Dilatation of strictures
Strictures (narrowings) of the GI tract may be amenable to stretching/dilatation. The dilation my be performed with a special tubular dilating balloon, or with a tapered dilator. In general, dilatation is more useful for benign strictures caused by scarring than for malignant (cancerous) strictures; scarring can stretch and achieve a permanent benefit, whereas malignant strictures will always recur. Most cases are done under Xray control, but if it is possible for the telescope to traverse the stricture pre-dilatation, then Xray may not be necessary.
A stent is a tube that passes through a narrowed region, holding it open. Stents are used in various parts of the body and for various conditions. In the GI tract, most stents are placed to open up malignant (cancerous) strictures, with the oesophagus being the commonest site. The stents are placed over a wire, via the endoscope, using real-time Xray guidance – this link will take you to a YouTube video that demonstrates the technique very well. Sometimes a dilatation of the stricture is necessary before stent placement can be achieved.
Argon Plasma Coagulation (APC)
APC is a form of electrosurgical (diathermy) energy. It uses argon gas to allow the current to jump a small distance from the electrode tip to the tissue that requires treatment. The fact that the diathermy tip does not need to touch the tissue means that the tip does not become gummed up with debris, and the superficial nature of the diathermy burn that is produced means that the incidence of perforation should be low.
Endoscopic Mucosal Resection (EMR)
There are a variety of EMR techniques that allow a small patch of mucosa to be removed, whether for direct treatment of an early lesion, or as a “big biopsy” to improve diagnostic accuracy. Enoscopic submucosal dissection ESD is a related technology that does allow resection in a deeper tissue plane.