Gu X, Sharafuddin M J, Titus J L, Urness M, Cervera-Ceballos J J, Ruth G D, Amplatz K
Department of Radiology, University of Minnesota Hospital and Clinic, Minneapolis, USA.
J Vasc Interv Radiol. 1997 Nov-Dec;8(6):947-56. doi: 10.1016/s1051-0443(97)70692-4.
To study the efficacy and delayed outcome of mechanical thrombectomy with the Amplatz thrombectomy device (ATD) in an experimental model of subacute inferior vena cava (IVC) thrombosis.
Mechanical thrombectomy was performed in 23 dogs with subacute infrarenal IVC thrombosis (6-15 days old). Heparin was administered during thrombectomy in all procedures (activated clotting time > or = 300 sec). Thirteen animals were killed immediately after thrombectomy, and the remaining 10 were allowed to survive for up to 1 month with no anticoagulation therapy.
Venographic patency of the IVC was restored in all animals, although residual mural thrombus remained in nine dogs (< 20% narrowing in seven, 20%-30% narrowing in two). No histopathologic evidence of mechanical wall disruption attributed to mechanical thrombectomy was seen. However, foci of organizing residual thrombus with associated transmural phlebitic changes with round-cellular infiltration were present in all acute specimens, including those appearing clear at venography. Venography at 1 week or 1 month after thrombectomy showed IVC rethrombosis in eight dogs (80%) who were not receiving anticoagulants. During mechanical thrombectomy, a small increase in mean pulmonary artery pressure occurred, with a corresponding decrease in systemic arterial oxygen saturation. No acute emboli were noted on the post-thrombectomy pulmonary angiograms. However, histopathologic examination of acutely explanted lungs in 11 animals showed arteriolar microemboli (100-500 microm) in four.
Mechanical thrombectomy with use of the ATD can effectively clear subacute IVC thrombus. However, rethrombosis is common and may be due to the high prevalence of phlebitis and residual thrombus. Anticoagulation may need to be continued after successful thrombectomy to prevent progression of residual thrombus and allow mural phlebitic changes to subside.
在亚急性下腔静脉（IVC）血栓形成的实验模型中，研究使用Amplatz血栓切除术装置（ATD）进行机械性血栓切除术的疗效及延迟结果。
对23只患有亚急性肾下IVC血栓形成（6 - 15日龄）的犬进行机械性血栓切除术。在所有手术的血栓切除术中均给予肝素（活化凝血时间≥300秒）。13只动物在血栓切除术后立即处死，其余10只动物在不进行抗凝治疗的情况下存活长达1个月。
尽管9只犬（7只狭窄<20%，2只狭窄20% - 30%）仍有残余壁内血栓，但所有动物的IVC静脉造影均恢复通畅。未发现因机械性血栓切除术导致机械性壁破坏的组织病理学证据。然而，在所有急性标本中，包括那些静脉造影显示清晰的标本，均存在伴有圆形细胞浸润的组织化残余血栓灶及相关的透壁性静脉炎改变。血栓切除术后1周或1个月的静脉造影显示，8只未接受抗凝治疗的犬（80%）出现IVC再血栓形成。在机械性血栓切除术中，平均肺动脉压有小幅升高，同时体动脉血氧饱和度相应降低。血栓切除术后的肺血管造影未发现急性栓子。然而，对11只动物急性切除的肺进行组织病理学检查发现，4只动物存在小动脉微栓子（100 - 500微米）。
使用ATD进行机械性血栓切除术可有效清除亚急性IVC血栓。然而，再血栓形成很常见，可能是由于静脉炎和残余血栓的高发生率所致。成功进行血栓切除术后可能需要继续抗凝治疗，以防止残余血栓进展并使壁内静脉炎改变消退。
