Trellis® System for DVT Treatment

The Trellis Peripheral Infusion System has been shown to provide superior treatment of DVT compared to conventional methods of locally delivered thrombolysis.

Isolated Thrombolysis is characterized by reduced lytic dosage, short treatment times, few complications, maintenance of valvular function and low costs.

Deep vein thrombosis (DVT) may result in pulmonary embolism (PE) and venous insufficiency. There has been recent interest in early intervention and removal of DVT to reduce the possibility of these outcomes and improve patient quality-of-life. Catheter-directed thrombolysis (CDT) has been employed for this purpose, though it has an inherent risk of major hemorrhage and a treatment time up to 40 hours. The authors evaluated the performance of a device designed for DVT treatment, the Trellis-8 isolated thrombolysis catheter. This device isolates delivery of lytic agent between two occlusion balloons, limiting systemic dispersion. A powered sinusoidal wire causes the catheter to oscillate, increasing the surface area of the thrombus exposed to lytic. 

Nineteen patients who had acute (<2 weeks) onset of above knee DVT were treated between January and July 2005. Nine patients were men, ten were women; mean age was 45 years. Three patients had bilateral involvement, thus, 22 legs were treated. Conditions leading to DVT formation were primarily due to malignancies as well as coagulation disorders and trauma. Symptoms were pain and/or swelling of the leg. Two patients were subject to bleeding risk. Four patients with a recent PE had an IVC filter placed prior to the intervention. The end-point of the study was restoration of rapid inline flow.

Median dose of tPA administered per patient was 13.4 mg, as opposed to 30-40 mg in CDT regimens. The mean procedure duration was 91 minutes per limb and mean Trellis treatment time was 21 minutes per thrombosed segment. Initial anatomic and clinical success was obtained in all patients. Three limbs (14%) showed >95% to 100% lysis, eighteen limbs (82%) showed 50% to 95% lysis and one limb (4%) showed lysis of <50%. Success in thrombus clearance appeared to be related to chronicity of the clot. After thrombolysis, an underlying stenosis was found to be present in each limb, primarily due to extrinsic compression or malignancy. Self-expanding stents were used in all cases to open these stenoses. There were no major complications. Significant systemic thrombolysis was absent in patients tested for serum fibrinogen levels or fibrin degradation products.

Follow-up ultrasound was obtained at 1-2 days and 1, 3, 6 and 12 months post-procedure. Primary patency of the treated segments was 86% at two days, with a primary assisted patency rate of 100% at 30 days. Many patients ultimately succumbed to malignancy. At one year, nine of eleven limbs (in nine surviving patients) showed valvular competence. The authors note the challenge of the patient population; 14 of 19 patients with malignancies, all in relatively poor health and/or immobile, with some patients exhibiting absolute contraindications to standard lytic therapy.
Reference: O’ Sullivan, G, Lohan, D, Gough, N, Cronin, C and Kee, S. Pharmacomechanical Thrombectomy of Acute Deep Vein Thrombosis with the Trellis-8 Isolated Thrombolysis Catheter. J Vasc Interv Radiol 2007; 18:715-724.

Deep vein thrombosis (DVT) is a critical problem in the US, accounting for 100,000 deaths per year. Though the common treatment for the disease has been anti-coagulation alone, recent results have shown mechanical removal of DVT promotes early restoration of patency and improved venous return. This study evaluates percutaneous mechanical thrombectomy of upper and lower extremity DVT for safety and efficacy. Primary end-points were restoration of and ongoing venous patency plus long term valvular competency.

Thirty patients with upper or lower extremity DVT were treated with the Trellis Infusion Catheter or the AngioJet. All patients were on an anticoagulation regime during the procedure and for at least six months post-procedure. Venography and intravascular ultrasound were used to assess thrombus reduction. Duplex ultrasound was used at 1, 6 months and annually to assess post-procedure patency. Twenty-five patients had lower extremity DVT, 5 had upper extremity DVT. Eighteen patients were treated with the Trellis, 12 with the AngioJet.

Eighty-four percent of the lower extremity patients had an IVC filter placed; all were retrieved within four weeks. Technical success in crossing the thrombus was achieved in all patients. Ninety percent of the patients were treated in a single setting. Mean procedure time was 145 minutes. Adjunctive procedures (PTV or PTV with stenting) were carried out in 28 of 30 patients. Four patients treated with the AngioJet and two treated with the Trellis required 12 hours of CDT with tenecteplase to achieve complete thrombus removal.

Mean tenecteplase dose was 6.2 mg for the Trellis and 10 mg for the AngioJet. There were no bleeding complications in the series. Venous patency was maintained in 90% of the patients and valvular function was maintained in 88% of the lower extremities treated at the mean followup of 6.2 months.
Arko, FR, Davis, CM, Murphy, EH, Smith ST, Timaran, CH, Modrall, G, Valentine, J and Clagett, GP. Aggressive Percutaneous Mechanical Thrombectomy of Deep Vein Thrombosis. Arch Surg 2007; 142:513-519.


While catheter directed thrombolysis (CDT) has been shown to be beneficial in treating thrombus, the technique has some negatives. These include risk of major bleeding complications, possibility of distal embolization, prolonged infusion time, and increased cost. Use of mechanical thrombectomy devices may ameliorate some of these, but have also resulted in recurrent thrombosis, distal embolization and high amputation rates. The Trellis infusion catheter was designed to improve on the performance of these devices.

The Trellis catheter isolates delivery of the lytic agent between two occlusion balloons, limiting the systemic dispersion of the lytic and decreasing bleeding complications. A sinusoidal wire attached to a power unit causes the catheter to oscillate, increasing the surface area of the thrombus exposed to lytic, hastening its dissolution. The dissolved clot may be aspirated through the catheter.

Data from cases in which the Trellis was used to remove arterial thrombus in twelve institutions (n=26) were collected for the manufacturer’s registry. Native artery was treated in 69% of patients, bypass graft in 31%. Average procedure duration was 2.1 hours, the average infusion time was .3 hours. All patients were treated within one angiography suite visit. Fifty four percent of the vessels required an adjunctive procedure, such as angioplasty and/or stenting. Overall technical success was 92%, which did not differ between acute and chronic thrombus. Thirty day amputation free survival rate was 96%. There were no major bleeding complications. Two of five embolization events required further intervention. Average total cost of the procedures was $3216 + $1240. This is on average $1320 less than a CDT procedure.
Reference: Sarac TP, Hilleman, D, et al. Clinical and Economical Evaluation of the Trellis Thrombectomy Device for Arterial Occlusions: Preliminary Analysis. J Vasc Surg 2004; 39: 556-559.

Treatment of acute DVT with anticoagulation, while decreasing the possibility of pulmonary embolism (PE), does not alleviate symptoms nor prevent chronic venous insufficiency. Thrombolysis can affect these areas but may cause complications, particularly major bleeding episodes. They describe a case study of the Trellis catheter, which may obviate some of these concerns.

A 52 year old woman presented with a swollen right leg. The patient had non-Hodgkin’s lymphoma, now in remission. Ultrasound showed thrombus in the posterior tibial veins and greater saphenous vein. The patient was put on anticoagulation therapy. After a worsening of symptoms, a second ultrasound showed the thrombus to have extended into the common femoral vein with occlusion of the femoral and external iliac veins. An IVC filter was placed and catheter directed thrombolysis (CDT) was employed for 36 hours using reteplase as the lytic. Only partial lysis was evident after use of 24 units of lytic. The Trellis catheter was inserted through a contralateral iliac approach. Treatment time was 45 minutes using 5 units of reteplase. This resulted in complete removal of all thrombus and a patent vessel. Swelling was resolved. Six month followup ultrasound shows no thrombus reoccurrence.
Reference: Ramaiah, V, Del Santo, PB, et al. Trellis Thrombectomy System for the Treatment of Iliofemoral Deep Venous Thrombosis. J Endovasc Ther 2003; 10: 585-589.

Key Learnings:

  • The Trellis catheter is composed of an over the wire catheter with two occlusion balloons, a zone of infusion, and a motor driven oscillating wire
  • Lytics may be isolated between the occlusion balloons and the Trellis catheter has demonstrated reduced systemic effects of thrombolytics
  • The dispersive action of the oscillating wire aids in increasing the surface area of the thrombus exposed to lytic
  • The Trellis catheter has been shown to be safe and effective in removing thrombus in native artery, native vein and synthetic graft material
  • Use of the Trellis catheter has resulted in less use of lytic, reduced treatment times, fewer complications and lowered costs in comparison to CDT
  • Use of the Trellis catheter has allowed maintenance of venous valvular function over the long-term
  • The Trellis catheter has allowed thrombus removal to be performed in a single visit to the angiography suite