Gastric peroral endoscopic pyloromyotomy (G-POEM) in patients with refractory gastroparesis: a review

Gastric peroral endoscopic pyloromyotomy (G-POEM or POP) is an endoscopic therapeutic modality for treatment of refractory gastroparesis. Since the first case reported in 2013, there are more than 200 papers published on G-POEM. In this narrative review, we summarize the short-term and long-term outcomes and review other important studies. The technical success rate is 100% and the short-term (within 1 year) success rate is about 50-80%. The procedure time is between 50 and 70 min while the average length of hospital stay was 2-3 days. The adverse event rate was around 10%. Few patients need further intervention. Three studies showed that at the 4-year follow-up, the response to G-POEM was durable, but there was a yearly recurrence rate of 13% or more. Redo G-POEM is feasible and can be of benefit for some patients. Most of the studies showed that long duration of illness is associated with poor outcomes. However, reliable predictors for successful outcomes are still unknown. Current literature indicates G-POEM is superior to gastric electric stimulator and surgical pyloroplasty. Endoflip has been used at G-POEM to predict the outcome, but the result is very preliminary. A recent sham study confirms the short-term efficacy of G-POEM. G-POEM is safe and about 50% of patients can be discharged to home on the same day. G-POEM allows for direct biopsy of the gastric muscle, which is the location of the pacemaker cells, the interstitial cells of Cajal; therefore, G-POEM may provide a new path for further research on the pathogenesis of gastroparesis.