Grabowski E F
Division of Pediatric Hematology/Oncology, New York, Hospital-Cornell University Medical Center, NY 10021.
Invest Radiol. 1988 Nov;23 Suppl 2:S351-8. doi: 10.1097/00004424-198811002-00008.
Although there have been reports of clot formation in angiographic syringes containing nonionic contrast agents, these clots are now believed to be aggregates of red cells that form in the low ionic strength, low pH, zero shear rate environment of contrast media syringes. In an in vitro controlled flow system that stimulates blood flow through a microvessel, we found that large (100 microns or more) red cell aggregates are not seen with any of the media tested (iohexol, sodium methylglucamine diatrizoate, and ioxaglate); aggregates that form under shear conditions are rouleaux. The degree of rouleau formation, compared with saline controls, is greatest with ioxaglate, least with diatrizoate, and intermediate with iohexol. Platelet adhesion/aggregation at a site of injury to vascular endothelium is not significantly affected by iohexol. Rouleaux formation, a potential determinant of local levels of thrombin and other platelet-activating substances, is shown to occur in the lee of mural platelet thrombi.
尽管有报道称，在装有非离子型造影剂的血管造影注射器中会形成凝块，但现在认为这些凝块是红细胞聚集体，它们在造影剂注射器的低离子强度、低pH值、零剪切速率环境中形成。在一个模拟血液流经微血管的体外控制流系统中，我们发现，在所测试的任何介质（碘海醇、葡甲胺钠泛影酸盐和碘克沙酸）中都未观察到大型（100微米或更大）红细胞聚集体；在剪切条件下形成的聚集体是叠连红细胞。与生理盐水对照相比，碘克沙酸的叠连形成程度最大，泛影酸盐最小，碘海醇居中。碘海醇对血管内皮损伤部位的血小板黏附/聚集没有显著影响。叠连形成是局部凝血酶和其他血小板激活物质水平的一个潜在决定因素，已证实在壁血小板血栓的下游会发生叠连形成。
