Less invasive than minimally invasive: peroral endoscopic myotomy with a slim scope in the treatment of esophageal achalasia - Coelho Conrado, Antonio Carlos; Guilherme Guerra, Joao; Hashimoto, Claudio Lyoiti; Averbach, Marcelo; Arcanjo dos Santos, Miguel; Draganov, Peter Vassilev (Endoscopy, 2018)