Association between postoperative pancreatic fistula and perfusion of remnant pancreas as objectively evaluated with intraoperative indocyanine green

Background: Postoperative pancreatic fistula (POPF) is a major determinant of morbidity, prolonged hospital stays, and thus increased healthcare costs following pancreaticoduodenectomy. Among various risk factors, the relationship of hypoperfusion at the remnant pancreas with POPF has not been clearly established. Indocyanine green (ICG) and near-infrared (NIR) imaging have become one of the ideal methods for fluorescence angiography. This study aims to quantitatively evaluate hypoperfusion with ICG-NIR fluorescence angiography and its association with POPF. Methods: Consecutive patients undergoing pancreaticoduodenectomy for periampullary pathologies were prospectively included in the study. Fluorescence angiography recordings with ICG-NIR, performed before the anastomosis with a standardized technique were dynamically analyzed through Python programming language by two independent researchers blinded to the patients' clinical information, converting them into fluorescence-time graphs. Perfusion data of patients with and without POPF and clinically relevant POPF, according to the ISGPS 2016 definition, were compared. Results: Out of 30 patients, 9 developed clinically relevant POPF, and 3 had biochemical leakage. POPF did not occur in 18 patients. The perfusion parameters STD Fmax and the slope parameter were statistically associated with the development of clinically relevant POPF (p=0.032 and p=0.008, respectively), with Fmax and T1/2max being nearly statistically significant (p=0.087 and p=0.054, respectively). When considering all POPF, Fmax, STD Fmax, T1/2max, and the slope were statistically associated between the two groups (p=0.049, p=0.034, p=0.026, p=0.015, respectively). Conclusion: The intraoperative assessment with ICG-NIR fluorescence angiography method is a potential tool for evaluating the risk of POPF.