Evaluation of a Novel Cystoscopic Compatible Cryocatheter for the Treatment of Bladder Cancer

Abstract

BACKGROUND: As the acceptance of cryoablative therapies for the treatment of non-metastatic cancers continues to grow, avenues for novel cryosurgical technologies and approaches have opened. Within the field of genitourinary tumors, cryosurgical treatments of bladder cancers remain largely investigational. Current modalities employ percutaneous needles or transurethral cryoballoons or sprays, and while results have been promising, each technology is limited to specific types and stages of cancers. OBJECTIVE: This study evaluated a new, self-contained transurethral cryocatheter, FrostBite-BC, for its potential to treat bladder cancer. METHODS: Thermal characteristics and ablative capacity were assessed using calorimetry, isothermal analyses, in vitro 3-dimensional tissue engineered models (TEMs), and a pilot in vivo porcine study. RESULTS: Isotherm assessment revealed surface temperatures below – 20°C within 9 sec. In vitro TEMs studies demonstrated attainment of ≤– 20°C at 6.1 mm and 8.2 mm in diameter following single and double 2 min freezes, respectively. Fluorescent imaging 24 hr post-thaw revealed uniform, ablative volumes of 326.2 mm3 and 397.9 mm3 following a single or double 2 min freeze. In vivo results demonstrated the consistent generation of ablative areas. Lesion depth was found to correlate with freeze time wherein 15 sec freezes resulted in ablation confined to the sub-mucosa and ≥30 sec full thickness ablation of the bladder wall. CONCLUSIONS: These studies demonstrate the potential of the FrostBite-BC cryocatheter as a treatment option for bladder cancer. Although preliminary, the outcomes of these studies were encouraging, and support the continued investigation into the potential of the FrostBite-BC cryocatheter as a next generation, minimally invasive cryoablative technology.

An In Vitro Investigation into Cryoablation and Adjunctive Cryoablation/Chemotherapy Combination Therapy for the Treatment of Pancreatic Cancer Using the PANC-1 Cell Line

“…All tests were performed in a laminar flow hood to ensure sample sterility. Freezing was conducted using the PSN (Pressurized Sub-Cooled Nitrogen) Cryosystem (CPSI Biotech, Owego, NY, USA) with an input N 2 pressure of 1500 psi [ 79 ]. The cryoablation probe utilized in these studies was a 1.5 mm diameter cryoprobe with a 3 cm long freeze zone at the distal end (FrostBite, CPSI Biotech).…”

“…To bridge this gap, we have previously reported on the use of in vitro, three-dimensional tissue constructs (TEM) as a clinically analogous test setup to provide for evaluation of the thermal performance of a cryoprobe as well as the assessment of the level of cell death associated with a given protocol [27,[76][77][78][80][81][82]. This model has been shown to provide vital information on in vivo response while reducing the expense and burden of exploratory animal studies [27,79,80].…”

In Vitro Investigation of Renal Cell Carcinoma Response to Combination Sorafenib and Cryoablation Treatment

“…After 72 hours of recovery, the necrotic diameter was found to decrease to 2 cm (± 0.7) equating to 8.4 cm 3 (±0.6). We have previously reported that this decrease in the necrotic volume at day 3 is a result of cellular infiltration and regrowth within the periphery of the cryogenic lesion in the region where temperatures are above the minimal critical temperature [28,31,32,34,35].…”

“…All tests were performed in a laminar flow hood to ensure sample sterility. Freezing was conducted using the PSN (Pressurized Sub-Cooled Nitrogen) Cryosystem (CPSI Biotech, Owego, NY) with an input N2 pressure of 1,500 psi [34]. The cryoablation probe utilized in these studies was a 1.5 mm diameter cryoprobe with a 3 cm long freeze zone at the distal end (CPSI Biotech).…”

“…To bridge this gap, we have developed and previously reported on the use of in vitro, 3-dimensional tissue constructs (TEM) as a clinically analogous test setup to provide for evaluation of the thermal performance of a cryoprobe as well as the assessment of the cellular responses (level of cell destruction) associated with a given interventional protocol [28][29][30][31][32][33]35]. This model has been shown to provide vital information on in vivo response while reducing the expense and burden of exploratory animal studies [31,34,35].…”