From the AGA Journals

Cryoballoon, cryospray found equivalent for eradicating Barret’s esophagus

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Evolving role and technology

The role of cryotherapy in Barrett’s esophagus eradication continues to evolve. Early data on liquid nitrogen (LN) cryospray included patients who failed radiofrequency ablation or had long segment or nodular disease, resulting in eradication rates lower than those for RFA. More recent studies, with cohorts similar to RFA studies, show comparable results with LN cryospray and the newer nitrous oxide cryoballoon. Cryotherapy tends to produce less postprocedure pain compared with RFA, especially when treating longer segments, and this is a common reason for choosing cryotherapy. This study by Alshelleh et al. compared complete eradication rates of dysplasia and intestinal metaplasia between cryospray and cryoballoon in a retrospective single-center study. Complete eradication rate of dysplasia was 95%-96% and that of intestinal metaplasia was 80%-85%, comparable with reported results for RFA.

Professor of Medicine, Division of Gastroenterology and Hepatology, University of Maryland, Baltimore, Maryland

Dr. Bruce D. Greenwald

How do these technologies differ? The cryoballoon catheter is self-contained and relatively inexpensive, while cryospray requires a console with LN tank and a decompression tube venting nitrogen gas during spray. The cryoballoon can treat only a small mucosal area with each freeze (although a hemicircumferential catheter is under study), while cryospray can “paint” a larger area with LN. A new cryospray catheter is under development that delivers circumferential treatment over several centimeters of tissue, like the RFA balloon catheter. The ability of the cryospray device to deliver essentially unlimited cold energy makes it useful in ablation of esophageal cancer, as well as for pulmonary and ENT applications. Expect improvement in both technologies, along with a better understanding of their role in ablation of Barrett’s and other tissues.

Bruce D. Greenwald, MD, is a professor of medicine in the division of gastroenterology and hepatology at the University of Maryland, Baltimore. He receives research funding from and serves as a consultant for Steris.


 

FROM TECHNIQUES AND INNOVATIONS IN GASTROINTESTINAL ENDOSCOPY

Cryoballoon and cryospray ablation were equivalent for eradicating dysplastic Barrett’s esophagus, according to the findings of a single-center retrospective study of 71 ablation-naive patients.

At 18 months, rates of complete eradication of dysplasia were 95.6% in patients who received cryoballoon therapy and 96% in recipients of cryospray, reported Mohammed Alshelleh, MD, of Northwell Health System, a tertiary care system in New Hyde Park, N.Y. Rates of complete eradication of intestinal metaplasia were 84.75% and 80%, respectively. However, selection bias was likely, and a post hoc power calculation suggested that the cryospray group was underpowered by four patients. “Prospective studies are needed to confirm [these] data,” Dr. Alshelleh and associates wrote in Techniques and Innovations in Gastrointestinal Endoscopy.

Cryotherapy is common for treating dysplastic Barrett’s esophagus when patients do not achieve remission with radiofrequency ablation. For treatment-naive individuals, prospective studies suggest that cryotherapy may be less painful and as effective as radiofrequency ablation, but no studies have directly compared the two commercially available systems: a cryogenic balloon catheter (C2 Cryoballoon, Pentax Medical, Montvale, N.J.) that delivers cryogenic nitrous oxide (–85° C) into an inflated balloon in direct contact with the esophageal mucosa, and a spray cryotherapy system (truFreeze, Steris Endoscopy, Mentor, Ohio), which flash-freezes the mucosa to –196° C by delivering liquid nitrogen through a low-pressure catheter that is not directly in contact with the esophagus.

For the study, the investigators retrospectively compared rates of complete eradication of dysplasia, and complete eradication of intestinal metaplasia, among ablation-naive patients at their institution who had received one of these two cryogenic modalities between 2015 and 2019. All patients were treated at least twice, at 3-month intervals, and were followed for least 12 months, or until complete eradication of intestinal metaplasia was confirmed by at least one endoscopic biopsy. In all, 46 patients received cryoballoon therapy and 25 received cryospray. Outcomes between the two modalities showed no significant differences in subgroups stratified by baseline histology, nor were there significant differences in rates of postprocedural stricture (8.7% in the cryoballoon group vs. 12% in the cryospray group). However, the investigators acknowledged that the study was underpowered. Overall, clinicians tended to prefer cryoballoon because it uses prefilled nitrous oxide cartridges, making it unnecessary to fill up a large nitrogen tank or use a “cumbersome decompression tube,” the investigators wrote. “However, in patients with a very large hiatal hernia or if there was a need to treat in a retroflexed position, spray cryotherapy was used given its ease of use over cryoballoon in these scenarios. Finally, cryospray is more amenable to treat larger surface areas of Barrett’s versus the focal cryoballoon that treats focal areas, and thus was the cryotherapy choice for a long segment of Barrett’s.”

The investigators reported receiving no grant support. One investigator disclosed ties to Olympus America, Pentax Medical Research, and Ninepoint Medical.

SOURCE: Alshelleh M et al. Tech Innov Gastrointest Endosc. 2020 Jul 26. doi: 10.1016/j.tige.2020.07.004.

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