Introduction: Ureteroenteric strictures (UES) are a common complication of radical cystectomy and urinary diversions. UES occurs in 4-25% of all patients undergoing urinary diversion. Anastomotic ischemia is implicated in the formation of stricture. We aim to describe the method for using SPY fluorescent angiography during open urinary diversion.
Methods: Evaluation of ureteral perfusion is commonly performed during robotic-assisted intracorporeal urinary diversion using indocyanine green (ICG) and firefly technology which allow for the detection of ICG indicating perfusion but provides no information on the density of perfusion. SPY is a similar technology that can be employed during open surgery that allows for the visualization of green ICG tracer but also provide a heat map that indicates density of vascularization. ICG dye is administered via IV before the bowel work to create the conduit segment is begun. Ureteral perfusion is assessed using SPY technology to visualize the tracer and perfusion density. SPY has 3 modes of fluorescence: standard green fluorescence, black and white mode, and heatmap mode. The black and white is most sensitive for determining perfusion to tissue. The distal-most aspect of the well perfused ureter is marked with a stitch. If the ureter has poor distal perfusion, it can be resected proximally. A conduit is created, and the bowel is anastomosed accordingly. After both ureteral anastomoses are complete, ICG is again administered via IV to assess for perfusion in the post-anastomosis ureter.
Results: We are conducting an ongoing prospective trial to better define the role and benefit of SPY. We have enrolled 16 patients to date with median follow-up time of 4.7 months and have not detected any ureteroenteric strictures within the experimental group. Our institutional rate of UES in patients who did not have SPY fluorescent angiography is 10.3%.
Conclusions: SPY fluorescent angiography can be used during open urinary diversion to ensure perfusion to ureteroenteric anastomosis. Research is ongoing to assess its role in urinary diversion and the prevention of ureteroenteric strictures.
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