[Carboxycryobiopsy and carboxycryoextraction of bladder tumor. Experimental study].

AIM: To evaluate the possibility of performing transurethral carboxycryobiopsy (CCB) and carboxycryoextraction (CCE) of a bladder tumor for pathomorphological examination, as well as to perform a comparative analysis of the safety (quality) of biopsy material (tumor tissue) during standard transurethral biopsy and carboxycryobiopsy. MATERIALS AND METHODS: In the first experiment in vitro, CCE of bladder tumor fragments obtained after transurethral resection was performed. In the second pilot study, cystoscopy followed by CCB and CCE in a patient with multiple bladder tumors was done. The procedure was performed by transurethral access. During cryopreservation of the bladder tumor, a biopsy was performed. After freezing, the tumor was removed from the bladder and sent for histological examination. RESULTS: The first experiment showed that cryoextraction of the fragments of a bladder tumor using carbon dioxide (CCE) in vitro is a feasible procedure and allows the evacuation of tumor tissues of various sizes. According to the second experiment, CCB and CCE of the bladder tumor using carbon dioxide allows to obtain a biopsy of a bladder tumor of sufficient size without compression or coagulation artifacts, which contributes to a more accurate histological evaluation. CONCLUSION: Our experiments showed that CCB and CCE of a bladder tumor using carbon dioxide are feasible procedures that contribute to obtaining better biopsy material for pathomorphological examination, and also allows to evaluate the effect of low temperatures of carbon dioxide on the biopsy material (tumor tissue).

[Kidney carboxycryoablation. Pilot study].

AIM: The aim of this experimental study was to evaluate the effect of low temperatures of carbon dioxide on a "living" blood-supplying organ (pig kidney), to determine the possibility of performing cryoablation of kidney tissue with carbon dioxide (carboxycryoablation), as well as to establish experimentally modes of carboxycryoablation of the kidney. MATERIALS AND METHODS: To carry out this experimental study, a female of the mini-pig line was used. We performed laparoscopic access to the kidney for carboxycryoablation. During the freezing of the kidney, three modes were compared: 60, 90, and 120 s on one kidney of one animal. Immediately after the completion of cryoablation, nephrectomy was performed, and the removed kidney was sent for histological examination. According to the histological study, the results of the use of carbon dioxide during cryoablation of porcine kidney tissue were evaluated. RESULTS: Cryoablation based on carbon dioxide (carboxycryoablation) leads to irreversible death (necrosis) and destruction of the affected tissue. A direct relationship between the exposure mode and the size of the cryonecrosis zone was noted. Thus, the most extensive zone of necrosis with a diameter of 10 mm was achieved when performing cryoablation in the exposure mode of 120 s. CONCLUSION: This experiment showed that carbon dioxide-based cryoablation remains a feasible procedure that leads to irreversible death (necrosis) and destruction of the affected tissue. However, further studies on the safety and efficacy of cryoablation of kidney tissue with carbon dioxide are required.

[Clinical case of delayed diagnosis of tuberous sclerosis].

A clinical case of successful drug treatment of multiple renal angiomyolipomas in patient with tuberous sclerosis is presented, which suggests potential role of medical treatment of benign kidney tumors.