Development of concentric photothermal ablation for duodenal mucosal resurfacing.

Objectives: Duodenal mucosal resurfacing (DMR) is a surgical method to treat type 2 diabetic mellitus. The current study developed laser-assisted photothermal DMR to ablate the duodenal mucosal surface in an instant and selective, compared with conventional DMR methods.

Methods: A 1470 nm wavelength was selected for the current study because of its high optical absorption coefficient in intestine tissue. A radial optical fiber was designed for concentric irradiation to the duodenal mucosal surface. Ex vivo liver tests were performed to evaluate various irradiation energy (25-400 J). Both numerical simulations and an ex vivo duodenum tests were conducted to confirm the thermal response of the duodenum to the laser irradiation. In vivo experiments were performed to evaluate the depth of the ablated duodenal mucosa after the treatment.

Result: The extent of the coagulation area in ex vivo liver tissue after laser irradiation increased with the energy delivery. Numerical simulations and ex vivo duodenum experiments showed a concentric temperature distribution in the duodenum wall. The histological assessment following in vivo experiments revealed that the 10 W for 15 s condition ablated the duodenal mucosal layer in the cross-sectional direction by more than 50%, compared to the control.

Conclusion: 1470 nm laser light with concentric radial irradiation under 10 W for 15 s ablated the sufficient depth of the duodenal mucosal layer. Further in vivo studies will be performed to confirm the efficacy of the photothermal DMR.

Significance: The current study demonstrated the feasibility of a novel photothermal ablation for DMR.