Kulikova D. Diagnostic and prognostic aspects of ultrasound signs of hemodynamic significance of the patent ductus arteriosus.

The thesis presents the results of the new strategy on how to define the hemodynamic significance of the patent ductus arteriosus in babies who have been born at full-term. Based on the analysis of clinical data, the results of electrocardiography, chest radiography, and ultrasound diagnostics, the study provides reliable indirect diagnostic signs associated with the patent ductus arteriosus. A comparative analysis of ultrasound and intraoperative data allowed optimizing the degree of the hemodynamic significance of the ductus, to identify the primary and additional ultrasound features that permit determining this significance. A new method for determination of the patent ductus arteriosus’ hemodynamic significance without using secondary changes in the heart was designed, tested and introduced to practice (sensitivity of the method is 8.4 %, the specificity of 86.8 %). The author advocates for the possibility of using additional ultrasound signs, which are crucial in diagnostics of combined patent ductus arteriosus with a secondary defect of the atrial septum of borderline size. A comparison of computed tomography and ultrasound data received further evolution in the diagnostics of a combination of patent ductus arteriosus and coarctation of the aorta. An algorithm with the use of prognostic chart has been designed and tested for the diagnostics of patent ductus arteriosus, both for an isolated defect and for combination with a secondary atrial septal defect, which made it possible to specify the role of ultrasound in the diagnosing and making prognosis for this pathology. The designed approaches provided an opportunity to foresee self-closure of the duct in a case of an isolated defect and neglect a small secondary defect when combined with a hemodynamically significant duct, which permits avoiding unnecessary surgical interventions, including the use of cardiopulmonary bypass, and reduced the use of invasive techniques for examining a patient. Key words: Patent ductus arteriosus, ultrasound, hemodynamic significance