Strictures may occur throughout the GI tract and can occur from a variety of benign and malignant etiologies. Stricture dilation may be indicated when there is associated clinical impairment or a need to access beyond the stricture for diagnosis or therapy. A variety of devices and techniques are available for use in the GI lumen and pancreaticobiliary system Dilation is accomplished by application of expansible forces against a luminal stenosis. Dilators used in GI endoscopy can be organized into 2 categories: fixed diameter push-type dilators (bougie dilators) and radial expanding balloon dilators. Fixed-diameter push-type dilators exert radial forces and also cause a shearing effect that exerts longitudinal forces as they are advanced through a stenosis. Balloon dilators only exert radial forces when expanded within a stenosis.
Wire-guided bougie dilators are flexible, tapered, polyvinyl chloride, latex-free cylindrical solid tubes with a central channel to accommodate a guidewire. Dilation can be performed with or without endoscopic, fluoroscopic, and/or wire guidance. Selection of different types of dilators depends on operator preference and the characteristics of the site needing dilation. Dilator diameters are measured in millimeters or French.
When there are malignant strictures & patients need palliative treatment for intestinal obstruction; obstructive jaundice and colonic obstruction– luminal stents [self expanding] are placed across the stricture for relieve of symptoms. There stents are usually placed through the scope systems and under fluoroscopic guidance.