EndoStim is a bipolar lead implanted in the lower esophageal sphincter, LES. It is connected to a subcutaneous electrical generator that generates electrical impulses according to a proprietary algorithm. The purpose of this device is to improve LES function in the hope of controlling gastro-esophageal reflux disease.
Neuro-modulation is a very interesting treatment modality for many diseases like gastroparesis, anal sphincter incompetence, urinary incontinence and even morbid obesity and diabetes. The pathophysiology of GERD is partly related to LES dysfunction and improving LES function may theoretically improve GERD control. The problem is that our understanding of esophago-gastro-duodenal motility is very limited. Neuro-modulation is only feasible when we decipher the complex neuro-muscular physiology of the gastrointestinal tract. There are one million gastrointestinal neurons talking to each other and coordinating hundreds of functions that we still don’t understand or even know about. The best example for neuro-modulation comes from our experience with gastroparesis treatment. Gastric pacing has been studied extensively in gastroparesis. The results have been controversial and most patients experience minimal improvement in gastric emptying with gastric pacing. If we don’t understand the basic pathophysiology governing gastric emptying how can we develop an effective gastric stimulator to treat the underlying problem?
The same rational applies to GERD. GERD is a multifactorial problem that results not only from LES incompetence. Transient Lower Esophageal Sphincter Relaxation, TLESR events do contribute to GERD but they are only part of a more complex pathophysiology. Preventing TLESR may theoretically improve GERD but the question is how and is it enough? How to stop reflux events associated with TLESR? Some advocate applying a chain of magnets around the sphincter like the LINX™ system and others are pushing for electrical stimulation like EndoStim. For mild reflux and in the absence of a hiatal hernia these approaches may work. Their mechanism of action is based on naïve assumptions more so than solid science. The most reliable treatment and only cure for reflux remains the Nissen fundoplication. We hope that continued research will improve our understanding of GERD. In particular, we need to study the neuromuscular functions of the gastrointestinal tract and how is gastric emptying regulated to understand diseases like gastroparesis, GERD, type-two diabetes and obesity. Short of improving our knowledge of these complex functions, we will continue to target the LES with constricting devices while ignoring the root cause of GERD.