Quantitative Intraoperative Microperfusion Analysis in Open Aortic Repair to Prevent Colonic Ischemia

Author(s): Andreas LH Gerken, Vera Englert, Johann S Rink, Steffen J. Diehl, Christel Weiß, Martin Sigl, Christoph Reißfelder, Kay Schwenke

Objective: With an incidence of 1.6 to 7.6%, postoperative colonic ischemia is a rare but dangerous complication after infrarenal open aortic repair (OAR) with a mortality rate of up to 50%. A potential risk factor is intraoperative ligation of the inferior mesenteric artery (IMA). The aim of this study is to determine the feasibility of the standardized intraoperative assessment of colonic microperfusion by laser Doppler flowmetry with "oxygen to see (O2C)" to facilitate the decision regarding IMA reimplantation. Methods: In this prospective pilot study, twenty-five patients underwent elective OAR. Measurements with the O2C were performed on the serosa of the sigmoid colon before and after OAR. If reimplantation of the IMA was necessary, a third measurement was performed accordingly. The decision regarding reimplantation was made by the surgeon using the O2C parameters flow, velocity, SO2, and rHb in combination with the macroscopic findings (backflow from the IMA and sigmoid color). Results: Significant relative changes in the O2C microperfusion parameters SO2, rHb, flow, and velocity were detected (P < .0001) intraoperatively after OAR. No reimplantation of the IMA was deemed necessary on the basis of macroscopic findings alone. However, low or decreasing O2C values in combination with the respective macroscopic findings led to three IMA reimplantations. In patients with IMA reimplantation, rHb and flow were significantly lower after OAR (P = .0335; P = .0265). No sigmoid ischemia occurred in any of the patients. The 30-day mortality rate was 0%. Overall, one or more minor complications (Clavien-Dindo grades I and II) occurred in 5 patients (20%). Major complications (grades III, IV, and V) did not occur postoperatively in any of the patients (0%). Conclusions: Objective measurement parameters obtained by O2C can be used to guide decisions regarding the need for IMA reimplantation. Further studies are needed to investigate the validity of the parameters.