Extensive Deep Venous Thrombosis Research Articles

Retrievable Gunther Tulip inferior vena cava filter: Experience in 317 patients

The aim of our study was to assess our experience with the retrievable Gunther Tulip (GT) inferior vena cava (IVC) filter, with regard to its insertion, efficacy, ease of placement and retrieval, and associated complications. Between November 2001 and October 2005, 322 GT filters were placed in 317 patients. Insertion indications included the following: pulmonary embolus (PE) prophylaxis in trauma patients (n = 232), PE prophylaxis in perioperative patients (n = 27), PE prophylaxis in moribund intensive care unit patients (n = 22), recent PE (n = 48), extensive deep venous thrombosis (n = 66), contraindication to anticoagulation (n = 63), anticoagulation complication (n = 8) and deep venous thrombosis with failed anticoagulation (n = 8). Some patients had more than one indication for caval filter placement. Two hundred and five attempted retrievals have been carried out, with 15 failures. Our successful retrieval rate is 92%. Nineteen filters were originally inserted permanently. There have been three minor complications associated with insertion and five with retrieval. The mean time from filter insertion to attempted retrieval was 76.95 days. The ideal filter implantation time gives the patient the benefit of PE protection, while avoiding the long-term risks associated with caval filters. Although GT retrieval times have lengthened considerably, our data suggest that this is at the expense of successful retrieval rates.

Multidetector-Row Computed Tomography Management of Acute Pulmonary Embolism

The purpose of this study was to evaluate the usefulness and safety of multidetector-row computed tomography (MDCT) pulmonary angiography and indirect venography management of acute pulmonary embolism (PE), including indication for inferior vena cava (IVC) filter. Seventy-one consecutive patients who were clinically suspected of PE and underwent 16-slice MDCT pulmonary angiography and indirect venography were enrolled. Management included indication of IVC filter for patients with extensive deep venous thrombosis (DVT) in submassive or massive PE. A right ventricular to left ventricular short-axis diameter by MDCT>1.0 was judged as submassive PE. All patients were followed for 1 year. MDCT identified 50 patients with venous thromboembolism and 47 patients had acute PE: 4 were judged as massive, 14 as submassive, and 29 as non-massive by MDCT; 3 patients had DVT alone and 7 patients had caval or iliac DVT. Only 1 patient with massive PE and DVT near the right atrium died of recurrence. No other patients died of PE. Management based on MDCT pulmonary angiography combined with indirect venography is considered to be safe and reliable in patients with suspected acute PE.

Percutaneous Treatment of Deep Vein Thrombosis in May-Thurner Syndrome

May-Thurner syndrome is an uncommon disease entity in which the left common iliac vein is compressed by the right common iliac artery with subsequent development of deep vein thrombosis and chronic venous insufficiency. We report our experience on the treatment of extensive iliofemoral deep venous thrombosis due to May-Thurner syndrome using endovascular techniques. The study group comprised 21 patients (8 men, 13 women; mean age 51 years) diagnosed with May-Thurner syndrome by venogram. Eighteen patients were treated with catheter-guided thrombolysis; 3 patients with short segment involvement did not require thrombolysis. After completion of the thrombolytic therapy, the residual venous narrowing was treated by balloon angioplasty and/or placement of a self-expandable stent. The mean total dose of urokinase was 4.28 +/- 1.89 million units, and the mean duration of infusion was 72 +/- 35 hr. Eighteen of the 21 patients received stent deployment. The mean diameter of the stents was 12.9 +/- 2.0 mm. Initial technical successes with immediate symptom resolution were achieved in 20 of the 21 patients (95%). We performed a follow-up venogram 6 months after procedure and checked clinical symptoms at outpatient clinics (mean follow-up duration 10.8 months). Among the patients who received stent implantation, 2 had recurrent thrombotic occlusion during the follow-up period. Three patients, who did not receive stent implantation, all had recurrent thrombosis. There were no major bleeding complications except in 1 patient who developed retroperitoneal hematoma. Catheter-guided thrombolysis and angioplasty with stent implantation is a safe and effective method for the treatment of May-Thurner syndrome.

Diagnosis of aseptic deep venous thrombosis of the upper extremity in a cancer patient using fluorine-18 fluorodeoxyglucose positron emission tomography/ computerized tomography (FDG PET/CT)

We describe a patient with a history of recurrent squamous cell carcinoma of the tongue and abnormal FDG uptake in the left arm during a re-staging FDG PET/CT. After revision of the patient's clinical history, tests and physical exam, the abnormal FDG uptake was found to correspond to an extensive aseptic deep venous thrombosis of the upper extremity.

Pregnancy-associated venous thromboembolism in combined heterozygous factor V Leiden and prothrombin G20210A mutations

Pregnancy and puerperium raise the risk of thromboembolic events, and these risks are increased in women who are carriers of thrombophilia factors. Prothrombin (FII) G20210A and factor V Leiden heterozygous mutations are associated with moderate risk of thrombosis. The association of these thrombophilic conditions is very rare in pregnancy, and the real risk of thrombosis is unknown. We describe a case of a pregnant woman who was found to be carrier of heterozygous factor V Leiden and prothrombin (FII) G20210A mutations. Five years before pregnancy she had had an episode of extensive deep venous thrombosis in the ileofemoral region, while using hormonal contraceptives. Anticardiolipin antibody (ACA), lupus anticoagulant and deficiencies of protein C, protein S and antithrombin III were evaluated by means of enzyme-linked immunosorbent assay (ELISA), dilute Russell Viper Venom time (dRVVT), coagulometric and chromogenic methods. Deoxyribonucleic acid (DNA) was amplified using the polymerase chain reaction (PCR) to study the factor V Leiden and G20210A mutations in the prothrombin gene and C677T mutation in the methylene tetrahydrofolate reductase (MTHFR) gene. In the sixth week of her first pregnancy, she developed another episode of deep venous thrombosis in the femoropopliteal veins of the right leg. She was treated with low-molecular weight heparin (nadroparin) until parturition (0.3 ml or 2,850 UI/day). The pregnancy evolved without any significant obstetric morbidity. The patient delivered a healthy baby by cesarean section. During the puerperium, she used prophylactic doses of nadroparin for (0.3 ml or 2,850 UI/day) six weeks and had no complications. We suggest that women who have an association of thrombophilia factors and a prior episode of venous thromboembolism must have antepartum anticoagulation management using unfractioned or low-molecular weight heparin and postpartum management using low-molecular weight heparin or oral anticoagulants. Anticoagulation is recommended during pregnancy because the real magnitude of the risk of major and life-threatening thromboembolic events in these women is unknown.

Extensive Deep Venous Thrombosis with Dilated Collaterals and Confirmatory Emergency Department Ultrasound

Extensive Deep Venous Thrombosis with Dilated Collaterals and Confirmatory Emergency Department Ultrasound

Superior Vena Cava Perforation and Cardiac Tamponade After Filter Placement in the Superior Vena Cava

The purpose of this paper is to report the complication of perforation of the superior vena cava (SVC) leading to cardiac tamponade after the insertion of a Trapease IVC filter in the SVC position. A 29-year-old man was hit by motor vehicle and sustained numerous injuries including a left skull fracture, intracerebral hemorrhage, and left open tibial shaft fracture. During his hospitalization, he developed an extensive symptomatic right upper extremity deep venous thrombosis involving the brachial, axillary, subclavian, internal jugular, and brachiocephalic veins. Owing to an intracerebral bleed, anticoagulation was contraindicated. Therefore, a Trapease filter (Cordis Inc.) was placed in the SVC via the left subclavian vein. Four hours later, the patient became hypotensive with associated tachycardia and tachypnea. Computed tomography of his chest revealed a hematoma around the SVC, a moderate amount of fluid within the pericardium, and a moderate-sized right pleural effusion. The patient was taken to the operating room and a pericardial window was performed. Approximately 500 cc of blood was evacuated from the pericardium and immediate improvement in vital signs was noted. The patient was discharged from the hospital 2 weeks later and at 6-month follow-up had made full recovery. This is the first case of SVC perforation leading to cardiac tamponade after the insertion of a Trapease filter. Owing to the rigid structure of the filter and associated motion of the SVC and pericardium, the Trapease filter may be contraindicated in the SVC.

Heparin-induced Thrombocytopenia and the Use of r-Hirudin during Cardiopulmonary Bypass

We report the successful use of r-hirudin (lepirudin) for cardiopulmonary bypass in a 67-year-old man who developed heparin-induced thrombocytopenia type II during heparin treatment of an extensive deep venous thrombosis. Lepirudin was monitored by the modified ecarin clotting time in a "mobile laboratory" set up next to the cardiac theatre, aiming for lepirudin levels of 3.5 to 4.5 microg/ml during bypass.

Deep venous thrombosis, protein S deficiency and homozygous Factor XII 46T mutation

We report a 13-year-old adolescent with extensive deep venous thrombosis, protein S deficiency and homozygous Factor XII 46T mutation. The patient awoke at night with pain, swelling and limited movement of his left leg. On arrival in the emergency room the pain had worsened considerably, with increasing oedema and marked cyanosis of the leg. There was no dyspnoea, cough, pleuritic pain or haemoptysis. The patient’s medical history was unremarkable and he was not on any medication. There was no history of thrombogenic situations such as surgery, trauma or immobilisation. He had a family history of superficial thrombophlebitis (grandfather and great-grandmother), deep venous thrombosis and protein S deficiency (father). On physical examination the patient appeared well and not fatigued. His temperature was 36oC, blood pressure 130/60 mm Hg, pulse 90 bpm and 26 breaths per min. The left leg showed marked cyanosis, warmth, swelling and oedema from the ankle to the groin. An important ecchymosis on the front part of the thigh was observed. There were no palpable cord or varicose veins, and distal pulses were positive. The rest of the examination was normal. Laboratory data showed a white cell count of 11600/ mm, differential count without abnormalities, a haemoglobin of 121 g/l and platelets 680000/mm. Routine blood chemistries (glucose, urea, creatinine, sodium, potassium) were in the respective reference ranges. Prothrombin time (PT) was 64%, activated partial thromboplastin time (aPTT) 36 s (control 31 s), fibrinogen 220 mg/dl and D-dimer 700 ng/ml (reference range 0–275 ng/ml). Chest X-ray films, electrocardiogram and echocardiogram were unremarkable and oxygen saturation was 98%. In the ultrasonographic examination of the legs there was evidence of massive deep venous thrombosis of the left leg extending from the left iliac vein to the popliteal region. A venography (Fig. 1) revealed extensive deep venous thrombosis affecting all of the venous drainage of the left leg including the iliac sector. The right leg’s deep venous system was completely permeable. Immediately after the diagnosis the patient started anticoagulant therapy with enoxaparin (1 mg/kg/12 h for 7 days), and secondary long-term anticoagulation with acenocumarol. An hypercoagulability study (Table 1), revealed the patient’s protein S deficiency (free 8%, total 40%), father’s protein S deficiency (free 5%, total 20% ), and the patient’s sister’s protein S deficiency (free 10%, total 41%). All of the patient’s mother’s values were in normal range. Studies of the Factor XII C>T polymorphism revealed that the patient and his sister were homozygous for Factor XII 46T, while his father and his mother were heterozygous for Factor XII C46T. The patient’s evolution has been satisfactory. A venography performed 6 months after diagnosis (Fig. 2) showed complete resolution of the thrombosis. He continues under anticoagulant therapy in excellent medical condition without post-phlebitic syndrome. Venous thromboembolic events (VTE) are significantly less frequent in children (5.3/10000 hospital admissions) [5], than in adults (2.5%–5%) [1]. Nevertheless, they represent a significant source of morbidity and mortality, and are being increasingly diagnosed in children as a result of diagnostic and therapeutic advances. Of VTE in young patients, 95% are secondary to underlying disorders (malignancy, trauma/surgery, R. Perez-Montes (&) AE C. Sedano AE L. Yanez AE A. Iriondo Department of Haematology, Marques de Valdecilla Hospital, Valdecilla Avenue s/n, 39008 Santander, Spain E-mail: hemsbc@humv.es Tel.: +34-942-203816 Fax: +34-942-202559

Removal of Vena Caval Filter at 224 Days

Patients at risk of pulmonary embolism usually receive anticoagulants, which are contraindicated in trauma victims. A woman with extensive deep venous thrombosis after a vehicle accident had a nitinol Recovery Filter inserted prophylactically. After her recovery, she requested filter removal because of her intention to become pregnant. The filter was removed percutaneously without difficulty 224 days after implantation.

Venous thromboembolism: diagnosis and management of deep venous thrombosis

Venous thromboembolism (VTE) affects 1-2 per 1000 people in the general population each year. Clinical diagnosis of deep venous thrombosis (DVT) is unreliable, and must be confirmed by compression ultrasonography or venography. A low clinical pretest probability of DVT and negative D-dimer result reliably exclude the diagnosis, with no need for diagnostic imaging. Initial treatment of DVT is with low-molecular-weight heparin or unfractionated heparin for at least 5 days, followed by warfarin (target INR, 2.0-3.0) for at least 3 months. A vena cava filter is indicated in patients who are ineligible for anticoagulant therapy or who experience embolism despite therapeutic anticoagulation. Thrombolysis or surgical embolectomy may be used as a limb-saving measure in patients with extensive proximal DVT and circulatory compromise that threatens the viability of the leg. Decisions regarding the optimal duration of anticoagulation to prevent recurrent VTE should be individualised and balance the risk of recurrence if warfarin is stopped against the risk of major bleeding and inconvenience of continuing treatment. The risk of recurrence is highest in people with recurrent unprovoked DVT or chronic predisposing factors (eg, cancer) who require indefinite anticoagulant treatment.

Fibrinogen Saint-Germain II: Hypofibrinogenemia due to heterozygous γ N345S mutation

We have identified a novel heterozygous fibrinogen gamma chain mutation, gammaN345S (Fibrinogen Saint-Germain II), in a subject with hypofibrinogenemia. There was no evidence by mass spectrometry of plasma fibrinogen containing the mutant chain. The hypofibrinogenemia was discovered in a 26-year-old man who experienced extensive deep venous thrombosis of the left leg associated with pulmonary embolism. Investigation of potential thromboembolic risk factors revealed heterozygosity of the factor V R506Q mutation (factor V Leiden) and heterozygosity of the prothrombin gene G20210A mutation. The hypofibrinogenemia may be contributory to the thrombophilic manifestations.

Extensive Deep Venous Thrombosis Associated with Chemotherapy for Testicular Cancer: A Case Report with Review of the Literature

The authors report a case of an extensive deep venous thrombosis occurring as a complication of chemotherapy with cisplatin, bleomycin and etoposide for a testicular germ cell tumour. During the first cycle of chemotherapy, the patient developed a dramatic picture of deep venous thrombosis, extending from the popliteal and iliofemoral veins up to the thoracic vena cava, close to the right atrium. Progression of thrombosis to the renal veins resulted in acute renal failure requiring dialysis. There are no reports in the literature of such an extensive thrombosis associated with this regimen. Of note, the remarkable results obtained with the early institution of thrombolytic therapy with streptokinase. Thromboembolic events are potentially lifethreatening complications that seem to occur more frequently than expected in patients receiving chemotherapy for germ cell tumours, in spite of young age. Preventive measures should not be overlooked in this setting. LIST OF ABBREVIATIONS GCT= germ cell tumours CMF= cyclophosphamide, 5-fluorouracil, methotrexate CMF/tam= cyclophosphamide, 5-fluorouracil, methotrexate, tamoxifen DVT= deep venous thrombosis BEP = bleomycin, etoposide, cisplatin TT= thrombolytic therapy DHL= lactate dehydrogenase β-hCG= human chorioninc gonadotropin β-subunit AFP= alphafetoprotein IV= intravenously RP= Raynaud phenomenon SH= systemic hypertension PVB= cisplatin, vinblastin, bleomycin FSH= follicle stimulating hormone LH= luteinizig hormone PTE= pulmonary thromboembolism

Is bilateral duplex scanning necessary in patients with symptoms of deep venous thrombosis?

Venous duplex ultrasound scanning (VDUS) has been shown to be an accurate non-invasive means to diagnose symptomatic deep venous thrombosis (DVT). The aim of our study was to determine whether bilateral VDUS is necessary in patients who present with symptoms of DVT. We retrospectively reviewed the results of bilateral lower extremity VDUS performed on 1029 inpatients at Royal Prince Alfred Hospital in the 24 months from 1 January 1998 to 31 December 1999. Of the 1029 patients, 705 (69%) presented with unilateral symptoms and 324 (31%) with bilateral symptoms. The overall incidence of DVT was 168 (16% of 1029 patients). In 705 patients with unilateral symptoms the diagnosis of DVT was confirmed in 120 (17.0%), of whom 20 (16.7%) had unsuspected bilateral DVT. There were 12 patients (1.7% of the 705 patients) who had DVT in the asymptomatic limb, without DVT identified in the symptomatic limb. Overall there were 32 (5% of 705) patients with unilateral symptoms who had unsuspected DVT in the asymptomatic limb. Of the 20 patients with bilateral DVT, only one patient had more extensive DVT in the asymptomatic limb than in the symptomatic limb, that was therefore likely to alter treatment. Bilateral symptoms of DVT were present in 324 (31.5%) patients, 48 (14.8%) of whom were found to have DVT. Nineteen (39.6%) of these DVTs were bilateral. Overall the diagnostic yield of VDUS was low in this study, with an incidence of 16% of DVT detected in symptomatic patients. Techniques that improve the diagnostic yield of VDUS in symptomatic patients are required. A significant proportion (23%) of the DVT detected in this study were bilateral, and a small but significant proportion (10%) of DVT found in patients presenting with unilateral symptoms were only in the asymptomatic contralateral limb. Our study supports bilateral VDUS in symptomatic inpatients, as the detection of DVT in asymptomatic limbs aids future patient management if symptoms develop in the asymptomatic limb.

Thrombolysis for Central Venous Occlusion Causing Bilateral Chylothorax in a Patient with Down Syndrome

A 20-year-old woman with Down syndrome (trisomy 21) and acute lymphoblastic leukemia presented with severe respiratory compromise secondary to bilateral chylothorax as a result of central venous thrombosis and extensive upper-limb deep venous thrombosis. The chylothorax was successfully managed by catheter-directed thrombolysis and angioplasty of the venous occlusions. The development of venous thrombosis was likely to have been multifactorial. It is recognized that there is an increased incidence of congenital lymphatic anomalies in Down syndrome, which may have been a contributing factor in the development of chylothorax in this patient. This report illustrates the angiographic findings, demonstrates the successful vascular recanalization, and discusses the etiology and management of central venous thrombosis and chylothorax. The case is also presented to contribute to the expanding evidence in support of catheter-directed venous thrombolysis in selected clinical circumstances.

Desquamative Interstitial Pneumonia Masquerading as Acute Life-Threatening Pulmonary Embolism

Desquamative Interstitial Pneumonia Masquerading as Acute Life-Threatening Pulmonary Embolism

Treatment of May-Thurner Syndrome with Catheter-Guided Local Thrombolysis and Stent Insertion

Background:May-Thurner syndrome is an uncommon disease entity in which the left common iliac vein is compressed by the right common iliac artery, with the subsequent development of deep vein thrombosis and chronic venous insufficiency. Herein, our experience on the treatment of extensive iliofemoral deep venous thrombosis due to May-Thurner syndrome, using endovascular techniques, is reported. Methods:Twenty-one symptomatic patients, 8 men and 13 women, with a mean age of 51 years, were referred for treatment. Eighteen of these patients were treated with catheter-guided thrombolysis, but three, with short segment involvement, did not require thrombolysis. After completion of the thrombolytic therapy, the residual venous narrowing was treated by balloon angioplasty and/or self-expandable stent placement. Patients were then followed-up by clinic visits and venography. Results:The mean total dose of urokinase and duration of infusion were 4.28±1.89 million units and 72±35 hours, respectively. Eighteen of the 21 patient received stent deployments. The mean diameter of the stents was 12.9±2.0 mm. Initial technical success, with immediate symptom resolution, was achieved in 20 of the 21 patients (95%). Among the patients who received stent implantation, two had recurrent thrombotic occlusion during the follow-up period. (mean 10.8 months); all three patients who did not receive stent implantation had recurrent thromboses There were no major bleeding complications, with the exception of one patient who developed a retroperitoneal hematoma. Conclusions:Catheter-guided thrombolysis and angioplasty with stent implantation are safe and effective for the treatment of May-Thurner syndrome. (Korean Circulation J 2004;34 (7):655-659)

Air plethysmography: The answer in detecting past deep venous thrombosis

Purpose: In this study we assessed the accuracy of air plethysmography (APG) as a means of detecting earlier deep venous thrombosis (DVT), in comparison with venography, to develop a preoperative test for patients with varicose veins. Methods: In this retrospective analysis of prospectively acquired data, 202 patients referred with the clinical suspicion of chronic venous obstruction (224 lower limbs) and 41 patients (41 lower limbs) who had symptoms and signs suggestive of DVT, but had deep veins that appeared normal on venography, were studied with both venography and APG. Results: The results of venography were negative for past DVT in 169 legs and confirmed past DVT in 96 limbs. The DVTs were confined to the calf in 19 limbs and were found at popliteal level, more proximal, or both in 77 limbs. A total of 95% of the limbs that had earlier proximal DVT (73 of 77) were identified by means of an APG outflow fraction with occlusion of the superficial veins in the first second (OFs) of less than 28%. This is analogous to the Q wave of the electrocardiogram, which is a means of denoting the presence of myocardial infarction. The specificity rate of the method in the detection of past proximal DVT was 96%, the positive predictive value was 92%, and the negative predictive value was 98%. Conclusion: APG is a practical, inexpensive, easy-to-perform, accurate, noninvasive method for the diagnosis of hemodynamically significant (ie, proximal or extensive calf DVT) chronic venous obstruction that could replace venography. (J Vasc Surg 2001;33:715-20.)

Percutaneous AngioJet Thrombectomy in the Management of Extensive Deep Venous Thrombosis

This study was undertaken to evaluate the efficacy of a percutaneous mechanical thrombectomy (PMT) device for rapid thrombus removal following deep venous thrombosis (DVT). Over a 37-month period, 17 patients (14 women; mean age, 41 y +/- 20) with extensive DVT were treated with initial attempts at PMT with use of the AngioJet rheolytic thrombectomy device. Sites of venous thrombosis included lower extremities in 14 patients and upper extremity and brachiocephalic veins in three. The etiology for venous thrombosis was malignancy in seven, idiopathic etiology in three, May-Thurner syndrome and immobilization in three each, and oral contraceptive use and hypercoagulable disorder in one each. The primary endpoint was venographic evidence of thrombus extraction. Perioperative complications, mortality, and recurrence-free survival were also evaluated. After PMT, four of 17 patients (24%) had venographic evidence of >90% thrombus removal, six of 17 (35%) had 50%-90% thrombus removal, and seven of 17 (41%) had <50% thrombus extraction. Adjunctive thrombolytic therapy was used in nine of 13 patients with <90% thrombus extraction by PMT; six patients (35%) had contraindications to pharmacologic thrombolytic therapy. An underlying lesion responsible for the occlusion was uncovered in 10 patients (59%). Significant improvement in clinical symptoms was seen in 14 of 17 patients (82%). No complications were noted directly relating to the use of the AngioJet thrombectomy catheter. None of the patients were lost to follow-up during a mean of 8.9 months +/- 5.3 (range, 2-21 months). At 4 and 11 months, recurrence-free survival rates were 81.6% and 51.8%, respectively. PMT with adjunctive thrombolytic therapy is a minimally invasive, low-risk therapeutic option in patients with extensive DVT, associated with clinical benefits including thrombus removal, patency, and relief of symptoms.

Endovascular Management of Acute Extensive Iliofemoral Deep Venous Thrombosis Caused by May-Thurner Syndrome

The authors report their experience on the treatment of acute extensive iliofemoral deep venous thrombosis (DVT) due to May-Thurner syndrome using endovascular techniques. During a 1-year period, 10 symptomatic women (age range, 22-52 years; mean, 35.5 years) were referred for treatment. After ascending venography, an infusion catheter system was placed and urokinase was infused locally into the thrombus burden. After near complete clot dissolution (> or = 95%) or lytic stagnation, the residual left common iliac vein narrowing was treated by means of angioplasty and/or placement of Wallstent endoprosthesis. All patients continued to receive oral warfarin. Patients were followed-up by means of clinic visits, and stent patency was assessed by means of duplex Doppler sonography performed at 1, 3, 6, and 12 months, and then yearly thereafter. The total dose of urokinase used and the duration of infusion were 5.87 +/- 2.57 million units (range, 3.18-10.7) and 51.95 +/- 21.57 hours (range, 26.5-89), respectively. After completion of thrombolytic therapy, the iliac vein narrowing was successfully treated by deployment of a Wallstent endoprosthesis in all 10 patients because of failure of angioplasty. No major bleeding complications occurred. Initial clinical success was 100%, with complete resolution of symptoms in all patients. One patient, who was hypercoagulable and was receiving chemotherapy for metastatic adenocarcinoma, had recurrent symptomatic acute DVT 1 month after therapy. She underwent successful repeated lysis. The remaining nine patients were asymptomatic, with a mean follow-up of 15.2 months (range, 6-36 months). One asymptomatic patient, at 36-month follow-up ultrasound, had iliac vein occlusion and well-developed venous collaterals. Serial ultrasonography in all 10 patients showed no evidence of valvular insufficiency in the femoral and popliteal veins. Catheter-directed thrombolytic therapy for the treatment of acute extensive iliofemoral DVT due to May-Thurner syndrome is an effective method for restoring venous patency and provides relief of the acute symptoms. The underlying left common iliac vein lesion invariably needs to undergo stent placement.