TIPS and TRICS, Liquid Nitrogen Cryotherapy Assisted Balloon Dilation for Refractory Strictures. Strictures have multiple etiologies, ranging from peptic, which are easy to treat, up through caustic, which are very difficult to treat. They often can become refractory in up to 30% of cases, and these have significant health care costs associated with them. Despite having multiple tools available to treat refractory strictures, ranging from dilation up through surgery, previous studies have shown that only one of three patients with refractory strictures achieve clinical resolution of dysphagia, thus highlighting a need to find alternative methods to treat these types of strictures. Which brings us to liquid nitrogen spray cryotherapy. This is a combination of fast, deep freezing with subsequent thawing that destroys the cellular components while preserving the extracellular matrix. This enables healing without significant scarring and fibrosis. Treatment is delivered via a spray catheter placed in the working channel of the endoscope. No direct tissue contact is required, can be treated over and through stents, mesh, and other appliances, does not require a flat surface to treat, and can treat in the retroflex position. No debridement is required for treated tissue. The optimal cryodilation technique remains unclear. There are several practice-guided recommendations that have had positive clinical outcomes. All patients should be sedated with general anesthesia, and CO2 for insufflation is paramount. It's recommended to use a low-profile, clear cap. The endoscopist should have access to fluoroscopy and tools to help fix perforations should they arise. Adequate positioning of the venting tube across the stricture is important, and gentle predilation may be needed for this. The dosing of cryogen remains unclear, but it is recommended to do 30 to 35 seconds of freezing, followed by 60 seconds of thawing, for 3 to 4 cycles. The endoscopist should dilate the balloon to the largest, safest diameter, and hold this for 90 seconds. Patients can be discharged home the same day. Case Presentation 28-year-old woman with no previous significant medical history who experienced an inadvertent ingestion of caustic solution while eating out at a local restaurant. After this, she developed a severe refractory esophageal stricture that required weekly EGDs with dilation to maintain esophageal patency. At our hospital, an esophageal stent was placed for four weeks and subsequently removed, but the stricture and associated dysphagia remained refractory. The decision was made to pursue spray cryotherapy-assisted balloon dilation for further treatment. This is the endoscopic view of the patient's caustic ingestion-related stricture. It's located in the mid-esophagus and appears overtly fibrotic. The inner diameter measures about 7 to 8 millimeters. A savory wire is passed, and over the savory wire, a venting tube is placed. The venting tube should be placed so that the black marks are straddling the stricture. In this patient's case, the stricture measures about 15 millimeters in length. After the venting tube is in place, the cryogen can start to be delivered. It is recommended that the cryogen delivery catheter be advanced out of the working channel about 3 to 4 millimeters. This allows the endoscopist to maintain adequate visualization during the procedure. It also prevents the lens of the endoscope from freezing. As the cryogen is being delivered, it is recommended to try and obtain a 360-degree freeze and spray in a circumferential fashion. In this patient's case, she's had multiple balloon dilations in the past with preferential mucosal tearing at the 4 o'clock position. This can be seen with the preferential scarring in this area. The cryotherapy allows for not only this previous area of mucosal tearing to be treated, but the other walls of the esophagus as well. While the cryogen is being delivered, it is recommended that a member of the nursing staff or a trainee be standing at the patient's abdomen and monitoring for worsening abdominal distension or stiffness. If this occurs, the endoscopist should be made aware immediately and the delivery of the cryogen should be halted. This is the endoscopic view of the esophagus after the cryogen was delivered. At this point, a through-the-scope controlled radial expansion balloon dilator was passed. It's recommended to inflate the balloon slowly and place across the center of the stricture. Looking across the balloon technique is preferential, as it allows the endoscopist to see the small tears forming and to make sure they aren't propagating too rapidly or too deeply. Again, it is recommended to hold the balloon dilation for 90 seconds while continuing to monitor. After an appropriate length of time, the balloon can be deflated, and the esophagus can be examined for any evidence of perforation or deep muscle injury. In this patient's case, submucosal fibers were seen on post-dilation inspection, and the stenosis appears improved. Following cryodilation, patient reported resolution of her dysphagia for a full three to four weeks post-procedure. Repeat EGD with cryodilation was able to be spaced to about six weeks after the initial procedure. Esophageal stricture appeared slightly less severe on that repeat exam. She was able to keep a cue five to six week dilation schedule for the next several months and she has been maintaining her weight and doing well on dilation schedule as needed. Liquid nitrogen spray cryotherapy assisted balloon dilation has also shown to be effective in refractory and asthmatic strictures. In a case series evaluating seven patients, all of them had decreased numbers of dilations in the six months following cryodilation. The majority of these patients had esophagogastric and asthmatic strictures following Ivor Lewis esophagectomy for esophageal adenocarcinoma resection. In conclusion, liquid nitrogen cryotherapy assisted balloon dilation is a safe and viable option for refractory strictures. The optimal cryodilation technique has yet to be standardized but several practice-based recommendations have shown clinical benefit. It also has potential for routine use in other types of esophageal refractory strictures in the colon or small bowel and in the pediatric population pending further investigative studies.

cryotherapy

esophageal strictures

balloon dilation

liquid nitrogen

caustic ingestion