Objective Perfusion Assessment in Gracilis Muscle Interposition—A Novel Software-Based Approach to Indocyanine Green Derived Near-Infrared Fluorescence in Reconstructive Surgery

Abstract

Gracilis muscle interposition (GMI) is an established treatment option for complex perineal fistulas and reconstruction. The outcome is limited by complications such as necrosis, impaired wound healing and fistula persistence or recurrence. Quantifiable methods of assessing muscle flap perfusion intraoperatively are lacking. This study evaluates a novel and objective software-based assessment of indocyanine green near-infrared fluorescence (ICG-NIRF) in GMI. Methods: Intraoperative ICG-NIRF visualization data of five patients with inflammatory bowel disease (IBD) undergoing GMI for perineal fistula and reconstruction were analyzed retrospectively. A new software was utilized to generate perfusion curves for the specific regions of interest (ROIs) of each GMI by depicting the fluorescence intensity over time. Additionally, a pixel-to-pixel and perfusion zone analysis were performed. The findings were correlated with the clinical outcome. Results: Four patients underwent GMI without postoperative complications within 3 months. The novel perfusion indicators identified here (shape of the perfusion curve, maximum slope value, distribution and range) indicated adequate perfusion. In one patient, GMI failed. In this case, the perfusion indicators suggested impaired perfusion. Conclusions: We present a novel, software-based approach for ICG-NIRF perfusion assessment, identifying previously unknown objective indicators of muscle flap perfusion. Ready for intraoperative real-time use, this method has considerable potential to optimize GMI surgery in the future.

Optimizing Indocyanine Green Dosage for Near-Infrared Fluorescence Perfusion Assessment in Bowel Anastomosis: A Prospective, Systematic Dose-Ranging Study

“…Despite the statistical significance, the signal intensity at lower dosages was still sufficient for perfusion assessment, suggesting that these differences may not have substantial clinical implications. The focus of ICG-NIRF imaging should be on the optimal dosage and imaging environment for software-based quantitative, objective perfusion assessment methods rather than the visual signal intensity, as previously reported [19][20][21][22].…”

Feasibility of Novel Software-Based Perfusion Indicators for the Ileal J-Pouch—On the Path towards Objective and Quantifiable Intraoperative Perfusion Assessment with Indocyanine Green Near-Infrared Fluorescence

“…The parametric pixel-to-pixel mapping holds great promise for intraoperative real-time use, as it is highly accurate and removes further subjectivity and bias from the perfusion assessment (no manual ROI placement is required, as every pixel represents an ROI). We have recently shown its feasibility for perfusion assessment in gracilis muscle interposition [ 42 ]. However, to implement its widespread use, further optimisation of intraoperative visualization, recordings and movement-correction software are needed, as our results reflect: for several recordings, the pixel-to-pixel analysis was not successful due to movement in the recording caused primarily by intestinal peristalsis and secondarily by aortic pulse (patients 14, 4, 6, 8, 10, 16, 17).…”

Indocyanine Green Fluorescence Guided Surgery in Colorectal Surgery

“…Nevertheless, a well-perfused gracilis flap is of utmost importance for the success of this technique. A recent study by Lobbes et al [ 24 ] reported a software-based approach for gracilis perfusion assessment, pointing to objective indicators for flap perfusion. This technique may be further developed and utilized in the future to optimize the outcome of gracilis muscle interposition.…”