Prosthetic Valve Thrombosis Presenting as an Acute Embolic Myocardial Infarction in a Pregnant Patient: Issues on Anticoagulation Regimens and Thrombolytic Therapy

Mechanical valves are inherently thrombogenic and require meticulous anticoagulation. Pregnancy produces a hypercoagulable state and achieving adequate anticoagulation is difficult. We present a pregnant patient who had a nonobstructive thrombus of mechanical mitral valve causing embolic acute myocardial infarction. Issues surrounding management of anticoagulation and use of thrombolytic therapy during pregnancy are discussed. Education regarding the critical nature of adequate anticoagulation in these patients is important.

Splenic embolus: 13 cases from a single medical department

BACKGROUND

Despite the spleen having a very rich blood supply, there is a paucity of reports of splenic emboli.

OBJECTIVES

To investigate the incidence of splenic emboli treated in a single general internal medicine department over the last 3 years.

METHODS

We examined the records of a 35 bed internal medicine department in a hospital in the center of Israel.

RESULTS

Over a period of 3 years 13 patients admitted to one internal medicine department developed acute abdominal pain and areas of hypoperfusion in the spleen on contrast computed tomography imaging. The patients were treated with anticoagulants, their course was benign and there were no long-term sequelae.

CONCLUSIONS

Embolus to the spleen is not rare in an internal medicine department. Diagnosis can be easily made by contrast CT scanning, and treatment with anticoagulants results in a good prognosis.

Percutaneous endovascular treatment of acute sequential systemic emboli

A 65-year-old woman was evaluated for acute right lower-extremity ischemia secondary to embolization from atrial fibrillation and subtherapeutic anticoagulation. Her symptoms quickly evolved in a dynamic fashion to involve multiple vascular beds, including a transient ischemic attack, abdominal pain secondary to mesenteric ischemia, and contralateral lower-extremity ischemia. Synchronous emboli were treated by using mechanical and pharmacologic thrombolysis via an endovascular approach under local anesthesia. This intervention allows prompt evaluation of multiple vascular beds with good short-term outcomes and minimal morbidity.

Direct aspiration using rapid-exchange and low-profile device for acute thrombo-embolic occlusion of the superior mesenteric artery

Acute thrombo-embolic occlusion of the superior mesenteric artery (SMA) is potentially fatal vascular emergency that requires rapid restoration of mesenteric blood flow as well as early diagnosis. Selective thrombolysis has been employed for this life-threatening event. Although failed thrombolysis is a well known phenomenon, which is directly connected with bowel necrosis, emergent laparotomy, and patient death, little progress has been made in its treatment strategy. Recently, direct aspiration using rapid-exchange and low-profile aspiration device has been reported as a simple, safe, and effective strategy to thrombus in coronary artery. We describe the utility of direct aspiration using this sort of aspiration device for failed thrombolysis of SMA thrombo-embolism.

Venous thromboembolic prophylaxis after elective total hip arthroplasty

Elective total hip arthroplasty is a common orthopaedic procedure that has been proven to relieve pain and reliably improves the quality of life of its patients. However, patients having a total hip arthroplasty are among those at greatest risk for venous thromboembolic disease. Therefore, most orthopaedic surgeons use routine prophylaxis. Although several agents have been shown to reduce the risk of thromboembolic disease, there is no clear preference for a particular agent in elective total hip arthroplasty. This evidence-based review focuses on the efficacy and safety of the agents that currently are used for prophylaxis against deep venous thrombosis. These agents include warfarin, low-molecular-weight heparin, fondaparinux, aspirin, and mechanical devices. Furthermore, the influence of shorter hospital stays on duration of prophylaxis and screening will be discussed. The most effective prophylactic agents for patients after total hip arthroplasty include low-molecular-weight heparin, warfarin, and fondaparinux. Pneumatic compression devices have been proven to reduce distal thromboembolic events but multi-center, randomized studies need to be done to determine the efficacy of mechanical prophylaxis with short hospital stays. The selection of a prophylaxis regimen is a balance between efficacy and safety, and individual patient factors can influence the prophylaxis regimen that is used.

Do complaints of amaurosis fugax and blurred vision after transcatheter device closure of atrial septal defect indicate microemboli to retinal vessels?

Atrial septal defect (ASD) is a common diagnosis in adults undergoing surgical repair. The aim of the study was to determine if ocular symptoms following treatment are due to microemboli. The study group included 20 adult patients (9 men, 11 women, mean age 57.2 years) with ASD who had undergone successful closure with the Amplatzer occluder. Patients were treated with aspirin or warfarin during the 6 months after the procedure. All were evaluated neurologically and an ocular medical history was obtained. Ocular examination included the 120-point Humphery visual field. Transcranial Doppler (TCD) was performed to monitor the middle cerebral artery. Two patients complained of amaurosis fugax at 1 and 3 months after the procedure, and two patients complained of blurred vision at 3 and 4 months after the procedure. TCD performed within 24 h of the complaints revealed no abnormalities. In all patients, the neurological and ocular examinations, including the visual field test, were normal. In conclusion, microembolic events do not appear to be the cause of the ocular complaints in patients with ASD treated with Amplatzer occluder. Further studies in larger samples are needed to confirm these results.

Fibrocartilaginous embolism in a chondrodystrophoid breed dog

An 8-year-old intact male Shih Tzu dog was admitted with acute-onset tetraplegia. Magnetic resonance imaging showed an abnormality of the cervical intramedullary spinal cord. Histopathological examination of a spinal biopsy confirmed the presence of intravascular cartilaginous emboli. This is the first report of an antemortem diagnosis of fibrocartilaginous embolism in a chondrodystrophoid breed dog.

Embolic cilioretinal artery occlusion due to carotid artery dissection

PURPOSE

To report a case of embolic cilioretinal artery occlusion caused by carotid artery dissection.

DESIGN

Interventional case report.

METHODS

A 38-year-old woman presented with acute visual loss in her right eye. Funduscopy showed a cilioretinal artery occlusion, which was confirmed by a fluorescein angiography. An embolus was found in the distal segment of the vessel.

RESULTS

Color Doppler images of right internal carotid artery (ICA) disclosed a pseudolumen, suggesting a diagnosis of carotid dissection. Retrobulbar color Doppler image showed relative low flow velocity in the ophthalmic artery without flow reversal. Magnetic resonance angiography and cerebral angiogram showed total occlusion of the right ICA. Follow-up visual field examination revealed an inferior central defect fed by the cilioretinal artery.

CONCLUSION

The pathogenesis of retinal artery occlusion caused by carotid dissection may be embolic or hemodynamic. In our case, a permanent visual defect was related to embolic occlusion of the cilioretinal artery.

Surgical therapy for acute superior mesenteric artery embolism

BACKGROUND

Acute mesenteric artery embolism has a high rate of morbidity and mortality. Early diagnosis and appropriate treatment are the most important factors associated with morbidity and mortality.

METHODS

During the period between 1997 and 2002, 24 patients underwent superior mesenteric artery embolectomy. The patients were divided into three groups according to the onset of symptoms and operation time. Group I (n = 12) patients were operated on in the first 6 hours after onset of symptoms; group II (n = 9) patients were operated on between 6 and 12 hours after onset; and group III (n = 3) patients underwent embolectomy after 12 hours. Low-dose (5 to 10 mg) local tissue-type plasminogen activator (t-PA) administration directly into the superior mesenteric artery was an additional procedure with the embolectomy in all patients.

RESULTS

The macroscopic view of the intestine was normal in 15 patients (12 patients in group I and 3 patients in group II) 30 minutes after the administration of local t-PA. Segmental resection was necessary in 4 patients in group II. Extended resection was necessary in 2 patients in group II and 3 patients in group III, and all of the patients died during the early postoperative period.

CONCLUSIONS

We suggest that explorative laparotomy should be done in patients with sudden abdominal pain, nausea, vomiting, mild leukocytosis, and metabolic acidosis who have previous valvular heart disease or atrial fibrillation. Ultimately, selective low dose t-PA (5 to 10 mg) administration reduces the length of intestinal portion to be resected.

Popliteal artery disease: diagnosis and treatment

The popliteal artery is a relatively short vascular segment but is affected by a unique set of pathologic conditions. These conditions, which may be common throughout the arterial system or exclusive to the popliteal artery, include atherosclerosis, popliteal artery aneurysm, arterial embolus, trauma, popliteal artery entrapment syndrome, and cystic adventitial disease. The clinical manifestations, imaging appearances, and treatment options associated with these pathologic conditions differ significantly. Consequently, the radiologist should be familiar with these conditions to direct imaging for accurate diagnosis and treatment and to prevent loss of limb.

FIBROCARTILAGINOUS EMBOLIC MYELOPATHY IN A SUMATRAN TIGER (PANTHERA TIGRIS SUMATRAE)

An adult, captive-born Sumatran tiger (Panthera tigris sumatrae) had been ataxic for approximately 3 mo and had been self-mutilating after an acute onset of unilateral paresis and Homer's syndrome. Histologic lesions in the cervical spinal cord were consistent with fibrocartilaginous embolic myelopathy (FCEM), and they included the presence of cartilaginous occlusion of spinal blood vessels. This is the first reported case of FCEM in a large felid and specifically a Sumatran tiger.

Modern aspects of antithrombotic treatment: an introduction

Intracardiac thrombosis and cardioembolisms may have impressive effects on quality of life, prognosis and therapeutic costs in patients with valve disease or replacement devices. Distinct pathophysiological differences exist regarding intracardiac thrombus formation in low-versus high-pressure areas. Important cardiac confounders for low-pressure areas are left atrial geometry and function, including atrial fibrillation or loss of active atrial contraction. In high-pressure areas, flow velocity and shear stress are raised, and this may result in flow turbulence, for example when blood passes a stenotic area. Other major factors which correlate with intracardiac thrombus formation are implantation of polymer material and the degree of endocardial damage resulting for example, from infective or rheumatic endocarditis. Because of the interaction of platelets and the plasma clotting system, a combination of oral anticoagulation therapy and antiplatelet drugs should prevent more thromboembolic events than might anticoagulation alone. Recent studies in patients with prosthetic heart valves have indicated a positive risk-benefit profile if low-dose antiplatelet drugs are added to moderate intensive oral anticoagulation therapy. Thromboembolic events and bleeding complications due to oral anticoagulation therapy are accepted key parameters to demonstrate the superiority of one replacement device over another. However, there is no consistent system for reporting morbid events. In order to organize low and narrow target INR ranges, point-of-care patient self-testing modalities have been introduced and used effectively in large sample sizes. In the near future, some promising new drugs--including direct thrombin or factor Xa inhibitors with broader therapeutic ranges and thus fewer side effects--will become available. The test for these drugs will be their potential to prevent intracardiac thrombosis and cardioembolism in a patient population which is under significant risk.

[Local lysis with alteplase for the treatment of acute embolic leg ischemia following the use of the duett closure device: preliminary results]

PURPOSE

To analyze retrospectively the result of the alteplase lysis therapy of embolic complications following the use of the Duett closure device.

METHODS AND MATERIALS

For 3.5 years, the Duett closure device was used in 1,398 angiographies to close the femoral puncture site. The Duett device consists of a balloon and a liquid procoagulant containing collagen and thrombin, which is injected into the puncture tract under endovascular balloon protection of the arterial puncture site. In 9 patients (0.64 %), the procoagulant was incidentally injected into the femoral artery causing acute leg ischemia. Eight patients received local lysis therapy with alteplase via a contralateral femoral access. One patient underwent surgery. On average, 21 mg alteplase (4 - 35 mg) were administered within 14 h (4 - 21 h). The course of the lysis was followed angiographically and clinically. All patients were interviewed by telephone 23 months (4 - 35 months) later.

RESULTS

In 3 patients, lysis was complete. In 5 patients, only little thrombotic material remained. In all patients, symptoms of ischemia resolved completely within the first hours after initiation of lysis. In 5 cases, bleeding occurred at the puncture site closed with the Duett device during lysis, including development of a false aneurysm in 2 cases. Complications led to premature termination (n = 2) or interruption of the lysis (n = 3). All complications were treated conservatively. Clinically, long-term sequelae were paresthesia and hypoesthesia in the lower leg and foot in 2 patients treated with lysis, and in the patient who underwent surgery.

CONCLUSION

Very rarely occurring embolic complications after use of the Duett closure device can be effectively treated with alteplase lysis. A high rate of complications is to be expected at the puncture site closed with the Duett device.

[True isolated atherosclerotic aneurysm of the axillary artery]

The true atherosclerotic aneurysm of the axillary artery is a rare condition. It either presents as a pulsatile axillary mass or arterial emboli in the hand and fingers. We report the case of a 70-year-old man with a 5 cm aneurysm of the axillary artery presenting with embolic disease to the hand. Angiography is helpful and provides valuable preoperative anatomic details. Surgery remains the treatment of choice but endovascular treatment can also be considered.

Superior mesenteric arterial embolism: a retrospective study of local thrombolytic treatment with urokinase in West China

Embolism of the superior mesenteric artery (SMA) is a rare disorder. To explore the selective criteria of local thrombolysis, evaluate its efficacy and discuss the therapeutic protocol of SMA embolism, a retrospective case control study was undertaken. Sixteen cases were divided into two groups: nine cases (group A) from May 1995 to April 1999 were given traditional treatment, while seven cases (group B) from November 1999 to June 2002 received comprehensive therapy including local thrombolysis. The local thrombolytic treatment was performed without procedure-related complications and the embolus was successfully lysed in four patients. The time between admission and diagnosis (or treatment) was shorter in group B than in group A (2.3 +/- 1.2 vs 12.3 +/- 9.2 hr, p = 0.013). Gangrenous bowel segments in group A were much longer than in group B (159.4 +/- 87.7 vs 45.7 +/- 61.6 cm, p = 0.009). However, mortality between the two groups was the same (p = 0.282, OR = 0.32, 95% CI = 0.039, 2.618) perhaps because of the small sample size. Angiography could shorten the duration from the onset of SMA embolism to therapy and certainly lowers the risk of mortality. Local fibrinolytic infusion may be an effective alternative to embolectomy in patients with SMA embolism but without intestinal infarction.

Acute branch retinal arterial embolism successfully treated with intravenous prostaglandin E1--case reports

The purpose of this paper is to report the use of intravenous prostaglandin E1, a potent vasodilator, to rapidly restore blood flow and vision in a patient with an acute branch retinal arterial occlusion. An 82-year-old woman with an acute decrease in the visual acuity of her left eye due to an acute superior temporal branch retinal arterial embolus was treated with 140 microg of intravenous prostaglandin E1. The medicine was repeated the following day. At the onset of the branch arterial occlusion her vision in the left eye was 20/50, the embolus could be seen in the superior temporal branch, and a white retinal edema extended down into the macula. At her first eye examination 4 days after treatment, her visual acuity had returned to 20/20, the retinal embolus was still present, but the white macular edema had disappeared. Intravenous prostaglandin E1 is a safe, potent vasodilator for the peripheral vascular system. If used immediately to treat acute branch arterial retinal occlusions, it can restore good vision. The authors report the first case of the use of intravenous prostaglandin E1 to treat a spontaneous acute branch retinal arterial embolus.

Cardiac sources of embolism should be routinely screened in ischemic colitis

OBJECTIVE

Potential cardiac sources of embolism may promote ischemic colitis. The aim of this study was to evaluate their role in segmental, nongangrenous ischemic colitis and to determine the usefulness of routine cardiac evaluation in patients with this disease.

METHODS

Sixty case and 60 control patients matched for age and gender were included and questioned regarding treatment and prior cardiovascular history or risk factors. Potential cardiac sources of embolism, classified as "proven" or " still debated," were screened using an electrocardiogram, rhythmic Holter monitoring over 24 h, and transthoracic echocardiography.

RESULTS

Sex ratio (male:female) was 1:2, and mean age was 70 +/- 14 yr. Case and control patients had similar drug use, prior cardiovascular history, and risk factors. A potential cardiac source of embolism was found in 26/60 case (43%), compared with 14/60 control patients (23%) (p = 0.02; OR = 2.5, 95% CI = 1.2-5.5). Excluding the "still debated," 21/60 case (35%), compared with 8/60 control patients (13%), had a "proven" cardiac source of embolism (p < 0.01; OR = 3.5, 95% CI = 1.4-8.4). Electrocardiogram alone misdiagnosed 72% of the "proven" cardiac sources of embolism, whereas the combination electrocardiogram plus Holter monitoring detected 71%, and electrocardiogram plus echocardiography 62%. Twelve of 21 case patients with at least one proven cardiac source of embolism, were previously unknown. Anticoagulant therapy was required in 32% of case patients and antiarrhythmic therapy in 25% of cases.

CONCLUSIONS

Potential cardiac sources of embolism were more common in patients with segmental, nongangrenous ischemic colitis than in control patients. Therefore, these patients should undergo a routine electrocardiogram, rhythmic Holter monitoring, and transthoracic echocardiography. Anticoagulant therapy should also be considered for this patient population.

Successful local fibrinolytic treatment and balloon angioplasty in superior mesenteric arterial embolism: a case report and literature review

We present the case of a 72-year-old man with atrial fibrillation who developed an embolic occlusion of the superior mesenteric artery. He was successfully treated with local fibrinolysis using streptokinase associated with angioplasty. Such local treatments without the need of surgery are very rarely reported in the literature because of the great difficulty in selecting patients without intestinal necrosis, but represent an important option in the algorithm for the management of acute mesenteric ischemia. The patient was in good condition without recurrent embolism during the six months follow-up.

[Conservative treatment of acute embolisms of the carotid bifurcation]

Embolic events of the carotid bifurcatin are a rare cause of cerebrovascular accidents. We observed two patients who showed a spontaneous recanalisation of an embolic occlusion of the extracranial vessels when treated with conservative procedure using heparin. Both patients had a near complete remission of the symptoms without impairment in their daily activities.

BB embolus causing monocular blindness in a 9-year-old boy

PURPOSE

To report a case of monocular blindness resulting from intravascular bullet migration.

DESIGN

Observational case report.

METHODS

A 9-year-old boy presented to the emergency room with a penetrating BB gun injury to the chest.

RESULTS

Carotid angiography localized the bullet to the right internal carotid artery. He subsequently suffered blindness in the right eye, a right pupil-involving third nerve palsy, left hemiparesis, and a probable left homonymous hemianopia.

CONCLUSION

BB gun injuries may result in devastating ophthalmologic as well as systemic consequences due to bullet embolization.

[Post-traumatic renal arteriovenous fistula. Conservative treatment with superselective embolization]

OBJECTIVE

Renal arterial-venous fistula is a low incidence clinical entity generally secondary to processes invasive to such organ. We report a new case with a bibliographic review, and evaluate the diagnostic and therapeutic approach.

METHODS/RESULTS

We report the case of a patient who suffered a left flank knife wound and developed an arterial-venous fistula presenting with hematuria that was solved by selective embolization.

CONCLUSIONS

Arterial-venous fistula is a low incidence entity, usually secondary to renal trauma (open or blunt) and invasive processes. Renal Doppler-Ultrasound is the initial diagnostic procedure when its diagnosis is strongly suspected and then angiography is both confirmatory and therapeutic.

Treatment of superior mesenteric artery embolism with a fibrinolytic agent: case report and literature review

Successful treatment of superior mesenteric artery embolism depends on an aggressive approach in patients at risk for mesenteric ischemia. This approach favors an early diagnosis and permits the reestablishment of arterial flow within an appropriate time, with prevention of vasospasm and control of organic insufficiencies. We report here a case of superior mesenteric artery embolism in which arterial flow was reestablished by selective intra-arterial infusion of streptokinase. The literature has reported 18 similar cases thus far. This procedure could be an alternative to embolectomy in selected patients, i.e., patients with an early diagnosis, no evidence of intestinal necrosis and with partial occlusion and/or occlusion of secondary branches of the superior mesenteric artery. Frequent arteriographies and intensive care are necessary in this approach. The patient should be continuously monitored because of the possibility of treatment failure and the need for embolectomy.

The morbidity related to atrial fibrillation at a tertiary centre in one year: 9.0% of all strokes are potentially preventable

Atrial fibrillation is a major risk factor for stroke. Anticoagulant therapy reduces this risk but increases the risk of haemorrhage. We aimed to compare the morbidity related to the treatment of atrial fibrillation with warfarin seen in one year at our hospital, with the morbidity in those patients in whom embolism was potentially preventable. There were 111 patients admitted to our hospital in a 12 month period with nonvalvular atrial fibrillation (NVAF) who had stroke, TIA or peripheral embolism. Atrial fibrillation was identified prior to admission in 87 of these 111 (78%) patients with thromboembolism, yet only 14 of these (16%) were receiving warfarin for stroke prophylaxis. Through chart review, a further 56 (64%) patients with embolism could have been receiving anticoagulant therapy if published clinical guidelines(1) were applied. Therefore, 40 episodes of thromboembolism were potentially preventable. Over the same period, there were 18 patients admitted with haemorrhage related to warfarin therapy for stroke prophylaxis in NVAF, including 10 gastrointestinal, five intracerebral, and three peripheral haemorrhages. Most haemorrhages were associated with a high International Normalized Ratio (INR) and the patients were left less disabled than those with embolism. Only one patient with haemorrhage had an absolute contraindication to warfarin therapy (6%). We conclude that the number of preventable strokes far outweighed the morbidity due to warfarin use in the management of NVAF.

Anticoagulation: the present and future

Thrombin is a central bioregulator of coagulation and is therefore a key target in the therapeutic prevention and treatment of thromboembolic disorders, including deep vein thrombosis and pulmonary embolism. The current mainstays of anticoagulation treatment are heparins, which are indirect thrombin inhibitors, and coumarins, such as warfarin, which modulate the synthesis of vitamin K-dependent proteins. Although efficacious and widely used, heparins and coumarins have limitations because their pharmacokinetics and anticoagulant effects are unpredictable, with the risk of bleeding and other complications resulting in the need for close monitoring with their use. Low-molecular-weight heparins (LMWHs) provide a more predictable anticoagulant response, but their use is limited by the need for subcutaneous administration. In addition, discontinuation of heparin treatment can result in a thrombotic rebound due to the inability of these compounds to inhibit clot-bound thrombin. Direct thrombin inhibitors (DTI) are able to target both free and clot-bound thrombin. The first to be used was hirudin, but DTIs with lower molecular weights, such as DuP 714, PPACK, and efegatran, have subsequently been developed, and these agents are better able to inhibit clot-bound thrombin and the thrombotic processes that take place at sites of arterial damage. Such compounds inhibit thrombin by covalently binding to it, but this can result in toxicity and nonspecific binding. The development of reversible noncovalent DTIs, such as inogatran and melagatran, has resulted in safer, more specific and predictable anticoagulant treatment. Oral DTIs, such as ximelagatran, are set to provide a further breakthrough in the prophylaxis and treatment of thrombosis.

Open-angle glaucoma secondary to blood clot in the Schlemm's canal following scleral buckle surgery and its treatment with tPA

Obstruction of the episceral venous system can present with glaucoma. We present two patients who were referred to us for management of acute glaucoma with presumed episceral venous compression. The first patient had open-angle glaucoma with probable elevated episcleral venous pressure and blood in the Schlemm's canal, following a 360 degrees scleral buckle surgery. The second patient had open-angle glaucoma from delayed peribulbar hemorrhage following uncomplicated cataract surgery with blood in the Schlemm's canal. Both patients were successfully treated with intracameral injection with tissue plasminogen activator (tPA).

Anticoagulation and microembolus detection in a case of internal carotid artery dissection

BACKGROUND

Microembolic signals (MES) have been demonstrated by transcranial Doppler (TCD) in cases of internal carotid artery dissection. The influence of treatment on MES in arterial dissection is uncertain. The authors here present a case of internal carotid artery dissection in which we detected a reduction of MES after the initiation of intravenous heparin.

METHODS

A 37-year-old woman developed a right temporal headache 10 days prior to admission. This was followed by episodes of left arm numbness and weakness. Magnetic resonance imaging (MRI) showed a right frontal and deep subcortical ischemic infarct. Catheter angiography confirmed a right internal carotid artery dissection with intracranial extension. She was then monitored with TCD for MES before and after intravenous heparin was started.

RESULTS

The first TCD, performed 12 days after symptom onset, showed 39 MES during 60 minutes of insonation of the right middle cerebral artery. Treatment with intravenous heparin resulted in a decline in MES by 50% after 96 hours. This decline continued and no further MES were detected after 11 days of anticoagulation.

CONCLUSION

The authors were able to demonstrate a decline of MES with heparin anticoagulation in a case of internal carotid artery dissection.

Local thrombolytic treatment for renal arterial embolism

OBJECTIVE

To determine the utility of local thrombolysis in the treatment of acute renal arterial occlusion.

METHODS

We used local thrombolytic treatment in a female patient, aged 76, with 72 h of anuria, right lumbar and flank pain. She had a 3-year history of ischemic heart disease and atrial fibrillation controlled with digital treatment. Also, she was nephrectomized on the left side 33 years ago for lithiasic pyonephrosis. A normal right urinary tract was demonstrated with ultrasound examination, KUB radiography and retrograde pyelography. The next step was diagnostic abdominal angiography and local thrombolytic treatment with streptokinase.

RESULT

Thrombolysis with streptokinase was successful following 72 h of renal artery occlusion. After 24 months the patient is doing well.

CONCLUSION

Local intra-arterial thrombolysis is the treatment of choice in renal artery occlusion.

Hypothenar hammer syndrome: management of distal embolization by intra-arterial fibrinolytics

We report a case of hypothenar hammer syndrome. The ulnar artery aneurysm was resected and a complete thrombectomy of the superficial palmar arch, the common digital and the proximal part of the collateral digital arteries was carried out. The arterial defect of the ulnar artery was repaired by a vein graft. Post-operatively, no clinical improvement was observed on the vascularisation of the second and third fingers. The arteriogram confirmed the presence of arterial obstruction on the distal part of the digital collateral arteries of this two fingers. The finger pulp started to show areas of skin gangrene and in view of the risk of finger necrosis, we decided to use fibrinolytics. This embolic events was dissolved by continuous fibrinolytic and anticoagulant intra-arterial infusion. The treatment was maintained for ten days restoring a normal digital vascularisation.

Effect of heparin reversal and fresh platelet transfusion on platelet emboli post-cardiopulmonary bypass in a pig model

Heparin reversal by protamine and fresh platelet transfusion may decrease bleeding complications post-cardiopulmonary bypass (CPB) and may increase the level of organ trapped platelet emboli. Platelet emboli were quantified in two groups of 12 Yorkshire pigs (30-35 kg), where 111indium labeled autologous platelets (INPLT: 850-1,200 microCi) were injected intravenously before and after CPB (BCPB, ACPB), and the platelet emboli level in intact organs and their samples (brain, heart, kidneys, lung, liver, and spleen) was quantified with an ion chamber and a gamma counter, respectively. All pigs were systemically heparinized (ACT > 400 sec). CPB was carried out at 2.5-3.5 L/min at 28 degrees C using a centrifugal pump, an oxygenator (OX:Bentley Univox 1.8 m2), an arterial filter (AF:0.25 m2), and a cardiotomy reservoir (CR: BMR 250) for 90 min. Heparin was reversed with an equivalent dose of protamine. The percent of INPLT dose (ID%, mean +/- SD) in organs of BCPB and ACPB pigs was calculated. The sequence of platelet emboli on a unit weight basis (ID%/g) had the following order: Spleen > Liver > Lung > Kidneys > Heart > Brain. The presence of significantly higher levels of emboli in brain, heart, and kidneys in the ACPB than the BCPB group suggest that platelet transfusion after heparin reversal with protamine may increase the risk of platelet emboli. However, it is an acceptable risk for patients having bleeding complications post-CPB.

Outcome and one year follow-up of intra-arterial staphylokinase in 191 patients with peripheral arterial occlusion

Wild-type or equipotent variants of recombinant staphylokinase (rSak) were given intra-arterially (as a 2 mg bolus injection followed by an infusion of 1 mg/h or 0.5 mg/h overnight, with concomitant heparin [1000 IU/h]) to 191 patients of less than 80 years (62 +/- 1 years, mean +/- SEM), with a peripheral arterial occlusion (PAO) of less than 120 days (mean 14 +/- 1 days, median 11 days, 5 to 95 percentiles 3 to 30 days). Ninety nine patients presented with acute or subacute ischemia, 57 with severe claudication, 33 with chronic rest pain and 2 with gangrene. Occlusion occurred in 122 native arteries and in 69 grafts. Revascularization was complete in 83 percent (158/191), partial in 13 percent (24/191) and absent in 4 percent (7/191) after administration of 12 +/- 0.5 mg rSak over 14 +/- 0.7 h. Complete revascularization of acute occlusions of popliteal or more distal arteries was less frequent (60 percent, 15/25) than of acute occlusions of more proximal native arteries (95 percent, 37/39, p <0.001) or grafts (89 percent, 50/56, p = 0.005). Additional endovascular procedures were performed in 47 percent and subsequent elective bypass surgery in 23 percent of patients. Major bleeding occurred in 12 percent (23/191), one month mortality was 3.1 percent (6/191) and one year mortality was 6.9 percent (12/174). However, four patients (2.1 percent) had an intracranial bleeding following therapy: a 85 year old woman with severe diabetic arteriopathy, who was included in violation of the protocol, a 79 and a 74-year-old woman and a 74-year-old man, all with severe hypertension and limb threatening ischemia; these four patients died within two months after treatment. Amputations were performed within the first year in 16 of 162 surviving patients (9.8 percent): in 7 percent (7/96) with an occluded native artery and 14 percent (9/66) with an occluded graft (p = 0.19). No significant difference in lysis rate, one month mortality or one year amputation-free survival was observed in occlusions of recent onset (< or =14 days, n = 126) as compared to occlusions of longer duration (>14 days, n = 65). Treatment was interrupted prematurely in 4 patients because of a suspected allergic reaction. Fibrinogen levels remained unaffected during treatment (3.3 +/- 0.1 g/l before vs. 3.3 +/- 0.1 g/l after infusion, n = 167). In conclusion, rSak appears to be a highly effective thrombolytic agent in patients with PAO, resulting in a low one month mortality (3.1 percent) and a high one year amputation free survival (84 percent), with an acceptable incidence of major bleedings, but with occasional fatal intracranial hemorrhages.

Internal carotid artery aneurysm visualized during successful endovascular treatment of carotid embolism

We herein present a case of an internal carotid artery embolism associated with a hidden internal carotid artery aneurysm. The aneurysm was visualized during successful endovascular treatment of the carotid embolism. In retrospect, the aneurysm was at risk of rupture during the procedure. In the endovascular treatment of cerebral embolism, the possibility that aneurysms are hidden by emboli must be borne in mind. Care should be taken not to injure unidentified arterial walls while advancing a catheter blindly.

Cardioembolic vs. noncardioembolic strokes in atrial fibrillation: frequency and effect of antithrombotic agents in the stroke prevention in atrial fibrillation studies

BACKGROUND

While atrial fibrillation (AF) increases the risk of cardioembolic stroke, some ischemic strokes in AF patients are noncardioembolic.

OBJECTIVES

To assess ischemic stroke mechanisms in AF and to compare their responses to antithrombotic therapies.

METHODS

On-therapy analyses of ischemic strokes occurring in 3,950 participants in the Stroke Prevention in Atrial Fibrillation I-III clinical trials. Strokes were classified by presumed mechanism according to specified neurologic features by neurologists unaware of antithrombotic therapy.

RESULTS

Of 217 ischemic strokes, 52% were classified as probably cardioembolic, 24% as noncardioembolic, and 24% as of uncertain cause (i.e., 68% of classifiable infarcts were deemed cardioembolic). Compared to those receiving placebo or no antithrombotic therapy, the proportion of cardioembolic stroke was lower in patients taking adjusted-dose warfarin (p = 0.02), while the proportion of noncardioembolic stroke was lower in those taking aspirin (p = 0.06). Most (56%) ischemic strokes occurring in AF patients taking adjusted-dose warfarin were noncardioembolic vs. 16% of strokes in those taking aspirin. Adjusted-dose warfarin reduced cardioembolic strokes by 83% (p < 0.001) relative to aspirin. Cardioembolic strokes were particularly disabling (p = 0.05).

CONCLUSIONS

Most ischemic strokes in AF patients are probably cardioembolic, and these are sharply reduced by adjusted-dose warfarin. Aspirin in AF patients appears to primarily reduce noncardioembolic strokes. AF patients at highest risk for stroke have the highest rates of cardioembolic stroke and have the greatest reduction in stroke by warfarin.

Venous thromboembolic prophylaxis in orthopedic surgery: knee surgery

Knee replacement surgery is associated with a high risk of venous thromboembolic complications, and the risk appears to be highest during the 7 days following surgery. Meta-analysis of a number of randomized, controlled trials has conclusively established the efficacy and safety of low molecular weight heparin (LMWH) prophylaxis in knee replacement surgery. It is clear that LMWHs exhibit distinct physico-chemical, biological, and pharmacodynamic properties, and recently the United States Food and Drug Administration has concluded that these are noninterchangeable drugs. The clinical experience with each LMWH varies widely, and the paucity of data on thromboprophylaxis with LMWHs other than enoxaparin limits relevant comparisons of efficacy and safety. Further clinical trials with different LMWHs are indicated and will help resolve the issue of LMWH inequivalence currently at the center of debate.

Renal artery embolism: therapy with intra-arterial streptokinase infusion

Two patients with acute renal artery embolism were reported. One patient had a history of rheumatic valvular heart disease and the other patient had hereditary cardiomyopathy. Both patients had atrial fibrillation on physical examination. Both patients presented with acute back pain and one patient had hematuria. The final diagnosis of acute renal artery embolism was made after one to three days of hospitalization and renal angiography was finally done documenting complete occlusion of the main branch of the renal artery on one side. Intra-arterial streptokinase infusion 5,000 unit per hour was given to both patients using an arterial pump for 17 hours to 30 hours with complete recanalization of the intrarenal branches and complete recovery of signs and symptoms of renal artery embolism although the renal scan still showed diminished renal function.

[Local thrombolysis in renal artery embolism]

Renal artery embolism is an infrequent entity that occurs in patients with underlying cardiac diseases. Diagnosis is usually difficult unless the index of suspicion is high. Local thrombolysis with low-dose fibrinolytic agents is an useful therapeutic intervention. We present 2 cases of renal artery embolism treated with intra-arterial urokinase and review clinical features and therapeutic options.

Intra-arterial segmental thrombolysis in patients with arterial embolism of cardiac origin

OBJECTIVE

It is well known that in the evolution of cardiac diseases, thromboembolic accidents are quite frequent. In patients with acute peripheral ischaemia, surgical treatment is usually the procedure of choice, but in some circumstances some of these patients cannot benefit from the surgical treatment. Conservative treatment rarely leads to satisfactory results. An alternative of therapy is the thrombolysis, but administration of Streptokinase in systemic dose can lead to serious thromboembolic accidents and hemorrhage. Intra-arterial administration of the drug, in small doses, can eliminate this risk. The aim of this study was to demonstrate the efficacy of intra-arterial thrombolysis in patients with cardiac diseases complicated with peripheral arterial emboli.

METHOD

In the period 1984-1997, we performed a number of 84 intra-arterial thrombolyses. Sixty-one of them were performed in case of chronic or acute arterial obstruction of the inferior limbs, occurring in the evolution of chronic arterial disease, 14 in the patients with acute obstruction caused by emboli from cardiac cavities, and 9 in the patients with arterial embolism of other origin. We applied this procedure infusing Streptokinase intraarterially, continuously, directly and progressively in the thrombus, with a rate of 2-4000 unit/min, and a total dose more than 100,000-120,000 units. All patients had been consulted previously in a surgical unit and for different reasons surgical treatment was not indicated.

RESULTS

We succeeded to repermeabilise the entire arterial route at all the patients (fact demonstrated by the clinical and Doppler examinations). We obtained complete primary repermeabilisation in 79% cases (11 cases), and repermeabilisation at 24 hours in all cases. We did not record major complications during this procedure.

CONCLUSIONS

At the cases we studied (a small number), this method seems to be an alternative of therapy with good results in the restoration of obstructed arterial circulation. Intra-arterial administration of Streptokinase, in small doses, can eliminate the haemorrhagic and thromboembolic risks that appear in case of systemic administration of the drug.

Local thrombolytic therapy for superior mesenteric artery embolism: complications and long-term clinical follow-up

PURPOSE

To evaluate the effectiveness and complications of local intraarterial fibrinolysis in selected patients with superior mesenteric artery (SMA) embolism.

MATERIALS AND METHODS

Intraarterial thrombolytic therapy was performed for acute SMA embolism in eight patients. Patients were selected for thrombolytic therapy on the basis of absence of peritoneal signs of intestinal necrosis at physical examination and absent findings of bowel infarction by CT.

RESULTS

Clinical success was achieved in five patients and technical success in six. Complications included death due to massive shower emboli from the left ventricle in one patient and extravasation in one patient, who required surgery on the following day. Within one month after thrombolytic therapy, one patient each died of myocardial infarction and cerebral infarction due to emboli, and one patient underwent aorto-SMA bypass surgery due to residual stenosis. In the long-term follow-up period (2-7 years), four patients were still alive, with another embolic episode of a lower limb in one patient. One patient died of an unrelated cause without experiencing another embolic episode.

CONCLUSION

Intraarterial fibrinolysis may be a therapeutic alternative in the management of SMA embolism in selected patients in whom an early diagnosis can be made. The long-term results depend on the occurrence of another embolic event.

Accuracy of visible retinal emboli for the detection of cardioembolic lesions requiring anticoagulation or cardiac surgery. Retinal Emboli of Cardiac Origin Study Group

AIM

To determine the accuracy of visible retinal emboli as a diagnostic "test" for the likelihood of receiving anticoagulation or cardiac surgery based on the results of transthoracic echocardiography, in the setting of acute retinal arterial occlusion.

METHODS

A multicentre retrospective diagnostic study at Kingston Eye Centre, Queen's University, Kingston, Ontario; Wills Eye Hospital, Philadelphia; Ottawa Eye Institute, Ottawa, Ontario; and the Halifax Infirmary, Halifax, Nova Scotia of 104 patients with both embolic and nonembolic acute retinal arterial obstruction who underwent transthoracic echocardiography was performed, to determine the accuracy of visible retinal emboli as a diagnostic "test" for anticoagulation or cardiac surgery. Anticoagulation or surgical intervention on the basis of abnormalities was detected solely through the technology of transthoracic echocardiography.

RESULTS

41 patients had visible retinal emboli (calcific, cholesterol, or fibrin). The remaining 63 had no evidence of embolic disease. The sensitivity of emboli for the likelihood of a patient receiving anticoagulation or cardiac surgery was 50%. The specificity, positive predictive value, and negative predictive value were 62%, 15%, and 90%, respectively. The likelihood ratio (LR = 1.31) obtained given the presence of a visible retinal embolus was neither clinically nor statistically significant (LR+ve = 1.31; 95% CI (0.91, 3.16)). This likelihood ratio, when applied to a patient with a pretest probability of 50%, results in a post-test probability of 56.7%.

CONCLUSIONS

These results demonstrate that the presence of a visible retinal embolus should not be the sole determinant of whether to order transthoracic echocardiography, as the likelihood ratio for a patient receiving anticoagulation or cardiac surgery, given the presence of a visible retinal embolus was only 1.31.