Thrombosis Of Leg Research Articles

Hypertensive crisis in an 11-year-old girl with kidney and inferior vena cava abnormalities and leg thrombosis: Answers.

Hypertensive crisis in an 11-year-old girl with kidney and inferior vena cava abnormalities and leg thrombosis: Answers.

Hypertensive crisis in an 11-year-old girl with kidney and inferior vena cava abnormalities and leg thrombosis: Questions.

Hypertensive crisis in an 11-year-old girl with kidney and inferior vena cava abnormalities and leg thrombosis: Questions.

O23 Pulmonary emboli in a teenager with GPA: management dilemmas

Case report - Introduction15 year old girl with the diagnosis of granulomatosis polyangiitis (GPA) managed with induction regimen of intravenous cyclophosphamide and whilst on maintenance mycophenolate mofetil (MMF) developed multiple cavitating lung lesions with the large cavity abutting pulmonary vein and bilateral segmental pulmonary embolism (PE) posing complex management dilemmas.Case report - Case description15-year-old girl presented with being unwell for 3 months with malaise, lethargy, joint pains, significant weight loss (10 kg), mouth ulcer and significant hearing loss. Investigations showed anaemia, raised inflammatory markers, and impaired kidney function (estimated glomerular filtration rate eGFR 40). Her ANCA was positive, hearing test showed significant mixed hearing loss and CXR was normal. The renal biopsy confirmed pauci-immune ANCA associated glomerulonephritis with 70% crescents. She was initially managed with intravenous pulse of steroids followed by oral weaning regime, double filtration plasmapheresis and commenced on induction regimen of intravenous cyclophosphamide. She received 6 doses of cyclophosphamide 500 mg/m2 and following good recovery with normalising kidney function; was commenced on maintenance MMF.At this point she developed new onset earache, sore throat, and hoarseness of voice with raised inflammatory markers and worsening symptoms despite antibiotics. This was presumed to a flare of vasculitis and hence was given further pulse of steroids and increased the dose of MMF. The ENT assessment did not reveal any subglottic stenosis. After few weeks, symptoms recurred with cough/hoarseness of voice and associated tiredness. Bloods showed raised inflammatory markers; CXR revealed cavitating lung lesions and a CT chest was arranged.CT chest showed apical sub pleural lung nodule and a large thick-walled cavity measuring 6.6x 4.4 cm abutting the pulmonary vein on the right side and bilateral segmental pulmonary emboli. The child was systemically stable with no respiratory distress and oxygen saturations were 100% in air.Case report - DiscussionThe management of GPA was further complicated by the pulmonary embolism and cavitating lung lesions abutting pulmonary vein.The management included escalation of immunosuppression with pulse of steroids, further dose of cyclophosphamide and commence Rituximab .The key challenges with the immediate management were risk of bleeding associated with the anticoagulation, treating the pulmonary embolism, risk of diffuse alveolar haemorrhage and managing the patient in a safe setting equipped with all the expertise required.The child was screened for cardiolipin antibodies on multiple occasions and these were negative. An ECHO was done to look for evidence of clot at the end of central line tip, but this was normal. Deep venous thrombosis of legs was ruled out by Doppler scanning. There was no clear source of emboli identified.Although there is emerging evidence for increased incidence of vascular events in GPA adult patients, the data on vascular events in children with GPA is scarce. Merkel and co-workers reported a high occurrence of pulmonary embolism (PE) and deep venous thrombosis (DVT) among GPA patients included in a randomized therapeutic trial (WeCLOT study) 1 .FAURSCHOU et al. reported that GPA was associated with a much lower relative risk of stroke than of pulmonary embolism and deep venous thrombosis; the risk of venous thromboembolic events among GPA patients was increased during early as well as late follow up periods. Currently there are no significant data on the use of antiplatelet and/or anticoagulant therapy in AAV. Following extensive multidisciplinary discussion with respiratory, haematology, cardiology, cardiothoracic surgical and paediatric intensive care teams, and the child was anticoagulated with close monitoring in paediatric high dependency unit and immunosuppression escalated alongside. Case report - Key learning points This case highlights the risk of thromboembolic events in children with GPAProposed mechanisms in the literature for thrombosis in vasculitis at molecular level would probably explain the episode in the absence of source identifiedMultidisciplinary team approach is crucial for management of complex patientsThere were few challenges due to geographical location of the patient and the regional variation of subspecialty cover provided for their local District General HospitalFor discussion- Role of Rituximab early in GPA?

Assessment of patients who tested positive for COVID-19 after recovery

Assessment of patients who tested positive for COVID-19 after recovery

Factors Affecting Recurrent Deep Vein Thrombosis after Pharmacomechanical Thrombolysis and Left Iliac Vein Stent Placement in Patients with Iliac Vein Compression Syndrome

PurposeThis study evaluated the factors affecting contralateral and ipsilateral recurrent deep vein thrombosis (DVT) after iliac vein stent placement in patients with iliac vein compression syndrome (IVCS). Materials and MethodsData from 130 patients (95 female patients) who underwent catheter-directed thrombolysis and stent placement for IVCS with left lower leg thrombosis at a single institution were retrospectively analyzed. Mean patient age was 69.0 ± 14.0 years old. Median follow-up was 14 months (range, 3–164 months). Anticoagulation therapy was prescribed for 6 months, followed by lifelong antiplatelet therapy. Multivariate logistic regression analysis was performed to evaluate the factors affecting the development of contralateral and ipsilateral recurrent DVT. ResultsSeven patients (5.4%) developed contralateral DVT (median, 26 months; range, 2–61 months), and 11 patients (8.5%) developed ipsilateral DVT (median, 1 month; range, 0–53 months). Stent location (odds ratio [OR], 11.564; 95% confidence interval [CI], 1.159–115.417) and in-stent thrombosis during follow-up (OR, 15.142; 95% CI, 1.406–163.119) were predictors of recurrent contralateral DVT. Thrombophilia (OR, 47.560; 95% CI, 2.369–954.711), remaining inferior vena cava filter (OR, 30.552; 95% CI, 3.495–267.122), and in-stent thrombosis during follow-up (OR, 82.057; 95% CI, 2.915–2309.848) were predictors of ipsilateral DVT. ConclusionsContralateral DVT occurs late and is associated with extension of the iliac vein stent to the inferior vena cava and in-stent thrombosis. Ipsilateral DVT occurs relatively early and is associated with thrombophilia, remaining inferior vena cava filter, and in-stent thrombosis.

Fatal pulmonary thromboembolism: deep vein thrombosis incidence at coronial autopsy

Most pulmonary thromboemboli arise from deep vein thrombosis of the lower legs.1 When pulmonary thromboembolism is identified as the cause of death at autopsy, it has been recommended that the calves should be dissected to locate the source of the embolus.2,3 However, it is uncertain how often deep vein thrombosis will be found and if the incidence is altered by risk factors for pulmonary thromboembolism. This research aimed to determine how often deep vein thrombosis of the lower legs was found at Coronial autopsy when death had resulted from pulmonary thromboembolism, and to ascertain if risk factors affect the likelihood of finding deep vein thrombosis. Autopsy reports of pulmonary thromboembolism deaths in the year 2016 were identified on the National Coronial Information System. Dissection information and risk factors for pulmonary thromboembolism were recorded. Risk factors were analysed by logistic regression to determine if there was predictive value on the probability of finding deep vein thrombosis. A total of 235 pulmonary thromboembolism fatalities were identified. Deep vein thrombosis was found in 76.6% full-body autopsies. A recent hospital admission was found to have a statistically significant positive influence (p=0.01) on finding deep vein thrombosis of the lower legs.

P717 Isolated left ventricular tamponade in a patient with severe pulmonary hypertension due to chronic thromboembolisms: a case report

Abstract A case presents a 37 years old patient who presented to emergency department with progression of dyspnea. Patient had a history of pulmonary hypertension due to chronic thromboembolism and known, repetitive thrombosis of both legs with both of them postthrombotically altered, especially left leg. During his emergency department workup he had a pulmonary angiography performed which showed evidence of old thromboembolism in right pulmonary main branch and circumferential pericardial effusion which was dominantly locularized behind left ventricular posterior wall. Emergency echocardiography was performed which showed marked respiratory variations in mitral and aortic flow with mid to late diastolic left ventricular collapse. Also left ventricular cavity was severely reduced ( EDD 29 mm) due to prominent interventricular septum (right ventricular pressure overload) and hyperkinetic posterior wall (pericardial effusion). There were no apparent signs of compression of right ventricular chambers. Clinically patient had no pulsus paradoxus and had an RR of 115/70 mmHg. Emergency pericardiocentesis was performed using subxiphoid approach. However, pericardiocentesis setting was challenging because patient also had ample of ascites which made orientation by aspiration impossible. Instead puncture was performed under fluoroscopy while slowly instilling the contrast until contrast was delievered intradiaphragmally. From there needle was advanced 3-4 mm into pericardial cavity and pigtail catheter was placed. A total of 2200 ml of milky pericardial fluid was removed during the following 48 hours (cytology – mixed type; triglycerides 1.9 mmol/L). Patient was initially treated with corticosteroids and colhicin, but had a relapse of pericardial effusion once drainage was stopped so re-pericardiocentesis was performed. This time a total of 7200 ml of pericardial fluid was drained so we opted for pericardial fenestration (into left pleural space). Unfortunately, patient died on the 8th postoperative day due to complications (developed subcutaneous emphysema at the place of insertion of thoracal drainage and developed respiratory, then refractory cardiac arrest).

Thrombophlebitis hiding under a KILT \u2013 case report on 40\u2009years long-term follow-up of neonatal renal vein thrombosis

BackgroundNeonatal renal vein thrombosis is a recognised cause of renal and inferior caval vein atresia (IVCA). However, the long-term impact of the condition is underrecognized with a high burden of morbidity for the patient, especially in adulthood. IVCA has been shown to be an independent risk factor for deep venous thrombosis (DVT) with a high risk of recurrence. The acronym KILT for kidney and inferior vena cava anomaly with leg thrombosis summarizes the pathological situation.Case presentationWe present the case of a 40-year-old patient with pain in the right lower limb resulting from acute thrombophlebitis. No risk factors could be identified. His history was remarkable with two episodes of deep venous thrombosis first of the left, then the right leg 22 years earlier; at that time also, no risk factor was identified. Because of the idiopathic character of that thrombosis, the patient remained on long-term anticoagulation with phenprocoumon. The present thrombophlebitis occurred while the INR was not therapeutic in the preceding weeks. A CT with contrast showed atresia of the inferior vena cava and of the right kidney, and presence of numerous collaterals. A thorough medical history revealed a renal vein thrombosis as a neonate. Anticoagulation was intensified, and stent placement became necessary after a further 2 years.Discussion and conclusionsKILT syndrome is a rare but underrecognized condition. Complications may arise in young adulthood only, and it is of prime importance to instruct parents of the pediatric patient of the possible consequences of renal vein thrombosis and to assure guidance from the treating physicians throughout adulthood. Diagnosis of IVCA is by CT with contrast or by MRI, and lifelong anticoagulation may be necessary. Since the KILT syndrome is widely underdiagnosed, we challenge the clinicians to keep it in mind when confronted with thrombophlebitis or thrombosis of the young, male and with no other identifiable risk factors for deep vein thrombosis.

Treatment of cancer-associated thrombosis after craniotomy.

e13510 Background: The high rates of mortality from venous thromboembolism (VTE) in neurooncological patients determine the relevance of the topic. The risk of VTE in patients with glioma reaches 36% during the treatment period, 16.1% during the first 6 months and increases by 3 times after tumor biopsy. The aim of this study was to evaluate the efficacy and safety of VTE treatment with fondaparinux after surgical interventions for brain tumors. Methods: The study included 32 cancer patients aged from 27 to 76 years (mean 56.5 years) in the acute period of VTE, the first month after craniotomy. Creatinine clearance below 30 ml/min, active bleeding, thrombocytopenia below 50x109/l were exclusion criteria. Glioma was diagnosed in 15 patients (46.9%), metastasis - 9 (28.1%), and meningioma - 8 patients (25%). Radical interventions were performed in 12 (37.5%) cases, palliative - 20 (62.5%). In 81.2% of cases (26 patients) deep vein thrombosis of lower extremities (DVT) was detected, 3 patients (9.4%) had combination with pulmonary embolism. VTE developed in the postoperative period with radiotherapy in 9 cases (32%), dexamethasone - 13 (40.6%). Surgical treatment of DVT was performed in 8 patients (thrombectomy, plication of the femoral vein). Segmental deep vein thrombosis of the lower leg was detected in 14 (43.8%) cases. Results: The efficiency of anticoagulant therapy was assessed by a decrease of thrombinemia markers (fibrinogen, SFMC and D-dimer). After a week of anticoagulant therapy, a significant reduction in the level of D-dimer was observed. However, the decline in fibrinogen and SFMC was statistically insignificant. VTE therapy was performed with fondaparinux in a therapeutic dose from 10 days to 1 month, followed by a transition to oral anticoagulants. There was no hospital mortality. Hematuria developed in one case (3.1%), and was managed conservatively. There were no hemorrhagic complications in the operative intervention zone. Two patients (6.25%) had a recurrence of VTE during the period of radiation therapy. Conclusions: An integrated approach to the treatment of VTE in patients undergoing craniotomy provides a low incidence of recurrent VTE and major bleeding.

Kidney and inferior vena cava abnormalities with leg thrombosis syndrome in a 22-year-old

Kidney and inferior vena cava abnormalities with leg thrombosis syndrome in a 22-year-old

Venous thromboembolic complications in stroke patients: prevention problems

Objective: Clinical assessment of the efficacy and safety of the use of the Protocol for the prevention of Venous Thromboembolic Complications (VTEC), including the use of standard doses of anticoagulants and elastic compression of the lower extremities. Materials and methods: A prospective analysis of 86 cases of stroke was performed. Depending on the amount of preventive measures of VTEC, patients were divided into two groups.In the first group (n 42), non-drug methods were used: compression knitwear, patients turns in bed every 2 hours, passive gymnastics and massage of paralyzed limbs, in the second group (n 44), non-pharmacological prophylaxis was supplemented with nadroparin. Results: Patients with acute stroke are at high risk of VTEC, and in almost all cases deep vein thrombosis of the lower leg was not accompanied by clinical symptoms and was diagnosed only during the ultrasound examination.The protocol for the prevention of VTEC is effective and safe in patients with hemorrhagic and ischemic stroke. During prophylaxis by the Protocol the frequency of VTEC is reduced from 32 to 24, while the frequency of hemorrhagic complications doesnt increase. Conclusion: The results of the study confirm the high efficacy and safety of the Protocol of prevention VTEC in patients with stroke.

An atypical Klippel-Treanunay-Weber syndrome

A 44 year old female was referred for hyperbaric oxygen treatment of leg ulcers. The patient had port-wine stain, hand vitiligo, hypertrophy of one extremity, collateral abdominal, and varicose leg veins. Calcium was 12 mg/dL and PTH was 309 ng/L. Hepatomegaly, deep vein thrombosis of the right leg, transudative ascites, hypersplenism, parathyroid adenoma, mesenteric cyst, and papillary thyroid carcinoma were identifi ed. The fi nal clinical diagnosis was Klippel-Treanunay-Weber syndrome.

Effectiveness and safety of oral direct factor Xa inhibitors for the treatment of venous thromboembolism in patients with cancer and/or older age.

Venous thromboembolism (VTE) is a multifactorial disease. Cancer and older age are risk factors for both recurrent VTE and bleeding under anticoagulant therapy. Oral direct factor Xa inhibitors (Xa inhibitors) have been widely used to treat VTE. However, their effectiveness and safety in cancer and elderly patients have not been fully elucidated. A total of 187 consecutive patients who started Xa inhibitors for VTE therapy between September 2014 and September 2016 were recruited. Patients' demographics, changes in VTE amount, VTE recurrence, clinically relevant bleeding, and death until February 2017 were compared between 92 cancer and 95 non-cancer patients, and 57 elderly (≥ 75years) and 130 non-elderly patients. Compared with non-cancer patients, cancer patients had a significantly higher incidence of deep vein thrombosis (DVT) in the proximal legs, superior vena cava, and upper extremities (p = 0.034), although the patients' demographics and incidence of pulmonary thromboembolism (PE) were similar between the two groups. There were no significant differences in VTE recurrence (p = 0.328) and clinically relevant bleeding (p = 0.078) between the two groups. Death occurred in 29 cancer patients, 23 of whom died of cancer, while there were no deaths among the non-cancer patients. Elderly patients had a lower body weight and creatinine clearance than non-elderly patients. No significant differences between the two groups were found in relation to PE (p = 0.544), DVT site (p = 0.054), recurrent VTE (p = 0.194), clinically relevant bleeding (p = 0.130) and death (p = 0.241). In comparisons among the four groups (elderly and non-elderly patients with and without cancer), recurrent VTE and clinically relevant bleeding were comparable (p = 0.493 and 0.227, respectively), while death was more frequent in cancer patients regardless of age (p < 0.001). The efficacy and safety of Xa inhibitors as VTE treatment were comparable between cancer and non-cancer patients, and in elderly and non-elderly patients. This suggests that Xa inhibitors may be promising drugs for VTE treatment, irrespective of age and comorbid cancer.

Deep Vein Thrombosis of the Left Leg: A Case of May-Thurner Syndrome.

A 56-year-old woman presented with gradually worsening shortness of breath associated with dull left leg pain over 5 days. She denied any recent travel, recent surgeries or immobilization.CT pulmonary angiography and CT venography revealed multiple bilateral pulmonary emboli and extensive left pelvic and left lower extremity deep vein thromboses. Contrast-enhanced CT showed that the right common iliac artery crossed the left common iliac vein and compressed it externally, indicative of May–Thurner syndrome. Catheter-directed thrombolysis of the left lower extremity was performed and heparin infusion was started. The patient also underwent left iliac vein balloon angioplasty with stenting and infra-renal inferior vena cava filter placement via the jugular approach to prevent further embolization.LEARNING POINTSMay–Thurner syndrome (MTS) should be suspected in patients in their second to fourth decade of life presenting with unprovoked deep venous thrombosis of the left leg.An iliac venogram is the diagnostic test of choice for MTS.MTS is treated only when it is symptomatic. The goal of treatment is to remove the clot to prevent post-thrombotic syndrome and to repair the anatomical defect.A stent was successfully deployed in the iliac vein of our patient and restoration of blood flow resulted in a dramatic improvement in the patient’s symptoms.

What Is Vascular Behçet's Disease?

Vascular Behçet’s disease (BD) would keep risk of anastomotic pseudoaneurysm due to deterioration of the disease even after vascular surgery was successfully done. Therefore, it is one of the least-welcome diseases for vascular surgeons. There still exist several points on a concept and criteria of the vascular BD which not only general practitioners but also the vascular surgeons do not understand. Clinical findings strongly suspecting vascular BD are follows; saccular aneurysms without atherosclerosis developed in younger than 50-year-old patients, superior vena cava syndrome or deep vein thrombosis in bilateral legs without apparent causes, and multiple superficial thrombophlebitis, etc. It is very difficult to make a diagnosis of BD in the patients whose onset of the disease is a vascular lesion, because vascular BD combines few ocular lesions. In such case, it is very important to find out not only oral and genital ulceration, but also past history of arthritis. To establish the vascular BD, we vascular surgeons have to collect cases of the vascular BD and to revise criteria of the disease. (This is a translation of Jpn J Vasc Surg 2017; 26: 19–23.)

Protein S deficiency complicated with repetitive peripheral arterial thrombosis successfully treated by mechanical thrombectomy device with Rotarex system

Protein S deficiency is an inherited thrombophilia associated with an increased risk of venous thromboembolism. However, arterial thrombosis is a relative rare complication of protein S deficiency and the prognosis of these patients was worse than those without protein S deficiency in the literature. Herein we reported a 43-year-old male with protein S deficiency experiencing several times acute peripheral arterial thrombosis of left leg. Surgical thrombectomy was performed initially but later endovascular treatment (EVT) was suggested. Although EVT was successfully performed by catheter-directed thrombolysis (CDT), arterial thrombosis still recurred three months later. CDT was tried again but thrombosis could not be treated by this strategy anymore. Therefore, we used mechanical thrombectomy device (Rotarex system) and successfully regained the straight-line blood flow to the foot after the procedure. Peripheral echo showed patent flow after 6 months follow-up. In conclusion, arterial thrombosis is a relative rare complication of protein S deficiency and prognosis was not well in the literature, our case reminds physicians that Rotarex system is a safe and highly efficient device for acute PAOD even in the patients with hypercoagulable state.

Visceral subpleural hematoma of the left diaphragmatic surface following left upper division segmentectomy

BackgroundPulmonary visceral subpleural hematoma is rare. We report visceral subpleural hematoma of the left diaphragmatic surface following left upper division segmentectomy. This very rare case was difficult to distinguish from thoracic abscess.Case presentationA 68-year-old man with hypertension had undergone video-assisted thoracoscopic left upper division segmentectomy for suspected lung carcinoma. Deep vein thrombosis of the lower leg was identified and edoxaban, a so-called novel oral anticoagulant, was started on postoperative day 7. The chest drainage tube was removed on postoperative day 12 because of persistent air leakage, but fever appeared the same day. Computed tomography revealed a cavity with mixed air and fluid, so antibiotics were started on suspicion of abscess. Computed tomography-guided drainage was attempted, but proved unsuccessful. Fever continued and surgical investigation was therefore performed. Visceral subpleural hematoma was identified under the diaphragmatic surface of the left basal lung. We excised the pleura, then performed drainage and applied running sutures. The parenchyma and visceral pleura were covered with polyglycolic acid sheet and fibrin glue. Edoxaban was restarted on postoperative day 12 of video-assisted thoracoscopic surgery and no recurrence of hematoma has been revealed.ConclusionsVisceral subpleural hematoma after thoracic surgery is extremely rare. Furthermore, correct diagnosis was difficult and surgery offered a good diagnostic and therapeutic procedure.

Inferior vena cava thrombosis due to polycystic kidney disease

Aim: Autosomal dominant polycystic kidney disease is the most common renal hereditary disease. During many years renal cysts become larger, the functional nephron mass decreases and enlarged kidneys compress the surrounding structures. We present the case of a patient with polycystic kidney disease and inferior vena cava thrombosis after kidney transplantation. Case report: Three months after kidney transplantation into the left iliac fossa, the 67 year-old woman was admitted to our hospital due to swelling oft the right leg. Clinical and ultrasound examination revealed deep vein thrombosis of right leg and therapy with heparine was introduced. Since there was no improvement, a computerized tomography examination was performed that confirmed deep vein thrombosis of the right leg, thrombosis of iliac veins on the right side and partial thrombosis of the distal part of the inferior vena cava. As radiologic imaging revealed compression of the right polycystic kidney onto the inferior vena cava, we performed nephrectomy of the polycystic kidney to prevent complete thrombosis. The postoperative course was uneventful, with a regression of the right leg edema and stable graft function. Discussion and conclusion: In patients with large polycystic kidneys, compression of the inferior vena cava may lead to its thrombosis. A nephrectomy should be performed in time.

Case of successful treatment of a high risk acute tele with hypothony in a patient with polymorbid pathology

The presented article features the management of a high-risk patient with polymorbid pathology: cancer, stroke and venous thromboembolism. In spite of anticoagulant therapy with heparin, unilateral deep vein thrombosis of the lower leg was complicated by a primary episode of verified acute bilateral pulmonary artery thromboembolism of high-risk with hypotension and bilateral infarct-pneumonia. After urgent diagnosis of PE had been made, the following management of the patient in the acute phase was suggested: timely modern replacement artificial ventilation of the lungs for eight days, vasopressor support for six days, anticoagulant therapy, fluid replenishment and effective in its results, enteral nutrition. The pattern of evolving pulmonary hypertension and acute right ventricular dysfunction, coagulation disorders was tracked down. Residual thrombosis proved to linger by detection of steep D-dimer rise on the ninth day of the acute period. The signs of thrombosis persisted despite anticoagulant therapy, with the simultaneous complete disappearance of blood clots according to computed tomography. That was accompanied by severe disorders of the heart rhythm recalcitrant to antiarrhythmic and electropulse therapy. Further treatment in the settings of a specialized center revealed occult extra routes of impulse conducting that justified necessity of catheter ablation. On the ninetieth day the patient was alive and stable. Presented approach of diagnostic and therapeutic steps proved to be effective.

Surgical repair of a popliteal vein aneurysm to prevent thromboembolic complications

SummaryThe case reported here involves a 72-year-old female patient with right-sided popliteal vein aneurysm, which became apparent during follow-up ultrasound scanning after deep venous thrombosis of the left leg with pulmonary embolism. Due to the size of the aneurysm, the decision was made to perform surgery. The aneurysm was tangentially resected by means of plication. Aneurysms of the deep venous system carry a considerable risk of a thromboembolic event and therefore require treatment, even when they are asymptomatic. Surgical treatment of an aneurysm of the deep leg veins is a safe and low-risk procedure for the prevention of pulmonary embolism.