Gastric peroral endoscopic myotomy (G-POEM) for refractory gastroparesis

Gastroparesis is a chronic functional disorder characterized by severe symptoms and objective documentation of delayed gastric emptying, in the absence of any mechanical obstruction. The pathogenesis of gastroparesis comprises abnormalities of gastric motility (corpus and fundus dysmotility and antral hypomotility), pyloric resistance to gastric outflow (pyloric lower compliance or hypertone), and lack of antroduodenal motor coordination. Several conditions have been correlated to gastroparesis: diabetes, post-surgical sequelae, medications, neurological/muscular disorders and collagen vascular diseases. Diabetes is the most frequent condition associated with gastroparesis, which has been reported in up to 50% of patients suffering from long-lasting disease. The therapy of gastroparesis is primarily medical, with prokinetic or antiemetic drugs, but response may be limited, and side effects can arise; if medical therapy fails, pyloromyotomy remains the main option, either surgical or endoscopic. Gastric peroral endoscopic myotomy (G-POEM) may be considered nowadays an effective potential therapeutic intervention in alternative to surgery, relatively easy to perform in experienced hands, with a technical success of 100%, a favorable safety profile, and positive outcomes in the short-term as documented in three meta-analyses. However, to date, the definition of clinical success in gastroparesis is still not standardized, the correlation between symptom improvement and the objective documentation of an improvement in gastric emptying remains in some cases uncertain, reliable data to help in predicting which categories of gastroparesis and which symptoms could benefit most from the intervention, and long-term outcomes are still lacking.