Hyponatremia is the most common disorder of water and electrolyte balance encountered in clinical practice. Conditions associated with hyponatremia require hospitalization in 15–20% of cases. Hyponatremia is a predictor of poor outcome in a wide range of diseases and therefore requires an interdisciplinary approach. This problem leads to an increase in complications and the length of hospital stay and mortality. The review focuses on the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), which accounts for approximately one third of all cases of hyponatremia and is more common in endocrinology than other fluid and electrolyte disorders along with central diabetes insipidus. The article presents modern approaches to the treatment of SIADH based on international clinical guidelines.

Background: Due to its availability, high information content and harmlessness, ultrasound is an extremely effective method of differential diagnosis of thyroid pathology. Despite the sufficient arsenal of diagnostic methods, thyroid biopsy with cytological examination is the «gold» standard in diagnostic algorithms. Most often, fine — needle aspiration biopsy is carried out using disposable syringes of different capacities (5, 10, 20 ml3). The procedure is performed in most cases according to the «Free hand» method, this leads to several problems associated with the peculiarity of the study, primarily with the low vacuum created in the syringe and insufficient collection of cytological material, as well as insufficient practical experience for a novice specialist.

Aim: Determination of the range of the possibility of using vacuum aspiration fine needle biopsy under the control of ultrasound navigation in patients with focal thyroid pathology.

Materials and methods: On the basis of the Problem Research Laboratory «Diagnostic studies and minimally invasive technologies» of the Smolensk State Medical University, a device for vacuum fine — needle aspiration biopsy was developed. In the period 2019–2020, 780 vacuum fine — needle aspiration biopsy was performed under the control of ultrasound navigation in patients with thyroid nodules. The level of vacuum in the syringe during sampling of the material was — 0,5 bar (- 50 kPa).

Results: A comparative analysis of the cytological results obtained with the help of vacuum fine — needle aspiration biopsy and the «Free hand» method shows a decrease in obtaining the category of Bethesda 1 by 3.3% and Bethesda 3 by 10.2%.

Conclusion: This indicates the effectiveness and in formativeness of the use of vacuum fine — needle aspiration biopsy in patients with focal thyroid pathology in comparison with the standard «Free hand» method, as well as with vacuum fine — needle aspiration biopsy due to constant visual monitoring and the lack of movement of the syringe piston to create a discharge when taking cytological material, the probability of needle deviation from the biopsy zone is reduced, which increases the effectiveness of the study and facilitates the work of a novice specialist.

This is a clinical case of surgical treatment of persistence of secondary hyperparathyroidism (SHPT) in a patient with chronic kidney disease after previous parathyroidectomy. Programmed hemodialysis started in 2014, and in 2016 SHPT was diagnosed. In November 2018, indications for surgical treatment were presented in one of the clinics. According to scintigraphy, an increase in the functional activity of all four parathyroid glands (PTG) was observed, according to ultrasound data, the localization of the right lower, left upper and lower PTG was established. Removal of 3x PTG was performed without revision of the thymus horns (11.2018), while in the postoperative period, an adequate decrease in parathyroid hormone was not observed. After additional examination, according to ultrasound, scintigraphy and computer tomography of the neck with intravenous enhancement, it was found that both lower PTGs are located in the upper horns of the thymus. In July 2020, a repeated surgical intervention was performed in the volume of the right lower and left lower parathyroidectomy with a positive intraoperative test. Remission of SHPT was achieved. At present, no consensus has been reached on the extent of surgery for SHPT, since no statistically significant differences were found in the incidence of persistence / recurrence of SHPT. A complete assessment of the results of preoperative imaging techniques is required when planning surgery. Intraoperative monitoring of parathyroid hormone is an effective technique for assessing the radicality of surgical treatment.

Paragangliomas represent 15 to 20% of all chromaffin tissue tumors. Most often, paragangliomas are located in the abdominal cavity along the large vessels — in the para-aortic region from the diaphragm to the aortic bifurcation. One of the most common extra-adrenal pheochromocytomas is the Zuckerkandl tumor, originating from the para-aortic accumulation of sympathetic tissue located in the area of the inferior mesenteric artery’s origine or in the zone of the aortic bifurcation itself. Due to the technical difficulty in performing laparoscopic removal of paragangliomas, conversion to laparotomy is frequent and reaches 80%. The article describes a clinical case of a patient suffering from this type of neoplasm, with diagnosis details and treatment by a successful radical laparoscopic intervention with a large chromaffinnoma located in a difficult anatomical zone removal.