Cryotherapy for non-muscle invasive bladder cancer-preliminary results in an animal model

Initial treatment for Non-Muscle Invasive Bladder Cancer (NMIBC) has remained mostly unchanged in recent decades. Cryotherapy with CO2 has been commonly used in medicine for many years. In this study, we present the results of a pre-clinical study aimed at developing a novel cryoablation device to treat superficial low-grade bladder lesions.

Following initial technical and developmental studies, a rigid cryotherapy device was developed. A technical and efficacy assessment was conducted utilizing the porcine model. Overall, twenty-six ablation areas (up to four per animal) were evaluated. Following an initial routine cystoscopy, the bladder irrigation medium was replaced with CO2 insufflation, and each area was treated with 2 cycles (15 s each) of direct liquid CO2 spraying. After five days, the bladder epithelium was harvested for pathological evaluation.

No bladder perforation was noted on pathology. The initial efficacy and usability of the device were demonstrated. Pathological evaluation of treated tissue morphology revealed focal mucosal edema and necrosis with associated surrounding reactive fibrosis, with penetration depths ranging from 0.5 to 4 mm, without profound muscularis propria damage.

Initial results suggest the safety and feasibility of cryotherapy utilizing CO2 spraying. Pathological analysis confirms its potential in treating non-muscle invasive bladder cancer. Ongoing clinical studies aim to validate these results in human subjects, offering a potential paradigm shift in non-muscle invasive bladder treatment.