Inflow thrombosis does not adversely affect thrombolysis outcomes of symptomatic iliofemoral deep vein thrombosis

 Jeyabalan G, Marone L, Rhee R, et al. J Vasc Surg. 2011;54:448-453.

Reviewed by: Bo Eklöf, MD, Lund, Sweden.

Abstract

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The presence of popliteal or tibial vein clots is thought to adversely affect thrombolysis for iliofemoral deep vein thrombosis (DVT). The authors retrospectively studied the effects of inflow thrombosis on functional and anatomical outcomes in 44 patients treated by pharmacomechanical thrombectomy (PMT) with local lytic therapy. The Covidien Trellis device was used in 30% of patients; Medrad’s AngioJet was used in 33%; a combination of Trellis and AngioJet was used in 35%; and, in 49% of patients, catheter-directed thrombolysis (CDT) was added using a multiple sidehole catheter or the ultrasound-assisted EKOS catheter. Preoperative ultrasound imaging showed that 89% of patients had popliteal and tibial clots. All patients underwent computed tomography of the chest, abdomen, and pelvis. Caval interruption with a temporary inferior vena cava (IVC) filter via jugular approach was performed in 43% of patients. There was no data on the rate of retrieval. Access to the thrombus was obtained in the prone position through the popliteal vein. In patients with thrombosis of the access site, 2 mg of tissue plasminogen activator were delivered through the sheath at the beginning of the procedure. Iliac vein stenoses seen on completion venogram were treated with self-expanding stents in 49% of patients. Symptom duration was 13.4 days on average, but 45% of patients had symptoms for more than14 days. All patients were treated with routine anticoagulation and graduated compression stockings. Antiplatelet therapy with aspirin was initiated in patients undergoing iliac stenting. Successful lysis (>50%) was achieved in 91% of patients, and symptom resolution or improvement in 91%. No major systemic bleeding complications occurred. At a mean follow-up of 8.7 months, 93% of patients had no symptom recurrence, 82% had preserved valve function and no reflux on duplex imaging, with a mean Clinical (severity)—Etiology—Anatomy—Pathophysiology (CEAP) class of 1.4 and a mean Villalta score of 3.3. Inflow thrombus had no adverse effect on symptom relief, treatment duration, patency, CEAP class, or valve reflux.

Comments

This interesting study is an exercise in the use of the new procedures that are involved in the large ATTRACT trial (Acute venous Thrombosis: Thrombus Removal with Adjunctive Catheter-directed Thrombolysis) in the US. It is a retrospective study with a small number of patients with good short-term results. Several questions can be raised about the retrieval rate of IVC filters and the patency of the thrombectomized iliac vein.

Early thrombus removal has been bolstered by the new endovenous procedures that have replaced open surgical thrombectomy: catheter-directed thrombolysis (CDT) and pharmacomechanical thrombectomy (PMT)—Medrad’s AngioJet, Covidien’s Trellis, and EKOS ultrasound assisted thrombolysis. It is also supported by the American College of Chest Physicians recommendations of 2008. In 2002, El Sharawy et al published the results of a small randomized control trial (RCT) that demonstrated a significantly better patency and a lower incidence of deep venous reflux 6 months after treatment with CDT.¹ In 2010, Sharifi et al reported the results of the TORPEDO trial (Thrombus Obliteration by Rapid Percutaneous Endovenous intervention in Deep venous Occlusion), an RCT comparing percutaneous endovenous intervention (PEVI) plus anticoagulation with anticoagulation alone in 183 patients with symptomatic proximal DVT.² The PEVI modalities were CDT (33 patients), AngioJet (23 patients), Trellis (11 patients), manual aspiration (47 patients), balloon venoplasty (68 patients) and stent (27 patients). All patients received retrievable IVC filters. After a mean follow-up of 30 months, recurrent venous thromboembolism (VTE) developed in 4.5% of patients in the PEVI groups vs 16% in the control group (P=0.02), while postthrombotic syndrome (PTS) developed in 6.8% vs 29.6% (P<0.001), respectively. Length of stay was 2.7 days vs 5.8 days (P< 0.001). Sharifi et al concluded that PEVI was superior to anticoagulation alone in reducing recurrent VTE and PTS. There are three ongoing RCTs: ATTRACT in the US, CaVenT (Catheter-directed Venous Thrombolysis in acute iliofemoral vein thrombosis) in Norway, and CAVA (CAtheter Versus Anticoagulation alone for acute primary (Ilio)femoral DVT) in the Netherlands. ATTRACT is a NIH-sponsored trial with the primary objective of determining if CDT in symptomatic patients with acute proximal DVT reduces the occurrence of PTS over a 24-month follow up. A total of 692 patients will be included in 50 centers in the US. The patients will be randomized to either CDT plus standard anticoagulation or standard anticoagulation alone. Each center must declare whether the technique of thrombus removal will be rheolytic thrombectomy (AngioJet catheter), isolated segmental pharmacomechanical thrombolysis (Trellis), or CDT using the drip technique alone. The inclusion rate is slow: in June 2011 only 156 patients had been enrolled at 35 sites nationwide. The results at 6 months of the Norwegian CaVenT study, in which 50 patients were treated with CDT and 53 patients with standard anticoagulation alone, were presented in 2009.³ Patency of the iliofemoral segment was 64% in the CDT group compared with 36% in the control group. Deep venous reflux was found in 60% of patients in the CDT group and in 66% in the control group. This high reflux rate in the CDT group may be due to the fact that a history of up to 3 weeks was accepted for inclusion in the study. The Dutch multicenter trial CAVA will compare ultrasound-assisted CDT with standard anticoagulation therapy in acute iliofemoral DVT (<14-day history). The primary objective is to study the reduction of PTS after 1 year. The secondary objectives are to study clot lysis, patency of affected vein, valve function, DVT recurrence rate, QOL, and costs. The trial has started but inclusion rate is slow.

In 2009, Baekgaard et al reported the results of a Danish nonrandomized control trial in which CDT was performed in 103 patients with acute iliofemoral DVT.⁴ A 6-year follow-up demonstrated patency of the iliofemoral segment without reflux in 82% of patients. In this study, only patients without involvement of popliteal vein were included. The rate of simultaneous angioplasty and stenting of remaining iliac vein obstruction is high in most reported series.

References:
1. El Sharawy M, El Zayat E. Early results of thrombolysis vs anticoagulation in iliofemoral venous thrombosis. A randomized clinical trial. Eur J Vasc Endovasc Surg. 2002;24:209-214.
2. Sharifi M, Mehdipour M, Bay C, et al. Endovenous therapy for deep venous thrombosis: The TORPEDO trial. Cath Cardiovasc Interv. 2010;76:316-325.
3. Enden T, Klöw NE, Sandvik L, et al. Catheter-directed thrombolysis versus anticoagulant therapy alone in deep venous thrombosis: results of an open randomized, controlled trial reporting on short term patency. J Thromb Heamost. 2009;7:1268-1275.
4. Baekgaard N, Broholm R, Just S, et al. Long-term results using catheter-directed thrombolysis in 103 lower limbs with acute iliofemoral venous thrombosis. Eur J Vasc Endovasc Surg. 2010;39:112-117.