Killewich L A, Nunnelee J D, Auer A I
University of Maryland, Baltimore.
J Vasc Surg. 1993 May;17(5):934-8; discussion 938-9.
This study tests the hypothesis that the absence of deep venous thrombosis (DVT) on lower extremity color-flow venous duplex examination (LECFD) combined with a non-high-probability ventilation/perfusion (V/Q) scanning results rules out pulmonary embolus (PE). The use of LECFD as a diagnostic aid for PE is based on data that show that 90% of PE originate from lower extremity DVT, and therefore on the assumption that PE cannot be present if DVT is not present as the source.
Over a 3-year period 51 patients with clinically suspected PE underwent LECFD and pulmonary angiography (PA) within 72 hours of each other. Forty-one patients also underwent V/Q scanning during the same time period. The results of LECFD and V/Q scans were compared with the results of PA, the gold standard for the diagnosis of pulmonary emboli.
Results of LECFD were positive for DVT in seven of 16 cases of angiographically documented PE. Thus the "sensitivity" of LECFD as a diagnostic aid in cases of suspected PE is 44%. The results of LECFD and V/Q scans were combined and compared with the results of PA. A high-probability V/Q scanning result was considered positive for PE. Intermediate- and low-probability scanning results were considered negative, because in the literature the decision to begin heparin therapy is not made on the basis of this result. The combination of test results was considered positive if either test result was positive and negative only if results of both were negative. With these criteria the combination of test results was positive in only 62% of cases of angiographically documented PE.
If treatment of suspected PE were based on LECFD alone or on duplex combined with V/Q scanning, 40% to 50% of patients with PE would remain untreated. In cases of suspected PE where these noninvasive tests do not confirm its presence, PA should be performed.
本研究旨在验证以下假设：下肢彩色血流静脉双功超声检查（LECFD）未发现深静脉血栓形成（DVT），且通气/灌注（V/Q）扫描结果为非高概率，可排除肺栓塞（PE）。将LECFD用作PE的诊断辅助手段，是基于数据显示90%的PE起源于下肢DVT，因此假设如果不存在作为源头的DVT，则不会出现PE。
在3年期间，51例临床怀疑为PE的患者在彼此72小时内接受了LECFD和肺血管造影（PA）检查。41例患者在同一时期还接受了V/Q扫描。将LECFD和V/Q扫描的结果与PA的结果进行比较，PA是诊断肺栓塞的金标准。
在16例经血管造影证实为PE的病例中，有7例LECFD结果显示DVT呈阳性。因此，LECFD作为疑似PE病例诊断辅助手段的“敏感性”为44%。将LECFD和V/Q扫描的结果合并，并与PA的结果进行比较。V/Q扫描结果为高概率被视为PE阳性。中概率和低概率扫描结果被视为阴性，因为在文献中，不会基于此结果决定开始肝素治疗。如果任一检测结果为阳性，则检测结果组合被视为阳性；只有当两者结果均为阴性时，才被视为阴性。根据这些标准，在经血管造影证实为PE的病例中，检测结果组合仅在62%的病例中呈阳性。
如果对疑似PE的治疗仅基于LECFD或基于双功超声与V/Q扫描的联合检查，40%至50%的PE患者将得不到治疗。在疑似PE的病例中，如果这些非侵入性检查未证实其存在，则应进行PA检查。
