Manotti C, Quintavalla R, Ugolotti U, Del Favero C, Dettori A G
Centro Malattie Emostatiche, Ospedale Regionale di Parma, Italy.
Invest Radiol. 1992 Dec;27(12):1025-30. doi: 10.1097/00004424-199212000-00009.
A few case reports have suggested a possible thrombogenic effect of nonionic contrast media. In vitro investigations have lead to conflicting results. The authors performed three ex vivo studies to evaluate the influence of an ionic, ioxaglate, and a nonionic, iopamidol, low-osmolality contrast medium on a series of clotting and fibrinolytic parameters, after intravenous or intra-arterial administration, during routine diagnostic procedures.
In the first study, iopamidol was given to 20 consecutive patients through an arterial catheter for digital subtraction arteriography (DSA). In the second study, iopamidol was compared with ioxaglate. The media were randomly and blindly administered intravenously to 21 consecutive patients undergoing brain computed tomography (CT). Finally, ioxaglate was administered intra-arterially to 20 consecutive patients, in a situation comparable with that of the first study.
In the first study, a weak anticoagulant effect and an activation of fibrinolysis were found, associated with indirect markers of thrombin generation, such as increased plasma levels of fibrinopeptide A (FpA) and thrombin-antithrombin III complexes (TAT). In the second study, no significant changes were seen with either contrast medium, for thrombin or fibrinolysis activation parameters. In the third study, the intra-arterially administered contrast medium elicited a marked increase of FpA and TAT, together with an anticoagulant effect.
Both ionic and nonionic contrast media are able to interfere with the clotting/fibrinolytic system in the general circulation when they are administered to patients at the usual dosages. Ioxaglate shows more marked anticoagulant and thrombin-generating effects than iopamidol. The procedure (ie, arterial catheter versus intravenous infusion) seems to be more important than the category of contrast medium in conditioning the magnitude of these effects.
少数病例报告提示非离子型造影剂可能具有致血栓形成作用。体外研究结果相互矛盾。作者进行了三项体外研究，以评估离子型造影剂碘克沙醇和非离子型造影剂碘帕醇这两种低渗造影剂在常规诊断程序中经静脉或动脉给药后，对一系列凝血和纤溶参数的影响。
在第一项研究中，通过动脉导管向20例连续患者给予碘帕醇用于数字减影血管造影（DSA）。在第二项研究中，将碘帕醇与碘克沙醇进行比较。将这两种造影剂随机且盲法静脉给予21例连续接受脑部计算机断层扫描（CT）的患者。最后，在与第一项研究类似的情况下，向20例连续患者动脉内给予碘克沙醇。
在第一项研究中，发现有微弱的抗凝作用和纤溶激活，伴有凝血酶生成的间接标志物，如血浆纤维蛋白肽A（FpA）水平升高和凝血酶 - 抗凝血酶III复合物（TAT）增加。在第二项研究中，两种造影剂对凝血酶或纤溶激活参数均未产生显著变化。在第三项研究中，动脉内给予的造影剂引起FpA和TAT显著增加，同时伴有抗凝作用。
离子型和非离子型造影剂以常规剂量给予患者时，均能干扰体循环中的凝血/纤溶系统。碘克沙醇比碘帕醇表现出更明显的抗凝和凝血酶生成作用。在调节这些作用的程度方面，给药途径（即动脉导管给药与静脉输注）似乎比造影剂类别更重要。
