Wells P S, Anderson D R, Ginsberg J
Department of Medicine, Ottawa Hospital and the University of Ottawa, Ontario, Canada.
Semin Thromb Hemost. 2000;26(6):643-56. doi: 10.1055/s-2000-13219.
Deep vein thrombosis (DVT) and pulmonary embolism (PE) are relatively common diseases and are amenable to therapy but with a potentially fatal outcome if untreated. The diagnosis can be made in most patients with use of the noninvasive imaging tests, but limitations exist. The standard first choice of investigation in patients with suspected DVT is compression ultrasonography (CUS). As with all tests, there is a potential for false-positive and false-negative results. The latter are especially an issue for calf vein thrombi, and this in part has led to the concept of serial CUS testing of the proximal venous system and not imaging of the calf. The premise of the repeat (serial) CUS test is that only thrombi that extend to the proximal system are clinically relevant, and these thrombi will be detected during subsequent testing. However, despite the safety of the serial CUS testing concept, it is inconvenient and expensive. The standard first choice of investigation in patients with suspected PE, the ventilation-perfusion (V/Q) lung scan is nondiagnostic in most cases. In the past few years, the diagnostic process has improved because of the validation of clinical models that accurately categorize patients as having low (5%), moderate (20% to 30%), or high probability (>60%) for venous thromboembolic disease. Among the improvements this provides is the elimination of serial CUS testing if the ultrasound results are normal and the clinical probability is low in patients with suspected DVT. In patients with suspected PE in whom further testing is necessary, determination of clinical probability allows selection of invasive (angiography) or noninvasive testing (serial ultrasound) in patients with non-high-probability V/Q scans. The fibrin degradation product D-dimer has had a high negative predictive value; negative results with enzyme-linked immunosorbent assay (ELISA) tests effectively rule out DVT or PE. In addition, a negative result with less-sentive D-dimer testing and a low clinical probability excludes DVT or PE.
深静脉血栓形成（DVT）和肺栓塞（PE）是相对常见的疾病，虽可进行治疗，但如果不治疗则可能导致致命后果。大多数患者可通过无创成像检查进行诊断，但也存在局限性。疑似DVT患者的标准首选检查是加压超声检查（CUS）。与所有检查一样，存在假阳性和假阴性结果的可能性。后者对于小腿静脉血栓尤其成问题，这在一定程度上导致了对近端静脉系统进行连续CUS检查而非对小腿进行成像的概念。重复（连续）CUS检查的前提是只有延伸至近端系统的血栓才具有临床相关性，并且这些血栓将在后续检查中被检测到。然而，尽管连续CUS检查概念安全，但它不方便且昂贵。疑似PE患者的标准首选检查是通气/灌注（V/Q）肺扫描，在大多数情况下是非诊断性的。在过去几年中，由于临床模型的验证，诊断过程有所改善，这些临床模型可准确将患者分类为静脉血栓栓塞性疾病的低（5%）、中（20%至30%）或高概率（>60%）。这带来的改进之一是，如果超声结果正常且疑似DVT患者的临床概率较低，则无需进行连续CUS检查。在疑似PE且需要进一步检查的患者中，确定临床概率有助于在V/Q扫描非高概率的患者中选择侵入性（血管造影）或非侵入性检查（连续超声检查）。纤维蛋白降解产物D-二聚体具有较高的阴性预测价值；酶联免疫吸附测定（ELISA）试验的阴性结果可有效排除DVT或PE。此外，敏感性较低的D-二聚体检测结果为阴性且临床概率较低可排除DVT或PE。
