Low-molecular-weight dextran for optical coherence tomography may not be protective against kidney injury in patients with renal insufficiency

BACKGROUND Low-molecular-weight dextran(LMWD)is considered a safe alternative to contrast media for blood displacement during optical coherence tomography(OCT)imaging.AIM To investigate whether the use of LMWD for OCT is protective against kidney injury in patients with advanced renal insufficiency.METHODS In this retrospective cohort study,we identified 421 patients with advanced renal insufficiency(estimated glomerular filtration rate<45 mL/min/1.73 m2)who underwent coronary angiography or percutaneous coronary intervention;79 patients who used additional LMWD for OCT imaging(LMWD group)and 342 patients who used contrast medium exclusively(control group).We evaluated the differences between these two groups and performed a propensity score-matched subgroup comparison.RESULTS The median total volume of contrast medium was 133.0 mL in the control group vs 140.0 mL in the LMWD group.Although baseline renal function was not statistically different between these two groups,the LMWD group demonstrated a strong trend toward the progression of renal insufficiency as indicated by the greater change in serum creatinine level during the 1-year follow-up compared with the control group.Patients in the LMWD group experienced worsening renal function more frequently than patients in the control group.Propensity score matching adjusted for total contrast media volume consistently indicated a trend toward worsening renal function in the LMWD group at the 1-year follow-up.Delta serum creatinine at 1-year follow-up was significantly greater in the LMWD group than that in the control group[0.06(-0.06,0.29)vs-0.04(-0.23,0.08)mg/dL,P=0.001],despite using similar contrast volume.CONCLUSION OCT using LMWD may not be protective against worsening renal function in patients with advanced renal insufficiency.

Dietary hypercholesterolemia aggravates contrast media-induced nephropathy

Background Contrast media adinistration can result in severe nephrotoxicity under pothological conditions such as diabetic nephropathy, congestive heart failure, dehydration, et al. The purpose of this study was to evaluate the effects of dietary hypercholesterolemia on contrast media-induced changes in renal function, blood flow, and histopathology.Methods Rats were fed either on a normal rodent diet (group N) or a high-cholesterol supplemented diet (group H; 4% cholesterol and 1% cholic acid) for 8 weeks. Half of the animals (n=6) from each diet group were then given a tail vein injection of 60% diatrizoate (6 ml/kg; group NC and group HC) and the other half were administered saline. Total serum cholesterol, triglyceride, serum creatinine, creatinine clearance rate, fractional excretion of sodium and potassium, and cortical nitric oxide production were determined one day following contrast media administration. Renal blood flow was determined by color Doppler flow imaging and pulsed-mode Doppler. Renal histopathology was observed by light microscopy.Results Total serum cholesterol and resistance indices of renal blood vessels increased significantly, while creatinine clearance rate and production of nitric oxide in the renal cortex decreased markedly in group HC and group H when compared to group N and group NC. The creatinine clearance rate decreased significantly in group HC compared to group H. Serum creatinine levels and fractional excretion of sodium and potassium in group HC were significantly higher than those in the other three groups. Severe tubular degeneration and necrosis, protein cast accumulation, and medullary congestion were found in group HC. Conclusion Hypercholesterolemia is a risk factor for contrast media-induced nephropathy. Hypercholesterolemia aggravates contrast media-induced nephrotoxicity through the reduced production of nitric oxide.

超声造影定量分析失血性休克复苏期肾血流灌注的动物实验

目的超声造影(CEUS)是一种无创性检查技术,可监测器官的血流灌注,本研究探讨CEUS定量监测失血性休克(HS)复苏期肾血流灌注的价值。材料与方法采用前瞻性研究方法,将40只健康新西兰大耳白兔随机分为5组,选1组为正常对照组(T1);其余采用Wiggers改良法建立HS模型,选1组为休克组(T2),其余按复苏治疗时间分为复苏2 h组(T3)、复苏6 h组(T4)、复苏24 h组(T5)。均进行CEUS检查,获取定量参数峰值强度(A)、达峰时间(TTP)、曲线下面积(AUC)和上升支斜率(Grad),并分析上述参数与病理结果的相关性。结果与T1组比较,T2组TTP延长,A、AUC及Grad减低(P<0.05),成功建立HS模型。与T2组比较,T3、T4组A、AUC及Grad增加(P<0.05),TTP不缩短(P>0.05)。T5组与T2组比较各参数差异均有统计学意义(P<0.05),与T1组比较各参数差异均无统计学意义(P>0.05),提示复苏后各灌注参数逐渐恢复。病理结果显示,复苏后肾小管上皮细胞肿胀及血管充血病理改变逐渐恢复。结论 CEUS能有效地定量评价HS复苏期肾血流灌注的改变,是一种无创性的监测方法。

超声造影对弥漫性肾病肾血流灌注的评价

目的探讨实时灰阶超声造影评价弥漫性肾病血流灌注改变的临床价值。方法选取对照组(健康人24例)和病例组(弥漫性肾病患者25例),对所有受检者造影前1d检测血清肌酐(Cr)、尿素氮(BUN)。经静脉团注SonoVue(0.03ml/kg)行肾脏灰阶超声造影,观察并存储注射造影剂后0～3min的动态图像,利用定量分析软件进行离机时间-强度曲线(TIC)分析,分别计算两组肾皮质达峰时间(ATc)、皮质峰值强度变化(△Ac)、皮质TIC斜率(βc)、髓质达峰时间(ATm)、髓质峰值强度变化(△Am)、髓质TIC斜率(βm)、髓质皮质达峰时间之差(△AT)、皮质髓质峰值强度变化值之差(△Ac-m)。对以上检测结果进行统计学分析,并研究上述参数与血BUN和Cr值相关性。结果两组肾脏ATc、ATm、βc差异有统计学意义(P<0.05),与TIC曲线形态结果一致;病例组△AT较对照组有延长趋势;ATm、△AT与BUN、Cr呈正相关(r=0.68、r=0.66、r=0.71、r=0.69,P均<0.05)。结论超声造影技术可较敏感反映弥漫性肾病肾脏血流灌注变化特点,有望成为评价肾血流灌注的临床实用技术。