Publications

2024

1. NPJ Digit. Med.

   Real-time near infrared artificial intelligence using scalable non-expert crowdsourcing in colorectal surgery

   G. Skinner, T. Chen, G. Jentis, and 6 more authors

   npj Digital Medicine, 2024

   Abs Bib PDF

   Surgical artificial intelligence (AI) has the potential to improve patient safety and clinical outcomes. To date, training such AI models to identify tissue anatomy requires annotations by expensive and ratelimiting surgical domain experts. Herein, we demonstrate and validate a methodology to obtain high quality surgical tissue annotations through crowdsourcing of non-experts, and real-time deployment of multimodal surgical anatomy AI model in colorectal surgery

   @article{skinner2024digmed,
     title = {Real-time near infrared artificial intelligence using scalable non-expert crowdsourcing in colorectal surgery},
     author = {Skinner, G. and Chen, T. and Jentis, G. and Liu, Y. and McCulloh, C. and Harzman, A. and Huang, E. and Kalady, M. and Kim, P.},
     journal = {npj Digital Medicine},
     volume = {7},
     number = {1},
     pages = {99},
     year = {2024},
     doi = {10.1038/s41746-024-01095-8},
     url = {https://doi.org/10.1038/s41746-024-01095-8},
   }

2. Surg. Endosc.

   Dye-less Quantification of Tissue Perfusion by Laser Speckle Contrast Imaging is Equivalent to Quantified Indocyanine Green in a Porcine Model

   G. Skinner, M. Marois, J. Oberlin, and 3 more authors

   Surgical Endoscopy (Accepted), 2024

   Abs Bib

   Introduction: Subjective surgeon interpretation of near infrared perfusion video is limited by low interobserver agreement and poor correlation to clinical outcomes. In contrast, quantification of indocyanine green fluorescence video (Q-ICG) correlates with histologic level of perfusion as well as clinical outcomes. Measuring dye volume over time, however, has limitations; it’s not on-demand, has poor spatial resolution, and is not easily repeatable. Laser speckle contrast imaging quantification (Q-LSCI) is a real-time, dye free alternative, but further validation is needed. We hypothesize that Q-LSCI will distinguish ischemic tissue and correlate over a range of perfusion levels equivalent to Q-ICG. Methods: Nine sections of intestine in three swine were devascularized. Pairs of indocyanine green fluorescence imaging and laser speckle contrast imaging video were quantified within perfused, watershed, and ischemic regions. Q-ICG used normalized peak inflow slope. Q-LSCI methods were laser speckle perfusion units (LSPU), the base unit of laser speckle imaging, relative perfusion units (RPU), a previously described methodology which utilizes an internal control, and zero-lag normalized cross-correlation (X-Corr), to investigate if the signal deviations convey accurate perfusion information. We determine the ability to distinguish ischemic regions, and correlation to Q-ICG over a perfusion gradient. Results: All modalities distinguished ischemic from perfused regions of interest; Q-ICG values of 0.028 and 0.155 (p<0.001); RPU values of 0.15 and 0.68 (p<0.001); X-corr values of 0.73 and 0.24 (p<0.001). Over a range of perfusion levels, RPU had the best correlation with Q-ICG (r=0.79, p<0.001) compared with LSPU (r=0.74, p<0.001) and X-Corr (r=0.46, p<0.001). Conclusion: These results demonstrate that Q-LSCI discriminates ischemic from perfused tissue and represents similar perfusion information over a broad range of perfusion levels comparable to clinically validated Q-ICG. This suggests that Q-LSCI might offer clinically predictive real-time dye-free quantification of tissue perfusion. Further work should include validation in histologic studies and human clinical trials.

   @article{skinner2024surgendosc,
     title = {Dye-less Quantification of Tissue Perfusion by Laser Speckle Contrast Imaging is Equivalent to Quantified Indocyanine Green in a Porcine Model},
     author = {Skinner, G. and Marois, M. and Oberlin, J. and McCulloh, C. and Schwaitzberg, S. and Kim, P.},
     journal = {Surgical Endoscopy (Accepted)},
     volume = {},
     number = {},
     pages = {to appear},
     year = {2024},
     doi = {},
     url = {},
   }

3. Dis Colon Rectum

   Clinical Utility of Laser Speckle Contrast Imaging and Real-Time Quantification of Bowel Perfusion in Minimally Invasive Left-Sided Colorectal Resections

   G. Skinner, Y. Liu, A. Harzman, and 8 more authors

   Diseases of the Colon & Rectum, 2024

   Abs Bib PDF

   BACKGROUND: Left-sided colorectal surgery demonstrates high anastomotic leak rates, with tissue ischemia thought to influence outcomes. Indocyanine green is commonly used for perfusion assessment, but evidence remains mixed for whether it reduces colorectal anastomotic leaks. Laser speckle contrast imaging provides dye-free perfusion assessment in real-time through perfusion heat maps and quantification. OBJECTIVE: This study investigates the efficacy of advanced visualization (indocyanine green versus laser speckle contrast imaging), perfusion assessment, and utility of laser speckle perfusion quantification in determining ischemic margins. DESIGN: Prospective intervention group using advanced visualization with case-matched, retrospective control group. SETTINGS: Single academic medical center. PATIENTS: Forty adult patients undergoing elective, minimally invasive, left-sided colorectal surgery. INTERVENTIONS: Intraoperative perfusion assessment using white light imaging and advanced visualization at 3 time points: T1—proximal colon after devascularization, before transection, T2—proximal/distal colon before anastomosis, and T3—completed anastomosis. MAIN OUTCOME MEASURES: Intraoperative indication of ischemic line of demarcation before resection under each visualization method, surgical decision change using advanced visualization, post hoc laser speckle perfusion quantification of colorectal tissue, and 30-day postoperative outcomes. RESULTS: Advanced visualization changed surgical decision-making in 17.5% of cases. For cases in which surgeons changed a decision, the average discordance between the line of demarcation in white light imaging and advanced visualization was 3.7 cm, compared to 0.41 cm (p=0.01) for cases without decision changes.There was no statistical difference between the line of ischemic demarcation using laser speckle versus indocyanine green (p=0.16). Laser speckle quantified lower perfusion values for tissues beyond the line ofischemic demarcation while suggesting an additional 1 cm of perfused tissue beyond this line. One (2.5%) anastomotic leak occurred in the intervention group. LIMITATIONS: This study was not powered to detect differences in anastomotic leak rates. CONCLUSIONS: Advanced visualization using laser speckle and indocyanine green provides valuable perfusion information that impacts surgical

   @article{skinner2024dcr,
     title = {Clinical Utility of Laser Speckle Contrast Imaging and Real-Time Quantification of Bowel Perfusion in Minimally Invasive Left-Sided Colorectal Resections},
     author = {Skinner, G. and Liu, Y. and Harzman, A. and Husain, S. and Gasior, A. and Cunningham, L. and Traugott, A. and McCulloh, C. and Kalady, M. and Kim, P. and Huang, E.},
     journal = {Diseases of the Colon & Rectum},
     volume = {67},
     number = {6},
     pages = {850-859},
     year = {2024},
     doi = {10.1097/DCR.0000000000003098},
     url = {},
   }

2023

1. JOGS

   Real-time First-In-Human Comparison of Laser Speckle Contrast Imaging and ICG in Minimally Invasive Colorectal & Bariatric Surgery

   Chibueze A. Nwaiwu, Christopher J. McCulloh, Garrett Skinner, and 4 more authors

   Journal of Gastrointestinal Surgery, 2023