Real-time intraoperative assessment of residual liver functional reserve using pulse dye densitometry

Background: For a safe major hepatectomy, preoperative methods that can reliably estimate postoperative liver function are necessary. The aim of this study was to assess the utility of ICG-R15 measured by pulse dye densitometry to predict residual liver function prior to hepatectomy. Patients and method: In 29 patients who underwent various types of hepatectomies, indocyanine green (ICG)-R15 was measured by pulse dye densitometry at the time of opening the abdomen (laparotomy phase), clamping the Glisson's pedicles to cutting (clamping phase), and closing abdomen after hepatectomy (resection phase). The relationships among these measurements and postoperative liver function were examined. Results: The mean ICG-R15 was 12.3 ± 6.0% preoperatively (±SD), 9.3 ± 7.0% at laparotomy, 18.8 ± 11.6% at clamping, and 20.1 ± 10.9% at resection. The preoperative and laparotomy and the clamping and resection ICG-R15 values correlated significantly. Eleven (38%) patients developed postoperative hyperbilirubinemia [total bilirubin (T-Bil) >3.0 mg/dl]. The postoperative peak T-Bil correlated significantly with clamping ICG-R15 (r = 0.637, p = 0.0002), but not with preoperative ICG-R15 (r = 0.283, p = 0.137), total clamp time (r = 0.005, p = 0.975), and blood loss (r = 0.097, p = 0.615). Multivariate analysis identified ICG-R15 measured at clamping as the only determinant of postoperative peak T-Bil (r = 0.612). ICG-R15 measured at clamping correlated with the postoperative hospital stay (p = 0.046). Conclusions: ICG-R15 can be measured in real time during surgery by pulse dye densitometry. ICG-R15 measured by this technique before hepatectomy provides a direct and reliable measure of postoperative residual liver function, thus helping in surgical decision making regarding the extent of hepatectomy.