探讨超声及超声造影在肾细胞癌伴下腔静脉瘤栓合并血栓诊断中的价值。

回顾性纳入北京大学第三医院2015年1月至2018年5月行手术治疗的肾细胞癌合并下腔静脉瘤栓患者113例。所有患者均于术前行下腔静脉超声检查，对无法确认瘤栓或者血栓的22例患者行超声造影检查，均取得术后病理结果。以术后病理为"金标准"，将患者分为合并血栓组27例、不合并血栓组86例。对2组患者的临床资料、病理及超声特征进行对比分析，绘制不同参数评估血栓形成的ROC曲线，计算曲线下面积（AUC）。应用四格表计算超声造影诊断下腔静脉瘤栓合并血栓的敏感度、特异度、准确性、阳性预测值及阴性预测值。

合并血栓组较不合并血栓组的瘤栓Mayo分级更高（P=0.011）；肿瘤最大长径更小[（7.42±2.87）cm vs（9.37±2.88）cm，P=0.013]；瘤栓更宽[（25.82±13.79）mm vs（19.79±10.73）mm，P=0.019]；残余管腔未见血流信号者更多[（19/27，70.4%）vs（37/86，43.0%），P=0.016]；肾肿瘤未见无回声坏死区者更多[（17/27，63.0%）vs（34/86，39.5%），P=0.046]；瘤栓肾静脉入口处前后径更大[（26.90±8.12）mm vs （20.59±6.87）mm，P<0.001]；腔静脉节段性切除比例更高[（12/27，44.4%） vs （9/86，10.5%），P<0.001]。绘制肿瘤最大长径评估血栓形成的ROC曲线，得出AUC为0.668（P=0.006），最佳截断值为<6.90 cm；瘤栓宽度评估血栓形成的AUC为0.669（P=0.016），最佳截断值为>24.6 mm；瘤栓肾静脉汇入下腔静脉入口处前后径评估血栓形成的AUC为0.766（P<0.001），最佳截断值为>23.6 mm。超声造影诊断下腔静脉瘤栓合并血栓的敏感度、特异度、准确性、阳性预测值及阴性预测值分别为71.4%、93.3%、86.3%、83.3%及87.5%。

肿瘤越小、瘤栓越宽越容易形成血栓；超声造影可提高下腔静脉瘤栓合并血栓的诊断效能，但仅依据栓子是否增强鉴别血栓和瘤栓可能存在偏差。

To evaluate the value of ultrasound and contrast-enhanced ultrasound (CEUS) in the diagnosis of renal cell carcinoma with tumor thrombus in the inferior vena cava (IVC).

A retrospective analysis was performed on 113 patients with renal cell carcinoma complicated with tumor thrombus in the IVC who underwent surgical treatment at the Peking University Third Hospital from January 2015 to May 2018. All patients were examined by IVC ultrasound before operation, and 22 patients in whom tumor thrombus or thrombus could not be confirmed underwent CEUS examination. Postoperative pathological results were obtained in all patients. According to the postoperative pathology, the patients were divided into either a thrombosis group (n=27) or a non-thrombosis group (n=86). The clinical data and pathological and ultrasonic characteristics of the two groups were compared. The ROC curves of different parameters to evaluate thrombosis were drawn, and the area under the curve (AUC) was calculated. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CEUS in the diagnosis of IVC tumor thrombus complicated with thrombosis were calculated by the four-fold table method.

In univariate analysis, the Mayo grade of tumor thrombus was higher (P=0.011), the maximum long diameter of tumor was smaller [(7.42±2.87) cm vs (9.37±2.88) cm, P=0.013], and the tumor thrombus was wider [(25.82±13.79) mm vs (19.79±10.73) mm, P=0.019] in the thrombosis group than in the non-thrombosis group. There were more patients without blood flow signal in the residual lumen [(19/27, 70.4%) vs (37/86, 43.0%), P=0.016] and more cases without anechoic necrosis in renal tumors [(17/27, 63.0%) vs (34/86, 39.5%), P=0.046] in the thrombosis group. The anteroposterior diameter of renal vein entrance of tumor thrombus was larger [(26.90±8.12) mm vs (20.59±6.87) mm, P<0.001] and the proportion of patients with segmental resection of the IVC was higher [(12/27, 44.4%) vs (9/86, 10.5%), P<0.001] in the thrombosis group. The ROC curve of the maximum long diameter of tumor was drawn; the AUC was 0.668 (P=0.006), and the best cut-off value was < 6.90 cm. The AUC of thrombus width was 0.669 (P=0.016), and the best cut-off value was>24.6 mm. The AUC of the anteroposterior diameter of the renal vein of tumor thrombus flowing into the IVC was 0.766 (P<0.001), and the best cut-off value was>23.6 mm. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CEUS in the diagnosis of IVC tumor thrombus complicated with thrombosis were 71.4%, 93.3%,86.4%, 83.3% and 87.5%, respectively.

The smaller the tumor and the wider the tumor thrombus, the more likely a thrombus is formed. CEUS can improve the diagnostic efficiency for IVC tumor thrombus complicated with thrombosis, but only according to whether the thrombus is enhanced, there may be a deviation in the identification of bland thrombus and tumor thrombus.