Sa1607 Endoscopic Full-Thickness Specimens of the Gastrointestinal Wall for the Detection of Neuromuscular Disease

Abstract

Endoscopic Full-Thickness Specimens of the Gastrointestinal Wall for the Detection of Neuromuscular Disease Annette Fritscher-Ravens*, Mark Ellrichmann, Thilo Wedel, Klaus-GERD Hadeler, Ines Hellwig, Peter J. Milla Internal Medicine I, Interdisciplinary Endoscopy, Kiel, Germany; Anatomy, University Kiel, Kiel, Germany; Animal breeding, Loeffler Institute, Mariensee, Germany; Child Health, University College London, London, United Kingdom Introduction: Gastrointestinal (GI) neuromuscular pathology (GINMP) is associated with a broad spectrum of functional GI disorders, e.g. gastroparesis, slow-transit constipation, intestinal pseudoobstruction. Irritable bowel syndrome (IBS) is now considered to be a related disorder. Diagnosis of GINMP requires full-thickness (FT) specimens (FTS) currently accomplished by laparoscopy. Efforts to construct a device for FTS via endoscopy have not succeeded to date. Aims: 1)To test whether a novel prototype device can obtain FTS of O 1cm from the gut to enable histological analysis of GINMP; 2)to investigate for any complications and damage of adjacent tissues in the peritoneal cavity. Methods: In 30 pigs FTS were taken from the posterior gastric wall. A new modified endoscopic device using a circular cutter within an end cap mounted on the endoscope was used without electrocautery to avoid tissue damage. A metal anchor was pushed to the peritoneal side, the metal cutter pressed against it from the endoluminal side and rotation enabled sampling. The peritoneal anchor also served as abutment to avoid damage of adjacent organs and to retrieve the FTS. Endoscopic t-tags were used for closure. Mini-laparoscopy was performed to inspect the resection site for any damage caused. After 2 weeks survival, peritoneal lavage was performed prior to euthanasia and autopsy. Results: 29/30 procedures were successfully performed; 1 case of bleeding needed endoscopic treatment. All but one FTS were retrieved with the anchor in place. Time to obtain FTS was mean 8.3 min (6.0-15.5 min), for defect closure 18.5 min (range: 7.2-32 min). T-tag closure was successful in all cases. No major complications were seen. Post-procedure laparoscopy proved no other organ damage. Some very minor bleedings were seen in 6/29 cases. The size of FTS was O 9.1 mm with little evidence of edge damage. At autopsy, the scars appeared to have healed well. There was no abscess nor other abnormality. Histology and immunohistochemical work-up proved the presence of well-preserved submucosa and of both the submucosal and myenteric nerve plexus as well as intramuscular nerve fibers. The circular and longitudinal muscle layers were of very good tissue quality. The anchor pushed through the center of the FTS did not substantially alter the quality of the material. Conclusion: Using a new modified prototype endoscopic FTS-device we showed that it was possible to reliably obtain FTS in a quality that provided sufficient tissue for histological analysis of GINMP. All relevant histological and immunohistochemical techniques showed excellent staining qualities required for diagnosing the different subtypes of GINMP. The damage caused with an earlier prototype device was avoided due to the new anchor system. The improved functionality of the device might enable first studies in patients.