Репозиторий Университета

© 2018 ABC-press Publishing House. All rights reserved.  Background. There is a category of patients with renal masses, due to severe concomitant diseases, can not perform the operation or may be associated with a threat to life. In addition, many patients with small tumor sites are extremely concerned about their disease and are negative about the tactics of active observation and insist on treatment. These patients can be offered alternative methods of treatment of renal cell carcinoma (RCC), the leading of which is cryoablation. Objective: to evaluate the effectiveness and safety of percutaneous cryoablation of the kidney tumor under ultrasound control. Materials and methods. In the Urology Clinic of the I.M. Sechenov First Moscow State Medical University during the period from 2015 to 2017 performed 23 percutaneous cryoablation of RCC, 7 (men - 4, women - 3) of which were performed under local anesthesia. In 4 patients due to severe concomitant diseases, general anesthesia was associated with an extremely high risk. Three patients refused from dynamic observation and from traditional surgical treatment; preferred an alternative treatment in the form of a percutaneous cryoablation under local anesthesia. In 4 cases, the formations were located in the lower segment along the posterior surface of the kidney, in 3 - along the lateral surface in the middle segment. The size of the formations was not used 4 cm (T1a). The age of the patients was 62.3 years (51 to 83 years). Right-sided localization of the tumor was noted in 3 patients, left-sided - in 4. One patient had a single kidney. At the preoperative stage and 6 months after the operation, all patients underwent ultrasound with dopplerography, multislice computerized tomography with contrast, and computer 3D modeling, which helped to clearly assess the size of the tumor, clarify the prevalence of the tumor process and the spatial ratio of the internal surface of the tumor node to the elements of the bowl-and-pelvis system. In all the observations, the formations were located along the posterior or lateral surface of the kidney; in the lower or middle segment; without invasion of the sine. We used a 3 rd generation cryomash machine SeedNet gold (Galil Medical), cryoprobes IceSeed and IceRod. Intraoperative, immediately before cryoablation, a tumor biopsy was performed, the presence of RCC in all patients was confirmed morphologically. Results. According to the ultrasound examination with echodopplerography at 6 months after the operation, the size of the tumor node's formations decreased on average by 6-8 mm, while there was no blood flow in them. When multislice computerized tomography with 3D modeling was performed, the formation was reduced and the accumulation of the contrast preparation was completely absent or their accumulation gradient did not exceed 10 HU (initially it was about 200 HU). There were no intraoperative complications. In 1 observation, a postoperative hematoma measuring 7 × 3 cm was resolved conservatively and did not require surgical treatment. Conclusions. Percutaneous cryodestruction under local anesthesia using ultrasound guidance seems to be an effective and safe technique for treating patients with stage T1a RCC with localization in the posterior or lateral surface in the lower or middle segments without invasion of the renal sinus and surrounding tissues. It is planned to continue monitoring patients to assess the long-term effectiveness of cryoablation.

© 2018 SPIE. We have proposed a concept of monitoring ice ball formation in biological tissues during cryodestruction process via spatially-resolved detection of elastic light backscattering. For this purpose, we developed an experimental setup for study cryodestruction by using applicators based on sapphire shaped crystals with internal channels for optical irradiation of biotissues and detection of backscattered light. Due to the unique physical properties of sapphire, i.e. high thermal, mechanical, and chemical strength, high thermal conductivity and optical transparency, the sapphire cryoapplicators yield combination of the tissue cryodestruction with the optical control of tissue freezing. We have shown experimentally that using the proposed concept of applicator with several channels, it is possible to monitor changes of the ice ball during the cryodestruction process.

© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. We have developed cryo-applicators based on the sapphire shaped crystals fabricated using the edge-defined film-fed growth (EFG) and noncapillary shaping (NCS) techniques. Due to the unique physical properties of sapphire: i.e. high thermal, mechanical, and chemical strength, impressive thermal conductivity and optical transparency, these cryo-applicators yield combination of the tissue cryo-destruction with its exposure to laser radiation for controlling the thermal regimes of cryosurgery, and with the optical diagnosis of tissue freezing. We have applied the proposed sapphire cryo-applicators for the destruction of tissues in vitro. The observed results highlight the prospectives of the sapphire cryo-applicators in cryosurgery.