Wu Min-Kai, Luo Xiao-Yun, Zhang Fu-Xian
Department of Vascular Surgery, The Ninth Clinical Medical College of Peking University, Beijing Shijitan Hospital, Beijing 100038, China.
Chin Med J (Engl). 2016 Sep 20;129(18):2149-52. doi: 10.4103/0366-6999.189918.
Deep vein thrombosis (DVT) may be associated with iliac vein compression. Up to now, the majority of data has come from a retrospective study about the correlation between DVT and iliac vein compression. This prospective study was to determine the incidence of DVT in individuals with iliac vein compression and identify risk factors predictive of DVT.
A total of 500 volunteers without symptoms of venous diseases of lower extremities and overt risk factors of deep venous thrombosis between October 2011 and September 2012 in Shijitan Hospital were enrolled in this cohort study. All the participants underwent contrast-enhanced abdominal computed tomography (CT) to evaluate iliac vein compression. Baseline demographic information and degree of iliac vein compression were collected. They were categorized into ≥50% or <50% iliac vein compression group. Ultrasound examination was performed to screen DVT at the time of CT examination and 3, 6, 9, and 12 months after the examination. Primary event was DVT of ipsilateral lower extremity. Correlation between DVT and iliac vein compression was estimated by multivariate Logistic regression after adjusting for age, gender, malignancy, surgery/immobilization, chemotherapy/hormonal therapy, and pregnancy.
In 500 volunteers, 8.8% (44) had ≥50% iliac vein compression and 91.2% (456) had <50% iliac vein compression. Ipsilateral DVT occurred in six volunteers including two in iliofemoral vein, two in popliteal vein, and two in calf vein within 1 year. Univariate analysis showed that the incidence of DVT was 6.8% in ≥50% compression group, significantly higher than that in <50% compression group (0.7%) (χ2 = 12.84, P = 0.01). Patients with malignancy had significantly higher incidence of DVT than those without malignancy (χ2 = 69.60,P< 0.01). Multivariate Logistic regression indicated that iliac vein compression and malignancy were independent risk factors of DVT. After adjustment for malignancy, patients with ≥50% iliac vein compression had 10-fold increased risk of developing DVT (adjusted relative risk [RR] = 10.162, 95% confidence interval [CI]: 1.149-89.865, P = 0.037). In subgroup analysis, patients with malignancy and ≥50% iliac vein compression had 12-fold increased the risk of DVT than those without malignance and ≥50% compression (RR = 12.389, 95% CI: 2.327-65.957, P = 0.003).
Iliac vein compression is common, but the incidence of DVT is low. Only individuals with ≥50% iliac vein compression or compression combined with other risk factors might have significantly increased the risk of DVT. Further study is recommended to improve prevention strategies for DVT in significant iliac vein compression.
深静脉血栓形成（DVT）可能与髂静脉受压有关。到目前为止，大多数数据来自关于DVT与髂静脉受压之间相关性的回顾性研究。这项前瞻性研究旨在确定髂静脉受压个体中DVT的发生率，并识别预测DVT的危险因素。
2011年10月至2012年9月期间，在世纪坛医院招募了500名无下肢静脉疾病症状且无深静脉血栓形成明显危险因素的志愿者参与这项队列研究。所有参与者均接受了腹部增强计算机断层扫描（CT）以评估髂静脉受压情况。收集了基线人口统计学信息和髂静脉受压程度。他们被分为髂静脉受压≥50%组或<50%组。在CT检查时以及检查后3、6、9和12个月进行超声检查以筛查DVT。主要事件为同侧下肢DVT。在调整年龄、性别、恶性肿瘤、手术/制动、化疗/激素治疗和妊娠因素后，通过多因素Logistic回归估计DVT与髂静脉受压之间的相关性。
在500名志愿者中，8.8%（44名）髂静脉受压≥50%，91.2%（456名）髂静脉受压<50%。1年内，6名志愿者发生同侧DVT，其中2例发生在髂股静脉，2例发生在腘静脉，2例发生在小腿静脉。单因素分析显示，≥50%受压组DVT发生率为6.8%，显著高于<50%受压组（0.7%）（χ2 = 12.84，P = 0.01）。恶性肿瘤患者的DVT发生率显著高于无恶性肿瘤患者（χ2 = 69.60，P<0.01）。多因素Logistic回归表明，髂静脉受压和恶性肿瘤是DVT的独立危险因素。在调整恶性肿瘤因素后，髂静脉受压≥50%的患者发生DVT的风险增加10倍（调整后相对风险[RR]=10.162，95%置信区间[CI]：1.149 - 89.865，P = 0.037）。在亚组分析中，有恶性肿瘤且髂静脉受压≥50%的患者发生DVT的风险比无恶性肿瘤且髂静脉受压≥50%的患者增加12倍（RR = 12.389，95%CI：2.327 - 65.957，P = 0.003）。
髂静脉受压常见，但DVT发生率较低。只有髂静脉受压≥50%或受压合并其他危险因素的个体发生DVT的风险可能会显著增加。建议进一步研究以改进对严重髂静脉受压患者DVT的预防策略。
