Thoracoscopic Laser Speckle Contrast Imaging for Segment Resections

Rationale Lung cancer remains to be the leading cause of cancer-related deaths worldwide1. The current standard-of-care for small lung cancer is a total lobectomy. Albeit effective with respect to the radical excision of the tumour, the substantial loss in lung tissue may be clinically relevant, especially in combination with frequently co-existing lung diseases. Thoracoscopic segmentectomy is a combination of adequate oncological resection with lung-tissue-sparing properties and is being increasingly used because of its several advantages compared with lobar resections. By defining the segment that has to be excised pre-operatively, the key to successful pulmonary segmentectomy is to subsequently intraoperatively recognize the intersegmental planes correctly. The conventional and most common method uses a ventilation method (inflation/deflation technique). With the increasing availability of endoscopic imaging systems, indocyanine green (ICG) fluorescence imaging is a more advanced method to determine intersegmental planes. The major limitation is the use of an exogenous contrast agent. After injection, the ICG only has very limited "imaging time window" (minutes) in which the images can be used to determine the intersegmental planes. Furthermore, the use of dye limits repeatability of measurements due to rest ICG, the extra operating room time required for the injection, wash-in and wash-out of the dye as well as change of camera settings. These limitations leave room for new technologies and improvements. The investigators hypothesized that an endoscopic laser speckle imaging device could overcome the limitations of ICG-fluorescence imaging and could thus be a very useful addition in intersegmental plane detection. PerfusiX-Imaging (LIMIS Development BV, Leeuwarden, The Netherlands) is such an endoscopic laser speckle contrast imager that has been developed in the Medical Centre Leeuwarden since 2014. LSCI has never been used to identify intersegmental planes, ho