Prediction, prevention and management of gastroesophageal reflux after per-oral endoscopic myotomy: An update

Table 2 Patient and procedures related factors potentially affecting the incidence of reflux after per-oral endoscopic myotomy

Factors	Conclusions reported in published studies	Ref.
Patient related factors
Female gender	Symptoms of GERD more likely in females	[6,11,17]
	No effect of gender on post POEM reflux	[11]
Age	Age > 65 yr is a risk factor for GERD (RR: 1.72)	[7]
Hiatus hernia	Presence of hiatal hernia predisposes to post POEM reflux	[14]
Obesity	BMI > 35 is a risk factor for GERD	[14,20]
	BMI > 30 is an independent risk factor	[17]
	Increase in BMI after POEM is a risk factor for new onset GERD symptoms	[15]
	Obesity is not a risk factor for GERD	[21]
Manometry parameters and GERD
LES pressure	Pre-operative resting LES pressure ≤ 45 mmHg (OR: 1.86)	[17]
IRP	Low IRP after POEM is a risk factor	[19,23]
POEM technique related factors
Length of myotomy	Long esophageal myotomy predisposes to increased esophageal acid exposure	[7,32]
	Myotomy length < 7 cm associated with less PPI use	[70]
	No impact of esophageal myotomy length on GERD	[17,33,34]
	Long gastric myotomy predisposes to severe esophagitis	[22]
	Short (1 cm) gastric myotomy associated with less symptoms and reflux esophagitis	[41]
	Myotomy along gastric side not associated with ≥ LA grade B esophagitis	[57]
Posterior POEM	Posterior myotomy leads to higher rates of increased esophageal acid exposure	[5]
	Reflux rates similar between anterior and posterior POEM	[54,55]
Full thickness myotomy	Clinically relevant GERD higher after full thickness myotomy	[23]
	Incidence of GERD similar between selective circular and full thickness myotomies	[38,56]
Sling fibers	Preservation of sling fibers reduces ≥ LA grade B esophagitis	[42,43]
	No significant effect of sling fiber preservation on the rate of GERD	[44]
NOTES fundoplication	POEM-F reduces the incidence of GERD at 1-yr	[47]
	Fundoplication wrap remains intact in 83% cases at 1-yr	[47]
	Loosening of wrap in substantial proportion (41.2%) at 3-months	[50]

BMI: Body mass index; GERD: Gastroesophageal reflux disease; LA: Los Angeles; NOTES: Natural orifice transluminal endoscopic surgery; PPI: Proton pump inhibitor; NR: Not reported; LES: Lower esophageal sphincter; IRP: Integrated relaxation pressure.