CIO 2021-22 External Skin Warming During Cryoablation—Novel Technique With In Vivo Temperature Data

Purpose: External skin warming is a critical technique for cutaneous protection when performing cryoablation of superficial tumors. Existing techniques for cutaneous protection include hydrodissection, pneumodissection, and application of warm, fluid-filled gloves. The efficacy of these techniques is reduced in patients with adhesions from prior surgeries or radiation therapy. We describe a novel technique of applying warmed water soaked gauze to the skin to achieve cutaneous protection from frostbite injury during a desmoid cryoablation including in vivo data on temperature effects.

Material and Methods: A 38-year-old female with a large painful desmoid tumor of the posterior chest wall presented following local recurrence after surgical resection. A cryoablation was planned with 8 IceForce probes (Boston Scientific, Marlborough, MA, USA). The lateral component of the tumor resided 8 mm underneath the skin. Hydro-dissection was unsuccessful at increasing the tumor-skin distance due to adhesions with the surgical scar. A temperature probe (Multi-point 1.5 Thermal Sensor, Boston Scientific, Marlborough, MA, USA) was inserted with the target thermocouple located 5 mm under the skin and superficial to tumor. An OR fluid warmer was utilized to warm sterile water to 48.9 degrees Celsius. Gauze 4x4 sponges were soaked in the warmed water and applied to the skin overlying the tumor.

Results: Initial temperature at the thermocouple 5 mm below the skin surface was 34.9 degrees Celsius. Following application of the sterile water-soaked gauze to the skin temperatures were recorded in 1 second intervals for 6 minutes. New gauze was applied every 1.5 minutes. A maximum subcutaneous temperature of 40.1 degrees Celsius was achieved after 5 minutes, and no further warming occurred out to 6 minutes. Cryoablation was successfully performed. Follow-up MRI at 6 months demonstrates durable tumor response to cryoablation. No thermal cutaneous injury was encountered.

Conclusions: Warming the skin with external application of sterile gauze soaked in warmed water is an effective, non-invasive means to achieve cutaneous protection during cryoablation when alternative methods fail. In vivo thermocouple data demonstrated a 5-degree Celsius temperature rise can be achieved with external warming methods.