Diagnosis Of Embolism Research Articles

Scintigraphic probability and angiographic diagnostic certainty in acute pulmonary embolism.

The objectives of this study were to determine if diagnostic certainty on angiography correlates with scintigraphic probability for the diagnosis of pulmonary embolism. From a total of 160 consecutive patients who underwent both nuclear imaging and invasive selective pulmonary angiography, we reviewed the xenon-133 ventilation images in 2 posterior oblique views and the Tc-99m macroaggregated serum albumin perfusion scans and angiograms of 40 patients (15 men, 25 women; average age 57 years) who were discharged from the hospital on anticoagulants with a diagnosis of pulmonary embolism. The angiograms were reviewed and the diagnosis of embolism was considered certain in the presence of an intraluminal filling defect, a trailing embolus, or a branch occlusion equal to or larger than a segmental branch (n=29; 73%), and uncertain when the studies were reinterpreted as either equivocal or negative or in the presence of a single, small subsegmental filling defect of questionable clinical significance. The ventilation-perfusion scans were read as high (n=18; 45%), intermediate (n=10; 25%), or low (n=12; 30%) probability. The proportion of patients with diagnostic certainty on angiography in the high-, intermediate-, and low-probability scintigraphic subgroups was, respectively, 100% (18 of 18), 70% (7 of 10), and 33% (4 of 12) (P=0.004). In patients diagnosed with pulmonary embolism based on selective angiography, a lower probability of pulmonary embolism on ventilation-perfusion scintigraphy correlates with a lesser degree of diagnostic certainty on angiography and a higher incidence of single subsegmental emboli.

Diagnostic approaches to suspected deep vein thrombosis and pulmonary embolism.

The present paper aims at reviewing our present knowledge on the diagnosis of deep vein thrombosis and pulmonary embolism with a particular emphasis on clinically suspected outpatients. The various contemporary diagnostic tools (including clinical probability assessment, fibrin D-Dimer measurement, venous compression ultrasonography, ventilation/perfusion lung scintigraphy, helical CT scan, and echocardiography) are presented and rational sequential strategies are discussed in their various aspects, including validation in outcome studies, and cost-effectiveness analyses.

Another neurological complication of central venous cannulation

Another neurological complication of central venous cannulation

Surgical Closure of Patent Foramen Ovale for Stroke Prevention: Vancouver General Hospital Experience

95 Background and Purpose Patent foramen ovale (PFO) is implicated as a potential cause of stroke, particularly in young patients with otherwise cryptogenic events. The natural history, risk of stroke recurrence and optimal secondary stroke prevention remains uncertain. Therapeutic options include long-term antiplatelet therapy, anti-coagulation therapy, and PFO closure by surgery or device. We report the results of 53 patients treated with surgical closure. Methods and Materials We have followed 53 consecutive surgically treated patients (23 men and 30 female). All patients were evaluated by a stroke neurologist, a cardiologist with expertise in adult congenital disease and a cardiovascular surgeon. Patients who met the following criteria were included: 1) embolic TIA or stroke, 2) PFO or PFO and atrial septal aneurysm (ASA), 3) investigations included cerebral angiography, transesophageal echocardiography, and hypercoagulable studies, 4) presumptive clinical diagnosis of paradoxical embolism with no other etiology detected. Follow up was obtained by clinic visit and standardized telephone questionnaire. Results Prior to surgery 27 patients had stroke and 26 had TIAs; 12 had multiple cerebrovascular events. The mean age at symptom onset was 41.8 ± 9.3 yrs (range 19 to 59). 22 patients had an isolated PFO and 31 had both a PFO and an ASA. Average PFO size measured at surgery was 8.8 ± 7.7 mm. 40 were treated with primary closure, 13 with suture and patch closure. Average post-surgical hospital stay was 4 days. There was no surgical mortality or major morbidity. Minor perioperative morbidity occurred in 13 patients. Average follow up postsurgery was 22.2 ± 17.4 months (range 0.7 to 90.8 months). There were no recurrent strokes and 1 recurrent TIA. Conclusions Surgical closure of PFO can be safely performed with low morbidity and mortality. In this group of carefully selected patients, there have been no recurrent strokes. Further studies are necessary to define high-risk patients for recurrent stroke who may benefit from surgical closure.

Surgical Closure of Patent Foramen Ovale for Stroke Prevention: Vancouver General Hospital Experience

95 Background and Purpose Patent foramen ovale (PFO) is implicated as a potential cause of stroke, particularly in young patients with otherwise cryptogenic events. The natural history, risk of stroke recurrence and optimal secondary stroke prevention remains uncertain. Therapeutic options include long-term antiplatelet therapy, anti-coagulation therapy, and PFO closure by surgery or device. We report the results of 53 patients treated with surgical closure. Methods and Materials We have followed 53 consecutive surgically treated patients (23 men and 30 female). All patients were evaluated by a stroke neurologist, a cardiologist with expertise in adult congenital disease and a cardiovascular surgeon. Patients who met the following criteria were included: 1) embolic TIA or stroke, 2) PFO or PFO and atrial septal aneurysm (ASA), 3) investigations included cerebral angiography, transesophageal echocardiography, and hypercoagulable studies, 4) presumptive clinical diagnosis of paradoxical embolism with no other etiology detected. Follow up was obtained by clinic visit and standardized telephone questionnaire. Results Prior to surgery 27 patients had stroke and 26 had TIAs; 12 had multiple cerebrovascular events. The mean age at symptom onset was 41.8 ± 9.3 yrs (range 19 to 59). 22 patients had an isolated PFO and 31 had both a PFO and an ASA. Average PFO size measured at surgery was 8.8 ± 7.7 mm. 40 were treated with primary closure, 13 with suture and patch closure. Average post-surgical hospital stay was 4 days. There was no surgical mortality or major morbidity. Minor perioperative morbidity occurred in 13 patients. Average follow up postsurgery was 22.2 ± 17.4 months (range 0.7 to 90.8 months). There were no recurrent strokes and 1 recurrent TIA. Conclusions Surgical closure of PFO can be safely performed with low morbidity and mortality. In this group of carefully selected patients, there have been no recurrent strokes. Further studies are necessary to define high-risk patients for recurrent stroke who may benefit from surgical closure.

Pulmonary Embolism as a Consequence of Applying Sequential Compression Device on Legs in a Patient Asymptomatic of Deep Vein Thrombosis

INTRAOPERATIVE pulmonary embolism (PE) is an uncommon complication of emergency intraabdominal surgery. Best practice recommendations for longer surgical cases include the fitting of antithrombotic leg devices such as stockings and pneumatic compression devices. 1,2 Although these devices certainly prevent thrombosis in deep vein thrombosis (DVT)-prone surgical patients, 1,2 we were unable to find reports of any significant complications caused by them (besides minor skin bruising, sores, etc.), namely, dislodgment of a pre-existing thrombus, causing a life-threatening PE. Although PE has been observed after tourniquet deflation in orthopedic surgery cases, 3 we report a case of PE possibly related to pneumatic sequential compression device.

Cost-effectiveness of enoxaparin versus low-dose heparin for prophylaxis against venous thrombosis after major trauma.

We attempted to determine health and economic outcomes from the perspective of an integrated health system of administering enoxaparin 30 mg twice/day versus heparin 5000 U twice/day for prophylaxis against venous thrombosis after major trauma. A decision-analytic model was developed from best literature evidence, institutional data, and expert opinion. We assumed that 40% of proximal deep vein thromboses (DVTs) and 5% of distal DVTs are diagnosed and confirmed with initial or repeat duplex scanning; 50% of undiagnosed proximal DVTs result in pulmonary embolism; 2% and 1% of undiagnosed proximal DVTs will lead to readmission for DVT and pulmonary embolism, respectively, and pulmonary embolism-related mortality rates range from 8-30%. Length of hospital stay data and 1996 institutional drug use and acquisition cost data were used to estimate the cost of enoxaparin and heparin therapy. Diagnosis and treatment costs for DVT and pulmonary embolism were derived from institutional charge data using cost:charge ratios. A second analysis of patients with lower extremity fractures was completed. One-way and multiway sensitivity analyses were performed. For 1000 mixed trauma patients receiving enoxaparin versus heparin, our model showed that 62.2 (95% CI -113 to -12) DVTs or pulmonary emboli would be avoided, resulting in 67.6 (8 to 130) life-years saved at a net cost increase of $104,764 (-$329,300 to $159,600). Enoxaparin versus heparin resulted in a cost of $1684 (-$3600 to $9800) for each DVT or pulmonary embolus avoided and a discounted cost/life-year saved of $2303 (-$8100 to $19,000). For 1000 patients with lower extremity fractures, enoxaparin versus heparin resulted in a cost of $751 (-$4200 to $3300) for each DVT or pulmonary embolus avoided and a discounted cost/life-year saved of $1017 (-$10,200 to $6300). Although enoxaparin increases overall health care costs, it is associated with a cost/additional life-year saved of only $2300, which is generally lower than the commonly used hurdle rate of $30,000/life-year saved. The cost-effectiveness ratio is more favorable in patients with lower extremity fractures than in the general mixed trauma population.

Clinical Diagnosis of Brain Embolism (Part 2 of 2)

Data from large published stroke registries are reviewed concerning donor sources, recipient sites and clinical findings in patients with brain embolism. Clinical diagnosis of brain embolism should be

Trapped Venous Embolus in a Patent Foramen ovale Causing Recurrent Paradoxical Embolism

The combination of deep venous thrombosis, patent foramen ovale and arterial emboli suggests the diagnosis of paradoxical embolism. In these cases, only very rarely, a causal relationship between the venous thrombus and the patent foramen can be established. An instructive case of trapped venous embolism within the foramen ovale is described proving a causal relationship between arterial embolism and its venous origin.

Renal Artery Embolism Correlation With Scintigraphic and Radiographic Findings

The diagnosis of renal artery embolism should be considered in patients with cardiac disease who present with abdominal or flank pain in association with deteriorating renal function. Often the diagnosis is delayed or missed owing to the nonspecific, varied, and protean clinical manifestations. A case is presented of bilateral renal artery emboli, and initial and long-term scintigraphic and radiographic correlations are provided. Renal scintigraphy should be the initial study of choice. In addition, this procedure allows for sequential noninvasive evaluation of renal function.

Clinical and hemodynamic spectrum, diagnosis, and treatment of acute pulmonary embolism: The aggressive approach

Clinical and hemodynamic spectrum, diagnosis, and treatment of acute pulmonary embolism: The aggressive approach

The significance of Doppler signals detected by TCD in the diagnosis of embolism in neurosurgery and cerebral angiography

Recently, several authors have reported the character of embolic signals in TCD (transcranial Doppler sonography) as follows: (1) high intensity signals (3-60 dB) greater than the background Doppler spectrum;(2) random occurrence within the cardiac cycle; (3) transient appearance and short duration; (4) bell-shaped signals focused on a small band of frequencies within the Doppler spectrum; (5) harmonic sound quality; (6) monitoring time of over 30 minutes; required and (7) signals must be differentiated from artifacts. We studiedthe detectability of embolic signals using a Doppler recording system. Embolic signals of the middle cerebralartery were monitored by TCD using an experimental animal model and 3 patients with epilepsy or brain tumor who underwent cerebral angiography by the Seldinger method. In the animal model, artificial air emboli were easily detected as short-term and hyper-intense ultrasonic signals, while thrombotic emboli were not identified definitely. Furthermore, our clinical cases suggested that microscopic air emboli at the site of injection of the contrast medium may be prevented by slow washout with saline. We propose new criteria for embolic signals.

Cerebellar infarction. Clinical and neuroimaging analysis in 293 patients. The Tohoku Cerebellar Infarction Study Group.

We performed this multicenter study to explore the full spectrum of the clinical characteristics and neuroimaging findings of cerebellar infarction, including patients with mild to severe illnesses. We studied 293 consecutive patients with cerebellar infarction diagnosed by computed tomography and/or magnetic resonance imaging who were admitted to 36 hospitals during 5 years. Cerebellar infarcts constituted 2.3% of the total patients with acute brain infarction. The backgrounds and risk factors were similar to those in patients with infarctions of the cerebral hemispheres. At least 24% were embolic, and the diagnosis of embolism could not be ruled out in 27%. Infarcts involving the superior cerebellar artery (SCA) region (52%) and the posterior inferior cerebellar artery (PICA) region (49%) were far more frequent than those involving the anterior inferior cerebellar artery (AICA) region (20%). Patients with SCA infarcts exhibited obtunded consciousness and ataxia more frequently than those with PICA infarcts (P < .05). Infarcts in the PICA regions were associated with abnormalities of the PICA (64%) or the vertebral arteries (57%), whereas infarcts in the SCA and AICA regions were associated with abnormalities in the SCA or AICA, respectively, in approximately 30% of patients, in the basilar artery in approximately 16%, and in the vertebral artery in more than 60% of patients. Outcomes were poorer with SCA infarcts than with AICA and PICA infarcts. These data indicate similar frequencies of SCA and PICA infarcts and illustrate the difference in clinical presentation and outcomes between SCA and PICA infarcts. They also indicate that not only in situ thrombosis but also cardiogenic or artery-to-artery embolism and the insufficiency of collateral circulation play important roles in the pathogenesis of cerebellar infarction.

Delayed onset of coagulopathy following amniotic fluid embolism: two case reports

Two cases of amniotic fluid embolism with markedly similar clinical presentations occurred in the same unit in a 6 month period. Both patients were under general anaesthesia for caesarean section at the time of embolism. Having been successfully extubated and found to be haemodynamically stable, they developed a coagulopathy after an interval of 2 hours. There had been initial uncertainty as to the diagnosis in the first patient and the haematological sequelae were not fully anticipated. Experience in dealing with the first patient who died, may have influenced the survival of the second. The diagnosis of amniotic fluid embolism should be considered at an early stage in all cases of maternal collapse and the appropriate preparations made to combat a potential coagulopathy.

392. 当院における急性肺塞栓症の診断法と治療法(X 線検査-7 血管造影検査法)

392. 当院における急性肺塞栓症の診断法と治療法(X 線検査-7 血管造影検査法)

Stroke due to paradoxical embolism

We present a case of stroke in a young girl, preceded by a deep vein thrombosis and pulmonary embolism, both clinically asymptomatic, and accompanied by upper limb acute ischemia. Diagnosis of paradoxical embolism through a patent foramen ovale was made on clinical grounds and with contrast echocardiography. We discuss the main points leading to diagnosis, stressing the importance of contrast echocardiography. We also suggest that paradoxical embolism could be a more frequent cause of stroke than usually suspected.

AIRWAY PRESSURE MONITORING AS AN AID IN THE DIAGNOSIS OF AIR EMBOLISM

We designed a prospective study to compare the validity of airway pressure (AWP) monitoring with that of end-tidal CO2 (ETCO2) monitoring for early detection of air embolism. Subjects included 76 patients of both sexes who underwent neurosurgery in the sitting position. Anesthesia was maintained with O2, N2O, narcotics, pancuronium, and intermittent positive pressure ventilation (IPPV). Continuous monitoring was done of HR, ECG, intraarterial pressure, AWP, and ETCO2. A sudden and sustained decrease in ETCO2 during anesthesia in a hemodynamically stable patient was considered as a sign of air embolism. Concomitant changes in AWP and cardiovascular parameters were also recorded simultaneously. Onset time, stage of surgery, and duration of disturbances were recorded. At the same time, the chest was auscultated for any murmur. Aspiration of air through the CVP catheter was attempted for diagnosis and management of air embolism. ETCO2 monitoring detected 24 episodes (31.5%) of air embolism in 16 patients. We observed 10 episodes (13.1%) of tachycardia in nine patients and nine episodes (11.8%) of hypotension in eight of the 16 patients. Murmur was noted in four patients and air aspiration in six patients. Only six patients of the 16 had an increase in AWP along with the decrease in ETCO2. We conclude that AWP monitoring is neither a sensitive nor reliable indicator of air embolism.

DSA Diagnosis of Pulmonary Embolization from Intracardial Thrombus in a Patient with Permanent Pacing Catheter

Pulmonary embolization in patients with implanted pacemakers is rare and an intracardiac thrombus attached to the distal end of a newly implanted ventricular endocardial electrode following removal of a previously implanted lead is a curiosity. We have documented such a case by digital subtraction angiography, a minimally invasive procedure that demonstrates both an intracardiac thrombus and secondary pulmonary embolization in a single procedure, which also allows simplified follow-up evaluation following therapy.

Venous Air Embolism During a Craniofacial Procedure

The possibility of venous air embolism exists whenever the craniofacial operative field is above the level of the heart. Craniotomy with the high-torque craniotome is hypothesized to have produced venous air embolism in the patient described in this report. The diagnosis of venous air embolism is determined by transesophageal Doppler probe, transesophageal echocardiogram or external echocardiogram, and end-tidal N2 and CO2 determinations. Treatment includes control of the air entry sites, aspiration of air from the right atrium via a catheter placed prior to operation, and discontinuing nitrous oxide. If these measures are unsuccessful, the operative field should be transposed below heart level and the procedure terminated. In the event of significant hemodynamic compromise, closed cardiac massage should be tried; if that fails, open cardiac massage and direct aspiration are necessary. The true incidence of venous air embolism in craniofacial operations may be much higher than previously suspected. We therefore recommend placement of appropriate monitoring equipment to detect intracardiac air in those major craniofacial procedures in which there is a potential for intravascular air ingress.

Definitive diagnosis of amniotic fluid embolism with survival

Definitive diagnosis of amniotic fluid embolism with survival