Grewal Jasmine, Al Hussein Mosaad, Feldstein Jaimee, Kiess Marla, Ellis Jennifer, Human Derek, Leipsic Jonathon
Division of Cardiology, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
Congenit Heart Dis. 2013 Jan-Feb;8(1):40-7. doi: 10.1111/j.1747-0803.2012.00699.x. Epub 2012 Aug 16.
Thromboembolic complications have been noted after the Fontan operation. However, the prevalence of silent events among an adult contemporary population is not known. Noninvasive screening by any method including computed tomography (CT) has been technically limited to date.
The objective of this study was to evaluate a novel dual-energy CT (DECT) protocol in determining the prevalence of "silent" intracardiac thrombus and thrombus in the Fontan and pulmonary circulations among adults after the Fontan operation.
All post-Fontan patients attending the Pacific Adult Congenital Heart Clinic were approached for study participation. Those agreeable underwent a full clinical assessment, cardiopulmonary stress testing, transthoracic echocardiogram, and DECT low kilovoltage imaging protocol.
Twenty-three patients were included in the study (30 ± 10 years, 26% women). Three (13%) patients had evidence of silent thrombi detected on DECT. All three of these patients had an extracardiac conduit and mural thrombus was found within the conduit. Older age at the time of the Fontan operation was associated with the presence of thrombus (21 ± 14 vs. 11 ± 6 years, P =.05).
Thirteen percent of adult patients post-Fontan procedure have clinically silent thrombi. These were all found among patients with an extracardiac conduit traditionally thought to be at low risk for thromboembolism. Given the significant risk of thromboembolic complications, large randomized prospective studies looking at anticoagulation therapy in all Fontan patients are urgently needed. In the meanwhile, given the important rate of silent thrombi, a systematic robust screening protocol that includes noninvasive low radiation methods such as DECT methods should be considered.
在Fontan手术之后已注意到血栓栓塞并发症。然而，当代成年人群中无症状事件的发生率尚不清楚。包括计算机断层扫描（CT）在内的任何方法进行的无创筛查在技术上至今仍受到限制。
本研究的目的是评估一种新型双能CT（DECT）方案在确定Fontan手术后成人心脏内“无症状”血栓以及Fontan和肺循环中血栓发生率方面的作用。
邀请所有在太平洋成人先天性心脏病诊所就诊的Fontan术后患者参与研究。同意参与的患者接受了全面的临床评估、心肺应激试验、经胸超声心动图检查以及DECT低千伏成像方案。
23名患者纳入研究（年龄30±10岁，女性占26%）。3名（13%）患者经DECT检测有无症状血栓的证据。所有这3名患者均有心脏外管道，且在管道内发现了壁血栓。Fontan手术时年龄较大与血栓的存在相关（21±14岁 vs. 11±6岁，P = 0.05）。
Fontan手术后13%的成年患者有临床无症状血栓。这些均在传统上被认为血栓栓塞风险较低的有心脏外管道的患者中发现。鉴于血栓栓塞并发症的重大风险，迫切需要开展大型随机前瞻性研究来观察所有Fontan患者的抗凝治疗。同时，鉴于无症状血栓的重要发生率，应考虑采用包括DECT等无创低辐射方法在内的系统可靠筛查方案。
