# Optimizing duodenal tissue acquisition for mechanistic studies of duodenal ablation in type 2 diabetes

## TL;DR

Researchers developed a safer and more effective way to collect duodenal tissue for studying how ablation affects type 2 diabetes and metabolic syndrome.

## Contribution

An optimized tissue acquisition protocol using cold snare resections for high-quality histological and scRNA-seq analysis of duodenum.

## Key findings

- Eighty percent of specimens showed optimal tissue orientation with minimal damage.
- High-quality tissue dissociation for scRNA-seq was achieved in 72% of samples in DIRECT and 92% in EMINENT-2.
- No severe adverse events occurred during the procedure in either study.

## Abstract

Histological analysis of regular duodenal biopsies to study morphologic changes after duodenal ablation for type 2 diabetes (T2D) and metabolic syndrome is hampered by variability in tissue orientation. We designed an optimized tissue acquisition protocol using duodenal cold snare resections to create tissue microarrays (TMAs) and to allow for single-cell RNA sequencing (scRNA-seq).

The open-label DIRECT study included patients undergoing an upper gastrointestinal interventional endoscopy for non-duodenal indications. All underwent one ot two single-piece duodenal cold snare resections. Endpoints were safety, adequate histological orientation of specimen and TMA, and tissue dissociation quality for scRNA-seq. The optimized tissue acquisition protocol was validated in a duodenal ablation study, EMINENT-2.

In DIRECT, nine patients were included in whom a total of 16 cold snare resections were obtained. No severe adverse events (SAEs) occurred. Eighty percent of specimens and corresponding TMAs showed optimal tissue orientation. Further improvement was achieved by reducing tissue damage during endoscopic retrieval and improving histologic evaluation by eliminating ink use and pinning the tissue on cork. High-quality tissue dissociation scores for scRNA-seq were achieved in 13 of 18 samples (72%). In EMINENT-2, 38 cold snares were obtained without SAEs, histopathologic analysis showed good orientation in all samples, and dissociation scores for scRNA-seq were qualified in 35/38 (92%) samples.

Duodenal cold snare resection is safe and can provide high-quality tissue for optimally oriented TMAs and high-quality tissue dissociation scores for scRNA-seq (Clinicaltrials.gov, NCT06333093, NCT05984238). This approach will allow mechanistic studies about the effects of duodenal ablation on metabolic syndrome and T2D.