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).

Keywords: TUR biopsy, carboxy cryoextraction, carboxy cryobiopsy, bladder tumor, carbon dioxide