Abstract
BACKGROUND: Anastomotic leakage (AL) remains a major postoperative complication after rectal cancer surgery, even with advances in minimally invasive techniques. Indocyanine green (ICG) fluorescence imaging is widely used to assess bowel perfusion, but conventional methods rely heavily on subjective visual interpretation. The SPY-QP software enables quantitative evaluation of ICG fluorescence, potentially improving the accuracy of perfusion assessment. METHODS: The SPECTACLE study is a multicenter, prospective, single-arm trial designed to evaluate whether SPY-QP-based quantitative blood flow assessment can reduce AL rates compared with historical controls from the EssentiAL study. Perfusion assessment is performed according to an algorithm we developed based on our previous retrospective analysis. We plan to enroll 400 patients undergoing laparoscopic or robotic rectal cancer resection with anastomosis. The primary endpoint is the incidence of AL (Grades A-C) within 30 days postoperatively. Secondary endpoints include changes in surgical strategy based on perfusion findings, operative time, intraoperative complications, and other postoperative outcomes. DISCUSSION: This study aims to provide robust evidence on whether objective perfusion assessment using SPY-QP can reduce AL after rectal cancer surgery, potentially leading to broader adoption of quantitative imaging in colorectal surgery. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs032230212.