Laparoscopic infrared imaging

Background: As an adjunct to direct visual imaging, an infrared endoscope w as developed to assist in the identification of various anatomic structures and to assess tissue viability during laparoscopic procedures. A camera se nsitive to emitted energy in the mid-infrared range (3 to 5 mum) was incorp orated into a two-channel visible-light laparoscope, Methods and Materials: Laparoscopic procedures were performed in a porcine model, inexperienced laparoscopists being asked to localize and differentia te structures before dissection using the visible-light system and then the infrared system. To determine clinical utility, nine laparoscopic urologic procedures were performed with the assistance of the infrared system. Results: In the clinical evaluation, infrared imaging proved to be useful i n differentiating between blood vessels and other anatomic structures. In c ontrast to the experience with the conventional endoscope, vessel identific ation, assessment of organ perfusion, and transperitoneal localization of t he ureter was successful in all instances using the infrared system. In the porcine model, this system also permitted assessment of bowel perfusion du ring laparoscopic occlusion of mesenteric vessels and distinguished between the cystic duct and artery. Conclusion: Infrared imaging is a potentially powerful adjunct to laparosco pic surgery. It may improve the differentiation and localization of anatomi c structures and allow assessment of physiologic features, such as perfusio n, not previously attainable with laparoscopic techniques.