Endoscopic full-thickness resection (EFTR) is a therapeutic option for the treatment of challenging lesions such as subepithelial tumors (SETs) and epithelial neoplasia extending deeper than the mucosa or associated with significant fibrosis. EFTR may offer a less invasive treatment alternative relative to surgical approaches in selected patients.

The gastroduodenal FTRD System (gdFTRD System) is an instrument for endoscopic full-thickness resection or deep partial wall resection and diagnostic tissue acquisition through removal of suitable lesions in the stomach and duodenum.

The prospectively generated data of the gdFTRD registry shall be used to evaluate the application of the gdFTRD in clinical routine, to verify the acceptability of already known risks and to identify unknown risks and complications.

The gdFTRD registry is a registry on cases completed with the gdFTRD System. The gdFTRD System is used for full-thickness resection but the procedure is not part of the study. Only data processing is conducted within the study. For data processing, an EDC system is used.

There are no patient reported outcomes, only physician-entered data on baseline, intervention/procedure, complications/adverse events and follow-up visits.

Automatic plausibility checks have been programmed for quality assurance. Furthermore, warnings and hints will be given on predefined entries not allowed or to double-check values out of normal ranges. No source data verification is planned but data management will check the entries for completeness.

No coding according to MEDRA or similar systems is planned. As the procedure is not part of the study, every participating site must operate according to their own SOPs. The sponsor and CRO have SOPs in place for conducting a study. Furthermore, data protection requirements and all applicable regulations are followed.

The sample size was calculated based results of peer-reviewed publications on the gdFTRD System. As only continuous and categorial variables will be assessed, no separate statistical analysis plan is planned. In case the collected data allows for exploratory post hoc subgroup analysis further tests can be done according to the descriptions in the protocol. Missing data will not be included in the analysis and shall not be imputed.

Inclusion criteria:

• All patients of legal age in whom the gdFTRD was used for treatment in the upper GI tract (stomach and duodenum) independently from the registry and
• who gave informed consent to data processing

Exclusion criteria:

• Patients aged under 18 years
• Patients in whom the colonic FTRD, diagnostic FTRD or non-device assisted EFTR was used for treatment
• Patients who did not give informed consent to data processing

All patients of legal age in whom the gdFTRD was used for treatment independently from the registry.

Anonymized data will be used for publication of all participant data.