Gastric per-oral endoscopic pyloromyotomy (G-POEM) has been assessed as new modality for treatment of refractory gastroparesis. G-POEM is promising method, which is still under investigation as its safety and efficacy has not been established yet. The ideal closure technique in patients undergoing G-POEM needs to be established. Several techniques may be used for endoscopic mucosal closure: endoscopic clips, OTSC (over the scope clips), endo-loop based methods (KING closure) or endoscopic suture.

The aim of this prospective, open-label study is to compare efficacy and safety of two methods for incision closure in patients who undergo G-POEM: endoscopic clips vs. endoscopic suturing system (OverStitch).

Based on principles of NOTES (natural orifice transluminal endoscopic surgery), a mini-invasive therapeutic procedure such as per-oral endoscopic myotomy (POEM) or gastric per-oral endoscopic pyloromyotomy (G-POEM) have been assessed as new modalities for treatment of oesophageal achalasia or refractory gastroparesis. G-POEM is a new and promising method, which is still under investigation as its safety and efficacy has not been established yet. There are several questions, which need to be answered before G-POEM is considered as a standard clinical procedure. These questions concern, among others, efficacy, safety, technical performance etc. Mucosal incision should be endoscopically closed to prevent leakage into the abdominal cavity. Obtaining adequate mucosal closure is one of the most important steps of the procedure and is essential in avoiding major morbidity. The ideal closure technique in patients undergoing G-POEM needs to be established. Several techniques may be used for endoscopic mucosal closure: endoscopic clips, OTSC clips, endo-loop based methods (KING closure) or endoscopic suture. At present, simple closure with endoscopic clips has been the most frequently described method for mucosal closure in patients undergoing G-POEM. However, as gastric mucosa is thicker compared to the esophagus, where clips are used for POEM without any major problems, several authors have described problems during gastric incision closure - it takes a rather longer time, some clips cannot be placed and in some patients, other closure method had to be used. Thus, endoscopic clips may not be an ideal closure method in the stomach. A platform that replicates a principle of surgical suturing is endoscopic suturing system.

The aim of this prospective, open-label study is to compare efficacy and safety of two methods for incision closure in patients who undergo G-POEM: endoscopic clips vs. endoscopic suturing system (OverStitch).

Investigators plan to randomize 30-40 patients (15-20 in both arms, ratio 1:1).

The assigned closure method will be decided by an endoscopist prior to starting closure.

Inclusion Criteria:

1. Refractory (> 6 months) and severe (based on a validated total Gastroparesis Cardinal Symptom Index) gastroparesis, with confirmed gastric emptying based on a gastric emptying study: standardized protocol of scintigraphy in all patients (performed less than 6 months prior to enrolment). The total GSCI (Gastroparesis Cardinal Symptom Index) score must be >2.0

   • Abnormal gastric emptying is defined as retention of Tc-99 m >60% at 2 h and/or ≥10% of residual activity at 4 h on a standardized sulphur colloid solid-phase gastric emptying study.
   • Abnormal gastric emptying breath test based on a solid normal range determination for the test used (e.g. T1/2 > 109 min)

2. Severe refractory disease is defined as GCSI >2.0 and failure or recurrence in patients who received available optimal pharmacological therapies.

3. Persons 18 years or older at the time of signing the informed consent

4. Signed informed consent

Exclusion Criteria:

1. No previous attempt with at least one prokinetic drug
2. No previous attempt to withdraw anticholinergic agents and glucagon like peptide -1 (GLP-1) and amylin analogues in patients treated with these substances
3. Active treatment with opioids or a history of treatment with opioids within 12 months before enrolment
4. Previous gastric surgery (Billroth I or Billroth II)
5. Known eosinophilic gastroenteritis
6. Organic pyloric (or intestinal) obstruction (fibrotic stricture, etc.)
7. Sever coagulopathy
8. Oesophageal or gastric varices and /or portal gastropathy
9. Advanced liver cirrhosis (Child B or Child C)
10. Active peptic ulcer disease
11. Pregnancy or puerperium
12. Malignant or pre-malignant gastric diseases (dysplasia, gastric cancer, GIST): patients with a history of such disease after its cure are eligible for enrolment
13. Any other condition, which in the opinion of the investigator would interfere with study requirements
14. Uncontrolled diabetes mellitus
15. Diagnosis of rumination syndrome or "eating" disorder (mental anorexia, bulimia nervosa)
16. Inability to obtain informed consent