Table 2.

Adverse events associated with POEM.

Authors	Patients (n)	Adverse events*, n	Additional treatment
Inoue et al. [13]	17	1 pneumoperitoneum	Veress needle
Swanström et al. [14]	5	2 small perforations in gastric cardia 3 capnoperitoneum	Endoscopic clips Veress needle
von Renteln et al. [15]	16	6 minor cutaneous emphysema 8 capnoperitoneum treated with Veress needle 1 small perforation at GEJ, treated with endoscopic clips	Veress needle Endoscopic clips
Costamagna et al. [16]	11	2 small perforations at junctional flap Asymptomatic pneumomediastinum in all patients 2 transient cervical emphysema	Endoscopic clips
Chiu et al. [17]	16	1 aspiration pneumonia 2 transient cervical emphysema	Hospital admission and monitoring
Hungness et al. [21]	18	7 capnoperitoneum 1 contained perforation at the EGJ	Veress needle
Ren et al. [25]	119	66 subcutaneous emphysema 30 pneumothorax 35 mediastinal emphysema 1 delayed hemorrhage 58 pleural effusions 59 inflammations/atelectases of the lungs 47 aeroperitonea
Zhou et al. [24]	12	1 small perforation at GEJ, treated with endoscopic clips 3 capnoperitoneum, one treated with Veress needle 4 pneumothorax, one treated with thoracic tube 4 mediastinal emphysema 2 subcutaneous emphysema	Endoscopic clips Veress needle Thoracic tube
Verlaan et al. [18]	10	No complications reported	None
Minami et al. [20]	28	1 perforation at GEJ, treated with endoscopic clips 2 postoperative bleedings	Endoscopic clips
Lee et al. [19]	13	No complications reported	None
Von Renteln et al. [22]	70	3 clip dislocation at mucosal closure 1 perforation at mucosal entry site 3 mucosal injuries 1 bleeding requiring intervention 1 cap detached in submucosal tunnel 1 delayed bleeding (hematoma)	Endoscopic reclipping Endoscopic clips Endoscopic clips Endoscopic hemostasis Endoscopic removal Hospital admission and monitoring

*includes all reported outcomes, including nonclinically significant and asymptomatic adverse events.