DISTAL LIMB ISCHEMIA FOR MORE THAN SIXTY MINUTES DURING FEMORAL ARTERY CANNULATION IS ASSOCIATED WITH POSTOPERATIVE ACUTE KIDNEY INJURY

Abstract

<h3>Objective</h3> Peripheral artery cannulation is routinely performed in patients undergoing minimally invasive cardiac surgery (MICS) on cardiopulmonary bypass (CPB). Typically, the femoral artery is the preferred cannulation site. This technique poses inherent risks associated with both retrograde flow to the body and vital organs as well as antegrade flow to the cannulated limb. Ideally, cannula size is large enough to maintain optimal cardiac indices on CPB. On the other hand, larger cannula size increases the risk for femoral artery obstruction, leading to distal limb ischemia. This phenomenon is well knowns on patients undergoing prolonged femoral artery cannulation such as extracorporeal membrane oxygenation (ECMO) patients. Even the need for fasciotomies and limb amputation is described. However, very little research focused on both short- as long-term effects of femoral artery cannulation for a limited time span, such as CPB during MICS. <h3>Design and method</h3> We performed a monocentric prospective cohort study on 280 consecutive patients undergoing MICS with femoral artery cannulation. Regional oxygen saturation (rSO2) was measured via Near Infrared Spectroscopy (NIRS) bilaterally on the calf muscles. Distal limb ischemia was defined as a ∆rS02 > 15% between the cannulated and non-cannulated for more than four minutes. This criterium was based on a study by Patton-Rivera who found a 100% correlation between these NIRS parameters and clinical signs of distal limb ischemia in ECMO patients. We focused on incidence, risk factors and sequelae such as perioperative acute kidney injury (AKI) as defined by the KDIGO criteria. <h3>Results</h3> 74 out of 280 patients in our cohort suffered NIRS diagnosed distal limb ischemia (26,4%). Mean duration of cannulation was 108,70 minutes (±41,79) No association between intraoperative distal limb ischemia and postoperative AKI was found for the whole cohort. However, in the subgroups suffering ischemia in the cannulated limb for ≥60minutes (42 patients) and for ≥ 90 minutes (26 patients), a statistically significant association with postoperative AKI was found (p=0,018 and p=0,027 respectively). No patients suffering distal limb ischemia required de novo postoperative renal replacement therapy. <h3>Conclusions</h3> NIRS diagnosed distal limb ischemia for more than sixty minutes is significantly associated with postoperative AKI as defined by the KDIGO criteria. None out of 74 patients suffering distal limb ischemia required de novo hemodialysis however.