**4.2 Mechanical thrombectomy**

No large randomised control studies have been published looking at mechanical thrombectomy in DVT.

An analysis by Karthikesalingam et al (2011) on 16 retrospective case series on the use of mechanical thrombectomy in DVT, with a total of 481 patients, looked at its efficacy. They found successful thrombolysis (>50% lysis) in 83-100% of patients. Bleeding complications requiring transfusion were seen in 7.5%. Symptomatic PE was seen in <1%. No procedure related deaths or strokes were seen. Of the studies that did look at mid term follow up, 75- 98% of patients demonstrated significant improvement of symptoms and similar improvement in radiological findings.

### **5. Adjunctive procedures**

DVT, particularly in the iliocaval system, can be associated with chronic venous obstruction, which can lead to valvular insufficiency and consequently venous hypertension. This in turn is associated with a higher incidence of post thrombotic syndrome (PTS). There are multiple other causes of venous obstruction, which include May Thurner syndrome, external compression (e.g. cancer, lymphocoeles) and retroperitoneal fibrosis. Very frequently, thrombolysis and thrombectomy can uncover the underlying lesion which precipitated the venous thrombosis. Failure to identify and treat these lesions, despite successful thrombolysis, can result in higher rates of recurrence, and the development of PTS.

The advantage of CDT as compared with anticoagulation therapy alone in the treatment of acute DVT, is that it allows the opportunity to treat the underlying lesion and restore flow in most cases. Obviously, non mechanical underlying issues must also be addressed, such as underlying prothrombotic syndromes.

The objective is to restore flow and the measures employed usually involve angioplasty and stenting of the lesion. Angioplasty and stenting in the setting of obstruction has been shown to improve quality of life and improve symptoms (Hartung et al 2005, Neglen P et al 2005, Raju S et al 2002;). The lesions treated usually lie within the IVC, iliac and femoral veins. It has not been shown that angioplasty and stenting of lesions below this

Grunwald and Hofmann (2004) retrospectively analysed 74 patients who underwent CDT for DVT and compared Urokinase, Alteplase and Reteplase. They found that there was no statistical difference between infusion times, success rates and complication rates between the three agents. However, they did find that the new recombinant agents are significantly

No RCTs have been published looking at CDT in acute DVT. However, currently the TORPEDO trial is underway which is a large scale RCT looking at the efficacy of CDT vs anticoagulation in treatment of DVT. Mid term results show that CDT is superior to anticoagulation therapy alone in the prevention of recurrence of DVT, reduction in PTS, and

No large randomised control studies have been published looking at mechanical

An analysis by Karthikesalingam et al (2011) on 16 retrospective case series on the use of mechanical thrombectomy in DVT, with a total of 481 patients, looked at its efficacy. They found successful thrombolysis (>50% lysis) in 83-100% of patients. Bleeding complications requiring transfusion were seen in 7.5%. Symptomatic PE was seen in <1%. No procedure related deaths or strokes were seen. Of the studies that did look at mid term follow up, 75- 98% of patients demonstrated significant improvement of symptoms and similar

DVT, particularly in the iliocaval system, can be associated with chronic venous obstruction, which can lead to valvular insufficiency and consequently venous hypertension. This in turn is associated with a higher incidence of post thrombotic syndrome (PTS). There are multiple other causes of venous obstruction, which include May Thurner syndrome, external compression (e.g. cancer, lymphocoeles) and retroperitoneal fibrosis. Very frequently, thrombolysis and thrombectomy can uncover the underlying lesion which precipitated the venous thrombosis. Failure to identify and treat these lesions, despite successful

The advantage of CDT as compared with anticoagulation therapy alone in the treatment of acute DVT, is that it allows the opportunity to treat the underlying lesion and restore flow in most cases. Obviously, non mechanical underlying issues must also be addressed, such as

The objective is to restore flow and the measures employed usually involve angioplasty and stenting of the lesion. Angioplasty and stenting in the setting of obstruction has been shown to improve quality of life and improve symptoms (Hartung et al 2005, Neglen P et al 2005, Raju S et al 2002;). The lesions treated usually lie within the IVC, iliac and femoral veins. It has not been shown that angioplasty and stenting of lesions below this

thrombolysis, can result in higher rates of recurrence, and the development of PTS.

Similarly the ATTRACT Trial is currently underway looking at the efficacy of CDT.

less expensive than Urokinase in the United States.

reduction of hospital stays.

thrombectomy in DVT.

**4.2 Mechanical thrombectomy** 

improvement in radiological findings.

underlying prothrombotic syndromes.

**5. Adjunctive procedures** 

level is of any benefit. However, chronic lesions do benefit as well as acute obstructions (Titus 2011).

The procedure is similar to angioplasty of the arterial system. Once access is achieved, heparin is given if anticoagulation has not been already instituted. A wire is passed across the lesion, followed by a catheter. Any wire can be used however 0.035in wires are preferred. This is usually not too difficult in an acute thrombus, which is soft, and has not had time to organise. Contrast is injected beyond the lesion to ensure intraluminal position. The catheter is then exchanged for a balloon which is usually sized approximately 20% greater than the expected calibre of the vein. Angioplasty of the venous system is different from the arterial system, in that the balloons can be oversized to a greater extent than in the arteries. There is also a greater propensity for veins to have elastic recoil, such that even with aggressive angioplasty using high pressure balloons, the veins collapse back to their obstructed state. In other cases there is persistent stenosis in the vein post angioplasty. When this is the case, stenting is performed. These are also oversized in relation to the vein.

#### **6. Use of IVC filters**

The use of CDT and mechanical thrombectomy devices carry the theoretical increased risk of pulmonary embolisation. This has not been proven in any large scale study, and it is unclear based on current data whether this is true. In a review study by Grossman 1998, 2 out of 263 (0.7%) patients developed a PE post CDT. This is compared to the incidence of PE in patients treated with heparin alone for DVT ranging from 0-56% for symptomatic emboli, and 0-8% for asymptomatic emboli (Leizorovicz et al 1994, Sirgusa et al 1996, Levine et al 1995, Piccioli et al 1996).

In addition, no large studies are available that looks at whether IVC filters reduce the incidence of PE following CDT or mechanical thrombectomy. Given the lack of data on their use, prophylactic IVC filters prior to commencement of CDT and/or mechanical thrombectomy has been debated.

In a systematic review (Karthikesalingam et al 2011) of mechanical thrombectomy between 1999 and 2009, the use of prophylactic IVC filters was variable between the various authors. Almost all authors report 0% PE on follow up CTPA whether IVC filters were inserted or not. One author (Arko et al 2007) reports a 17% PE rate, all asymptomatic, in patients where no IVC filter was placed. In those that had a filter, Arko found no PE. All deaths were unrelated to the thrombectomy (either myocardial infarct or cancer) and no patients died of PE.

The role IVC filters therefore is not known and there are no current recommendations regarding their use. However they are not without risk, albeit small. Filter migration, filter fracture, break through PE have all been described, as well as complications associated with their retrieval.

Placement of IVC filters remain at the discretion of the interventionist. In the presence of free-floating IVC thrombus or in patients with limited cardiopulmonary reserve who are unlikely to tolerate minor embolic events, IVC filtration may be appropriate with use of permanent (Tarry WC Ann Vasc Surg 1994) or temporary filters (Lorch et al 2000).

Endovascular Therapies in Acute DVT 67

Fig. 2. Same patient. Thrombus extends into common femoral vein.

Fig. 1. 20 y.o. girl with acute DVT and swollen, dusky leg. Popliteal access has been achieved and venogram demonstrates thrombus in the femoral vein.

Fig. 1. 20 y.o. girl with acute DVT and swollen, dusky leg. Popliteal access has been achieved

and venogram demonstrates thrombus in the femoral vein.

Fig. 2. Same patient. Thrombus extends into common femoral vein.

Endovascular Therapies in Acute DVT 69

Fig. 4. Same patient. IVC filter placed prior to commencement of procedure. Infusion

catheter placed through the thrombus and Urokinase infusion commenced.

Fig. 3. Same patient. Thrombus extending into iliac veins.

Fig. 3. Same patient. Thrombus extending into iliac veins.

Fig. 4. Same patient. IVC filter placed prior to commencement of procedure. Infusion catheter placed through the thrombus and Urokinase infusion commenced.

Endovascular Therapies in Acute DVT 71

Fig. 6. Post 18 hours CDT. Persistent thrombus in iliac veins.

Fig. 5. Post 18 hours CDT. Thrombus still present in femoral vein.

Fig. 5. Post 18 hours CDT. Thrombus still present in femoral vein.

Fig. 6. Post 18 hours CDT. Persistent thrombus in iliac veins.

Endovascular Therapies in Acute DVT 73

Fig. 8. Improvement of thrombus in iliac veins post Angiojet.

Fig. 7. Post mechanical thrombectomy with Angiojet system demonstrates clearance of thrombus.

Fig. 7. Post mechanical thrombectomy with Angiojet system demonstrates clearance of

thrombus.

Fig. 8. Improvement of thrombus in iliac veins post Angiojet.

Endovascular Therapies in Acute DVT 75

Fig. 10. Stent deployed in the left iliac vein with good flow through the vessel.

Fig. 9. Angioplasty of the common iliac vein

Fig. 9. Angioplasty of the common iliac vein

Fig. 10. Stent deployed in the left iliac vein with good flow through the vessel.

Endovascular Therapies in Acute DVT 77

Lorch H, Welger D, Wagner V, et al. 2000. Current practice of temporary vena cava filter

Mewissen. 1999. CDT for lower extremity Deep venous thrombosis: report of a national

Molina JE, Hunter DW & Yedlicka JW. Thrombolytic therapy for iliofemoral venous

Neglen P, Raju S. 2005. *Endovascular treatment of chronic occlusions of the iliac veins and the* 

Patel K, Basson MD, Borsa JJ, et al, May 2011. Deep Venous Thrombosis. In: *Emedicine*.

Piccioli A, Prandoni P Goldhaber S. Epidemiologic characteristics, management

Prandoni P, Lensing A, Cogo A, et al. 1996. The Long-Term clinical course of Acute Deep

Raju S, Fountain T & McPherson SH. 1998. Catheter directed thrombolysis for deep venous

Raju S, Owen S Jr, Neglen P. 2002. The clinical impact of iliac venous stents in the

Schweizer J, Kirch W, Koch R, et al. 1998. Short and long term results after thrombolytic treatment of deep venous thrombosis. *J Am Coll Cardiol.* 36:1336-1343. Sharafuddin MJ, Sun S, Hoballah JJ, et al. 2003. Endovascular management of venous

Sirgusa S, Cosmi B, Piovella F, et al. 1996. Low molecular weight heparins and

Tarry WC, Makhoul RG, Tisnado J, et al. 1994. Catheter directed thrombolysis following

Titus JM, Moise MA, Bena J, et al. 2011. Ilioifemoral stenting for venous occlusive disease. *J* 

Vedantham S, Millward S, Cardella J, et al. 2006. Society of Interventional Radiology

Wells PS & Forster AJ. Thrombolysis in deep vein thrombosis: is there still an indication?

thrombotic and occlusive diseases of the lower extremities. *J Vasc Interv Radiol*.

unfractionated heparin in the treatment of patients with acute venous thromboembolism: results of a meta analysis. *The American Journal of Medicine*.

ven cava filtration for severe deep venous thrombosis. *Ann Vasc Surg*.

Position Statement: Treatment of Acute Iliofemoral deep Vein Thrombosis with use of Adjunctive Catheter directed Intrathrombus Thrombolysis. *J Vasc Interv Radiol.*

management of chronic venous insufficiency. *J Vasc Surg*; 35:8-15.

*inferior vena cava. Rutherford RB, editor. Vascular Surgery.* 6th ed. Philadelphia:

and outcome of deep venous thrombosis in a tertiary-care hospital: The Brigham and Women's Hospital DVT registry. 1996. *American Heart Journal*.

insertion: a multicenter registry. *J Vasc Interv Radiol*. 11(1): 83-8.

multicenter registry, *Radiolog*; 211:39-49

thrombosis. 1992. *Vasc Surg*. 26:630-637.

http://emedicine.medscape.com/article/1911303-overview

Venous Thrombosis. *Annals of Internal Medicine.* 125:1-7.

thrombosis. *J Miss State Med Assoc*. 39(3):81-4.

Elsevier Saunders;. pp 2321-32.

Available from:

132(5).

14(4)4:405-23.

100(3): 269-277.

8(6):583-590.

17:613-616.

*Vasc Surg*. 53(3): 706-712.

2001 *Thromb Haemost*. 86 (1):499-508.

#### **7. Conclusion**

Endovascular techniques are important therapeutic options in the prevention of limb loss, recurrence and post thrombotic syndrome related to acute DVT, and have been shown to be superior to anticoagulation therapy alone. It also is advantageous in uncovering and treating underlying lesions that contribute to the DVT.

No guidelines are available currently in terms of patient selection, techniques and the use of IVC filters and at present these decisions are made on a case by case basis at the discretion of the interventionist. Large randomized controlled trials underway currently will hopefully be able to shed more insight on these issues.

#### **8. References**


Endovascular techniques are important therapeutic options in the prevention of limb loss, recurrence and post thrombotic syndrome related to acute DVT, and have been shown to be superior to anticoagulation therapy alone. It also is advantageous in uncovering and

No guidelines are available currently in terms of patient selection, techniques and the use of IVC filters and at present these decisions are made on a case by case basis at the discretion of the interventionist. Large randomized controlled trials underway currently will hopefully

Arko FR, Davis CM, Murphy EH, et al. 2007. Aggressive Percutaneous Mechanical

Comerota AJ & Aldridge SC. 1993. Thrombolytic therapy for deep venous thrombosis: a

Francis CW, Blinc A, Lee S, Cox C. 1995. Ultrasound accelerates transport of recombinant tissue plasminogen activator into clots. *Ultrasound Med Biol*;21(3):419e24 Gallus AS, 1998. Thrombolytic therapy for venous thrombosis and pulmonary embolism.

Grosman C & McPherson S. 1999. Safety and efficacy of catheter directed thrombolysis for

Grunwald MR and Hofmann LV. 2004. Comparison of UK, Alteplase, and reteplase for CDT

Hartung O, Otero A, Boufi M, et al. 2005. Mid term results of endovascular treatment of

Karthikesalingam, EL Young, RJ Hinchliffe, et al. 2011. A systematic review of percutaneous

Lang EV, Kulis AM, Villani M, et al. 2008. Hemolysis comparison between the OmniSonics

Lee MS, Makkar R, Singh V et al. 2005. Pre-procedural administration of aminophylline does

Leizorovicz A, Simonneau G, Decousus H et al. 1994. Comparison of efficacy and safety of

Lensing AW, Prins MH, Davidson BL, et al. 1995. Treatment of deep venous thrombosis

deep venous thrombosis: a meta analysis. *BMJ*. 309 (6950): 299-304.

symptomatic chronic non-malignant iliocaval venous occlusive disease. *J Vasc Surg*.

Mechanical thrombectomy in the treatment of DVT. *Eur J Vasc endovasc Surgery*, 41:

OmniWave endovascular system and the Possis AngioJet in a porcine model. *J Vasc* 

not prevent AngioJet rheolytic thrombectomy-induced bradyarrhythmias. *J Invasive* 

low molecular weight heparins and unfractionated heparin in initial treatment of

with low-molecular-weight heparins: a meta-analysis. *Arch Intern Med*;

iliofemoral venous thrombosis. *Am J Roentgenol*. 172: 667-672.

Thrombectomy of Deep Venous Thrombosis. *Archives of Surgery*. 142

treating underlying lesions that contribute to the DVT.

clinical review. *Can J Surg*. 36(4): 359-64.

of DVT. *Journal Vasc Interv Radiol*; 15:347-352

be able to shed more insight on these issues.

*Clin Haematol*. 11(3):663-73.

*Interv Radiol*;19(8):1215e21

*Cardiol*;17(1):19e22

155:601–607.

**7. Conclusion** 

**8. References** 

(6):513-519

42(6):1138-44.

554-565


http://emedicine.medscape.com/article/1911303-overview


**Radiological Imaging and Intervention in** 

Radiological imaging plays a central role in the diagnosis, and treatment, of deep venous thrombosis (DVT) in the upper and lower limb. The intention of this chapter is not to distract the reader with a detailed account of the physics behind generating ultrasound (US), computed tomography (CT) and MR (magnetic resonance) vascular imaging. This would demand a chapter in its own right, and this information can be readily found in textbooks. Instead, emphasis will be placed on the clinical indications for requesting imaging in the diagnosis of DVT, as well as the potential limitations of these modalities. This will be supplemented with a review of current evidence and guidelines, and examples of the common image findings. The latest advances in venous MR imaging will be discussed, as will the role of interventional radiology in the treatment of DVT. Finally, considering that it is now universally accepted that DVT and pulmonary embolus (PE) are essentially manifestations of the same disease – namely, venous thromboembolism (Moser et al., 1994)

Conventional venography (angiography) has traditionally been regarded as the "reference standard" for imaging the venous system (de Valois et al., 1990). This was performed by opacifying veins with iodinated contrast injected into the vessel via direct puncture, or targeted catheterisation usually from a punctured femoral vein at the groin (fig. 1). Venous imaging has always been challenging with angiography, in particular with the diagnosis of deep vein thrombosis (DVT). Completely occluded veins do not opacify and hence thrombosis has to be inferred rather than directly visualised. Unfortunately, this is compounded by the fact that even normal veins can be rendered invisible by virtue of the direction of venous flow towards the heart, which is counter to the diagnostic need. Contrast injection into an artery will reveal all the distal branches, but the same procedure in veins may not permit adequate visualisation of the tributaries. Furthermore, cannulation of peripheral veins can be hampered by the extent of limb swelling which accompanies DVT.

– the imaging and radiological management of PE will also be addressed.

**2. Diagnostic imaging in venous thrombosis** 

**2.1 Historical venography** 

**1. Introduction** 

 Ananthakrishnan Ganapathy and Chris Cadman *Glasgow Royal Infirmary radiology department, Glasgow,* 

**Venous Thrombosis** 

Andrew Christie, Giles Roditi,

 *Scotland* 

Zhu DW. The potential mechanisms of bradyarrhythmias associated with AngioJet thrombectomy. 2008.*J Invasive Cardiol*; 20 (8 Suppl. A):2Ae4A **5** 
