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

Abstract

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 heatmaps 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 three 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 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 line of ischemic demarcation using laser speckle versus indocyanine green (p = 0.16). Laser speckle quantified lower perfusion values for tissues beyond the line of ischemic 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 decision-making in minimally invasive left-sided colorectal surgeries. See Video Abstract.