Subacute Ischemia Research Articles

Perkutane mechanische Thrombektomie mittels Rotationsthrombektomie Aktuelle Studienlage

Acute and subacute ischemia of the limbs is still one of the most frequent reasons for amputation. There are different therapy options for reperfusion therapy including balloon thrombectomy, local lysis and rotational thrombectomy. Balloon thrombectomy, the standard surgical treatment, has proven an effective tool for the treatment of acute vascular obstructions. Nevertheless technical problems and complications can occur. Localized lysis on the other hand could be time - consuming and cost intensive, requiring intensive care monitoring and reangiograms. To achieve a successful result, at least one lower limb artery or major collateral has to be reopened to establish a sufficient situation. During the last years considerable advances have been made in endovascular interventions for the treatment of acute and subacute limb ischemia. The Straub Rotarex is one of the modern peripheral mechanical thrombectomy device, which combines mechanical thrombus fragmentation and removal of the material using negative pressure. There are different clinical and experimental studies, which have shown promising results in restoring blood flow to the occluded vessels. Studies mainly exist for the lower extremities. Some case reports showed effective treatment of the subclavian and axillary arteries. The advantages of the Rotarex system is simple handling, a short intervention time and the avoidance of lytic substances with consequent reduced risk of hemorrhage complications. In this article an overview about the main Rotarex studies is given which analyzed the results of percutaneous rotational thrombectomy in patients with subacute an acute thrombotic occlusions in peripheral arteries.

Hypoxia Preconditioned Mesenchymal Stem Cells Improve Vascular and Skeletal Muscle Fiber Regeneration After Ischemia Through a Wnt4-dependent Pathway

Mesenchymal stem cells (MSC) are multipotent postnatal stem cells, involved in the treatment of ischemic vascular diseases. We investigate the ability of MSC, exposed to short-term hypoxic conditions, to participate in vascular and tissue regeneration in an in vivo model of hindlimb ischemia. Transplantation of hypoxic preconditioned murine MSC (HypMSC) enhanced skeletal muscle regeneration at day 7, improved blood flow and vascular formation compared to injected nonpreconditioned MSC (NormMSC). These observed effects were correlated with an increase in HypMSC engraftment and a putative role in necrotic skeletal muscle fiber clearance. Moreover, HypMSC transplantation resulted in a large increase in Wnt4 (wingless-related MMTV integration site 4) expression and we demonstrate its functional significance on MSC proliferation and migration, endothelial cell (EC) migration, as well as myoblast differentiation. Furthermore, suppression of Wnt4 expression in HypMSC, abrogated the hypoxia-induced vascular regenerative properties of these cells in the mouse hindlimb ischemia model. Our data suggest that hypoxic preconditioning plays a critical role in the functional capabilities of MSC, shifting MSC location in situ to enhance ischemic tissue recovery, facilitating vascular cell mobilization, and skeletal muscle fiber regeneration via a paracrine Wnt-dependent mechanism.

Obstructive thrombosis of a bileaflet mitral valve assessed with real-time three-dimensional transoesophageal echocardiography

A 55-year-old woman was admitted for sub-acute ischaemia of the left leg. Three years earlier, the patient underwent a mitral replacement with a bileaflet valve for a symptomatic rheumatic mitral valve disease. Two months before admission, she presented a non-severe acute biliary pancreatitis associated with a …

Une cause rare d’ischémie embolique de la main : un anévrisme isolé d’une branche de l’artère axillaire

A 48-year-old man was admitted for subacute ischemia of the right hand of sudden onset. The patient, who participated in amateur sports, had an uneventful medical history. Duplex ultrasonography revealed thrombosis of the right radial and ulnar arteries. On heparin, the clinical course was favorable and investigations to search for an embolic source revealed an aneurism of the posterior circumflex artery (arteriography). The etiological work-up was negative as was the search for other aneurismal locations. Surgical excision was carried out. Pathology examination of the surgical specimen revealed a thrombosed aneurism that had developed on an atherosclerotic plaque. Aneurisms of the posterior circumflex artery have been described in professional baseball and volleyball players, but all sports that involve repetitive movements of the arm at extension, external rotation and forced abduction can complicate such damage. Compression of the aneurismal artery by the humeral head leads to extrusion of the thrombus under pressure and to retrograde embolisation towards the leg arteries. Thus, in the same way as for hypothenar hammer syndrome, signs of distal ischemia in an athlete should lead to a search for this type of injury.

Asymmetry Analysis in Rodent Cerebral Ischemia Models

An automated method for identification and segmentation of acute/subacute ischemic stroke, using the inherent bi-fold symmetry in brain images, is presented. An accurate and automated method for localization of acute ischemic stroke could provide physicians with a mechanism for early detection and potentially faster delivery of effective stroke therapy. Segmentation of ischemic stroke was performed on magnetic resonance (MR) images of subacute rodent cerebral ischemia. Eight adult male Wistar rats weighing 225-300 g were anesthetized with halothane in a mix of 70% nitrous oxide/30% oxygen. Animal core temperature was maintained at 37 degrees C during the entire surgical procedure, including occlusion of the middle cerebral artery (MCA) and the 90-minute post-reperfusion period. To confirm cerebral ischemia, transcranial measurements of cerebral blood flow were performed with laser-Doppler flowmetry, using 15-mm flexible fiberoptic Doppler probes attached to the skull over the MCA territory. Animal MR scans were performed at 1.5 T using a knee coil. Three experts performed manual tracing of the stroke regions for each rat, using the histologic-stained slices to guide delineation of stroke regions. A strict tracing protocol was followed that included multiple (three) tracings of each stroke region. The volumetric MR image data were processed for each rat by computing the axis of symmetry and extracting statistical dissimilarities. A nonparametric Wilcoxon rank sum test operating on paired windows in opposing hemispheres identified seeds in the pixels exhibiting statistically significant bi-fold mirror asymmetry. Two brain reference maps were used for analysis: an absolute difference map (ADM) and a statistical difference map (SDM). Although an ADM simply displays the absolute difference by subtracting one brain hemisphere from its reflection, SDM highlights regions by labeling pixels exhibiting statistically significant asymmetry. To assess the accuracy of the proposed segmentation method, the surrogate ground truth (the stroke tracing data) was compared to the results of our proposed automated segmentation algorithm. Three accuracy segmentation metrics were utilized: true-positive volume fraction (TPVF), false-positive volume fraction (FPVF), and false-negative volume fraction (FNVF). The mean value of the TPVF for our segmentation method was 0.8877; 95% CI 0.7254 to 1.0500; the mean FPVF was 0.3370, 95% CI -0.0893 to 0.7633; the mean FNVF was 0.1122, 95% CI -0.0502 to 0.2747. Unlike most segmentation methods that require some degree of manual intervention, our segmentation algorithm is fully automated and highly accurate in identifying regions of brain asymmetry. This approach is attractive for numerous neurologic applications where the operator's intervention should be minimal or null.

Lokale Lyse bei akuter peripherer Extremitätenischämie: Therapiealternative und Grundlage weiterer Interventionen

Intraarterial thrombolysis of acute arterial occlusions in the lower limbs is an established therapeutic procedure. However, its value as a primary treatment is discussed controversially and it is mostly seen as a competing procedure to primary vascular surgical interventions. From January 2001 to December 2004, we performed a total of 132 intraarterial thrombolysis procedures in 112 patients with acute or subacute ischaemia of the lower limbs. In the majority of the cases, there was an ischaemia of stage I or II a according to Rutherford, a few further cases were in stage II b at the start of treatment. The patients' ages at the time of thrombolysis was 64.7+/-11.3 years (mean value+/-standard deviation, range: 27-91 years). There were 46 female and 86 male patients. The average duration of thrombolysis was 35.2+/-20.8 hours (mean+/-standard deviation, range: 6-142 hours). As median 2 (range: 0-8) angiographic controls were performed. In 100 cases (75.8%), an operation could be avoided by thrombolysis alone or in combination with an supplementary intervention. On the other hand, in 32 cases (24.2%) a subsequent operative therapy including 10 major amputations (7.6%) was necessary. Because of hemorrhagic complications, 15 thrombolysis procedures (11.4%) had to be terminated prematurely but only 2 patients required an inguinal revision. Therapy-related mortality was 0.8% (1 patient). In the majority of our patients, primary intraarterial thrombolysis was successful and often led to the discovery of the underlying vascular lesion. It can serve both as a therapeutic alternative to a primary vascular surgical intervention and as the foundation further interventional or vascular surgical therapies although this cannot always be predicted for individual cases.

Buflomedil in Peripheral Arterial Disease

Peripheral arterial disease (PAD) is a distinct clinical manifestation of atherosclerosis, with an associated long-term risk of coronary and cerebrovascular events that is equivalent to that of a primary diagnosis of myocardial infarction or ischemic stroke.1,2 The prevalence of PAD, as estimated by an abnormal ankle-to-brachial systolic pressure index (ABI 55 years of age in Western societies.3–5 The majority of patients with PAD are asymptomatic, but recognition of the disease is clinically important because it may be the primary manifestation of systemic atherosclerosis. Indeed, numerous studies have demonstrated a correlation between the global risk of cardiovascular events and ABI, which portends a more dire outcome for those with increasing degrees of hemodynamic compromise in the limb.6,7 The major risk factors for PAD, aside from age, are cigarette smoking, diabetes mellitus, dyslipidemia, hyperhomocysteinemia, and hypertension. Among these, the recent explosion in the worldwide prevalence of diabetes mellitus is of particular concern, particularly because the risk of both mortality and limb loss in diabetic PAD patients is increased several-fold. Thus, a major focus of clinical management in PAD is on secondary prevention, including the aggressive treatment of these risk factors by dietary and behavioral modification, combined with medical therapies. Present evidence suggests that PAD patients should receive lifelong antiplatelet therapy, treatment with a hydroxymethylglutaryl coenzyme A reductase inhibitor (statin), and appropriate antihypertensive therapy, which should probably include an angiotensin-converting enzyme inhibitor.8 Article p 816 Symptomatic PAD, which affects approximately one third of all PAD patients, is most commonly manifested as intermittent claudication (IC), a walking impairment that results at least in part from a classic mismatch between blood supply and metabolic demand of the leg muscle groups. Critical limb ischemia, the most severe form …

Popliteal Artery Entrapment Syndrome: 3 Unusual Features in the Same Patient

Popliteal artery entrapment syndrome, although uncommon, usually affects young men under 50 years old. We describe the case of a 56 years old woman with acute right limb ischemia due to popliteal and distal arteries thrombosis. She had no history of leg pain and no cardio-vascular risk factor. Diagnosis of popliteal artery entrapment syndrome was made after successful thrombolysis. Treatment was completed surgically. Regarding age, sex and clinical manifestation, our patient put together three uncommon features of popliteal artery entrapment syndrome. This diagnosis should be considered even in patients over 50 without any cardiovascular risk factor presenting with subacute or acute limb ischemia.

Arm temperature distribution in thermographic pictures after radial artery harvesting for coronary bypass operation

The radial artery (RA) beside the left internal mammary artery and veins is often used for coronary artery bypass grafting. The aim of this study was to assess arm temperature changes after removal of the radial artery and determine whether there is an effect on hand function. Between April and December 2005, fifty patients underwent myocardial revascularization employing the pedicle RA as one of the coronary grafts. The study protocol included thermographic and clinical examination one day before the surgery and on the sixth day after the procedure. An Agema 900 Thermovision System was used for thermographic evaluation. Thermovision examinations were carried out at rest and after a handgrip test before and after radial artery harvesting. Temperature was measured on each finger and on the forearm (separately on the radial and ulnar side of the forearm). All examinations were performed in the same conditions. Hand endurance was compared with the 2 min handgrip test before and after the surgery. A comparison of hand temperature changes during the handgrip test before and after radial artery harvesting showed no significant difference (P>0.05). Before the surgery a significant increase in temperature over the ulnar artery was observed after the handgrip test. There were no clinical symptoms of acute or subacute hand ischemia. No clinical evidence of hand claudication was detected. There was no significant difference in hand endurance after radial artery harvesting. This study suggests that removal of the radial artery changes the hand temperature distribution but does not affect hand function in the short-term. In the study group, radial artery harvesting did not cause clinically relevant changes in blood support of the arm.

Artère sciatique persistante : possibles faux-négatifs de l'imagerie

Persistent sciatic artery is a rare congenital malformation due to the lack of regression of the dorsal arterial axis of the embryo that can be revealed by serious complications. We report a case of bilateral persistent sciatic artery revealed by subacute distal ischemia. This case illustrates the possibility of false negative imaging and the importance of ruling out this diagnosis in case of recurrent and apparently idiopathic distal embolism.

Is initial success of thrombolytic therapy with rt-PA in patients with lower limb ischemia durable? A long-term follow-up series

Catheter-directed intraarterial thrombolytic therapy with rt-PA has been established as an alternative to surgery in selected patients with lower limb ischemia. The purpose of this study is to evaluate its long-term results and to try to identify patient variables influencing outcome. The results of thrombolytic treatment for acute or subacute lower limb ischemia in 82 patients (51 male, 31 female) were retrospectively analysed. Clinical data (time of symptoms onset, clinical stage, type of affected vessel, anatomical localisation) as well as comorbidities were recorded. The success rate of thrombolysis as well as the incidence of adverse events was evaluated. Patients with initial success were followed up after a median of 52,5 months. Thrombolytic therapy was successful in 67 cases (82%). An additional endovascular or surgical procedure was necessary in 39 of these patients (48%). The overall bleeding rate was 18% and the mortality and major amputation rate was 1%. 42 patients with early clinical success were available for follow-up. 34 of them (81%) were free of ischemic symptoms and the overall limb salvage rate was 96%. We could not identify factors significantly influencing early or long-term results, although there was a trend towards better results in patients with acute ischemia and in patients with occluded native arteries. Intraarterial local thrombolytic therapy has a relatively high initial success rate in selected patients with lower limb ischemia, but is associated with a significant number of bleeding complications. Furthermore, additional procedures are required in almost half the patients. Initial success is durable at the long-term in the majority of cases. Better selection of patients and refinements of the thrombolytic therapy might help to further improve results and lower the bleeding complications.

Cannabis arteritis: a new case report and a review of literature

Cannabis arteritis manifests in cannabis users, independently of tobacco consumption. Around 50 cases were reported in the literature since the first description of this entity in 1960. We report the case of a 36-year-old man, cannabis user, without vascular risk factor who developed digital necrosis on the right foot. The pedal pulses were not palpable. He had no abnormal laboratory findings. Arteriography revealed distal segmental lesions and occlusion of popliteal artery. This arteritis was linked to cannabis use, but the patient did not stop cannabis consumption. His symptoms became even worse and he eventually developed sub-acute ischaemia in his left leg despite vascular treatments. Amputation of the right second toe and of the left leg finally became necessary. Cannabis arteritis is relatively similar to thromboangiitis obliterans in its clinical and arteriographical presentation. A parallelism can be made between the role of tobacco in thromboangiitis obliterans pathogenesis and the role of cannabis in cannabis arteritis. Cannabis use must be searched in young patients presenting with arteriopathy. Cannabis arteritis may indeed represent a frequent cause of juvenile peripheral obstructive arterial disease, but is probably under-diagnosed.

Cerebral phaeohyphomycosis caused by Cladophialophora bantiana and Fonsecaea monophora: report of three cases

Three cases of cerebral phaeohyphomycosis are described. Two cases (Cases 1, 2) are caused by highly neurotropic fungi, Cladophialophora bantiana, and the other one (Case 3) is the first reported case in the United States, caused by the newly defined Fonsecaea monophora. (Case 1): A 65-year-old woman had been treated for a presumed diagnosis of Guillain-Barré syndrome and was found to have a ring-enhancing, fluid-filled lesion in the right frontal lobe. The lesion was aspirated twice and then resected completely. (Case 2): A 45-year-old woman with a history of severe dermatomyositis presented with subacute ischemia in the left brainstem. Approximately 2 months later, she developed acute obstructive hydrocephalus and was found to have small cystic lesions in the left ambient cistern, fourth ventricle and cerebral aqueduct, which had probably caused the previous ischemic symptoms due to emboli/ thrombi. (Case 3): A 62-year-old, post livertransplant woman developed multiple brain and bone abscesses. Cultures from these lesions grew the same fungi. Histologically, all three cases revealed multiple epithelioid and giant cell granulomata with groups of golden-brown yeast-like cells as well as chains of budding cells. In Case 3, scattered muriform cells, characteristic of chromoblastomycosis, were present. In Cases 2 and 3, the fungi were easily identified on frozen sections, which may be considered useful in determining post-operative therapy.

Correlation of magnetic resonance imaging findings with hexamethylpropyleneamine oxime brain single photon emission computed tomography in ischemic stroke patients in the subacute stage

To evaluate the correlation between magnetic resonance imaging (MRI) findings and 99mTc-hexamethylpropyleneamine oxime (HMPAO) brain single photon emission computed tomography (SPECT) during the subacute stage in ischemic stroke patients. The T1 and T2-weighted images and brain SPECT findings of 84 patients (mean age 60.69 +/- 12.47 years) with subacute cerebral ischemia during the period 1998-2004 were reviewed. All HMPAO SPECT and MRI studies were performed between 3 and 7 days (mean time delay 4.76 +/- 1.29 days) after the onset of stroke symptoms. An ischemic lesion was seen both in T1 and T2-weighted images with perfusion defects above 60% (severe defect) according to count/pixel data of the lesion in HMPAO SPECT studies in 30 (90.9%) of 33 patients. Otherwise, the ischemic lesion was seen only on T2-weighted images with perfusion defects between 30% and 60% (moderate defect) in HMPAO SPECT studies in 25 (89.3%) of 28 patients. In 20 (87%) of 23 patients who had perfusion defects below 30% (mild defect) on HMPAO SPECT, only non-specific findings such as cerebral atrophy and/or periventricular ischemic-gliotic lesions could be seen in MRI. The difference between these ratios was statistically significant (P < 0.01). Brain 99mTc-HMPAO SPECT findings indicate good correlation with MRI findings. When the ischemic lesions could be seen in both T1 and T2-weighted images, the patients frequently had severe perfusion defects. When only seen in T2-weighted images, the perfusion defect was moderate. When only non-specific findings were revealed by MRI, only mild perfusion defects were found by SPECT.

Ischémie subaiguë d’un membre inférieur et toxicité artérielle périphérique de la cocaïne chez une patiente présentant une artériopathie juvénile

A 35–year –old woman was hospitalized for subacute ischemia of the left leg following an intermittent claudication for some weeks. She also presented paleness and coldness of both hands. The radial pulses could not be palpated. Smoking was the only cardiovascular risk factor. Duplex ultrasonography and angiography revealed a left popliteal thrombus combined with low diameter leg arteries and in the upper limbs stenosis of the left radial artery and thrombosis of the right radial artery. Search for a metabolic, embolic or thrombophilic etiology was negative. More minute history taking revealed use of cannabis and recent nasal administration of cocaine. Her condition improved with heparin therapy except for the upper limbs with ischemia of the hands and disabling Raynaud's phenomenon. This report highlights the combined arterial toxicity of drugs often used together by drug addicts. The association of cannabis use and tobacco smoking is not rare in patients with Buerger-like juvenile arteriopathy and cocaine may provoke peripheral vascular disease by embolism or in situ thrombosis. Interrogation of a patient presenting with Buerger-like peripheral arterial disease should insist on detecting use of drugs in association with tobacco smoking. (J Mal Vasc 2006; 31: 76-78).

Thrombolysis for Acute Lower Limb Ischaemia—A Prospective, Randomised, Multicentre Study Comparing Two Strategies

Objectives To test if initial high-dose, pulse-spray thrombolysis improves the early and late outcome of lower limb ischaemia as compared with low-dose infusion alone. Design Prospective randomised multicentre study. Material and methods Patients with acute and sub-acute (<30 days) lower limb ischaemia were randomised following angiography. Group 1 ( n=58) received pulse-spray infusion of recombinant plasminogen activator (rt-PA, 15 mg/h) for 2 h followed by low-dose infusion if needed. Group 2 ( n=63) were only treated with low-dose infusion (0.5 mg/h) of rt-PA for 48 h. Underlying lesions were corrected if required. Results The study was stopped prematurely. Complications were equally frequent in both groups. More than 75% lysis was accomplished in 78 versus 67% of the patients ( p=0.21). Primary endpoints (re-occlusion, incomplete lysis, life-threatening complication, amputation, or death) were reached in 24 versus 32% of the patients ( p=0.35). Neither vascular patency nor clinical parameters differed during the first year, but re-interventions tended to be more frequent ( p=0.040 at 1 month; p=0.090 at 1 year) and of a greater magnitude ( p=0.028) in group 2. Conclusions There was no obvious advantage with initial high-dose thrombolysis, which may be a type-2 error. A reduction of major re-interventions was recorded.

Subacute bloodstream blockade effect by self-contraction of spider silk

The present experiment was designed to test the subacute bloodstream blockade effect of supercontraction of spider silk on the femoral artery of rats. Observation on ligated femoral artery lasted 10 days. Blood flow, systolic/diastolic blood pressure, and oxidatively modified proteins in serum were measured before and after ligation. Meanwhile, histological manifestations of femoral artery at different times were observed by HE stain. We found that blood flow and systolic/diastolic blood pressure of femoral artery showed a descending tendency. Biochemical assay showed that oxidatively modified proteins significantly increased in the first 3 days and reached peak on the third day. Histological examination demonstrated that there was a progressive procedure from partial to complete occlusion of lumen of blood vessel and there was possibility of recanalization at last in the occlusive vessel. Our study indicated that ligation by spider silk might be applied to models of subacute ischemic disease such as subacute femoral artery ischemia, subacute or chronic ischemic cardiocerebrovascular disease, etc.

A protocol for the safe treatment of acute lower limb ischaemia with intra-arterial streptokinase and surgery.

Over a 5-year period 70 patients, presenting with subacute ischaemia of the lower limb (more than 12 h), were treated with low-dose intra-arterial streptokinase. There were 72 infusions and effective lysis was achieved in 52 (72 per cent), with an average infusion time of 25 h. A total of 23 (32 per cent) also underwent percutaneous transluminal angioplasty when lysis showed an underlying stenosis, and a further 19 (26 per cent) required surgery to remove persistent stenosis, organized thrombus or atheromatous debris. Significant bleeding occurred in 4 patients (6 per cent) and 13 (18 per cent) underwent amputation. There were five deaths (7 per cent), one of which was directly related to the infusion, while three were due to myocardial infarction. All of the major complications occurred in the early part of the study and both the selection of patients and the technique of infusion were modified to improve safety. Complementary treatment by percutaneous transluminal angioplasty and surgery was used more frequently in the later part of the study. The technique is not recommended for the white leg of acute ischaemia (less than 12 h), or for lysis of clot in a retroperitoneal Dacron graft, but may be uniquely valuable to demonstrate the cause of subacute ischaemia.

Early results and 1-year follow-up after intra-arterial thrombolysis.

Intra-arterial thrombolysis (IAT) was used as first-line treatment for 100 occlusions causing acute, subacute or chronic ischaemia. Streptokinase was used in 90 cases and tissue plasminogen activator in the remaining ten. Complete lysis, as determined radiologically, was achieved in 55 per cent of cases and partial lysis in 20 per cent. Lysis was more effective the earlier it was used. Major complications occurred in seven cases: five patients suffered major haemorrhage, two of whom died, and two had haemorrhagic cerebrovascular accidents. Of the patients with complete or partial clearance of thrombosis, 19 had no underlying apparent cause, 23 underwent angioplasty and 15 had an operation. The 1-year patency rate following complete lysis was 58 per cent. The 1-year patency rate after successful treatment commencing within 1 week of symptoms starting was 71 per cent, compared with 36 per cent for later treatment. Aortofemoral bifurcation grafts were cleared in three of five cases and all remain patent. Eight popliteal aneurysms were demonstrated by IAT and were ligated and bypassed; all these grafts remained patent at follow-up. IAT is less effective in chronic than acute occlusion. It should be reserved for patients in whom the occlusion is of short duration or for those with a thrombosed aortofemoral bifurcation graft or popliteal aneurysm.

Popliteal aneurysms identified by intra-arterial streptokinase: A changing pattern of presentation

Five patients presenting with chronic or subacute leg ischaemia due to thrombosed popliteal artery aneurysm are described. Only one of these aneurysms was diagnosed before intra-arterial streptokinase infusion, which successfully lysed the thrombus in all cases. One aneurysm had been symptomatic for 5 years and another for 2 years. Popliteal aneurysm may well be underdiagnosed as a cause of chronic leg ischaemia.