Aortic arch atheromas may be important sources of cerebral embolism. Aortic plaques are frequently found somewhat distal to the origin of the cerebral arteries, implying that cerebral embolization from such plaques depends on local retrograde blood flow components in this area. Therefore, we investigated the occurrence of blood flow reversal in this part of the aorta. Furthermore, since the presence and magnitude of retrograde flow might be influenced by aortic wall properties, we also studied the relationship between plaque size and distribution, aortic strain and degree of retrograde flow.
We evaluated aortic arch ante- and retrograde blood flow velocities in 56 patients by transesophageal echocardiography using color-Doppler-guided pulsed-Doppler techniques. The velocity-time integrals (VTI) were measured and the diastolic/systolic VTI ratio was calculated.
Retrograde diastolic blood flow was noted in all subjects, and diastolic/systolic VTI ratios were higher (p < 0.05) in patients with plaque ≥4 mm (n = 17) compared to those (n = 39) without. Patients exhibiting plaques exclusively in the aortic arch showed the highest VTI ratios (p < 0.01) and tended to have the lowest strain values. Aortic strain was also reduced in patients >50 years of age (p < 0.01).
Our findings demonstrate retrograde aortic flow in all subjects and its proportion increases in subjects with atherosclerosis, particularly in the aortic arch. Aortic plaques situated distally to the origin of the cerebral arteries are therefore possible sources of cerebral emboli.
Secondary prevention; Ischemic stroke; Ultrasonography; Doppler ultrasound
Pedunculated thrombus in the aortic arch that is associated with cerebral infarction is very rare requires prompt diagnosis and treatment to prevent occurrence of another devastating complication. Transesophageal echocardiography is useful for detecting source of embolism including aortic thrombi. The treatment options of aortic thrombi involves anticoagulation, thrombolysis, thromboaspiration, and thrombectomy. Here we report a case of huge thrombus in the aortic arch, resulting in acute multifocal cerebellar embolic infarct in patient without any risk factors for vascular thrombosis. Thrombi in the aortic arch were diagnosed by transesophageal echocardiography and treated with anticoagulants successfully.
Aortic thrombus; Echocardiography
Primary aortic sarcoma is a rare condition that is frequently associated with distal embolization. In addition, growth characteristics of primary aortic sarcoma lead to the narrowing of the involved aortic lumen. A 72-year-old Korean male with primary aortic sarcoma showed progressive unexplained blood pressure elevation that didn’t improve with additional antihypertensive drug therapy. Because follow-up measures were not taken, the patient ultimately developed hypertensive encephalopathy with concurrent embolic dissemination. Although we successfully performed open transcatheter embolectomy in both legs, the patient died because of multiple organ failure 3 days after surgery. Given the ominous prognosis for this condition, this case report highlights the fact that the value of early detection and prompt evaluation of altered vital signs should not be overemphasized. We describe a rare case of primary aortic sarcoma that showed hypertensive encephalopathy caused by thoracic aortic occlusion and also had embolic metastases to the lower extremities.
Aorta; Sarcoma; Hypertensive encephalopathy
Hemostatic clot formation entails thrombin-mediated cleavage of fibrinogen to fibrin. Previous in vitro studies have shown that the thrombin concentration present during clot formation dictates the ultimate fibrin structure. In most prior studies of fibrin structure, clotting was initiated by adding thrombin to a solution of fibrinogen; however, clot formation in vivo occurs in an environment in which the concentration of free thrombin changes over the reaction course. These changes depend on local cellular properties and available concentrations of pro- and anti-coagulants. Recent studies suggest that abnormal thrombin generation patterns produce abnormally structured clots associated with an increased risk of bleeding or thrombosis. Further studies of fibrin formation during in situ thrombin generation are needed to understand fibrin clot formation in vivo.
thrombin; fibrinogen; fibrin; plasmin; fibrinolysis; clot structure; hemophilia; thrombosis
Fibrin plays a vital structural role in thrombus integrity. Thus, the ability to assess fibrin architecture has potential to provide insight into thrombosis and thrombolysis. Fibrin has an anisotropic molecular structure, which enables it to be seen with polarized light. Therefore, we aimed to determine if automated polarized light microscopy methods of quantifying two structural parameters; fibrin fiber bundle orientation and fibrin's optical retardation (OR: a measure of molecular anisotropy) could be used to assess thrombi. To compare fibrin fiber bundle orientation we analyzed picrosirius red-stained sections obtained from clots formed: (A) in vitro, (B) in injured and stenotic coronary arteries, and (C) in surgically created aortic aneurysms (n = 6 for each group). To assess potential changes in OR, we examined fibrin in picrosirius red-stained clots formed after ischemic preconditioning (10 minutes ischemia + 10 minutes reflow; a circumstance shown to enhance lysability) and in control clots (n = 8 each group). The degree of fibrin organization differed significantly according to the location of clot formation; fibrin was most aligned in the aneurysms and least aligned in vitro whereas fibrin in the coronary clots had an intermediate organization. The OR of fibrin in the clots formed after ischemic preconditioning was lower than that in controls (2.9 ± 0.5 nm versus 5.4 ± 1.0 nm, P < 0.05). The automated polarized light analysis methods not only enabled fibrin architecture to be assessed, but also revealed structural differences in clots formed under different circumstances.
birefringence; blood coagulation; fibrin; polarization microscopy; thrombosis
Acute occlusion of an abdominal aortic aneurysm is a rare phenomenon. Its possible complications include distal spasm followed by arterial thrombosis, ischemia of the distal limbs, distal embolization, acidosis, hyperkalemia, and the development of venous thrombosis of the lower limbs. Surgical correction is often complicated by cardiac decompensation, renal failure, fatal pulmonary embolism, and metabolic derangements related to toxins released from the revascularized limb. Unless contraindicated, immediate systemic heparinization must be undertaken when the diagnosis is first suspected.
We present a case of sudden occlusion of an abdominal aortic aneurysm complicated by venous thrombosis involving both lower extremities. After undergoing surgical revascularization, the patient sustained massive fatal pulmonary emboli. Prophylactic interruption of the inferior vena cava may be indicated in patients who present with this complication of abdominal aortic aneurysm.
Pulmonary embolectomy is a treatment option in selected patients with high-risk pulmonary embolism (PE). Efficiency of thrombus degradation in PE largely depends on the architecture of its fibrin network, however little is known about its determinants. We present the case of a 56-year-old woman with high-risk PE and proximal deep-vein thrombosis, whose thrombotic material removed during embolectomy from the right atrium and pulmonary (lobar and segmental) arteries has been studied using scanning electron microscopy (SEM). SEM images showed that distally located thrombi are richer in densely-packed fibrin fibers and contain more white cells and less erythrocytes than the proximal ones and the atrial thrombus. Fibrin fibers alignment along the flow vector was observed in the thrombi removed from high-velocity flow pulmonary arteries, and not in the atrial thrombus. The content of denser fibrin network and platelet aggregates was increased in segmental thromboemboli. Our findings describe the relation between thrombus architecture and location, and might help to elucidate thrombus resistance to anticoagulant therapy in some PE patients.
Pulmonary embolism; Right atrium; Thrombus architecture; Fibrin
Thrombin concentration modulates fibrin structure and fibrin structure modulates clot stability; however, the impact of localized, cell surface-driven in situ thrombin generation on fibrin structure and stability has not previously been evaluated.
Human fibroblasts were incubated with factors Xa, Va, prothrombin and fibrinogen, or plasma. Fibrin formation, structure, and lysis were examined using laser scanning confocal microscopy and transmission electron microscopy.
in situ thrombin generation on the cell surface produced clots with a significantly denser fiber network in a 10-μm region proximal versus distal to (40 – 50 μm) the cell surface. This morphology was not altered by addition of integrin-blocking RGDS peptide and was not apparent in clots made by exogenous thrombin addition, suggesting that spatial morphology was dictated predominantly by localized thrombin generation on the fibroblast surface. The fibrin network lysed more rapidly distal versus proximal to the cell surface, suggesting that the clot’s structural heterogeneity affected its fibrinolytic stability.
in situ thrombin generation on the cell surface modulates the three-dimensional structure and stability of the clot. Thrombus formation in vivo may reflect the ability of the local cell population to support thrombin generation and therefore, the three-dimensional structure and stability of the fibrin network.
coagulation; fibrin clot structure; thrombin generation; fibrinolysis
Endovascular repair of inflammatory aortic aneurysms has been reported as an alternative to open surgical treatment. In selective cases, adjunctive bypass surgery may be required to provide an adequate landing zone. We report a case of endovascular repair of an inflammatory aortic aneurysm in a patient with Behçet's disease using a carotid-carotid bypass graft to provide an adequate landing zone. A 45-yr-old man with a voice change was referred to our hospital with the diagnosis of saccular aneurysm of the distal aortic arch resulting from vasculitis. Computed tomography showed a thoracic aortic aneurysm with thrombosis. Right to left carotid-carotid bypass grafting was performed. After 8 days, the patient underwent an endovascular stent graft placement distal to the origin of the innominate artery. The patient was discharged with medication and without postoperative complications after 5 days. Hybrid endovascular treatment may be suitable a complementary modality for repairing inflammatory aortic aneurysms.
Endovascular Repair; Aortic Aneurysm; Inflammatory; Carotid-Carotid Bypass; Behçet Syndrome
Management of aortic arch aneurysm and dissection continues to evolve as endovascular options play an increasing role in treating thoracic aortopathies. Although conventional open treatment of aortic arch disease with total arch replacement still remains the gold standard, in patients with old age and/or high comorbid disease index, there is significant associated morbidity and mortality. The hybrid arch procedure, which aims to minimize cardiopulmonary bypass and circulatory arrest times, is a particularly appealing surgical option in this cohort of patients. The hybrid arch concept essentially entails three main principles: (I) open debranching of the great vessels; (II) creation of proper proximal (zone 0 landing) and distal landing zones, and; (III) concomitant or delayed endovascular stent grafting of the aortic arch. The classification scheme for hybrid arch debranching procedures is based on the extent of proximal and distal landing zone reconstruction required, and thus the need and extent of cardiopulmonary bypass and circulatory arrest management strategies to be employed. In this illustrated article, we describe the details of the type II hybrid arch debranching procedure, where the ascending aorta and aortic arch pathology is typically treated by reconstruction of ascending aorta ﹢ arch vessel debranching, with concomitant antegrade stent grafting of the aortic arch.
Hybrid arch repair; aortic aneurysm; debranching procedure; thoracic aortic endovascular stent grafting
Right-sided aortic arch with aberrant left subclavian artery is an uncommon anomaly. We describe a case of Kommerell’s diverticulum involving the distal portion of a right-sided aortic arch and the origin of an aberrant left subclavian artery in a 74-year-old man with hoarseness. The patient underwent successful endovascular repair of the aneurysm with use of a Gore TAG thoracic endoprosthesis and coil embolization of the left subclavian artery. Postoperative computed tomography showed complete exclusion of the lesion, without endoleaks. Endovascular repair is feasible and can be effective in such cases.
endovascular repair; Kommerell’s diverticulum; right-sided aortic arch
Quantifying mechanical properties of blood clots is fundamental to understanding many aspects of cardiovascular disease and its treatment. Nevertheless, there has been little attention to quantifying the evolving composition, structure, and properties when a clot transforms from an initial fibrin-based mesh to a predominantly collagenous mass. Although more data are needed to formulate a complete mathematical model of the evolution of clot properties, we propose a general constrained mixture model based on diverse data available from in vitro tests on fibrinogenesis, the stiffness of fibrin gels, and fibrinolysis as well as histological and mechanical data from clots retrieved from patients at surgery or autopsy. In particular, albeit resulting from complex kinetics involving many clotting factors, we show that the rapid (minutes) in vitro production of fibrin from fibrinogen can be modeled well by an Avrami-type relation and similarly that the fast (tens of minutes) in vitro degradation of fibrin in response to different concentrations of plasmin can be captured via a single “master function” parameterized by appropriate half-times that can be inferred from laboratory or clinical data. Accounting simultaneously for the production and removal of fibrin as well as chemo-mechano-stimulated production of fibrillar collagens yields predictions of changing mass fractions and bulk mechanical properties that correspond well to experimentally available data. Constrained mixture models thus hold considerable promise for modeling the biomechanics of clot evolution and can guide the design and interpretation of needed experiments and stress analyses.
Coagulation; blood clot; fibrin gel; collagen organization; mechanical stress
A shaggy aorta with unstable atheromatous plaques has a high risk of neurologic complications in cases of arch aneurysm. We report the use of a modified arch-first technique involving arch replacement for a beating heart after reconstruction of supra-aortic vessels while maintaining normal blood pressure. The procedure was performed in a patient who had an arch aneurysm, complicated by an aberrant right subclavian artery (ARSA) and a shaggy aorta ascending to the aortic arch. This modified arch-first technique is an alternative surgical approach that is used for arch aneurysms involving a shaggy aorta, in order to prevent embolic debris-related complications.
arch aneurysm; arch-first technique; aberrant right subclavian artery
Atherosclerotic aortic arch plaques (AAP) have been linked to an increased risk of thrombo-embolic events as a cause of acute ischemic stroke of undetermined etiology.
To find out the presence of atherosclerotic plaques in aortic arch and their potential role as a source of embolism in cerebral infarction of undetermined etiology.
We performed trans-esophageal echocardiography (TEE) and multislice computerized tomography (MSCT) of the aortic arch on 30 patients with acute ischemic stroke of undetermined cause from a total series of 150 non-selected patients with acute ischemic stroke studied prospectively by clinical evaluation, laboratory investigations, cranial computed tomography, color coded duplex ultrasonography of the carotid arteries and transcranial Doppler (TCD).
Using trans-esophageal echocardiography eight patients (29.6%) had atherosclerotic aortic arch plaques, while using multislice computerized tomography atherosclerotic aortic arch plaques were revealed in twelve patients (40%). Atherosclerotic aortic arch plaques were significantly related to older age, male gender, hypertension, ischemic heart disease and low-grade atherosclerotic carotid lesions. Multislice computerized tomography of the aortic arch was more sensitive than trans-esophageal echocardiography in detecting the site, size and characters of atherosclerotic aortic arch plaques.
Atherosclerotic aortic arch plaques are a frequent finding in patients with acute ischemic stroke of undetermined cause supporting the hypothesis that aortic plaques have embolic potential. In addition, multislice computerized tomography is more sensitive than trans-esophageal echocardiography in detecting atherosclerotic aortic arch plaques and better characterization of these plaques especially relevant one.
Aorta; Atherosclerotic plaques; Echocardiography; Multislice Computerized Tomography; Stroke
A pentapeptide, Gly-Pro-Arg-Pro-Pro, with high affinity for α-chain-fibrin was labeled with 99mTc (99mTc-TP850) and evaluated in swine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE).
Scatchard analysis was performed to determine fibrin affinity for TP850 and the number of binding sites (receptors) per milligram of fibrin. DVT was induced in the left jugular vein and PE was induced by introducing a preformed autologous blood clot into the right atrium using a 7-French introducer sheath inserted into the right jugular vein. 99mTc-TP850 was injected at 4, 24, 48, 72, 96, or 120 h later. Animals were imaged for up to 4 h after injection, heparinized, and sacrificed. Lungs were extirpated, radiographed, and imaged, and the PE was removed. Other tissues, including blood and normal lungs, were harvested and, concomitantly, 99mTc was counted for determination of target-to-tissue ratios and the percentage injected dose per gram of tissue.
The affinity for human fibrin was 10−9 mol/L and there were >1015 receptors per milligram of fibrin. DVT and PE were visualized for up to 4 h after injection with high DVT/blood (7.9–22.6), DVT/muscle (31.1–89.4), PE/blood (1–155), and PE/lung (0.8–245) ratios. Thereafter, the PEs fragmented spontaneously below the spatial resolution of the γ-camera and, despite the high associated radioactivity, could not be localized in vivo. The fragmented clots were detectable by scintigraphy on excised lungs and provided excellent concordance with radiograms.
99mTc-TP850 with its modest affinity (10−9 mol/L), rapid blood clearance, and high DVT and PE uptake is a promising agent for imaging vascular thrombosis.
imaging vascular thrombosis; imaging pulmonary embolism; imaging venous thrombosis; 99mTc-antifibrin peptide
Doppler ultrasound was used to investigate 48 infants and children (age 2 days-16 years, weight 1.0-58 kg) with aortic arch abnormalities. In only 38 of the 42 with an important coarctation was an increased blood flow velocity from the distal arch demonstrated. In three with interruption of the aortic arch an increased velocity recorded from the region of the distal arch was thought to represent ductal flow. There was little difference between the peak to peak and instantaneous maximum gradients in the 20 patients with important coarctation in whom direct pressure measurements both proximal and distal to the obstruction were made at catheterisation. There were poor agreements between Doppler and measured peak to peak and instantaneous gradients in the 17 patients found to have both an increased velocity and important coarctation. It is concluded that although an increased blood flow velocity in the distal arch is usually demonstrated in coarctation this may not occur with severe obstruction. Furthermore, the maximum velocity is not related to the anatomical severity of the obstruction and the Doppler estimate of pressure drop in coarctation may not even reliably predict that measured at catheterisation.
Aortic rupture has a high mortality rate and can be considered a medical emergency. The standard treatment for aortic rupture is surgical repair. An aortic stent graft for a ruptured descending aorta is considered an effective alternative treatment. However, an aortic stent graft is difficult when the aortic aneurysm is in the aortic arch due to supra-aortic vessels. We report on a patient with a ruptured aortic arch aneurysm treated with a hybrid procedure, which involved a carotid to carotid bypass operation and an aortic stent graft. A 71-year-old male patient visited our cardiovascular center suffering from hemoptysis. The chest CT and aortography showed a 9 cm sized aortic arch aneurysm 0.5 cm distal to the left subclavian artery and a hemothorax in the left lung. The patient refused to undergo a full open operation. We performed a carotid to carotid bypass in advance, and two pieces of aortic stent grafts were placed across the left carotid artery and left subclavian artery. The follow up CT showed the aortic stent grafts, no endoleaks and no thrombus in the aortic arch aneurysm. The patient was discharged from the hospital without complication.
Aorta, thoracic; Aortic rupture; Stents
Rationale: Although acute pulmonary embolism is epidemiologically associated with chronic thromboembolic pulmonary hypertension, the factors responsible for resistance to thrombolysis and a shift toward vascular remodeling within the pulmonary arteries of patients with chronic thromboembolic pulmonary hypertension are unknown.
Objective: Determine whether fibrin from patients is more resistant to plasmin-mediated lysis than fibrin from healthy control subjects.
Methods: Fibrinogen purified from patients and control subjects was used to prepare fibrin clots, which were subsequently digested with plasmin for various periods of time. The degradation of the α-, β-, and γ-chains of fibrin and the appearance of peptide fragments over time were assessed by polyacrylamide gel electrophoresis and Western blotting.
Measurements and Main Results: Densitometry of Coomassie-stained gels revealed significantly slower cleavage of all three polypeptide chains of fibrin from patients compared with control subjects (p < 0.05). In particular, release of N-terminal fragments from the β-chain of fibrin, which promote cell signaling, cell migration, and angiogenesis, was retarded in patients compared with control subjects (p < 0.01).
Conclusions: The relative resistance of patient fibrin to plasmin-mediated lysis may be due to alterations in fibrin(ogen) structure affecting accessibility to plasmin cleavage sites. The persistence of structural motifs of fibrin, such as the β-chain N-terminus, within the pulmonary vasculature could promote the transition from acute thromboemboli into chronic obstructive vascular scars.
blood coagulation factors; fibrinolysis; pulmonary embolism; thrombosis; vascular diseases
Fibrin polymerization is a necessary part of hemostasis but clots can obstruct blood vessels and cause heart attacks and strokes. The polymerization reactions are specific and controlled, involving strong knob-into-hole interactions to convert soluble fibrinogen into insoluble fibrin. It has long been assumed that clots and thrombi are stable structures until proteolytic digestion. On the contrary, using the technique of fluorescence recovery after photobleaching, we demonstrate here that there is turnover of fibrin in an uncrosslinked clot. A peptide representing the knobs involved in fibrin polymerization can compete for the holes and dissolve a preformed fibrin clot, or increase the fraction of soluble oligomers, with striking rearrangements in clot structure. These results imply that in vivo clots or thrombi are more dynamic structures than previously believed that may be remodeled as a result of local environmental conditions, may account for some embolization, and suggest a target for therapeutic intervention.
Fibrinogen degradation, fibrin polymerisation, and the insertion of cross links into fibrin by fibrin stabilising factor lead to the appearance of new antigenic determinants. Antibodies against these antigenic sites may react specifically with the derivatives but not with the parent molecules. We have utilised a monoclonal antibody, which interacts with the cross linked fragment D dimer and related high molecular weight fibrin derivatives, to develop an enzyme immunoassay which measures cross linked fibrin derivatives in plasma and serum using D dimer as standard. Mean concentration in plasma from normal subjects was 75 ng/ml with an upper limit of about 144 ng/ml. Concentrations in patients with pulmonary embolism, deep venous thrombosis, arterial thromboembolism, and disseminated intravascular coagulation were raised in all cases. Confirmation of the specific increase of cross linked fibrin derivatives in patients with disseminated intravascular coagulation was obtained by parallel monitoring of their fibrin degradation products in serum using affinity chromatography and sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. In many patients the plasma concentrations greatly exceeded the serum values of cross linked fibrin degradation products, suggesting that the procedure can measure fibrin derivatives in plasma which are absent from serum.
Patients suffering from acute type A aortic dissection undergo replacement of the ascending aorta, the proximal hemiarch or complete aortic arch, depending on the extent of the individual pathology. In a subset of these treated patients, secondary pathologies of the distal anastomosis or the remaining distal part of the aorta occur. The treatment of these pathologies is challenging, requiring major surgical re-do procedures with aortic arch replacement under extracorporeal circulation and hypothermic circulatory arrest.
We report our experience of five patients with complex aortic pathologies after previous aortic surgery treated with a single stage re-do hybrid procedure, consisting of bypass grafting of the supraaortic branches off-pump, stent graft placement for endovascular aortic repair (TEVAR) and surgical debranching of the aortic arch.
In all patients the surgical vascular grafts and stent grafts were deployed successfully, there were no intraoperative deaths. Four out of five patients were discharged from hospital in good clinical condition. One patient died postoperatively due to cardiac tamponade. In one patient a type I endoleak persisted leading to occlusion of a bypass branch requiring surgical revision at one year after debranching.
We discuss the prerequisites, all steps and potential pitfalls of this hybrid aortic arch replacement. The current procedure avoids cardiopulmonary bypass and circulatory arrest, which may benefit early patient outcome; however, patient and device selection plays a key role for immediate success and midterm outcomes. In addition, precise procedural planning and development of customized stents may help to develop this procedure into a true alternative for conventional aortic arch replacement.
Aortic debranching; Off-pump surgery; TEVAR; Aortic dissection
Atrial fibrillation (AF) is the most common sustained dysfunction in heart rhythm clinically and has been identified as an independent risk factor for stroke through formation and embolization of thrombi. AF is associated with reduced cardiac output and short and irregular cardiac cycle length. Although the effect of AF on cardiac hemodynamic parameters has been reported, it remains unclear how the hemodynamic perturbations affect the potential embolization of blood clots to the brain that can cause stroke. To understand stroke propensity in AF, we performed computer simulations to describe trajectories of blood clots subject to the aortic flow conditions that represent normal heart rhythm and AF. Quantitative assessment of stroke propensity by blood clot embolism was carried out for a range of clot properties (e.g., 2–6 mm in diameter and 0–0.8 m/s ejection speed) under normal and AF flow conditions. The simulations demonstrate that the trajectory of clot is significantly affected by clot properties as well as hemodynamic waveforms which lead to significant variations in stroke propensity. The predicted maximum difference in stroke propensity in the left common carotid artery was shown to be about 60% between the normal and AF flow conditions examined. The results suggest that the reduced cardiac output and cycle length induced by AF can significantly increase the incidence of carotid embolism. The present simulations motivate further studies on patient-specific risk assessment of stroke in AF.
A 75-year-old man presented with acute coronary syndrome; he had a saphenous vein graft thrombosis. Percutaneous coronary intervention of bypass graft vessels is more challenging due to a higher incidence of periprocedural distal micro-emobilization and myocardial infarction. Current guidelines for percutaneous coronary intervention advocate the use of distal embolic protection devices, especially in patients with large thrombus burden, undergoing percutaneous intervention for vein graft disease. This patient was treated by manual aspiration of graft thrombus using a microvena catheter and successful clot removal was achieved. There are yet no best available therapeutic options for patients undergoing percutaneous coronary intervention of saphenous vein graft lesions.
Saphenous vein graft; Aspiration catheter; Acute coronary syndrome; Angioplasty
Accurate classification of stroke has significant impact on patient care and conduction of stroke clinical trials. The current systems such as TOAST, SSS-TOAST, Korean TOAST, and A–S–C–O have limitations. With the advent of new imaging technology, there is a need to have a more accurate stroke subclassification system. Chinese ischemic stroke subclassification (CISS) system is a new two step system aims at the etiology and then underlying mechanism of a stroke. The first step classify stroke into five categories: large artery atherosclerosis (LAA), including atherosclerosis of aortic arch and intra-/extracranial large arteries, cardiogenic stroke, penetrating artery disease, other etiology, and undetermined etiology. The second step is to further classify the underlying mechanism of ischemic stroke from the intracranial and extracranial LAA into the parent artery (plaque or thrombosis) occluding penetrating artery, artery-to-artery embolism, hypoperfusion/impaired emboli clearance, and multiple mechanisms. Although clinical validation of CISS is being planned, CISS is an innovative system that offers much more detailed information on the pathophysiology of a stroke.
ischemic stroke; subclassification; etiology; mechanism; Chinese
Pulmonary embolism occurs more frequently after hepatectomy than previously thought but is infrequently associated with peripheral deep vein thrombosis. In this paper, we report 2 cases of postoperative hepatic vein thrombosis after liver resection. Both patients had undergone major hepatectomy of a non-cirrhotic liver largely exposing the middle hepatic vein. Clots were incidentally found in the middle hepatic vein 4 and 17 d after surgery despite routine systemic thrombo-prophylaxis with low molecular weight heparin. Coagulation of the transition plan in a context of mutation of the prothrombin gene and inflammation induced biloma were the likely predisposing conditions. Clots disappeared following curative anticoagulation. We conclude that thrombosis of hepatic veins may occur after liver resection and is a potential source of pulmonary embolism.
Hepatectomy; Hepatic veins; Thrombosis; Pulmonary embolism; Anticoagulants