Friday, May 8, 2020

Factors Affecting Recurrent Deep Vein Thrombosis after Pharmacomechanical Thrombolysis and Left Iliac Vein Stent Placement in Patients with Iliac Vein Compression Syndrome


Clinical question

Are there factors associated contralateral and ipsilateral recurrent deep vein thrombosis (DVT) after thrombolysis and stent placement in patients with iliac vein compression syndrome (IVCS)? Is overextension of the stent associated with contralateral or ipsilateral recurrent DVT?

Take-away point
Extension of iliac vein stent to the inferior vena cava (IVC) and in-stent thrombosis are associated with contralateral DVT. Thrombophilia, remaining IVC filter, and in-stent thrombosis are associated with ipsilateral DVT.

Reference
Factors Affecting Recurrent Deep Vein Thrombosis after Pharmacomechanical Thrombolysis and Left Iliac Vein Stent Placement in Patients with Iliac Vein Compression Syndrome. Kim, K.Y., Hwang, H.P., Han, Y. Journal of Journal of Vascular and Interventional Radiology (JVIR), Volume 31, Issue 4, 635-643. 

Click here for abstract

Study design
Single arm, retrospective, single-center study of 130 patients with left lower extremity thrombosis who underwent thrombolysis and stent placement with a median follow-up of 14 months and standardized 6-month anticoagulation followed by lifelong antiplatelet therapy.

Funding source
No reported funding

Setting
Academic hospital, Jeonbuk National University Medical School and Hospital, South Korea.




Figure 1. Categorization of stent position: (a) 100% coverage from the confluence to the contralateral wall of the inferior vena cava; (b) 50%–100% coverage; and (c) less than 50% coverage. (d) A diagram illustrating the three categories, respectively.

Summary


Left iliac stent placement after pharmaceutical thrombolysis in patients with iliac vein compression syndrome (IVCS) is safe and effective. However, precise placement remains challenging. Overly caudal placement may lead to stent collapse with caudal migration. Overly cranial placement may lead to overextension into the inferior vena cava (IVC) with implications of contralateral deep vein thrombosis (DVT). Analyses with a multi-factorial approach remain scarce regarding potential contributing factors to contralateral and ipsilateral recurrent DVT.

The authors performed a retrospective single-center study of 130 patients who underwent pharmaceutical thrombolysis and iliac vein stent placement for IVCS, categorized into 3 groups based on the left iliac stent’s IVC extension (Figure 1). Patients lost to follow-up within 3 months were excluded. Hypercoagulable work up was performed in 105 patients. IVC filter was placed in 111 patients. All filters were removed within 2 months after placement. Mechanical thrombectomy was performed in mixed-stage cases. Pre-stent balloon angioplasty was followed by stent placement oversized 10-20%. All patients were prescribed anticoagulation for 6 months followed by lifelong antiplatelet therapy. Median follow-up was 14 months. Univariate and multivariate analysis were performed between clinically relevant factors and development of contralateral and/or ipsilateral DVT.

7 and 11 patients developed contralateral and ipsilateral DVT, respectively. Contralateral DVT tend to occur later compared to ipsilateral DVT (median of 26 and 1 month, respectively). 2/7 and 5/7 contralateral DVT occurred before and during the 6-month anticoagulation period, respectively. 7/11 and 4/11 ipsilateral DVT occurred before and during the 6-month anticoagulation period, respectively. In-stent thrombosis and stent location (100% overextension into IVC) were associated with contralateral DVT. Thrombophilia, remaining IVC filter, and in-stent thrombosis during follow-up were associated with ipsilateral DVT.

Commentary


The authors in this paper examined a focused group of IVCS patients undergoing pharmaceutical thrombolysis and left iliac vein stent placement with relatively standardized workup and management. Results demonstrated in-stent thrombosis was associated with contralateral and ipsilateral DVT; overextension associated with contralateral DVT; and thrombophilia and remaining IVC filter associated with ipsilateral DVT. These results suggested that overextension into the IVC should be restrained to decrease risks of contralateral DVT. In addition, earlier IVC filter retrieval may be considered to decrease risks of ipsilateral DVT. Lastly, patients with thrombotic disease may warrant more frequent follow-ups to ensure stent patency. Although limited by its retrospective nature, variety of stents and IVC filters used, and small number of recurrent DVTs, this study has provided important information on iliac stent placement location and management of patients with IVCS.

Post AuthorNingcheng (Peter) Li, MD, MS
Integrated Interventional Radiology Resident, PGY-3
Department of Interventional Radiology
Oregon Health and Science University, Dotter Interventional Institute
@NingchengLi

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