A novel fluorescence technique for identification of the pulmonary segments by using the photodynamic diagnosis endoscope system: An experimental study in ex vivo porcine lung

Abstract

Photodynamic diagnosis is a technique that has been proposed to enhance tumor detection and resection. We modified this technique to identify pulmonary segments and examine the feasibility of this technique in ex vivo porcine lungs. The photodynamic diagnosis endoscope system consisted of the D-Light system as the excitation light source and a TRICAM camera as the fluorescence sensing endoscope (Karl Storz GmbH & Co, Tuttlingen, Germany). Vitamin B2 was used as the fluorescence substance. Two kinds of segmentectomy were performed in right porcine lung. After identification of the segmental bronchus, the fluorescent substance was injected transbronchially. The fluorescent segment was observed using the photodynamic diagnosis endoscope system, and the identified intersegmental plane was cut using scissors. The operative data collected were the success rate of accurately identifying the pulmonary segments. The duration and light intensity of fluorescence of the target segment were recorded to provide an objective measurement of success. The same parameters were also measured for the adjacent segment. Overall, 20 segmentectomies were performed, 10 of each kind--cranial segmentectomy and L2 segmentectomy. In all procedures, it was possible to identify the target segment by its yellow-green fluorescence. No unexpected injuries of the major segmental bronchi and vessels nor incorrect recognition of target segments occurred. The success rate of accurately identifying pulmonary segments was 100%. The duration and light intensity of this fluorescence technique was enough to perform pulmonary segmentectomy. This florescence technique using vitamin B2 and the photodynamic diagnosis endoscope system is useful to identify the target pulmonary segment easily and clearly in ex vivo porcine lung.