Multifunctional Use of Negative Pressure Drainage Device NPWT, or negative pressure drainage, is a form of endoscopy that provides drainage of the esophagus and other gastrointestinal tracts. NPWT can be used for a variety of conditions and procedures. A non-powered NPWT system is commonly used for treatment of esophageal reflux, while a powered system can be used for endoscopic surgery....