Thrombus Embolization Research Articles

Sub-Massive Pulmonary Embolism with Large Intra-Cardiac Bi-Atrial Thrombi Successfully Treated with Systemic Thrombolytic Therapy

Herein we report a case of 46-year-old male patient who was presented with chest pain and dyspnea and was diagnosed with sub-massive pulmonary embolism (PE) and intra-cardiac bi-atrial thrombus, echocardiography showed decreased right ventricular systolic function. Following treatment with 100 mg tissue plasminogen activator (tPA), the patient reported clinical improvement, in addition to improved ventricular function as assessed by echocardiography. In the present report, we describe a case of sub-massive PE with intra-cardiac bi-atrial thrombus successfully managed with thrombolytic treatment without occurrence of adverse events.

Thrombus Aspiration in STEMI.

ST-segment elevation myocardial infarction (STEMI) remains an important cause of morbidity and mortality. In the USA, the development of an organized STEMI network has allowed STEMI patients greater access to primary PCI. The most important goal in the management of STEMI is timely reperfusion and establishment of normal coronary flow. However, periprocedural thrombus embolization, which can obstruct the distal microvasculature and impair tissue perfusion, is associated with unfavorable outcomes. Over the last years, aspiration thrombectomy has emerged as a novel technique to prevent distal coronary thromboembolism during primary PCI. The initial excitement after the publication of the TAPAS trial changed the practice paradigm among interventional community worldwide. Aspiration thrombectomy was recommended by several society guidelines and became the "standard of care" during primary PCI. However, recent data and publication of two large randomized controlled trials questioned the effectiveness (TASTE trial) and the safety (TOTAL trial) of this technique. Therefore, the recent ACC/AHA/SCAI-focused update document recommended against the routine use of manual thrombectomy during primary PCI. This review will summarize recent data and trials regarding thrombus aspiration in STEMI.

Understanding Venous Thromboembolism in Patients with Cancer

Venous thromboembolism (VTE) is 1 of the most common complications from cancer and its treatments. It can manifest as a deep vein thrombus or pulmonary embolism in all stages of cancer. Therefore, the purpose of this article is to discuss the ways in which cancer predisposes patients to VTE and the diagnostic and management options available. The article further discusses the importance of anticoagulation as a mainstay of therapy for the prevention and management of VTE and the implications for practice.

Losartan and captopril treatment rescue normal thrombus formation in microfibril associated glycoprotein-1 (MAGP1) deficient mice

IntroductionMAGP1 is a glycoprotein present in the elastic fibers and is a part of the microfibrils components. MAGP1 interacts with von Willebrand factor and the active form of TGF-β and BMP. In mice lacking MAGP1, thrombus formation is delayed, increasing the occlusion time of carotid artery despite presenting normal blood coagulation in vitro. MAGP1-containing microfibrils may play a role in hemostasis and thrombosis. In this work, we evaluated the function of MAGP1 and its relation to TGF-β in the arterial thrombosis process. Methods and resultsWe analyzed thrombus formation time in wild type and MAGP1-deficient mice comparing Rose Bengal and Ferric Chloride induced arterial lesion. The potential participation of TGF-β in this process was accessed when we treated both wild type and MAGP1-deficient mice with losartan (an antihypertensive drug that decreases TGF-β activity) or captopril (an angiotensin converting enzyme inhibitor that was used as a control antihypertensive drug). Besides, we evaluated thrombus embolization and the gelatinolytic activity in the arterial walls in vitro and ex vivo. Losartan and captopril were able to recover the thrombus formation time without changing blood pressure, activated partial thromboplastin time (aPTT), PT (prothrombin time), platelet aggregation and adhesion, but decreased gelatinase activity. ConclusionsOur results suggest that both treatments are effective in the prevention of the sub-endothelial ECM degradation, allowing the recovery of normal thrombus formation.

Impact of kidney ischemic lesions on renal function after fenestrated endovascular repair

Fenestrated endovascular aortic repair (fEVAR) is being used increasingly in the treatment of complex aortic aneurysms; however, this procedure can be associated with visceral and renal complications. Because the causes of possible renal function (RF) impairment have not been fully examined yet, we conducted a study to investigate whether there are risk factors associate with renal ischemic lesions (RILs) and if they influence RF in patients treated for complex aortic aneurysm with fEVAR. We evaluated the clinical, anatomic, and technical characteristics of consecutive patients treated with fEVAR from 2008 to 2014. RIL were identified by postoperative computed tomography angiography and the volume of renal parenchyma involved quantified. A decrease in RF (>30% glomerular filtration rate reduction) was evaluated at discharge, and at the 6- and 12-month follow-ups. Among 53 patients, we analyzed 38 (72%) juxta/pararenal and 15 (28%) thoracoabdominal aortic aneurysms (33 [64%] with ≥3 fenestrations) and 102 renal arteries. Fifteen patients (30%) showed RIL, which was caused by accessory renal artery (ARA) coverage in 6 cases (38%), distal embolism in 6 (38%), renal artery thrombosis in 2 (18%), and iatrogenic embolization for intraoperative bleeding during fEVAR in 1 (6%). The volume of renal parenchyma involved was less than 25% in 10 (67%) and 25% to 50% in 5 (33%) cases. In no cases was more than 50% renal volume affected. On multivariate analysis, RIL predictors were the presence of ARA (odds ratio [OR], 8.00; 95% confidence interval [CI], 1.16-54.89; P = .03) and extensive thrombosis of the pararenal aorta (OR, 39.93; 95% CI, 3.36-474.23; P = .003). At discharge, chronic renal failure (CRF; OR, 4.80; 95% CI, 1.27-18.09; P = .01), diabetes (OR, 8.44; 95% CI, 1.33-53.51; P = .01), and extensive thrombosis of the pararenal aorta (OR, 5.50; 95% CI, 1.32-29.92; P = .01) were significantly associated with worsening RF. RIL, independent from volume, did not influence the postoperative RF. At 6 months and 1-year, preoperative CRF and perioperative declines in RF were identified as the only risk factors for worsening RF. RIL is a common fEVAR complication and is primarily owing to ARA coverage and aortic thrombus embolization. However, RIL does not influence RF, which is predicted by preoperative CRF, diabetes, and extensive aortic thrombus.

Surgical treatment for patients with renal cell carcinoma and venous thrombosis

Objective To investigate the efficacy and safety of radical nephrectomy associated with venous thrombectomy and the role of preoperative angioembolization. Methods From Sep 2006 to Dec 2014, the data from 15 cases with renal cell carcinoma and venous tumor thrombus were collected and analyzed retrospectively.The 15 patients included 8 men and 7 women, whose age ranged from 16 to 75 years.Before operation, all patients underwent imaging examinations which demonstrated the renal tumor and venous thrombus.The tumors size ranged from 5.4 to 14.5 cm.The levels of venous thrombus included 0 grade in 4 cases, Ⅰgrade in 2 cases, Ⅱgrade in 6 cases and Ⅲ grade in 3 cases.The 15 patients were divided into angioembolization group (n=5) and non–angioembolization group (n=10) according to the conduction of preoperative angioembolization. Results All cases successful accepted the nephrectomy.The venous thrombectomy were undergone in 14 cases except for one case due to the severe adhesion between renal vein and aorta.The average operative time was 243.3±77.0 min.The mean blood loss was 1 373.3±1 440.9 ml and the volume of blood transfusion was 533.3±521.9 ml.The average time of postoperative hospital stay was 12.7±5.2 days.Symptomatic tumor thrombus embolism didn't occur in all cases, perioperatively.There were no significant difference between these two groups in operative time, blood loss, blood transfusion volume and postoperative hospital stay (P>0.05). Eight cases were followed up with a period of 6 to 69 months.Four cases had disease–free survival during follow up.Two cases died at 30 and 55 months after surgery, respectively.One had tumor recurrence at 6 months after surgery.One patient accepted a 6–months target therapy (sunitinib) before surgery.However, his thrombus could not be removed during the operation.After the operation, he continued to choose the target drug therapy for 18 months.No progression for thrombosis or metastasis has been found. Conclusions Nephrectomy and venous thrombectomy could be safe and effective for renal cell carcinoma associated with venous thrombosis.Preoperative angioembolization could not reduce the perioperative risk such as blood loss. Key words: Carcinoma, renal cell; Nephrectomy; Thrombectomy; Angioembolization

Thrombolytic therapy with rt-PA and transcranial color Doppler ultrasound (TCCS) combined with microbubbles for embolic thrombus

ObjectiveTo investigate the efficacy of transcranial color Doppler ultrasound (TCCS) combined with microbubbles (MBs) and rt-PA (recombinant tissue plasminogen activator) for thrombolysis in vivo. MethodsAn arterial embolization model was established in Sprague-Dawley rats by retrograde placement of autologous thrombi into the common carotid artery followed by ligation of external carotid artery and temporary occlusion of the carotid artery and internal carotid artery by clamping. The animals were divided into 5 groups with 6 rats in each group: ① untreated control group, ② rt-PA group, ③ TCCS+MBs group, ④ TCCS+MBs+rt-PA group, ⑤ TCCS+MBs+1/2 rt-PA+group. Thrombolytic effects including recanalization rate and recanalization grade were evaluated with grayscale and color Doppler ultrasound post treatment. Examination of histological change in the involved vessel was performed at the end of the experiments. ResultsThrombolysis in terms of recanalization rate and recanalization grade was observed in the treated groups in a time-dependent manner, except the TCCS+MBs group. Addition of rt-PA remarkably enhanced the therapeutic lysis in TCCS+MBs group. However, no difference of therapeutic effects existed between TCCS+MBs+rt-PA group and TCCS+MBs+1/2 rt-PA group. ConclusionTCCS+MBs combined with rt-PA is a relatively effective approach for ischemic arterial thrombosis with an additive or synergistic effect.

Strategies for thromboprophylaxis in Fontan circulation: a meta-analysis

BackgroundThe Fontan circulation is associated with an increased risk of thromboembolic events (TEs). As many as 25% of these thrombotic events result in fatality. More subtle adverse effects on the...

Percutaneous Management of a Coronary Bifurcation Aneurysm with Mesh-Covered Stents and the Simultaneous Kissing Stent Technique

A 63-year-old man was admitted with a clinical diagnosis of acute coronary syndrome (non-ST-segment elevation), characterized by regional hypokinesia of the left ventricular posterior and lateral walls and by positive cardiac biomarkers. The coronary angiogram showed a 12.5-mm-diameter aneurysm with a mural thrombus and possible distal embolism to the bifurcation of the left circumflex coronary artery and the 2nd marginal branch. The aneurysm was managed percutaneously by implanting 2 mesh-covered stents in accordance with the "simultaneous kissing stent" technique. Follow-up angiography and optical coherence tomography at 5 postprocedural months documented complete sealing of the aneurysm and diffuse in-stent restenosis. No sign of ischemia occurred during the subsequent follow-up.

Corrective spinal surgery may be protective against stroke in patients with blunt traumatic vertebral artery occlusion.

OBJECT Approximately 10% of patients with blunt traumatic extracranial cerebrovascular injury have a complete occlusion of the vertebral artery (VA). Ischemic stroke due to embolization of thrombus from an occluded VA following cervical spine surgery has been observed. The risk of ischemic stroke with cervical spine surgery in the presence of an occluded VA, however, has never been determined. METHODS A retrospective chart review of 52 patients with a VA occlusion following a blunt trauma was performed. Clinical and radiographic characteristics were collected and analyzed. RESULTS Ten patients (19.2%) suffered an ischemic stroke attributable to a traumatic VA occlusion. Univariate analysis demonstrated that patients with ischemic stroke were significantly older (p = 0.042) and had a lower rate of cervical spine surgery (p < 0.005). Multivariate analysis found cervical spine surgery to be protective against ischemic stroke (OR 0.049 [95% CI 0.014-0.167], p = 0.014); increasing age and bilateral VA injury (bilateral occlusion or unilateral occlusion with contralateral dissection) were risk factors for ischemic stroke (OR 1.05 [95% CI1.02-1.07], p = 0.065 and OR 13.2 [95% CI 2.98-58.9], p = 0.084, respectively). CONCLUSIONS Traumatic VA occlusion is associated with a risk of ischemic stroke and mortality. Corrective cervical spine surgery potentially decreases the risk of ischemic stroke by stabilizing the spine and thereby reducing motion across the occluded segment of the VA and preventing embolization of thrombus. While a high stoke risk may be inherent to the disease, novel therapies should be investigated.

Alternative Stents in ST-segment Elevation Myocardial Infarction: Improving the Efficacy of Primary Percutaneous Coronary Intervention

Despite the efficacy of primary percutaneous coronary intervention in achieving epicardial reperfusion in ST-segment elevation myocardial infarction, it is often limited by impaired microvascular perfusion attributable to distal embolization of plaque and thrombus, and stent malappostion due to vessel constriction and thrombus apposition, attenuating the full benefits of myocardial reperfusion and resulting in unfavorable clinical outcomes. In the long run implantation of permanent metallic implants have negative effect the biological behavior of the target vessel with a continuous low device failure over the years. Recently, however, efforts have been realized to tackle these shortcomings and optimize mechanical reperfusion by improvements to stent design, as substantiated by the self-expanding stent, the mesh-covered stent and the bioresorbable vascular scaffold. In this article, we provide an overview of the role of these novel, innovatively designed, alternative devices in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction.

Robotic Level III Inferior Vena Cava Tumor Thrombectomy: Initial Series

Level III inferior vena cava tumor thrombectomy for renal cancer is one of the most challenging open urologic oncology surgeries. We present the initial series of completely intracorporeal robotic level III inferior vena cava tumor thrombectomy. Nine patients underwent robotic level III inferior vena cava thrombectomy and 7 patients underwent level II thrombectomy. The entire operation (high intrahepatic inferior vena cava control, caval exclusion, tumor thrombectomy, inferior vena cava repair, radical nephrectomy, retroperitoneal lymphadenectomy) was performed exclusively robotically. To minimize the chances of intraoperative inferior vena cava thrombus embolization, an "inferior vena cava-first, kidney-last" robotic technique was developed. Data were accrued prospectively. All 16 robotic procedures were successful, without open conversion or mortality. For level III cases (9), median primary kidney (right 6, left 3) cancer size was 8.5 cm (range 5.3 to 10.8) and inferior vena cava thrombus length was 5.7 cm (range 4 to 7). Median operative time was 4.9 hours (range 4.5 to 6.3), estimated blood loss was 375 cc (range 200 to 7,000) and hospital stay was 4.5 days. All surgical margins were negative. There were no intraoperative complications and 1 postoperative complication (Clavien 3b). At a median 7 months of followup (range 1 to 18) all patients are alive. Compared to level II thrombi the level III cohort trended toward greater inferior vena cava thrombus length (3.3 vs 5.7 cm), operative time (4.5 vs 4.9 hours) and blood loss (290 vs 375 cc). With appropriate patient selection, surgical planning and robotic experience, completely intracorporeal robotic level III inferior vena cava thrombectomy is feasible and can be performed efficiently. Larger experience, longer followup and comparison with open surgery are needed to confirm these initial outcomes.

Lack of Benefit of Ischemic Postconditioning After Routine Thrombus Aspiration During Reperfusion: Immediate and Midterm Results.

The underutilization of manual thrombus aspiration (MTA) may have reduced the benefits of ischemic postconditioning (PostCon), as it reduces thrombus embolization. We aimed to assess the benefits of PostCon in patients with ST-segment elevation myocardial infarction (STEMI) after the systematic utilization of MTA. A total of 87 patients were enrolled in a prospective, randomized trial (43 PostCon and 44 controls). After MTA, PostCon was performed on the treatment group by applying 4 cycles of alternate reperfusion and reocclusion (60 seconds each) using the angioplasty balloon. The primary end point was infarct size assessed by the area under the curve (AUC) of troponin T (TnT) activity. The secondary end points were left ventricle ejection fraction (LVEF) and major cardiac events (new myocardial infarction or cardiac death) both at discharge and at follow-up. The AUC for TnT was no different with respect to study arms (median [interquartile range]): PostCon = 8.9 (10.6) versus control = 8.2 (10.6), P = .68. Left ventricle ejection fraction improved from in-hospital to follow-up (9 ± 3 months) for the entire cohort (46.3% ± 7.3% vs 52.2% ± 10.7%, P < .001), with no differences between PostCon and controls (51.6% ± 9.5% vs 52.7% ± 11.9%, P = .89); major cardiac events at 14 ± 4 months of follow-up were also no different (PostCon = 1.0 (2.3%) vs control = 0, P = .49). In patients with STEMI treated with MTA, PostCon offered no benefits to infarct size, LVEF, or major cardiac events.

Ascending and Aortic Arch Thrombus: Cause of Myocardial Infarction and Lower Extremity Ischemia

Ascending aortic thrombus is a rare finding that might lead to life-threatening thromboembolic events. With no specific guidelines, controversy exists regarding management ranging from surgical resection, thrombolytic therapy, and thrombectomy to anticoagulation therapy. We report a particularly interesting case of a 61-year-old woman presenting with NSTEMI and lower extremity claudication from an embolic thrombus in the distal ascending aorta and proximal aortic arch treated medically with anticoagulation. Repeat imaging in 2 months revealed resolution of the thrombus. J Med Cases. 2015;6(4):156-158 doi: http://dx.doi.org/10.14740/jmc2074w

Neurological complications associated with epidural steroid injections.

Multiple case reports of neurological complications resulting from intraarterial injection of corticosteroids have led the Food and Drug Administration (FDA) to issue a warning, requiring label changes, warning of serious neurological events, some resulting in death. The FDA has identified 131 cases of neurological adverse events, including 41 cases of arachnoiditis. A review of the literature reveals an overwhelming proportion of the complications are related to transforaminal epidural injections, of which cervical transforaminal epidural injections constituted the majority of neurological complications. Utilization data of epidural injections in the Medicare population revealed that cervical transforaminal epidural injections constitute only 2.4% of total epidural injections and <5% of all transforaminal epidural injections. Multiple theories have been proposed as the cause of neurological injury including particulate steroid, arterial intimal flaps, arterial dissection, dislodgement of plaque causing embolism, arterial muscle spasm, and embolism of a fresh thrombus following disruption of the intima.

Pulmonary embolism in patients with transvenous cardiac implantable electronic device leads.

Cardiac implantable electronic devices (CIEDs) are commonly associated with transvenous lead-related thrombi that can cause pulmonary embolism (PE). We retrospectively evaluated all patients with transvenous CIED leads implanted at Mayo Clinic Rochester between 1 January 2000, and 25 October 2010. Pulmonary embolism outcomes during follow-up were screened using diagnosis codes and confirmed with imaging study reports. Of 5646 CIED patients (age 67.3 ± 16.3 years, 64% men, mean follow-up 4.69 years) 88 developed PE (1.6%), incidence 3.32 [95% confidence interval (CI) 2.68-4.07] per 1000 person-years [men: 3.04 (95% CI 2.29-3.96) per 1000 person-years; women: 3.81 (95% CI 2.72-5.20) per 1000 person-years]. Other than transvenous CIED lead(s), 84% had another established risk factor for PE such as deep vein thrombosis (28%), recent surgery (27%), malignancy (25%), or prior history of venous thromboembolism (15%). At the time of PE, 22% had been hospitalized for ≥ 48 h, and 59% had been hospitalized in the preceding 30 days. Pulmonary embolism occurred in 22% despite being on systemic anticoagulation therapy. Out of 88 patients with PE, 45 subsequently died, mortality rate 93 (95% CI 67-123) per 1000 person-years (hazard ratio 2.0, 95% CI 1.5-2.7, P < 0.0001). Though lead-related thrombus is commonly seen in patients with transvenous CIED leads, clinical PE occurs with a low incidence. It is possible that embolism of lead thrombus is uncommon or emboli are too small to cause consequential pulmonary infarction.

Platelet adhesion, aggregation, and embolism on artificial surfaces in non-parallel blood flow

When using artificial surfaces that come into contact with the bloodstream, it is important to consider the undesirable consequences of thrombus formation and embolization. Although great progress has been made by creating new surfaces and antithrombotic coatings or evaluating flow conditions, unexpected platelet adhesion and aggregation can lead to the sudden formation of an adverse thrombus. Our experiments in a stagnation point flow chamber with citrate-anticoagulated whole blood and ADP-stimulated platelets mimicked the situations of implanted artificial organs, e.g., mechanical circulatory support devices, or extravascular circulation. With video microscopy, real-time platelet characteristics were observed at shear rate levels between 50 and 500 s−1 on glass, von Willebrand factor, and polyurethane surfaces for at least 5 min after the first contact. Platelet adhesion and aggregation were observed with distinctness in aggregate size, surface coverage, aggregate size, probability of an embolic event, and platelet contraction. The probability of an embolic event increased at lower flow rates. Additionally, platelet contraction was affected by the flow rate. Raising the flow rate intensified the platelet contraction. With this setup, the microembolization caused by surface contact and flow and platelet contraction can be detected in a real-time direct observation. This capability addresses both technical and clinical issues, such as thrombus and embolus formation, and may improve the research on the hemocompatibility of biomaterials.

The Association Between Thromboembolic Complications and Blood Group in Patients With Atrial Fibrillation

ObjectiveTo determine whether blood type affects the risk of thromboembolic complications in patients with atrial fibrillation (AF). Patients and MethodsThe Mayo Clinic electronic medical record was searched (between January 1, 2004, and December 31, 2010) to identify all patients with AF with blood group assessment. Records were analyzed for stroke, transient ischemic attack, left atrium appendage thrombus, cerebral or peripheral embolism, and hemorrhagic stroke. All events were adjusted for Congestive heart failure, Hypertension, Age >75 Years, Diabetes mellitus, and Stroke/transient ischemic attack score. ResultsOf the 47,816 patients with AF, 14,462 had blood group type available (40% women; mean age, 73±12 years). These included 12,363 patients with nonvalvular atrial fibrillation (NVAF) (40% women; mean age, 73±12 years) and 2099 patients with valvular AF (41% women, mean age, 73±12 years). Within patients with NVAF, the rate of peripheral embolization was significantly lower in those with blood type O (2.0%) than in those with other blood types (3.0%; odds ratio, 0.66; 95% CI, 0.52-0.84; P<.001). Neither cerebral thromboembolic (8.1% for “O” vs 8.2% for “non-O” blood group for NVAF and 7.29% vs 7.76% for valvular AF) nor cerebral hemorrhage (2.0% each group) events rates differed by blood group. ConclusionBlood group O may be protective against peripheral cardioembolic complications of NVAF, which may relate, in part, to reduced circulating von Willebrand factor levels. Cerebral thromboembolic event rates did not differ by blood group.

Real time flow imaging in atrial fibrillation

Background Atrial fibrillation (AF) is a common cardiac arrhythmia, affecting 33.5 million patients worldwide. The most serious complication is stroke, which is generally attributed to embolism of thrombus from the left atrium (LA). Studies utilizing transesophageal echocardiography (TEE) have shown that decreased blood flow velocities in the LA are risk factors for stroke in AF. However, TEE requires esophageal intubation and cannot fully assess the complex 3D pattern of flow in the LA. In addition, a systematic analysis of the impact of beat-to-beat variations on LA flow characteristics and thus thromboembolic risk is lacking, particularly in the presence of arrhythmia. To better elucidate the role of beat-to-beat flow variations in

Intraoperative transesophageal echocardiographic detection of intracardiac thrombus and pulmonary embolism during orthotopic liver transplant

Introduction: Transesophageal echocardio-graphy (TEE) utilization during liver transplantation is beginning to gain favor in many medical centers. The intraoperative course during liver transplant includes periods of increased and decreased peripheral vascular resistance, large amounts of third spacing, high volume replacement needs, and the possibility of acute right heart failure and circulatory collapse at reperfusion. Additionally, these patients may have underlying systolic dysfunction and coronary artery disease. Intraoperative TEE provides the anesthesiologist with the only single monitoring modality that can be used to diagnose all of these. Fear of bleeding complications due to esophageal varices, and the lack of provider competency with TEE are often sited as reasons to avoid TEE in this patient population. Case Report: This is a case of an intracardiac thrombus and pulmonary embolism in a 44-yearold male undergoing orthotopic liver transplantation for Laennec’s cirrhosis. Conclusion: In this case, the routine use of intraoperative TEE provided for diagnosis of a