Welding of gallbladder tissue with a pulsed 2.15 μm thulium‐holmium‐chromium:YAG laser

Abstract

Percutaneous endoscopic approaches to cholelithiasis would be facilitated by methods for welding gallbladder tissues. We evaluated the bursting pressure and histologic appearance of canine gallbladder tissue welded with a thulium-holmium-chromium:YAG (THC:YAG) laser producing a 2.15 microns pulsed output. The tissue absorption characteristics at this wavelength as well as the pulsed nature of the output permit tissue welding with limited collateral thermal damage. The THC:YAG is compatible with a flexible fiberoptic delivery system. Bursting strengths of the welded junctions averaged 42 mm Hg, which is above physiologically encountered pressures. Histologic sections of the bonded tissues revealed tissue fusion and limited thermal injury to the surrounding tissue. We feel that THC:YAG laser welding may be a useful technique in the clinical development of percutaneous endoscopic biliary surgery.

Clear corneal incision in cataract surgery

“…Temperature-controlled photothermal welding, in which collagen denaturation is used to cause tissue adhesion, has also been used experimentally on aortic,52 gallbladder,5354 and corneal tissue 5556. Photosensitizers with laser irradiation have likewise shown success in corneal repair 57.…”

Gingiva Laser Welding: Preliminary Study on anEx VivoPorcine Model

“…In addressing these issues, two main strategies have been developed. The first approach 5,6 consists of matching the optical penetration depth to the thickness of the tissue to be welded. As water is the most abundant constituent of almost all tissues and the principal natural chromophore, Beer's law and the water absorption coefficient allow for the calculation of the optical penetration depth for a given laser wavelength; therefore, the laser welding of a given tissue thickness necessitates the choice of a suitable wavelength.…”

Modulated and continuous-wave operations of low-power thulium (Tm:YAP) laser in tissue welding

“…14 The tissue absorption characteristics by ͑TH-C͒:YAG laser in pulsed mode of operation permitted tissue welding with limited collateral thermal damage in percutaneous endoscopic biliary surgery. 15 On the other hand, a thulium fiber laser at 1873 nm with about 600 mW was used to produce full-thickness, watertight tissue closure during microsurgical laser welding of urinary tissues. 16 In another study, tissue welding by a continuous-wave ͑CW͒ Ho:YAG laser was compared to laser soldering by 808-nm diode laser, and both techniques revealed good bursting pressures of anastomoses.…”