3 The procedure
3.1 The aim of endoscopic radiofrequency ablation is to destroy squamous dysplasia in order to allow re‑epithelialisation with normal squamous epithelium.
3.2 The procedure is usually carried out with the patient under conscious sedation, in an outpatient setting. The area of squamous dysplasia is visualised using an endoscope. Spraying the oesophageal lining with Lugol's iodine identifies areas of dysplasia that can otherwise be difficult to find. An appropriately sized radiofrequency ablation probe attached to the endoscope is inserted into the oesophagus, and advanced to the target area. Controlled pulses of radiofrequency energy are delivered, which cause thermal ablation of a thin layer of cells in the affected areas. A circumferential ablation catheter is usually used for primary treatment, whereas a focal ablation catheter can be used for remaining patches of squamous dysplasia in any subsequent treatments. Radiofrequency ablation can also be used after doing endoscopic mucosal resection to remove larger, superficial abnormal areas. If follow‑up high resolution endoscopy and re‑biopsy show residual changes, repeat treatment can be done using radiofrequency ablation.