The role of thrombolytic therapy in the management of paradoxical embolism

Paradoxical emboli are considered a rare event, representing less than 2% of all arterial emboli. The most common intracardiac defect associated with paradoxical emboli is a patent foramen ovale. Most commonly, a pulmonary embolism is the cause of the acute increase in right atrial pressure leading to a reversal of intracardiac flow and passage of venous embolic material to the left heart. We present a patient with a pulmonary embolism and paradoxical emboli, and discuss therapeutic approach. We suggest that the treatment of choice for the patient with pulmonary embolism and non-limb-threatening acute ischemia due to a paradoxical emboli should be thrombolytic therapy and intracaval filter placement, followed by patent foramen ovale repair.     

Pulmonary Embolism and Concomitant Paradoxical Embolism. A Case Report

Although patent foramen ovale is a relatively common disease, the presence of paradoxical embolism is a rare clinical condition, representing less than 2% of arterial ischemias. We report the case of a 55-year-old male diagnosed with massive pulmonary embolism and paradoxical embolism in the right arm, secondary to patent foramen ovale. We also highlight some uncertainties in the diagnosis and treatment of patients with paradoxical embolism.     

Arterial embolism of venous origin: a clinical entity to keep always in mind

In patients with unexplained arterial embolism or unexplained cerebral vascular accidents, a diagnosis of paradoxical embolism should be taken into consideration. It consists in the passage of an embolus, originating in the venous system or the right side of the heart, via an abnormal right to left channel, into the systemic circulation. In the majority of cases the abnormal communication is a patent foramen ovale; its incidence varies from 6% to 29% in unselected autopsies. The diagnosis of paradoxical embolism requires the presence of four Johnson's criteria. Nowadays the diagnostic procedures have been simplified by introducing non-invasive techniques based on ultrasound evaluation. The treatment of paradoxical embolism must be individualized and consists above all in the use of anticoagulants. Here we report a case of right leg paradoxical embolism in a young woman who had been operated on three months earlier for breast cancer. After ilio-femoro-popliteal thromboembolectomy, Doppler of the lower limb veins was performed. The presence of iliac venous thrombosis led to a suspicion of paradoxical embolism, which was then confirmed by the demonstration of a patent foramen ovale. The diagnosis of paradoxical embolism is important because the condition is associated with significant morbidity and mortality rates.     

A case of renal paradoxical embolism

Acute renal failure due to paradoxical embolism is exceptionally reported. A new case gives the opportunity to review mechanisms, diagnosis and therapeutic issues. A 49-year-old woman without medical history is admitted for crural venous thrombosis and acute pulmonary embolism. At day 2, a left flank acute pain with fever, doubling of plasma creatinine, and controlateral recurrence at day 12, leads to diagnosis of acute bilateral renal infarction only at day 20. Paradoxical embolism is then suspected and confirmed by transoesophageal contrast echocardiography, disclosing patent foramen ovale with right-to-left shunt. Nine months later, successful percutaneous closure of patent foramen ovale with Amplatzer PFO occluder 25 mm allows subsequent discontinuation of oral anticoagulation. Diagnostic criteria for paradoxical embolism are present in our case. If this mechanism is often discussed in cryptogenic cerebrovascular stroke of young patients, it is exceptionally reported as responsible for clinical renal disease, particularly acute renal failure (whereas anatomical renal involvement is not unfrequent). The clue is the difficulty to suspect and confirm renal infarction, especially when classical causes of cardiac embolism are lacking. The relevance is the opportunity to save renal tissue in the acute phase, and to close patent foramen ovale (currently most often percutaneously) weeks or months after the acute bout.     

Paradoxical fat embolism after uncemented total hip arthroplasty: a case report

The authors report a paradoxical presentation of fat embolism after uncemented total hip arthroplasty. The patient presented vertigo and diplopia after surgery. Cerebral fat embolism was diagnosed by MRI. A patent foramen ovale was responsible for the venous to arterial circulation shunt. Treatment was conservative. Spontaneous and complete recovery occurred.     

Paradoxical embolism. An old but, paradoxically, under-estimated problem

The theoretical model of paradoxical embolism requires the presence of four parameters, namely, arterial embolism, venous thrombus, abnormal intracardiac communication and right-to-left shunt. Many aspects, however, of this well known entity are under consideration; diagnosis is often difficult to be established and the long term efficacy of preventive measures is undefined. We comment on a case report of recurrent paradoxical embolism with popliteal vein thrombosis and patent foramen ovale, and we briefly review the literature.     

Massive Pulmonary Embolism Permitting Paradoxical Systemic Arterial Embolism: Successful Surgical Management

The case of a young woman, receiving oral contraceptives, who developed massive pulmonary embolism producing circulatory collapse and paradoxical arterial embolism through a patent foramen ovale is documented. Limb viability was threatened. Emergency management included removal of arterial and pulmonary emboli, surgical closure of the patent foramen ovale, inferior caval partitioning, ovarian vein ligation, and short-term anticoagulation. Recovery was rapid and complete.     

Intraoperative identification of both a paradoxical embolism and its probable etiologic site

We report a case of upper extremity arterial ischemia in a 41-year-old man. Intraoperative transesophageal echocardiography identified a paradoxical embolization that traversed a patent foramen ovale as the probable etiology. The diagnosis of paradoxical embolism with intraoperative identification of the etiologic site of the deep venous thrombosis is a rare event. This case presents the use of transesophageal echocardiography beyond its monitoring function in helping diagnose the cause of arterial ischemia.     

Arterial embolism, venous thrombosis, pulmonary embolism: a suggestive triad]

The aim of this study is to present a relatively rare case of paradoxical arterial embolism, found in a patient who was sent to us for serious pulmonary embolism. Taking into account that the foramen ovale, despite being functionally competent, remains anatomically patent in 30% of the adult population, we cannot neglect the possibility of a paradoxical embolism, in the presence of a sudden embolic limb ischemia unless heart pathology or aortic lesions can be held responsible. Furthermore it must not be forgotten that deep venous thrombosis in the lower limbs or in the pelvic plexus may go unobserved on a purely clinical evaluation.     

Die venöse paradoxe Luftembolie

Paradoxical air embolism may occur with any venous air embolism. Air may either enter the systemic circulation through a patent foramen ovale or through transpulmonary passage of air. While small venous air emboli are mostly well tolerated, even the smallest paradoxical air emboli can have fatal consequences in the systemic circulation. Therapy and prophylaxis of paradoxical air embolism equal those of venous air embolism. This is especially true, since paradoxical air embolism may not become obvious under general anesthesia. More specific therapeutic regiments, such as hyperbaric oxygenation and the infusion of perfluorocarbons, are still in an experimental stage.     

Paradoxical embolism complicating massive pulmonary embolus.

Paradoxical embolism is an unusual but well recognized complication of venous thromboembolic disease. This case report of a patient with massive pulmonary embolism, who had a paradoxical embolus through a patent foramen ovale, emphasizes that in these circumstances surgical intervention is indicated.     

Transesophageal echocardiography and air embolism during posterior fossa neurosurgery. Intraoperative detection in the foramen ovale

Sitting position during neurosurgery is discussed because the risk of venous air embolism and paradoxical air embolism is increased. Preoperative transoesophageal echocardiography is proposed to screen patients with patent foramen ovale to avoid them for the sitting position. This work reported 2 patients in conflict with this screening. It is discussed the physiological principles governing the paradoxical air embolism and the actual recommended monitoring for this position.     

Thrombus straddling a patent foramen ovale and massive pulmonary embolism: Venous arterial extracorporeal membrane oxygenation as a valuable support tool

Thrombus straddling a patent foramen ovale and massive pulmonary embolism is a very rare and life‐threatening condition. Optimal management can be controversial because different therapeutic options are available and individual approach based in individual risk is needed. We present a case of a thrombus straddling the patent foramen ovale with massive pulmonary embolism, hemodynamic instability, and upper extremity embolism. We performed surgical pulmonary embolectomy, and venous arterial extracorporeal membrane oxygenation was needed to successfully overcome severe right ventricular impairment and pulmonary injury.     

Delayed recovery following laparoscopic partial hepatectomy

We present a 42-year-old woman with unexpected coma after laparoscopic partial hepatectomy. MRI demonstrated ischaemic cerebral lesions. Further investigation revealed a patent foramen ovale. Cryptogenic stroke arising from a paradoxical carbon dioxide embolism was diagnosed. After 5 days of intensive care, she made a near complete recovery. Perioperative stroke, paradoxical emboli during surgery, patent foramen ovale, carbon dioxide cerebral embolism and therapeutic strategies are discussed.     

Paradoxical embolus caught in transit through a patent foramen ovale

Diagnosing a paradoxical embolism is challenging, and it can be proven only if the thrombus is identified across the intracardiac defect. Very few cases have been diagnosed as an impending paradoxical embolism. Recently, the diagnosis and management of these entities have greatly improved with the advent of transesophageal echocardiography (compared with transthoracic echocardiography). Pulmonary hypertension may cause right-to-left shunting across a patent foramen ovale and predispose development of a paradoxical embolism. We report a patient with an impending paradoxical embolism that was caught in transit across the patent foramen ovale. The patient was treated successfully with emergent surgery.     

The seated position in patent foramen ovale?

Anesthetic management of patients presenting for posterior cranial fossa surgery in the seated position includes detection and treatment of venous air embolism. Atrial positioning of a central venous (cv) line may be verified by either X-ray or an atrial ECG tracing. We report a case where a chest X-ray film proved superior. A 26-year-old white female was scheduled for posterior cranial fossa exploration. A cv line was inserted via the left antecubital vein; the chest X-ray film documented correct positioning of the catheter tip within the atrium but an aberrant course of the superior vena cava. Echocardiography was performed in the induction room and indicated a patent foramen ovale. In view of the risk of paradoxical air embolism, surgery was postponed. Subsequent cardiologic and radiologic examinations revealed a patent foramen ovale and a persisting left superior vena cava draining into a dilated coronary sinus. Surgery was rescheduled and carried out uneventfully in the prone position. This case demonstrates: 1) an advantage of a thoracic-X-ray film compared to atrial ECG tracing as not only the catheter tip position, but also the course of the catheter can be identified; and 2) the usefulness of preoperative screening for a patent foramen ovale in patients scheduled for surgery in the seated position.     

Incidences of venous air embolism and patent foramen ovale among patients undergoing selective peripheral denervation in the sitting position

OBJECTIVE: The incidence and severity of venous air embolism (VAE), a potentially fatal complication, among patients undergoing selective peripheral denervation in the sitting position have never been clearly established. We designed this retrospective study to assess the incidence and severity of VAE, the incidence of paradoxical air embolism, and the occurrence of patent foramen ovale, as detected with transesophageal echocardiography, as well as the effects of its detection on patient treatment. METHODS: After institutional review board approval, data were collected from the charts of all patients who underwent selective peripheral denervation at our institution between 1988 and 2001. The severity of VAE was assessed by using a 5-point scale. RESULTS: Data for 342 patients were available for analyses. Seven patients exhibited VAE, yielding an incidence of 2%. The severity of VAE was 2/5 for three patients, 3/5 for three patients, and 4/5 for one patient. Air could be aspirated from the central venous catheter for three patients. No deaths occurred. Among the 96 transesophageal echocardiographic examinations performed, 5 cases of patent foramen ovale were detected (5.2%). For those patients, surgery was performed in the prone or park-bench position. No paradoxical air embolism was detected. CONCLUSION: This is the first large study to directly assess the incidence and severity of VAE among patients undergoing selective peripheral denervation in the sitting position. We recommend that the detection of a patent foramen ovale prompt a change in position for this surgical procedure.     

Paradoxical mesentery embolism and silent myocardial infarction in primary antiphospholipid syndrome: a case report

In this case, we describe a 33-year-old man presenting with acute mesenteric ischemia. When we searched for a source of embolism, a giant right atrial mass and patent foramen ovale was discovered. Standard electrocardiography showed signs of an old, silent anteroseptal wall myocardial infarction, confirmed by echocardiography and left ventriculography. Coronary angiography revealed complete occlusion of the left anterior descending artery. The diagnosis of primary antiphospholipid syndrome was confirmed by anticardiolipin antibodies test. Surgical myocardial revascularization along with the resection of the mass and the closure of the patent foramen ovale were performed. Histological examination of the operative specimen showed a thrombus. This is the first reported case presenting with acute paradoxical mesentery embolism accompanying an old myocardial infarction in a young patient with primary antiphospholipid syndrome.     

Surgical treatment of an amniotic fluid embolism with cardiopulmonary collapse

Amniotic fluid embolism is a rare but devastating condition associated with a very high rate of morbidity and mortality. The treatment has traditionally been aggressive supportive care. We report a case of a term pregnant woman with complete cardiovascular collapse secondary to a paradoxical amniotic fluid embolism. The embolism was seen on transesophageal echocardiogram during an emergency Cesarean section as a free-floating interatrial clot through a patent foramen ovale. She was subsequently and successfully treated with immediate cardiopulmonary bypass, thromboembolectomy, and closure of the patent foramen ovale.     

Simultaneous systemic and pulmonary embolism

A 71 year old woman was admitted in our hospital because of sudden-onset dyspnoea and angina like pain. We presumed acute pulmonary embolism and immediately performed bedside transthoracic (TTE) and transesophageal echocardiographic (TEE) studies. TTE and TEE showed a 1×10 cm large tubular thrombus, entrapped in a patent foramen ovale (PFO), in the right atrium. We performed emergency surgery because of the patient’s acute hemodynamic deterioration. Intraoperatively, we found a long and tubular shaped thrombus (approximately 1×12 cm) transversing from right to left atrium. Several therapeutic options exist for right heart thromboemboli. Surgery has the unique advantage of providing an opportunity to close the patent foramen ovale, thereby preventing recurrent paradoxical embolism.