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, however, based on the similarities between LSCI and ICG-fluorescence, this novel imaging approach is thought to be effective and potentially could be used as a standard-of-care. Objectives In this trial the investigators will study the utility of PerfusiX-Imaging for the identification of intersegmental planes during thoracoscopic segmentectomy. Study design The current study is a prospective, observational single-centre study in the Medical Center Leeuwarden. Study population A total of 10 patients undergoing an upper left or right lobectomy. Patient related study procedures All patients will undergo the standard-of-care program which includes perfusion assessment by ICG-fluorescence imaging. In addition to this standard-of-care, 2D-perfusion maps will be generated from images taken with PerfusiX-Imaging (LIMIS Development BV, Leeuwarden, The Netherlands). Not related to the patient, the PerfusiX-Imaging images will be shown to the surgeon postoperatively and peroperative questionnaires will be filled regarding the standard-of-care perfusion assessment. Study parameters/endpoints Due to the explorative character of this study, there is no formal hierarchy in the respective endpoints of this study. In this, all endpoints will add to the overall assessment of the feasibility of the PerfusiX-imaging derived visual feedback for detecting interlobar and intersegmental planes in lung tissue. The investigators will register whether it was possible to detect the intersegmental plane. Subsequently, compare the difference in location of both the interlobar and intersegmental planes as derived from visual feedback from the PerfusiX-imaging system is compared, with images derived from ICG imaging and the surgical eye. During the procedure, the time needed to generate and acquire the visual feedback from the PerfusiX-imaging system will be determined. The investigators will also determine the interpretability of the visual feedback from the PerfusiX-imaging system by users (surgeons). In addition, the investigators will determine Laser Speckle Perfusion Unit (LSPU) cut-off values of PerfusiX-imaging in lung tissue with the best sensitivity and specificity for the indication of level of tissue perfusion. Burden, risk and benefit to participation Burden Not applicable. Risks Not applicable. Benefit Not applicable.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* Scheduled to undergo upper left or right lobectomy
* Age 18 years or older
* Written informed consent

Exclusion Criteria:

\- Medical or psychiatric conditions that compromise the patient's ability to give informed consent

• BACKGROUNDAndolfi M, Potenza R, Seguin-Givelet A, Gossot D. Identification of the intersegmental plane during thoracoscopic segmentectomy: state of the art. Interact Cardiovasc Thorac Surg. 2020 Mar 1;30(3):329-336. doi: 10.1093/icvts/ivz278. PMID 31773135
• BACKGROUNDFunai K, Kawase A, Shimizu K, Sekihara K, Yamashita T, Shiiya N. Fluorescence navigation with indocyanine green for identification of intersegmental planes using a photodynamic eye camera. J Thorac Dis. 2020 Sep;12(9):4817-4824. doi: 10.21037/jtd-20-1448. PMID 33145054
• BACKGROUNDZhang Z, Liao Y, Ai B, Liu C. Methylene blue staining: a new technique for identifying intersegmental planes in anatomic segmentectomy. Ann Thorac Surg. 2015 Jan;99(1):238-42. doi: 10.1016/j.athoracsur.2014.07.071. Epub 2014 Nov 14. PMID 25440279
• BACKGROUNDNex G, Schiavone M, De Palma A, Quercia R, Brascia D, De Iaco G, Signore F, Panza T, Marulli G. How to identify intersegmental planes in performing sublobar anatomical resections. J Thorac Dis. 2020 Jun;12(6):3369-3375. doi: 10.21037/jtd.2020.01.09. PMID 32642262
• BACKGROUNDOh S, Suzuki K, Miyasaka Y, Matsunaga T, Tsushima Y, Takamochi K. New technique for lung segmentectomy using indocyanine green injection. Ann Thorac Surg. 2013 Jun;95(6):2188-90. doi: 10.1016/j.athoracsur.2012.12.068. PMID 23706452
• BACKGROUNDPischik VG, Kovalenko A. The role of indocyanine green fluorescence for intersegmental plane identification during video-assisted thoracoscopic surgery segmentectomies. J Thorac Dis. 2018 Nov;10(Suppl 31):S3704-S3711. doi: 10.21037/jtd.2018.04.84. PMID 30505555
• BACKGROUNDBriers JD, Fercher AF. Retinal blood-flow visualization by means of laser speckle photography. Invest Ophthalmol Vis Sci. 1982 Feb;22(2):255-9. PMID 7056639