A Novel Endoscopic Attachment Cap for Benign Esophageal Stricture Dilation in Children: a Randomized, Multicentric Pilot Study.

There are two categories of esophageal stricture in children: acquired and congenital. The development of benign esophageal stricture is based on significant fibromuscular alterations, inflammation in residual muscle layers and a deposition of collagen based on an inflammatory process . In children, these changes are most common in the context of a postoperative anastomotic stenosis in the case of esophageal atresia (usually type IIIb according to Vogt), as well as after caustic injury, peptic stricture and eosinophilic esophagitis. Rarely, children are born with congenital esophageal stricture. Therapeutic radiation can lead to stenoses requiring dilation. Likewise, children suffering from epidermolysis bullosa can suffer from esophageal stenosis. In rare cases, the ingestion of a foreign body in children causes symptomatic stenosis as a buried foreign body covered by esophageal hyper granulated tissue. Malignant stenosis is not considered in this study, as its treatment is different.

There are different options for endoscopic esophageal dilations of clinically relevant esophageal strictures, which promise effective treatment. Relevant strictures are usually noticed by dysphagia.

One possible dilation method uses the Savary-Gilliard bougies. These are wire-guided polyvinyl dilators. The advancement of the wire is performed under radiological fluoroscopy. Once the guide wire is placed into the stomach, the dilator is passed over the guidewire, lubricated, and pushed over the stenosis in order to dilate the stenotic area. There are also non-guidewire bougie dilators. Longitudinal shearing force and radial force occurs when the dilator passes across the stenotic area. Initially, the size of the dilator that corresponds to the diameter of the stenosis is used. The same procedure is then followed stepwise with a larger dilator of 1mm, respectively. It is generally recommended not to increase the dilator size more than 3mm in a single session.

A major disadvantage of this method is the exclusively tactile control of the dilation. At the end of the Bougie dilation, the result should be checked by reinserting the endoscope to rule out deeper mucosal injuries and persistent bleeding.

Furthermore, there is experience in the treatment of esophageal stenosis in children with balloon dilations. The balloon is inserted either blind or under endoscopic control, The balloon is then mostly inflated to 1 mm beyond the estimated stenosis diameter and the pressure is maintained for 1 minute or less. The dilation may be controlled radiologically or endoscopically. A dilation up to 5mm above the initial stricture diameter may not increase the risk of perforation. Only radial forces arise. Here, too, insufficient visual control is to be criticized. In particular, the distal area of the stenosis cannot be viewed during the procedure, or only with difficulty. In addition to the poor visual control, there is no tactile control of the dilation, since the volume of liquid applied to the balloon determines the diameter. Furthermore, there is no standard protocol for the stepwise dilation that is required for treating children at different ages. Finally, small esophageal balloons specifically for small children are missing, which is why balloon catheters from other areas and indications are used (e.g. urological balloon catheters, biliary catheters), respectively.