Chronic Thrombus Research Articles

Pulmonary endarterectomy under intermittent deep hypothermic circulatory arrest

Chronic thromboembolic pulmonary hypertension occurs in very few patients after acute embolism, and pulmonary thromboendarterectomy is the main and curative treatment. Here we have a patient with a chronic thrombus in the pulmonary artery that required thromboendarterectomy with deep hypothermic circulatory arrest.

A Multicenter, Retrospective Study of the Effectiveness of the Trellis-8 System in the Treatment of Proximal Lower-Extremity Deep Vein Thrombosis

Deep vein thrombosis (DVT) occurs in up to 600,000 patients in the United States annually and can lead to long-term morbidity because of the post-thrombotic syndrome. The multicenter isolated-pharmacomechanical thrombolysis device (ISOL-8) study was designed to determine the safety and efficacy of the Trellis™-8 peripheral infusion system when used as the primary intervention to achieve DVT thrombolysis in patients with proximal lower-extremity occlusive DVT, and track the incidence and severity of the post-thrombotic syndrome (PTS) symptoms in patients 2 years after treatment. Data were collected retrospectively from 6 centers on patients treated with the Trellis-8 system, an isolated-pharmacomechanical thrombolysis device (IPMTD). Patients with occlusive lower-extremity DVT involving at least the iliac and/or common femoral vein were included. Patient demographics, medical history, procedure outcomes, complications, and follow-up venous duplex and Venous Clinical Severity Score (VCSS) were collected through 24 months. Data analysis of outcomes were performed at 1 and 12 months. A 24-month analysis was not performed because of the small number of patients for whom 24-month data could be collected. A total of 151 limbs in 139 patients were treated with IPMTD. The mean ± standard deviation (SD) procedure time was 122.6 ± 63.4 min. Single session treatment was delivered in 69.9% (93 of 133) of cases. Occlusive DVT extended from the femoral into the external and/or common iliac vessel segments in most of the cases (113 of 151 limbs; 74.8%). Before treatment, 23.2% (35 of 151) of the treated limbs, based on a history of prior ipsilateral DVT or preoperative imaging revealing chronic venous scar, were expected to have some chronic venous disease despite presenting with acute symptoms. After treatment, 43.7% (66 of 151) of the limbs showed evidence of chronic thrombus. The average amount (mean ± SD) of thrombolysis, as determined by venogram, was highest in patients who had acute thrombus (81 ± 19.7%), compared with subacute thrombus (61 ± 22.5%) and complex cases involving acute and/or subacute thrombus on chronic scar (56 ± 26.5%). VCSS scoring showed the number of patients with none and/or mild pain, varicose veins, and skin changes at 1-month remained stable at 12 months whereas the percent of patients with none and/or mild venous edema improved from 71.7% at 1 month (38 of 53) to 86.8% (46 of 53) at 12 months. Twenty-four-month follow-up data were available for only 15% (23 of 151) of patients. No clinically significant pulmonary emboli or major periprocedural bleeding events were reported. Patients with acute lower-extremity DVT involving the proximal veins can be safely and successfully treated with IPMTD. Major procedural bleeding was absent. The occurrence of severe PTS after primary treatment with Trellis-8 system IPMTD is low. Further long-term follow-up data are needed to confirm the benefit of intervention for thrombus removal compared with standard medical management.

Abstract No. 523 - Skin and soft tissue findings in the vein clinic

No. 525 Initial experience with the AngioVac aspiration system J.T. Salsamendi, S. Bhatia, M. Doshi, M. Bordegaray, R. Arya, G. Narayanan; Radiology, University of Miami, Miami, FL Purpose: To present our experience with the AngioVac aspiration system, a new device designed for removal of intravascular material, such as thrombi and vegetations To review the available literature on AngioVac aspiration system Materials and Methods: The AngioVac system (AngioDynamics, Latham, NY) is a novel mechanical suction device that is designed for the removal of unwanted intravascular material while maintaining flow during extracorporeal circulation. It has been described for use in the retrieval of right atrial thrombus/mass, management of acute massive pulmonary embolism, treatment of symptomatic iliocaval thrombosis, protection against thrombus migration during catheter removal in right to left cardiac shunts, and removal of cardiovascular implantable device lead vegetations. The current case series describes the use of AngioVac in 6 consecutive patients. There were 3 female and 3 males (mean age, 49.6 y). In 5/6 cases, the AngioVac cannula was inserted percutaneously and the patient was placed on veno-venous bypass. In one of the cases, the cannula was inserted directly into the Fontan circuit after sternotomy and the patient was maintained on cardiopulmonary bypass. Results: Thrombus location included iliocaval (2), pulmonary arteries (PA) (1), Fontan circuit and Glenn shunt with pulmonary artery extension (1), right atrium (RA) (1), and IVC with renal vein extension (1). Near complete evacuation of thrombus was documented in 3/6 cases by angiogram, cross sectional imaging or intravascular ultrasound. Partial thrombus removal was confirmed in 3/6 patients. Reasons for subtotal thrombus removal included chronic thrombus (2) and inadequate suction cannula flow rates in the pulmonary arteries (1). 2/6 patients had access site hematomas which resolved without any interventions. PubMed search yielded 12 studies reporting experience with a total of 29 patients, which will be reviewed in a table format as provided below (Table 1). Conclusion: AngioVac is a useful tool for acute thrombus removal in the large vessels. More studies needed to establish the utility of AngioVac in treatment of intravascular and intracardiac material.

Abstract No. 525 - Initial experience with the AngioVac aspiration system

To present our experience with the AngioVac aspiration system, a new device designed for removal of intravascular material, such as thrombi and vegetations To review the available literature on AngioVac aspiration system The AngioVac system (AngioDynamics, Latham, NY) is a novel mechanical suction device that is designed for the removal of unwanted intravascular material while maintaining flow during extracorporeal circulation. It has been described for use in the retrieval of right atrial thrombus/mass, management of acute massive pulmonary embolism, treatment of symptomatic iliocaval thrombosis, protection against thrombus migration during catheter removal in right to left cardiac shunts, and removal of cardiovascular implantable device lead vegetations. The current case series describes the use of AngioVac in 6 consecutive patients. There were 3 female and 3 males (mean age, 49.6 y). In 5/6 cases, the AngioVac cannula was inserted percutaneously and the patient was placed on veno-venous bypass. In one of the cases, the cannula was inserted directly into the Fontan circuit after sternotomy and the patient was maintained on cardiopulmonary bypass. Thrombus location included iliocaval (2), pulmonary arteries (PA) (1), Fontan circuit and Glenn shunt with pulmonary artery extension (1), right atrium (RA) (1), and IVC with renal vein extension (1). Near complete evacuation of thrombus was documented in 3/6 cases by angiogram, cross sectional imaging or intravascular ultrasound. Partial thrombus removal was confirmed in 3/6 patients. Reasons for subtotal thrombus removal included chronic thrombus (2) and inadequate suction cannula flow rates in the pulmonary arteries (1). 2/6 patients had access site hematomas which resolved without any interventions. PubMed search yielded 12 studies reporting experience with a total of 29 patients, which will be reviewed in a table format as provided below (Table 1). AngioVac is a useful tool for acute thrombus removal in the large vessels. More studies needed to establish the utility of AngioVac in treatment of intravascular and intracardiac material.

Leriche syndrome masquerading as chronic kidney disease

Renal artery stenosis is causative in 2 - 5% patients with hypertension and accounts for 3 - 15% cases of chronic kidney disease (CKD). The affected renal artery is usually occluded by an atheromatous plaque in the elderly or by Takayasu arteritis in younger women. In comparison, occlusion caused by a chronic thrombus is uncommon. Leriche syndrome refers to the chronic thrombotic occlusion of the terminal abdominal aorta and the surrounding branches. This syndrome normally affects infrarenal arteries and chances of involving renal arteries are rare. We report a case of Leriche syndrome manifesting as chronic kidney disease, while its characteristic symptom-claudication is absent.

Platelets are highly activated in patients of chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a fatal disease that is distinct from pulmonary arterial hypertension (PAH). Although CTEPH is characterized by obstruction of major pulmonary artery because of chronic thrombus, it remains unclear whether CTEPH is associated with prothrombotic condition. In addition to conventional markers, GTP-bound levels of Rap1, RhoA, RalA, Rac1, and Ras in platelets, which are implicated for platelet activation, were measured in patients without pulmonary hypertension (non-PH, n=15), patients with PAH (n=19), and patients with CTEPH (n=25). Furthermore, the responsiveness to ex vivo thrombin stimulation was also evaluated. The ratios of the P-selectin positive platelets in the non-PH patients, patients with PAH, and patients with CTEPH were 1.40% (median and interquartile range, 0.83-1.82), 2.40% (1.80-3.39), and 2.63% (1.90-8.22), respectively (non-PH versus CTEPH, P<0.01). The activated GPIIb/IIIa-positive platelets were 6.01% (1.34-7.87), 11.39% (5.69-20.86), and 9.74% (7.83-24.01), respectively (non-PH versus CTEPH, P=0.01). GTP-bound RhoA was 1.79% (0.94-2.83), 4.03% (2.01-5.14), and 2.01% (1.22-2.48), respectively (non-PH versus PAH, P=0.04), and GTP-bound RalA was 1.58% (1.08-2.11), 3.02% (2.03-3.54), and 2.64% (1.42-4.28), respectively (non-PH versus PAH, P=0.023; non-PH versus CTEPH, P=0.048). In contrast, Rac1, Rap1, or Ras was not activated in any groups. The platelets of patients with CTEPH exhibited hyperresponsiveness to ex vivo thrombin stimulation compared with those of non-PH patients when evaluated for the surface markers. Either D-dimer or fibrin degradation product level was not increased in patients with CTEPH. These results provide the first direct evidence that platelets of patients with CTEPH are highly activated and exhibit hyperresponsiveness to thrombin stimulation.

Volume of new-onset thrombus is associated with the development of postimplantation syndrome after endovascular aneurysm repair

The objective of this study was to evaluate the impact of contrast medium volume, inferior mesenteric artery (IMA) patency, and pre-existing as well as new-onset thrombus on the inflammatory response after elective endovascular aneurysm repair (EVAR). The study included 87 patients undergoing elective endovascular repair of asymptomatic infrarenal aneurysms between January 2011 and November 2011. The patency of the IMA was determined by preoperative computed tomography angiography; the volume of the contrast medium used during the procedure was measured, and the volumes of chronic mural as well as new-onset thrombus were calculated from the preoperative and postoperative computed tomography angiograms with dedicated imaging software. The results were correlated to the occurrence of postimplantation syndrome (PIS) as well as to the main clinical and laboratory components of PIS: fever; increased white blood cell (WBC) count and C-reactive protein (CRP) level; decreased platelet count; and increased interleukin (IL)-6, IL-8, and IL-10 levels. Postoperatively, a statistically significant increase was recorded in the mean values of body temperature, WBCs, CRP, IL-6, IL-8, and IL-10, and a statistically significant decrease was recorded in the number of platelets. After adjustment for endograft type, the volume of new-onset thrombus was found to be significantly correlated with the peak postoperative temperature (β= .307; P< .05) and the increase in WBC count (β= .271; P< .05), CRP level (β= .484; P<.001), and IL-6 level (β= .288; P< .05). On the contrary, the volume of chronic mural thrombus, the patency of the IMA, and the volume of contrast medium were not found to significantly affect any parameter of the PIS. PIS occurred in 34 patients (39%). Multiple logistic regression analysis showed that both the volume of new-onset thrombus and the type of endograft were independently associated with the development of PIS. The volume of new-onset thrombus is associated with the development of PIS after EVAR, whereas chronic mural thrombus appears to be an inert material. IMA patency and contrast medium volume are irrelevant to the inflammatory response after EVAR.

Chronic thromboembolic pulmonary hypertension: time for research in pathophysiology to catch up with developments in treatment.

The modern treatment era in chronic thromboembolic disease has seen significant advances in both surgical and medical treatment. One such treatment, the pulmonary endarterectomy (where established chronic organized thrombus is removed), has dramatically affected morbidity and mortality. These advances have outstripped basic research into the causes and pathophysiology of disease, which remain largely poorly understood. In this review, we will set out to explain some of the historical reasons for this, including the difficulties inherent in human studies and the lack of good animal models. We will review some of the recent advances in pathophysiology from registries and translational research, and we will summarize the treatment options, with some discussion of very recently published work, including medical and surgical treatments, both traditional and more experimental work in non-invasive techniques.

Comment to: Acute and chronic consequences of polidocanol foam injection in the lung in experimental animals by Grandi L, Grandi RA, Tomasi CD, da Rocha JL, Cardoso V, Dal-Pizzol F. Phlebology 2013;28:441-4.

To assess the occurrence of pulmonary embolism and long-term inflammatory activation after polidocanol foam injection, domestic rabbits, of both sexes, weighing around 2 kg were used: a control group (injection of saline solution, n = 4) and an experimental group (injection of polidocanol foam 1 and 3 mg/kg, n = 4 each dose), administered in the lateral superficial auricular vein as a slow bolus over 1 min. Foam (1 mL polidocanol 3%+ 4 mL air) 0.3 mL and 1.0 mL was injected respectively for the 1 mg/kg and the 3 mg/kg group. Technetium (Tc99m) lung scintigraphy was realized 15 min after injection, then the rabbits were killed and the lungs were removed for histopathological evaluation. A separated group of animals was reserved for histopathological evaluation 30 days after injection. The pulmonary perfusion showed an important reduction of pulmonary perfusion in all injected cases; while in the control group no alterations were found. The pathological exam at earlier times shows the presence of platelet-fibrin clots mainly in the small pulmonary veins, independent of the dose administered and occasional presence of droplets corresponding to fat embolism, and an acute inflammatory response. In later times it was observed chronic thrombus in small veins with mixed chronic inflammatory response, sparse or more limited. This work shows that the injection of polidocanol foam in experimental animals leads to acute and chronic alterations in pulmonary perfusion and lung inflammation. If few amounts of polidocanol foam can be deposited into the lung (in low quantity, not causing significant pulmonary embolism) it can induce inflammation in the pulmonary parenchyma. The use of rabbits does not allow using maneuvers that can reduce the incidence of embolism (leg elevation, immobility). In addition, the veins used to in the rabbits cannot reflect the veins used in humans, with a shorter time than the time needed to inactivate polidocanol.

Aging techniques for deep vein thrombosis: a systematic review

Deep vein thrombosis is common with an incidence of 1 in 1000. Acute thrombus removal for extensive proximal deep vein thrombosis using catheter-directed techniques highlights the need for accurate assessment of thrombus age. This systematic review summarises experimental and clinical evidence of imaging techniques for aging deep vein thrombosis. Ultrasound elastography and magnetic resonance imaging were highlighted as the most studied imaging modalities. Elastography was shown to distinguish between acute and chronic clots, despite demonstrating difficulty in accurate aging of clots older than 10 days in rat models. Elastography is noted as a feasible adjunct to current first-line imaging for deep vein thrombosis using duplex ultrasonography. Combinations of magnetic resonance imaging techniques can identify acute, sub-acute and chronic thrombi using endogenous contrast agents and provide objective standardisation of the diagnostic process, with reduced onus upon operator dependency. Further validation is required of these novel imaging techniques prior to clinical implementation for deep vein thrombosis aging.

The current management of isolated degenerative femoral artery aneurysms is too aggressive for their natural history

Previous studies have combined anastomotic, catheter-induced, and atherosclerotic isolated femoral artery aneurysms (FAAs) to achieve adequate numbers for analysis and have recommended repair of asymptomatic FAAs with diameters ≥2.5 cm and all symptomatic FAAs. This study evaluated the contemporary management of isolated FAAs. Patients with FAAs were evaluated using a standardized, prospectively maintained database by a research consortium. From 2002 to 2012, 236 FAAs were identified in 182 patients (mean age, 72 years; male-to-female ratio, 16:1) at eight institutions. The mean nonoperative mean diameter was 2.8 ± 0.7 cm, and the operative diameter was 3.3 ± 1.5 cm. FAA location was the common femoral artery in 191, superficial femoral artery (SFA) in 34, and profunda femoris artery in 11. Synchronous aneurysms (mean, 1.7 per patient) occurred in the aorta (n = 113), in the iliac (n = 109), popliteal (n = 86), and hypogastric (n = 56) arteries, and in the contralateral common femoral artery (n = 34), SFA (n = 9), and profunda femoris artery (n = 2). Of the aneurysms repaired, 66% were asymptomatic; other indications for repair were claudication (18%), local pain (8%), nerve compression (3%), rupture (2%), acute thrombosis (1%), and rest pain (0.5%). Acute aneurysm-related complications (rupture, thrombosis, embolus) were associated (P < .05) with FAA diameter >4 cm and intraluminal thrombus, but not location. Mean diameter of asymptomatic aneurysms that developed acute complications was 5.7 ± 1.3 cm for rupture, 4 ± 1.1 cm for thrombosis, and 3.5 cm for embolus. Repair was by interposition or bypass graft in 177 FAAs and by endovascular repair in three SFA aneurysms. Two perioperative deaths, of myocardial infarction and multisystem organ failure, occurred at 30 days. Operative complications included wound infection (6%), seroma (3%), and bleeding (2%). No amputations occurred through 5 years in the operative or nonoperative groups. Survival in operated-on patients was 99% (n = 138) at 3 months, 92% at 1 year, and 81% (n = 20) at 5 years. This largest study of isolated FAAs demonstrates that (1) acute complications did not occur in FAAs ≤3.5 cm, repair criteria of asymptomatic FAAs should be changed to >3.5 cm, and chronic intraluminal thrombus should reduce the threshold for repair, and that (2) current indications for symptomatic FAA repair result in low morbidity and should remain unchanged.

McCleery Syndrome

Patients presenting with swelling of the upper extremity without thrombosis have McCleery syndrome or intermittent compression of the subclavian vein. The purpose of this study was to determine outcomes in these patients who underwent first rib resection and scalenectomy (FRRS). Using a prospectively maintained database from 2003 to 2011, patients were retrospectively reviewed for presentation, diagnosis, treatment, and clinical outcomes. Of the patients presenting with venous thoracic outlet syndrome, 19 (11%; 13 F/6 M; mean age 26 [10-44]) presented with intermittent arm swelling, of which 3 were identified as having chronic thrombus. A total of 20 FRRS operations were performed. First rib resection and scalenectomy is effective in relieving symptoms in patients with McCleery syndrome. These patients do not generally need a postoperative venogram unless they experience continuing symptoms. In patients with chronic thrombus, routine postoperative venography at 2 weeks is indicated. Patients can present with intermittent compression if an acute episode of deep vein thrombosis is not aggressively treated.

A Successful Free Fibula Transfer in the Patient With Chronic Peroneal Vein Thrombosis

Despite the rare incidence, occult chronic thrombosis of peroneal veins of the fibula graft during the flap harvest presents a challenge to produce a successful reconstruction. In this article, we present a case of a 54-year-old man with chronic thrombosis of peroneal veins found during the harvest of the free fibula osteocutaneous flap for reconstruction of the mandible defect after tumor ablation. With near-total obliteration of the lumens, a small lumen with residual blood outflow was identified under microscopic magnification. A successful flap transfer was made possible by using the recanalized lumen around the chronic thrombus of the vein for microanastomosis. The pathological analysis of the vein revealed that the recanalized lumens and the endothelial cells-specific CD31 immunohistochemical stain highlighted the endothelium of regenerative lumen around the chronic thrombus. The abundant deposition of thick collagen fibers also suggested a chronic nature of the thrombus. However, although a successful microsurgical free osteocutaneous flap transfer might be possible in the patient with lower-limb chronic peroneal vein thrombosis, a careful preoperative evaluation with imaging study is recommended for high-risk patients.

A popliteal artery entrapment syndrome after by-pass surgery.

A 36-year-old male was admitted to our radiology department with a presentation of claudication on the left side for two weeks after femoral artery to tibial artery by-pass surgery. Upon physical examination, the left leg appeared pale and cold. Left magnetic resonance angiography (MRA) with gadolinium was performed from the superficial femoral arteries through the proximal portion of the popliteal fossa. The images included the bilateral popliteal arteries during dorsiflexion, plantar extension and neutral positions. There appeared to be a left venous graft that was patent. It arose from the proximal popliteal artery and traveled to the anterior tibial artery. The graft was patent at the visualized aspect. There appeared to be a mild to moderate degree of stenosis of the popliteal artery in the neutral position. There was severe stenosis of the same segment of the popliteal artery during knee extension. The popliteal artery was compressed by the slip of the medial head of the gastrocnemius, which arose more laterally than normal (Figure 1 A–C). Figure 1. 3D gadolinium-enhanced MRA images reveal the mild degree of stenosis of the popliteal artery in the neutral and dorsiflexion positions (A, B); there is severe stenosis of the same segment of the popliteal artery in the extension position (C). These images ... Popliteal artery entrapment syndrome (PAES) is a rare congenital vascular pathology caused by a compression of the popliteal artery by adjacent muscle and tendon structures. This condition is most commonly observed in young men with ischemic symptoms of the lower extremities. Extrinsic arterial compression causes chronic vascular micro trauma, early arteriosclerosis and thrombus formation, leading to distal ischemia [1, 2]. The classic presentation, which includes calf or foot claudication or pain on exertion, can have many other etiologies, including atherosclerosis, exertional compartment syndrome, and other musculoskeletal or neurogenic disorders. The most commonly used classification of PAES was described by Love and Whalen [3]. Our case had type III PAES. The incidence of popliteal entrapment has been described to be between 0.165% and 3.5% [2, 4]. Noninvasive tests, such as duplex ultrasound and axial imaging, including multi detector computed tomography angiography (MDCTA) or MRA, can help identify the anatomical abnormalities [1, 4]. In conclusion, MRA MDCTA is a safe, rapid, and noninvasive diagnostic imaging technique that enables clinicians to determine the underlying pathology and the complications of PAES.

Acute and chronic consequences of polidocanol foam injection in the lung in experimental animals

To assess the presence of pulmonary embolism and inflammation after polidocanol foam injection into the peripheral veins of rabbits. The animals were treated with polidocanol foam (1 or 3 mg/kg) or vehicle. Early (15 minutes) and late (30 days) animals were evaluated by perfusional lung scintigraphy and histopathological examination. In the control group no alterations were found. After polidocanol foam injection it was observed that an important reduction of pulmonary perfusion in the early periods, was mainly in the left lung (P < 0.001), with consequent embolism in the histological evaluation. In late periods it was observed that the presence of thrombus was with fibrin in small veins, compatible with chronic thrombus and the presence of chronic pulmonary inflammation. The injection of polidocanol foam in experimental animals can induce venous embolism and chronic inflammatory infiltration.

A Behcet’s Disease Patient with Right Ventricular Thrombus, Pulmonary Artery Aneurysms, and Deep Vein Thrombosis Complicating Recurrent Pulmonary Thromboembolism

Intracardiac thrombus, pulmonary artery aneurysms, deep vein thrombosis, and pulmonary thromboembolism are rarely seen symptoms of Behcet's disease. A 20-year-old female patient was admitted for complaints of cough, fever, palpitations, and chest pain. On the dynamic thorax computed tomograms (CT) obtained because of significantly enlarged hilar structures seen on chest radiograms, aneurysmal dilatation of the pulmonary artery segments bilaterally, chronic thrombus with collapse, and consolidation substances compatible with pulmonary embolism involving both lower lobes have been observed. It is learned that, four years ago, the patient had been diagnosed with Behcet's disease and received colchicine treatment but not regularly. The patient was hospitalized. On the transthoracic echocardiogram, a thrombosis with a dimension of 4.2 × 1.6 cm was recognized in the right ventricle. On abdomen CT, aneurysmal iliac veins and deep vein thrombus on Doppler ultrasonograms were diagnosed. At the controls after three months of immunosuppressive and anticoagulant therapies, some clinical and radiological improvements were recognized. The patient suspended the treatment for a month and the thrombus recurred. We present our case in order to show the effectiveness of immunosuppressive and anticoagulant therapies and rarely seen pulmonary thromboembolism in recurrent Behcet's disease.

Midterm results of percutaneous endovascular treatment for acute and chronic deep venous thrombosis.

Treatment of deep venous thrombosis (DVT) with therapeutic anticoagulation has been increasingly challenged by aggressive percutaneous treatment using ultrasound-accelerated catheter-directed thrombolysis (US-CDT) or percutaneous pharmacomechanical thrombectomy (PMT). These techniques have been promoted to improve thrombus removal, prolong venous patency, prevent venous insufficiency, and reduce postthrombotic syndrome. This study reviews midterm results using these endovascular techniques for both acute and chronic DVT. A retrospective chart review was performed on patients treated for acute or chronic DVT with US-CDT and/or PMT. Charts were reviewed for patient demographics, medical history and treatment, operative details, and postoperative outcomes. Intraoperative venography and intravascular ultrasound quantified clot response to therapy. Duplex ultrasound defined the pre- and postoperative extent of venous thrombosis, venous patency, and valvular function. Between October 1, 2002 and September 30, 2010, 80 patients were treated for iliofemoral (n= 48), iliofemoropopliteal (n= 15), or femoropopliteal (n= 17) venous thrombosis. Mean age was 45.8 years (range, 15-78 years), and 24 patients (30%) had a documented history of hypercoagulable state. Intravascular ultrasound confirmed May-Thurner syndrome in 34 patients (42.5%). Fifty-two patients (65%) were treated for acute DVT; the mean time to intervention from symptom onset was 8.7 ± 4.5 days (range, 1-14 days). The remaining 28 patients (35%) had chronic symptoms and were treated at a mean of 8.6 ± 10.9 months (range, 1.5-36 months) after DVT diagnosis was made. Patients were treated with PMT (n= 43, 53.8%), US-CDT (n= 14, 17.5%), or both (n= 32, 28.7%). Clot lysis (>90%) was achieved in 72 of 80 patients (90%). Tenecteplase was used for all cases, and the mean dose was 8.6 ± 4.3 mg. Adjunctive procedures, including angioplasty with or without stent placement, were required in 90% (n= 47) of acute patients and in 96% (n= 27) of chronic patients (P= .33). Three patients (3.8%) had postoperative bleeding events requiring blood transfusion; there were no occurrences of intracranial hemorrhage or clinically significant pulmonary embolism. At a mean follow-up of 3.8 years (range, 1-8.9 years), venous patency was present in 49 of 52 acute patients (94%) and in 23 of 28 chronic patients (82%) (P= .12). Valve function was preserved in 41 of 52 (79%) acute patients vs 11 of 28 (39%) chronic patients (P < .001). US-CDT and PMT can effectively remove acute and chronic thrombus in the lower extremity deep venous system. Vein patency and valvular function is better preserved at midterm follow-up after treatment for acute DVT, howeverintervention should be considered in patients with chronic DVT as well.

A case of chronic left ventricular thrombus with ischemic cardiomyopathy

Left ventricular (LV) thrombus is a serious complication of anterior wall myocardial infarction (MI), especially in patients with severe LV dysfunction. LV thrombus carries a high risk of causing stroke and other thromboembolic complications despite adequate anticoagulation therapy. There is a benefit of anticoagulation in patients with ischemic cardiomyopathy to reduce thromboembolic events or in resolution of LV thrombus. Two-dimensional (2D) echocardiography is the most commonly used technique for the diagnosis and follow-up of such cases. Our patient developed a chronic LV thrombus with ischemic cardiomyopathy post anterior wall MI and was managed well on anticoagulants to prevent the thromboembolic events under strict vigilance and follow-up.

Characterization of Chronic Postthrombotic Intraluminal Venous Obstruction.

Acute deep venous thrombosis (DVT) managed with anticoagulation undergoes an evolution resulting in a spectrum of changes, ranging from complete recanalization to luminal obstruction. Long-term follow-up imaging of residual intraluminal pathology often reports that “chronic thrombus” remains. The concept that thrombus is present has therapeutic implications. The purpose of this investigation is to accurately characterize the intraluminal pathology existing in the lower extremity deep veins long after acute DVT.

Potential pitfalls in imaging of paediatric cerebral sinovenous thrombosis

Paediatric cerebral sinovenous thrombosis (CSVT) is a rare but serious condition. The imaging signs may be subtle with a number of potential pitfalls. We present a pictorial essay of the pitfalls of diagnosis of CSVT on CT and MRI. We describe, using examples, potential pitfalls on both imaging modalities including anatomical variants of the cerebral venous system, extra-axial fluid collections and enhancement of chronic thrombus. Pitfalls particular to CT are discussed including beam-hardening artefact, image windowing and neonatal physiological intravascular hyperdensity. We review the potential variability in the appearance of thrombus on MRI, dependent largely on the stage of thrombus evolution and the pulse sequence. The signal intensity of thrombi, although described as evolving in a typical pattern on T1- and T2-weighted MRI, may be affected by variability in the degree of oxygenation of red cells in the forming thrombus, dilution and secondary propagation of thrombosis. Individual MRI sequences should not be interpreted in isolation, but as a set, and compared with CT images if available.