Background: Allogenic blood product usage is associated with worse outcomes in open repair of descending and thoracoabdominal aortic aneurysms. This pilot study evaluated the safety and efficacy of a novel modification of the left heart bypass (LHB) circuit to reduce intraoperative blood transfusions.
Methods: In modified LHB, pump suckers collected shed blood that was directly retransfused through a femoral vein cannula. In standard LHB, cellsavers were used to collect, wash, and retransfuse shed blood. Consecutive patients undergoing elective surgical descending or thoracoabdominal aneurysm repair using modified (N.=12) or standard (N.=21) LHB were compared. Intraoperative blood product use was the primary outcome. Hypotensive episodes, lactate levels, and adverse events (early mortality, spinal cord injury, renal and respiratory insufficiency) were secondary outcomes.
Results: Groups were comparable regarding pre- and intraoperative variables. No perfusion-related adverse events occurred. With modified LHB, intraoperative blood product use was significantly reduced: packed red blood cells by 60% from 10 to 4 units (P=0.002), fresh frozen plasma by 70% from 17 to 5 units (P<0.001) as well as retransfused cellsaver volume by 75%, from 4500 mL to 1110 mL (P<0.001). Hemodynamic instability occurred in 1 (8.3%) vs. 6 (29%), P=0.22 and overall lactate levels were significantly reduced (P=0.045) with modified LHB. Adverse events combined occurred in 1/12 vs. (P=0.022).
Conclusions: The novel modified LHB with direct retransfusion was safe and associated with significantly reduced intraoperative blood product use, reduced lactate production and improved clinical outcomes as compared to standard LHB and could represent an important clinical improvement.