可转换型腔静脉滤器临床应用的个体化及安全性评估

背景与目的：腔静脉滤器置入是预防下肢深静脉血栓形成患者发生肺栓塞最直接和最有效的手段，已被临床广泛应用。可转换型滤器用于预防肺栓塞的时限更加灵活，转换操作更加简单，但其临床应用的资料尚不足，因此，本研究通过单中心回顾性分析，综合评估可转换型腔静脉滤器的临床应用特点。 方法：回顾性分析本中心行DSA引导下置入可转换型腔静脉滤器的52例患者资料。测量不同个体的下腔静脉直径，髂静脉分叉与低侧肾静脉开口距离，滤器释放时前跳距离，滤器释放后长度与宽度等指标，进一步明确置入安全距离。并收集滤器转换时间及转换术中情况，探讨复杂病例转换技巧。 结果：经测量，52例患者的髂静脉分叉与低侧肾静脉开口距离为（116.4±13.2）mm，远大于滤器释放后的平均长度（54.6±1.3）mm；滤器释放后的滤器平均宽度为（22.9±3.0）mm，略大于释放前下腔静脉平均直径（20.8±3.4）mm；19例（36.5%）发生滤器释放后的前跳，平均前跳距离为（6.5±1.8）mm。释放后，滤器均无明显倾斜。在拟行转换的48例患者中，42例（87.5%）一次性成功解锁，平均耗时（4.5±0.8）min；其中39例（81.3%）回收钩取出后，滤器未打开或未完全打开，均经猪尾导管搅拌后完全打开。在41例超期转换病例中（>2个月），37例患者（90.2%）一次性转换成功，其中4例患者（8.5%）有回收钩贴壁，经导丝成袢技术联合鹅颈抓捕技术辅助下成功转换。 结论：可转换型腔静脉滤器是一种安全有效、容易转换的滤器选择。在置入过程中应考虑前跳可能。在超过推荐转换时限的患者，一次性转换成功率仍然较高。

Individualized clinical application and safety assessment of convertible vena cava filter implantation

Background and Aims: Vena cava filter implantation is the most direct and effective approach to prevent the occurrence of pulmonary embolism in patients with deep vein thrombosis of the lower limbs, and has been widely used in clinical practice. The convertible vena cava filter has more flexible time limits and simpler conversion operation in using for prevention of pulmonary embolism. However, the data of its clinical application are still limited. Therefore, this study was conducted to comprehensively assess the clinical application characteristics of convertible vena cava filters through a single-center retrospective analysis.  Methods: The clinical data of 52 patients undergoing convertible vena cava filter implantation under DSA guidance in our center were retrospectively analyzed. The parameters for each individual case were measured to identify the safe distance of placement, which included the diameter of inferior vena cava, the distance between the bifurcation of the iliac veins and the opening of the low-side renal vein, the length of forward motion during release, and the length and width of the filter after release. In addition, the conversion time and intra-operative situation during filter conversion were collected, and the conversion skills in complicated cases were discussed. Results: After measurement, the mean distance between the bifurcation of the iliac veins and the opening of the low-side renal vein was (116.4±13.2) mm, which was far much longer than (54.6±1.3) mm of the mean length of filter after release. The mean width of filter after release was (22.9±3.0) mm, which was slightly greater than (20.8±3.4) mm of the mean diameter of the inferior vena cava. Forward motion during release occurred in 19 patients (36.5%), and the mean length of forward motion was (6.5±1.8) mm. There was no filter tilt occurred in all cases after release. In the 48 patients planned to perform filter conversion, filter was successfully unlocked in one session in 42 cases (87.5%) with anaverage time of (4.5±0.8) min, of whom, 39 cases (81.3%) with unopened or in completely opened after removal of the retrieval hook, the filters were completely opened by the assistance of pigtail catheter stirring. In the 41 patients undergoing overdue conversion (>2 months), filter conversion was finished in 37 cases (90.2%) in one attempt, of whom, 4 cases (8.5%) underwent the conversion by assistance of gooseneck snare catheter combined with guidewire looping technique, because of the vessel wall attachment of the retrieval hook. Conclusion: Convertible vena cava filter is a safe and easy-conversion filter option. Forward motion phenomenon should be considered during filter release. In patients exceeding the time limit of conversion, the conversion rate in one session is still high.