Issitt Richard, James Tim, Walsh Bronagh, Voegeli David
1 Perfusion Department, Great Ormond Street Hospital for Children, London, UK.
2 Faculty of Health Sciences, University of Southampton, Southampton, UK.
Perfusion. 2017 Sep;32(6):466-473. doi: 10.1177/0267659117705194. Epub 2017 Apr 20.
Acute kidney injury (AKI) following cardiopulmonary bypass affects 5% of patients, representing significant postoperative morbidity and mortality. Animal models have shown an increased uptake of lipid microemboli (LME) into the renal vasculature, potentially indicating ischaemic causation. This study tested a new lipid filtration system (RemoweLL) against a conventional system with no lipid-depleting capacity to determine the efficacy of the filtration system and its effects on renal function.
Thirty consecutive patients underwent coronary artery bypass graft surgery using either the RemoweLL filtration system (15 patients) or a conventional cardiopulmonary bypass circuit (15 patients). Renal function was assessed using cystatin C concentrations as a surrogate marker of glomerular injury, as well as perioperative glomerular filtration rate (GFR) and serum creatinine concentrations. Patients were defined as having acute renal injury if there was an increase in absolute serum creatinine ⩾3 mg/dL (26.4 µmol/L) or 1.5-fold increase from baseline as categorised using the AKIN criteria.
Postoperative differences in LME count between the two groups were highly significant [p<0.001]. Analysis of peak cystatin C concentrations showed significantly lower levels in the LME filtration group on the 2 postoperative morning [p=0.04]. Two-factor ANOVA revealed a trend towards interaction, but this failed to reach significance [p=0.06]. There were no differences throughout the study period in serum creatinine or GFR [p>0.05]. There were no differences in any of the serum or urinary electrolytes.
This study has shown a trend towards improved cystatin C removal with LME filtration; with significantly lower peak concentrations, although no further evidence of renoprotection could be demonstrated. Further research is warranted to establish possible renal benefits of LME filtration in patients undergoing cardiac surgery.
体外循环后发生的急性肾损伤（AKI）影响5%的患者，是术后显著的发病和死亡原因。动物模型显示脂质微栓子（LME）在肾血管系统中的摄取增加，这可能提示缺血性病因。本研究对一种新型脂质过滤系统（RemoweLL）与一种无脂质清除能力的传统系统进行了测试，以确定该过滤系统的有效性及其对肾功能的影响。
30例连续患者接受冠状动脉旁路移植手术，其中15例使用RemoweLL过滤系统，15例使用传统体外循环回路。使用胱抑素C浓度作为肾小球损伤的替代标志物，以及围手术期肾小球滤过率（GFR）和血清肌酐浓度来评估肾功能。如果血清肌酐绝对值增加⩾3mg/dL（26.4µmol/L）或根据AKIN标准从基线水平增加1.5倍，则将患者定义为发生急性肾损伤。
两组术后LME计数差异非常显著[p<0.001]。对胱抑素C峰值浓度的分析显示，术后第2天早晨LME过滤组的水平显著较低[p=0.04]。双因素方差分析显示存在交互作用趋势，但未达到显著水平[p=0.06]。在整个研究期间，血清肌酐或GFR没有差异[p>0.05]。血清或尿液中的任何电解质均无差异。
本研究显示LME过滤有改善胱抑素C清除的趋势；峰值浓度显著降低，尽管没有进一步的肾保护证据。有必要进行进一步研究以确定LME过滤对心脏手术患者可能的肾脏益处。
