nodular thyroid lesions is proposed.

Thyroid pathology is currently one of the most common human ailments. According to the World Health Organization, thyroid diseases are recorded in 10-15% of the world's entire population, and in Russia more than one million patients with lesions of this organ are registered annually. The increase in recent years in the number of patients with thyroid pathology is associated not only with a rise in morbidity but also with the improvement of diagnostic methods and, above all, with the widespread introduction of ultrasound examination into clinical practice (Abdulkhalimova M.M. et al., 1999; Shulutko A.M. et al., 2000; Semikov V.I., 2002). E.A. Valdina (2001) reports that on ultrasound examination nodules in the thyroid gland are detected in 20-44% of women and in 17-19% of men.

Despite many years of experience, there is no unified approach to the treatment of patients with nodular thyroid lesions. The majority of authors currently distinguish two main treatment strategies: surgical and conservative.

The leading method of treatment of thyroid nodules is considered to be surgical. Some surgeons potentially see a tumor in every nodular formation of the thyroid gland and therefore recommend operating on all detected thyroid nodules (Vlasov V.V., 1998; Granovskaya A.M. et al., 2001; Dewan S.S., 1996). In addition, they note that the administration of thyroid hormones is effective only in a few patients, whereas in the majority of them nodule growth is a predictable variant of the disease course.

Supporters of the conservative approach, on the contrary, in the majority of their publications cite data on the positive effect of drug therapy for small thyroid nodules. They note that after any operation on the thyroid gland specific complications may arise that reduce the quality of life of patients in the postoperative period. Monitoring of nodules using highly sensitive diagnostic methods makes it possible to detect minor changes in the size and structure of the formation and to make timely adjustments to treatment. This primarily applies to multinodular goiter, when the diagnosis is confirmed by ultrasound and cytological examination (Gharib H., Mazzaferri E.L., 1998).

In recent years, minimally invasive technologies under ultrasound guidance have been increasingly used in clinical practice; their therapeutic effect is achieved through targeted percutaneous destruction of nodular formations while preserving the main mass of functioning thyroid parenchyma surrounding the nodule (Aleksandrov Yu.K., 1997, 1998; Barsukov A.N., 2000; Bubnov A.N., 2000; Tolpygo V.A., 2001; Il'in A.A. et al., 2004; Lindner W., 1995; Chang H.S. et al., 1998; Barios M., 2000). In essence, these methods are operations, since they eliminate the pathological focus through the direct active action of physical or chemical factors (Aleksandrov Yu.K., 1998). On the other hand, these methods are minimally invasive, are easily tolerated by patients, are accompanied by a minimal number of complications, and achieve their effect through targeted destruction of nodules while preserving healthy hormone-producing parenchyma of the gland.

One such method is ethanol sclerotherapy, proposed in 1990 by T. Livraghi. In modern publications devoted to sclerotherapy, various experiences of its use are analyzed, both in individual patients (Braga-Basaria M. et al., 2002) and in larger patient populations - up to 2323 (Fukunari N., 2002). When evaluating the effectiveness of sclerotherapy, all authors emphasize the rapid and sustained reduction of true thyroid cysts and cystic nodules with a predominant cystic component (Aleksandrov Yu.K., 1998; Barsukov A.N., 1997; Bubnov A.N., 1997; Vetshev P.S. et al., 2002; Kim I.V. et al., 2004; Monzani F. et al., 1994). They note that this technique is less effective in the treatment of solid thyroid nodules.

However, in the available literature there is no consensus regarding the volume of sclerosant administered per unit volume of tissue, the frequency and interval of injections, and there are no clear criteria for evaluating the effectiveness of sclerotherapy. This apparently stems from differences in the understanding of the mechanisms of sclerosis and reduction of nodular tissue after its destruction by ethanol and from technical differences in the methods of sclerosant instillation used. In addition, the long-term results of treatment are also insufficiently covered.

Thus, it appears highly relevant to study the possibility of using ethanol sclerotherapy in the treatment of various thyroid diseases.

Aim of the Study

To develop and refine the method of percutaneous local chemical destruction with ethanol in patients with various thyroid pathologies.

Objectives of the Study

1. To refine the technique of ethanol sclerotherapy under ultrasound guidance in nodular thyroid lesions.

2. To evaluate the therapeutic capabilities and long-term results of ethanol sclerotherapy in various thyroid pathologies.

3. To study possible complications of this method and propose ways to prevent them.

4. To develop indications and contraindications for ethanol sclerotherapy in the treatment of patients with various thyroid diseases.

5. To develop a diagnostic and therapeutic algorithm for patients with nodular thyroid lesions.

6. To evaluate the economic effectiveness of sclerotherapy of nodular thyroid formations.

Scientific Novelty

The improved technique of ethanol sclerotherapy for various thyroid diseases is effective and safe for the patient.

For the first time, a differentiated approach to sclerotherapy in various thyroid pathologies has been developed, taking into account the structure of nodules and their initial volume.

Based on the studied morphological changes in thyroid parenchyma after ethanol injection and on ultrasound monitoring data, the optimal timing for repeated sclerotherapy sessions has been determined.

For the first time, an active treatment strategy for nodular/multinodular goiter using local ethanol destruction has been proposed, ensuring good long-term results in this category of patients.

Practical Significance of the Work

Ethanol sclerotherapy is an alternative method of treatment of nodular/multinodular non-toxic and toxic goiter.

To achieve complete safety of sclerotherapy in various thyroid pathologies it is necessary to apply: ultrasound monitoring, a single ethanol injection of no more than 1 ml, and, when indicated, the original technique of local anesthesia with injection of 0.5% novocaine solution between the layers of the third cervical fascia (according to V.N. Shevkunenko).

When performing sclerotherapy of solid nodules and diffuse toxic goiter, Doppler monitoring must be carried out both during treatment and during subsequent follow-up.

Early detection of benign thyroid nodules and the active and timely use of local ethanol destruction make it possible in the majority of patients to achieve complete or partial regression of the nodule and to prevent surgical intervention.

Implementation of the Work

The results of the research and the materials of the dissertation are used in the educational process of the Department of General Surgery of the Chelyabinsk State Medical Academy.

Practical recommendations on the technique of sclerotherapy have been implemented in the work of the Chelyabinsk Regional Center for Surgical Endocrinology based at Chelyabinsk City Clinical Hospital No. 1, the Smolensk Regional Clinical Hospital, and the Railway Clinical Hospital at Yaroslavl Station of the Northern Railway.

Methodological recommendations have been published: Sclerotherapy in the Treatment of Thyroid Diseases (Chelyabinsk, 2003).

Five certificates for rationalization proposals have been obtained.

Nine publications have been issued on the topic of the dissertation.

Approbation of the Work

The main provisions of the dissertation were reported and discussed at regional conferences and meetings of the scientific and practical societies of surgeons and endocrinologists (2002, 2003) and at annual Russian Symposia on Surgical Endocrinology (2000-2004).

Propositions of the Dissertation Submitted for Defense

1. The improved technique of ethanol sclerotherapy with dynamic ultrasound examination and Doppler monitoring, fractional administration of sclerosant, and the use of local anesthesia during local ethanol destruction make the sclerotherapy procedure maximally safe for the patient.

2. Percutaneous ethanol injections are the method of choice in the treatment of nodular/multinodular colloid non-toxic goiter.

3. Ethanol sclerotherapy in thyrotoxicosis makes it possible to reduce the production of thyroid hormones and achieve remission of the disease through local destruction of thyroid tissue, especially in autonomously functioning nodules.

4. A differentiated approach to the choice of adequate treatment strategy enables the majority of patients with nodular thyroid lesions to avoid surgery and the related complications.

Volume and Structure of the Work.

The dissertation is set out on 165 pages of computer text and consists of an introduction, six chapters, a conclusion, conclusions, practical recommendations, and a list of references. The work is illustrated with 29 tables and 61 figures. The bibliographic reference list contains 231 titles, of which 146 are domestic and 85 are foreign sources.