New Microwave Antenna Structures for Treating Gastro-Oesophageal Reflux Disease (GERD)

The design and initial pre-clinical evaluation of microwave traveling-wave antenna structures to deliver high-frequency microwave energy with controlled depth of penetration of the electric field to produce controlled ablation around the inner wall of the oesophagus (confined to the mucosal layer) at the junction between the stomach and the oesophagus is described in this paper. The structures were fabricated using flexible microwave substrates to enable them to be attached to the outer wall of oesophageal balloons for introduction into the oesophagus. It is shown that the uniform electromagnetic field produced along the length of the structure produces controlled circumferential tissue ablation, which could be used to tighten the muscles in the lower oesophageal sphincter, where the stomach connects to the oesophagus, to reduce or eliminate regurgitation and acid exposure to the oesophagus, a condition known as gastro-oesophageal reflux disease. This paper also presents the results obtained from in-vitro tissue studies and initial in-vivo work carried out using the porcine model. This is the first study to assess the use of microwave energy to treat medical conditions associated with the oesophagus.