Intraperitoneal virtual biopsy by fibered optical coherence tomography (OCT) at natural orifice transluminal endoscopic surgery (NOTES)

Abstract

Introduction: Fibered optical coherence tomography (OCT) in conjunction with natural orifice transluminal endoscopic surgery (NOTES) could provide a facility for rapid, in situ pathological diagnosis of intraperitoneal tissues in a truly minimally invasive fashion.

Materials and methods: A large porcine model was established to test this hypothesis. A standard double channel gastroscope (Olympus) was used to achieve a transgastric access to the peritoneum and initiate the pneumoperitoneum. Magnetic retraction was used to display the sigmoid colon along with its mesentery. A commercially available fibered OCT probe (NIRIS system, Imalux) was inserted via a working channel of the gastroscope and used to assess intraperitoneal tissues. Separately, OCT images of human tissue specimens ex vivo were contrasted with representative standard histopathological slides.

Results: Intraperitoneal OCT provided clear real-time images of both the serosal and muscularis propria mural layers as well as the submucosal-muscularis interface. Examination of mesenteric lymph nodes (including sentinel nodes) allowed visualization of their subcapsular sinus. Comparison of representative cross-sections however failed to evince sufficient resolution for confident diagnosis.

Conclusion: This approach is technically feasible and, if the technology is advanced and proven accurate in human patients, could potentially be used to individualize operative extent prior to definitive resection.