Tu1592 Multi-Center Experience With the Cryoballoon Focal Ablation System (CAS) for Esophageal Dysplasia

Abstract

Tu1592 Multi-Center Experience With the Cryoballoon Focal Ablation System (CAS) for Esophageal Dysplasia Kenneth K. Wang*, Ann M. Chen, Shai Friedland, Blair A. Jobe Gastroenterology, Stanford University, Palo Alto, CA; Gastroenterology, VA Palo Alto HCS, Palo Alto, CA; Gastroenterology, Mayo Clinic, Rochester, MN; Surgery, West Penn Allegheny Health System (WPAHS), Canonsburg, PA; Gastroenterology, Santa Clara Valley Medical Center, San Jose, CA Mucosal ablation using RFA with or without EMR is the current treatment of choice for Barrett’s esophagus with high-grade dysplasia. Although effective, RFA has drawbacks such as the need for precise sizing, mucosal cleaning, and need for multiple treatments over the same segment. Cryotherapy is currently being used for refractory dysplasia or squamous disease. However, currently-available devices have been limited by the need for large units and high volume suction. The CAS is a novel device that can perform cryotherapy without the need for suction in a self-contained handheld system. Methods: This is a retrospective cohort study of the initial experience with the CAS system performed in tertiary referral centers. The CAS is a battery-powered, handheld device that uses cryogen contained in disposable nitrous oxide cartridges. The disposable catheter (3.5mm in diameter) is delivered through the biopsy channel of a therapeutic endoscope and positioned alongside a segment of Barrett’s mucosa. A balloon is inflated on the distal catheter using nitrous oxide (Figure 1). The mucosa can be viewed through the transparent balloon. The mucosa to be treated is selected by using a short burst of nitrous oxide. After the short burst, a treatment session of 10 seconds can be delivered to the tissue. Results: The initial experience has been with 7 patients (6 males) treated with the CAS at three institutions. Median age is 65 years (IQR 42-73). Five (5/7, 70%) patients had Barretts Esophagus with high-grade dysplasia; one patient also has intramucousal carcinoma. Two patients (2/7, 30%) were being treated for squamous cell esophageal carcinoma. Six of seven (85%) had prior treatment. One patient had 4 areas treated with the CAS, while 2 patients each had cryoablation in 3 areas and 4 each had cryoablation in one area. Ablations were ten (10) seconds in duration. Complete ablation was achieved in 6 of the 7 patients: in one patient tumor in the upper esophageal sphincter was not treated completely because stable placement of the CryoBalloon could not be achieved.Reasons for physician choice of the CAS include failure of previous treatment, device ease-of-use and the conformable balloon. One of the patients with squamous cell carcinoma had two interventions with the CAS, both ablations considered effective. Follow-up histopathology for this patient showed fragments of benign squamous mucosa, negative for dysplasia or neoplasia.At followup endoscopy areas of treatment were all epithelialized with squamous mucosa. No strictures were noted at any treatment sites. Conclusions: CAS is a novel handheld cryotherapy device that can effectively treat areas of Barrett’s esophagus without need for suction with minimal side effects in this preliminary experience.