A strategy of aggressive regional therapy for acute iliofemoral venous thrombosis with contemporary venous thrombectomy or catheter-directed thrombolysis

Surgical venous thrombectomy

Rehabilitation of the technique of venous thrombectomy is justified, but, in order for this technique to be effective, it must only be performed in selected cases. In the authors' view it is of the utmost value in young patients when the venous thrombosis occurs accidentally, after traumatism or surgery and when a diagnostic is made without delay.

Deep Vein Thrombosis

Initially, patients with deep vein thrombosis (DVT) should be treated with a 5- to 7-day course of heparin or low-molecular-weight heparin (LMWH). They can be administered LMWH as outpatients. Patients with extensive iliofemoral thrombosis, major pulmonary embolism, or concomitant medical illness, and those at high risk for bleeding, should be treated as inpatients. Thrombolytic therapy may be considered for patients with extensive iliofemoral thrombosis if there is no contraindication to the use of thrombolytic drugs. Oral anticoagulants can be started within 24 hours of the initiation of heparin or LMWH. Warfarin is started at a dose of 5 mg, and subsequent doses are given in amounts sufficient to achieve an international normalized ratio of 2.0 to 3.0. Inferior vena caval filters should be considered for patients with overt bleeding or for those at high risk for hemorrhage. Warfarin can be used for secondary prophylaxis in most patients. Patients in whom there are contraindications to the use of oral anticoagulants and patients in whom recurrent venous thromboembolism (VTE) develops while they are receiving therapeutic doses of warfarin can be safely and effectively treated with LMWH. Patients with idiopathic DVT should be treated with anticoagulants for at least 6 months. Those with calf DVT or proximal DVT that complicates surgery or medical illness can be treated with anticoagulants for 6 weeks and 3 months, respectively, provided that there are no ongoing risk factors for recurrent VTE. Oral anticoagulants are teratogenic and should be avoided by patients who are pregnant; unfractionated heparin or LMWH are safe alternatives. Unfractionated heparin, LMWH, and oral anticoagulants can be safely administered to nursing mothers.

Ischemic venous thrombosis: its hidden agenda

Ischemic venous thrombosis (IVT) is the most severe form of venous thrombosis. The purpose of this article is to describe this rare clinical condition and to review 14 cases of IVT that involve the lower extremities, emphasizing its association with cancer. Between September 1995 and November 1997, 9 women and 5 men, ranging in age from 37 to 75 years (mean 58.6 years), were treated for IVT. Malignancy was the most prevalent risk factor, occurring in 86% (12 of 14) of the patients, and was not diagnosed in 58% (7 of 12) of the cases until after IVT occurred. A postoperative state and a previous history of thrombophlebitis were the next most common risk factors and were equal in frequency (39%). Venous gangrene was present in 79% (11 of 14) of the cases, resulting in 11 amputations in 9 patients. The mortality rate was 71% (10 of 14) of the patients, with 40% of the deaths occurring within 2 months of the diagnosis of IVT. These data support the belief that a strong association exists between IVT and cancer and that IVT may precede the diagnosis of cancer, representing a potential marker for an undiagnosed malignancy. Furthermore, the combination of extensive venous gangrene and disseminated cancer has a poor prognosis.

Transcatheter regional urokinase therapy in the management of inferior vena cava thrombosis

PURPOSE

To study the efficacy of local infusion of urokinase (UK) in the treatment of symptomatic inferior vena cava (IVC) thrombosis.

MATERIALS AND METHODS

Eight patients (five men and three women) who ranged in age from 19 years to 75 years (mean, 56 years) with symptomatic IVC thrombosis underwent local catheter-directed infusion of UK with use of up to three access sites. Infrarenal IVC thrombus and iliac vein thrombus was identified in all patients. Four patients had extension of thrombus proximal to the renal veins. Seven of eight patients had at least one risk factor for IVC thrombosis: hypercoagulable state (n = 3), IVC filter (n = 3), malignancy (n = 2), recent surgery (n = 2), and oral contraceptive use (n = 1). No serious procedure-related complications were encountered, although one patient died 5 days after UK therapy of pulmonary failure due to advanced lung cancer. UK was infused for an average of 79 hours (range, 24-140 hours) and a mean total dose of 7.4 million U of UK (range, 2.9-14.4 million U). Adjunctive balloon angioplasty was performed in three patients. No vascular stents were placed. Clinical and/or radiographic follow-up was obtained in all eight patients.

RESULTS

Thrombolysis was successful in seven of eight (88%) IVCs with no or minimal residual thrombus. The remaining seven patients had no lower extremity swelling 2-24 months (mean, 11 months) after the procedure. Three of seven patients had computed tomographic or venographic follow-up (mean, 9 months; range, 1.5-15 months), demonstrating unchanged or improved IVC patency.

CONCLUSIONS

Transcatheter regional infusion of UK for re-establishing venous patency in acute IVC thrombosis appears to be effective with good short-term and mid-term clinical benefit.

Catheter-directed thrombolysis in the treatment of phlegmasia cerulea dolens

Phlegmasia cerulea dolens is a potentially devastating complication of extensive deep venous thrombosis for which there is currently no consensus for treatment. Heparin anticoagulation, surgical thrombectomy, thrombolytic therapy, fasciotomy, and amputation have each been advocated. We present two cases of phlegmasia cerulea dolens successfully treated with catheter-directed venous thrombolytic therapy.

Thrombolytic therapy for venous thrombosis and pulmonary embolism

Streptokinase, urokinase, tissue plasminogen activator and similar drugs can all cause lysis of venous thrombi and pulmonary emboli, but there is small evidence that accelerated lysis achieves a significantly better clinical outcome, on average, in the shorter or longer term, than heparin alone. Thrombolytic therapy for deep leg vein thrombosis aims to restore flow and to preserve venous valves, and so to prevent chronic post-phlebitic disability, but no trial has convincingly demonstrated that the last can be achieved in more than a few patients. Only a small minority of people with extensive proximal thrombosis develop disabling post-phlebitic venous insufficiency, and there are no good clinical predictors of this outcome. As a result, any widespread use of thrombolytics would bring an immediate risk of major bleeding to many people who will never be destined to develop a clinically important problem. Thrombolytic therapy after venous thrombosis should be avoided except, perhaps, in a few carefully selected patients with severe obstruction. The case for using thrombolytics after recent pulmonary embolism is strongest in the limited number of patients with ongoing hypoxia, respiratory distress, pulmonary hypertension and right heart failure, because thrombolytic therapy often achieves an impressive and almost immediate clinical benefit in this clinical setting. Whether early relief from pulmonary artery obstruction translates into longer-term advantage over heparin remains uncertain, however, because no comparative trial has ever shown these drugs to reduce mortality after pulmonary embolism. In all cases, both the physician and the patient must balance the certainty of an immediate bleeding risk against the uncertainty of a better than marginal real benefit.

Treatment of deep venous thrombosis and pulmonary embolism. Current recommendations

The therapy of deep venous thrombosis consists of several elements and depends on the localization, the age and the extent of the thrombus. This article discusses various types of initial therapy and long-term treatment of venous thromboembolism and also reviews future perspectives of pharmacological treatment. The initial treatment regimens comprise thrombolysis, thrombectomy, inferior vena cava filters and the anticoagulation with either unfractionated heparin or low molecular weight heparins. Various thrombin-inhibitors have been tested for initial treatment of thrombosis, however, further investigations of their efficacy, safety and cost-effectiveness will have to provide firm evidence on their superiority when compared to unfractionated or low molecular weight heparins.

Venous thrombectomy for iliofemoral vein thrombosis--10-year results of a prospective randomised study

OBJECTIVES

To study if venous thrombectomy prevents late post-thrombotic sequelae, venous obstruction reflux, and improves venous physiology following an acute iliofemoral venous thrombosis.

DESIGN

Prospective randomised controlled study.

MATERIAL

Thirty patients returned for follow-up 10 years after an acute iliofemoral venous thrombosis initially treated with conventional anticoagulation treatment (medical group, n = 17) or with thrombectomy combined with a temporary arteriovenous fistula and anticoagulation (surgical group, n = 13). Clinical assessment, radionuclide angiography, duplex ultrasound and venous physiology tests were performed.

RESULTS

Leg swelling was recorded in 12 (71%) and leg ulcers in three (18%) of the medical patients and in, respectively, six (46%) and one (8%) of the surgical patients. The surgical patients had less severe sequelae (class 0-2). Radionuclide angiography demonstrated that the iliac vein was more commonly occluded following medical (59%) than following surgical (17%) treatment (p < 0.05). Duplex examination demonstrated slightly (n.s.) more reflux in the femoral and popliteal veins in the medical group. Venous physiology (occlusion plethysmography, foot volumetry, and foot vein pressures) did not show any significant differences, although the medical group tended to have a more severe pathology.

CONCLUSION

Venous thrombectomy improves venous patency and possibly reduces venous reflux and post-thrombotic sequelae as compared to anticoagulation treatment.

Iliac vein reconstructions to treat acute and chronic venous occlusive disease

PURPOSE

The treatment of permanent and benign iliac vein occlusion responsible for acute vein thrombosis or chronic symptoms remains controversial. Different methods of reconstruction using a reinforced expanded polytetrafluoroethylene bypass graft associated with an arteriovenous fistula and their intermediate-term results are analyzed.

METHODS

Eight consecutive patients (six men, two women; mean age, 45.6 years; range, 29 to 70 years) were treated over a period of 38 months for iliac vein obstruction. Three short bypass procedures between the left iliac vein and the right common iliac vein with temporary arteriovenous fistulas were carried out after an iliofemoral (and caval in two cases) venous thrombectomy, which revealed May-Thurner syndrome (n = 1) and a compression of the left common iliac vein by the left hypogastric artery (n = 2). Five long bypass procedures (one femorofemoral, two left common femoral-vena caval, one right superficial femoral-common iliac, and one bifemorocaval) with a definitive arteriovenous fistula were performed for long chronic venous occlusion in four cases (responsible for venous claudication [n = 3], recurrent ulcers [n = 1] and after iatrogenic ligature of the left external iliac vein during total cystectomy with double ureterostomy in one case.

RESULTS

There was no evidence of pulmonary embolism, and no deaths were recorded in the perioperative period. Two patients had an early bypass thrombectomy, but one returned with a further graft occlusion. Seven grafts remained patent after a mean follow-up of 19.5 months (range, 10 to 45 months). One successful thrombectomy was necessary during the twenty-third postoperative month.

CONCLUSIONS

Reconstruction of iliac veins in case of permanent compression, mostly discovered after venous thrombectomy, or for selected patients with symptomatic benign iliac vein occlusion, is safe and provides good intermediate-term results.

Thrombolytic and endovascular treatment of peripartum iliac vein thrombosis: a case report

This case report details the multidisciplinary treatment of peripartum left iliac vein thrombosis using percutaneous catheter-directed urokinase thrombolysis and balloon thromboplasty. Enhanced chances for long-term patency and the normalization of venous function make these minimally invasive procedures accepted options for the treatment of iliofemoral deep venous thrombosis in selected peripartum patients.

Effect of a femoral arteriovenous fistula on lower extremity venous hemodynamics after femorocaval reconstruction

PURPOSE

To study the hemodynamic effects of an arteriovenous fistula (AVF) used as an adjunct to venous reconstructions and to determine the optimal size for such a fistula.

METHODS

A model of limb circulation with an AVF (in vitro system) was constructed with silicon elastic tubes and 40% glycerin solution as the fluid medium. Pulsatile arterial flow and venous return was maintained with a roller pump and a centrifugal assist device. Flows and pressures were measured for three different fistula diameters (3, 4, and 5 mm). A canine model of venous hypertension with outflow obstruction was constructed in 15 adult mongrel dogs. After 7 to 13 days an externally supported 8-mm expanded polytetrafluoroethylene femorocaval graft was implanted with a distal AVF (3 mm, n = 5; 4 mm, n = 5; 5 mm, n = 5). Arterial and venous flows and venous pressures were measured proximal and distal to the fistula before and after exercise.

RESULTS

In the in vitro system, flows through the venous graft increased with increasing fistula size, but venous return decreased progressively, increasing the distal venous pressure. In the canine model, flow in the venous graft increased with each AVF (p < 0.01). Only the 3-mm AVF resulted in decreased distal femoral vein pressure (p < 0.01), orthograde flow, and improved venous return with exercise.

CONCLUSION

AVFs increased flow through the femorocaval grafts, yet they impeded venous return. The ideal AVF-to-graft ratio used in our study was 0.375, because it increased graft flow, permitted forward flow in the femoral vein while reducing pressure, and improved venous return with exercise.

The long-term outcome of proximal vein thrombosis during pregnancy is not improved by the addition of surgical thrombectomy to anticoagulant treatment

OBJECTIVES

To compare the long-term outcome for pregnant/puerperal women with iliofemoral venous thrombosis treated either with thrombectomy and additional anticoagulants or with anticoagulants alone.

DESIGN

Retrospective study of two treatment methods.

MATERIALS

Thirty women with iliofemoral venous thrombosis during pregnancy or puerperium were treated with thrombectomy and additional anticoagulants. Twenty-five women, with the same condition, treated with anticoagulants only were obtained from a registry. The mean follow-up time for both groups was 9 years. The patients of the two groups were well matched, had the same risk factor score and were comparable except for duration of symptoms before treatment.

METHODS

The follow-up comprised history and clinical examination, colour Duplex ultrasound and venous strain-gauge plethysmography.

RESULTS

Patency of iliac veins, symptoms of chronic venous disease, venous emptying and venous reflux did not differ between the groups. A significant reduction of outflow was found in 20% of the surgically treated patients and 16% of the controls. Impaired muscle pump function was seen in less than half of the patients in both groups.

CONCLUSIONS

Surgical thrombectomy does not offer any advantage over anticoagulation treatment alone in the long-term outcome for patients with iliofemoral venous thrombosis during pregnancy or puerperium.

Experimental impeller fragmentation of iliocaval thrombosis under tulip filter protection: preliminary results

PURPOSE

To assess the efficacy of catheter fragmentation of massive caval thrombosis and of filter protection against procedure-related pulmonary embolism.

METHODS

In 10 sheep, a self-expanding tulip-shaped filter made from Wallstent mesh (diameter 25 mm) was introduced from the right jugular approach into the proximal inferior vena cava. Experimentally induced massive iliocaval thrombosis was fragmented by an impeller catheter (expanded diameter 14 mm), which was advanced coaxially through the sheath of the expanded filter. Post-procedural cavography and pulmonary angiography were performed to document the extent of caval recanalization and pulmonary embolism.

RESULTS

In all cases, impeller fragmentation cleared the inferior vena cava and the iliac veins of thrombi completely. Fragments washed downstream were trapped in the filter. In two of the first cases, parts of the clots caused pulmonary embolism before the filter was in place. Further events were avoided by a modification of the experimental setup. Except for some small peripheral perfusion defects in two cases, pulmonary angiograms did not show any incidence of pulmonary embolism.

CONCLUSION

Our preliminary results suggest that impeller fragmentation of iliocaval thrombi under tulip filter protection is effective and does not cause significant pulmonary embolism.

Modern day treatment of acute deep venous thrombosis

Acute deep venous thrombosis is a spectrum of disease presentations. Proper treatment mandates precision in diagnosis and knowledge and availability of therapeutic alternatives. Natural history studies and therapeutic trials have indicated that thrombus resolution (elimination) is associated with improved long-term functional outcome. The preferred approach to most patients with proximal venous thrombosis is to eliminate thrombus either pharmacologically or mechanically, to provide unobstructed venous drainage to the affected extremity and to offer subsequent treatment to ensure that recurrent thrombosis does not occur. If these principles can be followed without placing the patient at an unacceptable risk of a complication, substantial strides can be made in the treatment of patients with acute DVT.

Use of a temporary caval filter to assist percutaneous iliocaval thrombectomy: experimental results

PURPOSE

To test a new filter design that allows coaxial insertion of thrombectomy devices and active clot removal.

MATERIALS AND METHODS

A prototype filter system was used in animal experiments. It is a transjugularly inserted coaxial system with a 16-F outer sheath and an inner tube that is covered by a tulip-shaped meshwork with a 22-mm diameter at its inserted end. The inner tube allows insertion of instruments up to 8 F. The filter was developed to assist with percutaneous mechanical thrombectomy in the iliofemoral and caval veins. The filter has been used as an assisting tool in nine sheep and eight pigs. It was combined with an impeller system in nine sheep for caval thrombectomy and with a hydrodynamic catheter for iliac thrombectomy in eight pigs after artificial induction of iliac or caval thrombosis.

RESULTS

The filters captured emboli from the intervention in six of nine sheep. The amount of captured emboli was reduced within the filter cone by the impeller instrument in five of six instances. Residual thrombus was removed by closing the filter in five of six sheep. In pigs, the filter captured emboli in three cases during hydrodynamic embolectomy. Pulmonary embolization did not occur with the filter in place. After filter removal, minor pulmonary clot embolization occurred in one case.

CONCLUSION

The temporary tulip filter was effective in these animal models in capturing and removing thrombus material that may dislodge from iliocaval veins during mechanical thrombectomy.