SAFETY AND EFFICACY OF LIQUID NITROGEN SPRAY CRYOTHERAPY AS AN ADJUNCT IN TREATING REFRACTORY BENIGN UPPER GASTROINTESTINAL STRICTURES: A RETROSPECTIVE MULTICENTER EXPERIENCE

Introduction:
While balloon dilation is the mainstay of treatment for benign upper gastrointestinal strictures, a large number of strictures will remain refractory to balloon dilation therapy. The use of liquid nitrogen spray with esophageal dilation is a novel method in treating refractory benign upper GI strictures. The goal of our study is to determine the efficacy and safety of cryotherapy as an adjunct to balloon dilation in refractory strictures.

Methods:
This is a multicenter, retrospective study evaluating the safety and efficacy of cryodilation procedures. Data obtained included patient demographics, treatment dates, frequency and type of endoscopic interventions performed, pre and post cryodilation diameters in mm, and adverse complications. Patient inclusion criteria included patients older than 18 years of age with a history of benign upper gastrointestinal strictures that have previously received balloon dilation. A cryodilation procedure involves liquid nitrogen spray of the stricture followed by balloon dilation. Each cycle consists of 20-30 seconds of stricture freezing followed by >60 seconds of thawing, and is repeated 1 or 2 more times. The efficacy of cryodilation was assessed by comparing the number of dilation procedures in the time period 180 days preceding cryodilation to the number of dilation procedures in the time period 180 days following the cryodilation procedure.

Results:
A total of 5 centers participated within the study with a total of 33 total subjects (mean age 58.5, 64% males) over a 3-year period. Etiologies of stricture included anastomotic in 45%, peptic 18%, radiation-induced 19%, post-endotherapy 9%, caustic 3%, congenital 3%, and idiopathic 3%. The number of dilations in the time period after cryodilation was significantly less than the number of dilations in the time period preceding cryodilation (0.7 vs 3.8, p value < 0.001). The average pre-dilation diameter of the stricture at time of cryodilation was 8.4 mm (range 1-14) and post cryodilation was 12.2 mm (range 3-16). There were 2 perforations in the time period prior to cryodilation (one bougienage and one balloon dilation), and 1 perforation in the time period after cryodilation.

Conclusion:
For benign upper gastrointestinal strictures, cryodilation appears to be an effective and safe technique to decrease the frequency of repeated endoscopic interventions. Further prospective studies are needed to further evaluate the safety and efficacy of this novel technique.