Trapped thrombus in a patent foramen ovale

A survey of the orthopaedic casualties evacuated (casevacs) to the Royal Hospital Haslar between November 1995 and April 1996 was performed. A total of 464 service persons and civilians were casevaced. Orthopaedic cases amounted to 55% of all evacuations. Of these, 54% were British Army personnel. Conditions necessitating casevac were classified as either acute, (occurring during the deployment), or chronic (where the condition was present prior to deployment). Of the acute cases, there was an even mix between bony and soft tissue injuries (STIs). Sporting activities were the commonest cause of injury. The condition had been present prior to deployment in 16% of cases. Half of these were considered to have been unfit for deployment. Strategies for prevention of unnecessary casevacs are discussed.     

Intracardiac thrombus trapped in a patent foramen ovale

We describe a case of impending paradoxical embolism due to a thrombus trapped in a patent foramen ovale in a 22-year-old woman. Transthoracic and transesophageal echocardiography detected the thrombus. She was operated on and discharged asymptomatic.     

Preoperative diagnosis of a patent foramen ovale: rational use of transthoracic and transesophageal contrast echocardiography

BACKGROUND: The detection or ruling out of a patent foramen ovale (PFO) can be determined noninvasively by contrast echocardiography (CE). The transesophageal technique is superior to the transthoracic technique regarding sensitivity, whereas the specificity of both methods is equally high. This prospective study shows the rational use of transesophageal CE for the detection of a PFO, in patients without cardiovascular disorders. METHODS: 165 patients (92 female, 73 male, age 48 +/- 18 years) with planned neuro-surgery in a sitting position, underwent CE to rule out a PFO. If the CE was positive, an alternative position was selected in order to avoid a paradoxical air embolism. RESULTS: Initially, a transthoracic CE was performed in all patients resulting in 21 patients (13%) being positive and 39 patients (24%) being negative by sufficient image quality. A transesophageal CE was performed in 96 of the remaining 105 patients (63%). Here, further 25 patients showed a positive CE in the sense of a PFO. The combined use of transthoracic and transesophageal CE revealed a PFO in 46 of 165 patients (28%). CONCLUSION: The use of both, transthoracic and transesophageal CE is an efficient approach to the preoperative detection of a PFO in the sense of quality and economics. Depending upon the image quality, the use of a transesophageal examination could be avoided in one third of the cases.     

Diagnosis and management of entrapped embolus through a patent foramen ovale

In the present study, we used five different polymorphic markers to construct the haplotype at the adenomatous polyposis coli (APC) locus in families with familial adenomatous polyposis (FAP) and in the normal Italian population. Non-ambiguous haplotypes were reconstructed from 246 normal chromosomes and 65 FAP chromosomes. In the control population, the four polymorphisms intragenic to APC gave rise to 16 haplotypes, the most common of which (II and XV) accounted for over 50% of all chromosomes. In FAP patients, 13 haplotypes were found but their distribution was not statistically different from normal subjects. Eighty complete chromosomal haplotypes (many fewer than the theoretical maximum of 208) for the five polymorphic sites assayed were observed in the control population, 35 being found in the FAP patients. We compared the distribution of these haplotypes within the two groups; no statistically significant differences between normal and FAP chromosomes were found. The elevated heterogeneity of FAP chromosomes was clearly confirmed by the observation that 19 patients who carried one or other of the two most common APC mutations (nt 3183 and nt 3927) showed 18 different haplotypes. On the basis of these results, we were not able to identify a founder FAP chromosome. Various mechanisms are presented to explain this observation.     

Venous thrombosis causing arterial embolization to the same limb through a patent foramen ovale

We describe a patient who presented with acute ischemia affecting the left lower limb. Because a transthoracic echocardiogram was abnormal, a transesophageal study was arranged. This demonstrated an atrial septal aneurysm and right-to-left shunting of contrast, raising the possibility of paradoxical embolism. The diagnosis was confirmed by contrast venography, which showed extensive thrombosis in the deep veins of the left thigh, and a ventilation-perfusion scan which was consistent with multiple pulmonary emboli. Among the lessons from this case was the finding that in patients with arterial embolism the likely origin of the embolus should be considered and, in the absence of common risk factors (atrial fibrillation, rheumatic heart disease, left ventricular dilatation, widespread atheroma), occult venous thrombosis and a right-to-left shunt should be sought. In this select group of patients, transesophageal echocardiography is significantly more sensitive than transthoracic study and should be the investigation of choice. Second, in the patient described in this report the clinical signs of deep venous thrombosis (DVT) were masked by the more prominent features of acute arterial ischemia. Without the incidental echocardiographic abnormality, it is likely that the important diagnoses of DVT, pulmonary embolism, and paradoxical embolism would not have been made.     

Misplacement of a transvenous lead from an implantable cardioverter-defibrillator into the left ventricle via a patent foramen ovale

HISTORY AND CLINICAL FINDINGS: 24-hour ECG monitoring in a 64-year-old man revealed self-limited (< 30 s) ventricular tachycardias (VT) of > 200/min. He had triple-vessel coronary artery disease with both anterior and posterior wall infarctions treated by three aortocoronary venous grafts. Physical examination was unremarkable except for a well healed thoracotomy scar. INVESTIGATIONS: Programmed ventricular stimulation induced prolonged monomorphic VT of 320 beats/min, despite aminodarone treatment. Left-heart catheterization demonstrated the three patent aortocoronary grafts and a left-ventricular ejection fraction of only 20%. TREATMENT AND COURSE: Because of the inducible and prolonged VT, despite antiarrhythmic treatment with amiodarone, a cardioverter-defibrillator was implanted (ICD). During threshold measurements of the pacemaker integrated into the ICD the pacemaker impulse was noted to produce a right bundle branch block pattern, the ICD lead having erroneously been placed in the left ventricle via a patent foramen ovale. The lead was left in place, because the ICD was functioning well and lead removal with the possible need of a thoracotomy carried a high risk. CONCLUSION: Extreme caution is needed to avoid malpositioning an implantable cardioverter-defibrillator. If the lead tip is unwittingly fixed in the left ventricle but functions well it should be left in place under prophylactic anticoagulation, because of the potentially high risk of its operative removal.     

Frequency of deep vein thrombosis in patients with patent foramen ovale and ischemic stroke or transient ischemic attack

To evaluate the additional value of transesophageal (TEE) compared with transthoracic (TTE) echocardiography and the role of patent foramen ovale (PFO) and deep vein thrombosis in the work-up of embolic events, patients with presumed cardiac embolic stroke or transient ischemic attack (neurovascular etiology was excluded) were prospectively studied by transthoracic and transesophageal contrast echocardiography. If PFO was detected echocardiographically, PFO size was assessed semiquantitatively and phlebography of both legs was performed. Two hundred forty-two consecutive patients (153 men, 60 +/- 15 years) were studied. In 197 patients, neuroimaging showed evidence of embolic infarction. TEE identified 138 potential cardiac sources of embolism in 111 patients, compared with 69 by TTE (p <0.01) in 59 patients. TEE detected potential cardiac sources in 52 patients with negative TTE examination and was significantly superior compared with TTE for identifying left atrial thrombi, spontaneous echo contrast, PFO, atrial septal aneurysm, and atheroma of the ascending aorta. In patients with a positive TTE, additional diagnostic information by TEE was found in only 6 patients and did not change therapy. Phlebography was performed in 53 patients with PFO and revealed deep vein thrombosis in 5 patients (9.5%); all had medium or large PFOs. Thus, in patients with cerebral ischemia of suspected cardiogenic origin and a normal TTE examination, TEE detects potential causes of embolism in 31% of patients and is therefore of diagnostic relevance. Conversely, in the presence of a diagnostic TTE an additional TEE confers only marginal diagnostic benefit. Deep venous thrombosis was detected in nearly 10% of patients with PFO as the sole identifiable cardiac risk factor. Given that in 4 of 5 patients deep vein thrombosis was clinically silent, phlebography should be performed in patients with medium or large interatrial shunts if paradoxical embolism is suspected.     

Diagnosis and therapy of a fluttering thrombus in the open foramen ovale

The finding of an extremely mobile thrombus in a patent foramen ovale (i.e., transit thrombus) without arterial embolism is rare. In our case-report diagnosis was made by routine-echocardiography. Clinically nonapparent deep vein thrombosis was documented by phleography and was thought to be the origin of the embolus. After implantation of a caval filter device cardiac surgery was performed and the embolus was removed without complications.     

An increased frequency of patent foramen ovale in patients with transient global amnesia. Analysis of 53 consecutive patients

OBJECTIVE: Alerted by the number of patients with transient global amnesia (TGA) in whom Valsalvalike activities immediately preceded the onset of TGA, we have investigated the frequency of patent foramen ovale (PFO) as the prerequisite for paradoxical embolism. DESIGN: Case series with comparison to a control group. SETTING: Hospitalized and ambulatory patients at the neurological departments of the Alfried Krupp Hospital, Essen, Germany, and the Rheinisch-Westf?lische-Technische Hochschule, Aachen, Germany. PATIENTS: Fifty-three consecutive patients with TGA were evaluated by the 2 centers between 1988 and 1995. RESULTS: Using contrast transcranial Doppler sonography we have observed a PFO in 55% of the patients with TGA, compared with 27% of a control group of 100 patients. This difference was statistically significant (P < .01). Twenty-five patients with TGA (47%), 15 of them with a proven PFO, reported a precipitating activity, such as the lifting of heavy weights, immediately before the TGA occurred. CONCLUSIONS: In addition to other pathological mechanisms, paradoxical embolism with temporobasal ischemia could possibly play a role in the clinical syndrome of TGA. This hypothesis could explain the frequent observation of preceding Valsalvalike activities in patients with TGA.     

Must the patient fast before intravascular injection of a non-ionic contrast medium? Results of a controlled study

PURPOSE: Prospective evaluation of food and fluid restriction before the intravascular injection of a non-ionic contrast medium. MATERIAL AND METHODS: 1000 patients (657 men, 343 women; average age 59 +/- 1/4 5 years) undergoing intravascular contrast injections (CT, phlebography, angiography, urography) were randomly allocated to two groups. Group A had no fluid or solids for at least four hours before the injection (499 cases); group B were allowed unlimited food and fluid (501 cases). Both groups were comparable in all other respects and all were given the non-ionic contrast medium iopamidol (300 mg l/ml). RESULTS: The incidence of acute complications was 3.5%. There was, however, no statistically significant difference between the two groups (p = 0.29). Late adverse reactions were seen in 3.9% patients. There was again no difference between the two groups (p = 0.33). No serious or life threatening complications occurred. CONCLUSION: Restriction of food and fluid before intravascular injection of contrast medium does not reduce the number of adverse side effects. For reasons of patient comfort and compliance, and to achieve adequate hydration, the patient should not fast before injection of contrast.     

Evaluation of a rapid technique for antibiotic sensitivity testing using an MS-2 automate and blood culture medium

The authors propose a rapid method for studying antibiotic sensitivity of bacteria isolated from blood cultures. An MS-2 automate is used directly with bacteria collected after centrifugation. With the exception of the sensitivity of Gram-positive cocci to the combination of sulfamethoxazole-trimethoprime and to Penicillin G and of Gram-negative bacillus to beta lactamines, the results were comparable to those obtained after isolation of bacteria on gel medium. Various causes for error are discussed.     

Precipitation of a cholegraphic contrast medium in a dog

Following intravenous injection of medium for cholegraphy, calcium salt was precipitated in the tubules of rats and a 'gallstone' containing contrast medium developed in a dog. A review is given of biotransformation of contrast media in the biliary and urinary tracts.     

Open foramen ovale in patients with arterial vascular occlusions of the retina and optic nerve

BACKGROUND: We examined the frequency and significance of persistent foramen ovale (PFO) in patients with ocular circulatory disturbance. PATIENTS AND METHODS: Forty patients with acute arterial occlusions of the posterior bulb segment were investigated by means of transthoracic and transesophageal echocardiography (TEE). The parallel presence of cerebral ischemia was clarified on the basis of existing CCT findings and by additional HMPAO-SPECT investigation. RESULTS: PFO was identified in nine of the patients investigated. The probability of paradoxical embolism arises from further findings: eight of those with PFO (89%) showed echocardiographic signs of right heart strain, indicating previous pulmonary embolism, compared with only three of those without PFO (10%). Five of those with PFO showed a potential source of embolism, two of them with phlebothromboses in their clinical history and three with additional atrial septal aneurysm. Cardiovascular risk factors were prevalent in the group without PFO. Both groups had a mean age of approximately 60 years. Signs of cerebral ischemia were present in the SPECT or CT findings for four of the patients with PFO and nine of those without. CONCLUSIONS: From our findings, it appears highly probable that ocular arterial occlusion is caused by paradoxical embolism. PFO should be taken into account in establishing a diagnosis, including diagnosis in elderly patients.