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PubMed1989

Evaluation of vein of Galen arteriovenous malformation in newborns by two dimensional ultrasound, pulsed and colour Doppler method.

Two babies with severe cardiac failure caused by a large arteriovenous malformation of the vein of Galen were evaluated with 2-dimensional ultrasound, pulsed and colour Doppler techniques. In both cases similar findings were recorded: dilated right cardiac chambers with high cardiac output in superior vena cava and ascending aorta; retrograde diastolic flow in descending aorta and continuous forward flow in arch arteries reflecting low resistance to flow in cerebral arteries; recirculation of microbubbles through the superior vena cava after passage unchanged through the cerebral malformation following contrast injection of saline into a peripheral vein or an arterial umbilical line. In addition, colour Doppler study of the brain clearly showed the malformation and the dilated straight sinus. Arteriovenous malformation of the vein of Galen can be noninvasively and easily detected by ultrasound studies of the heart and the brain.

Cerebral Veins↗

PubMed1983

Quantitative recovery of expired nitrogen and nitrous oxide from venous gas emboli.

It has not been previously established whether venous gas emboli dissolve from pulmonary blood vessels into adjacent airways, or pass as microbubbles directly into the systemic circulation. We reported here the quantitative recovery of embolized gases from the airways, in amounts which substantiate the complete elimination of such gases by dissolution. A computer controlled quadrupole mass spectrometer was used to measure the net expired volumes of N2 or N2O following the injection of 40 ml boluses of these gases into the airways (AW) or right ventricles (RV) of 5 mongrel dogs. Every 20 ms, linearized flow signals were multiplied by gas concentrations, and the products summed for inspired and expired volumes of each breath. Intubated dogs were ventilated with 100% oxygen under Na-pentobarbital and either succinylcholine chloride or pancuronium bromide anesthesia; Swan-Ganz catheters were used for RV injections and for monotoring cardiovascular parameters. The overall mean % volume recoveries were 70.4 for AW-N2O, 68.2 for RV-N2O, 83.7 for AW-N2, and 46.7 for RV-N2. As expected, the AW percent volume recoveries increased with decreasing aqueous solubilities, and represented maximal values obtainable for RV emboli, due to alveolar reabsorption of gases excreted from the pulmonary circulation. Although all RV-N2O could thus be accounted for, RV-N2 recoveries were significantly less than AW-N2. The remaining RV-N2 did not pass as bubbles into the pulmonary veins, but continued to obstruct the pulmonary arterioles, as demonstrated with the use of nitrous oxide challenges in the inspired gas mixture.

Animals↗

PubMed1992

Left ventricular opacification after peripheral venous injection of a modified albumin solution.

The usefulness of a modified albumin solution was assessed in 8 dogs after peripheral venous and inferior vena cava injections. The contrast agent is a mixed solution made of glucose, albumin and glycerin, with sonicated microbubble diameter of 5.0 +/- 2.3 microns. Multiple injections (8 ml each) of this contrast agent (total 80 injections) into peripheral vein and inferior cava were performed. The blood pressure from femoral artery was measured before, during and after injections. Two-dimensional echocardiograms were recorded in a modified long axis view on videotapes for play back analysis. The pulmonary transit time and left ventricular contrast persistent time was determined for each injection. The videodensity of the region of interest (ROI) at the center of right ventricle and left ventricle was measured. The background videodensity of both ventricles was evaluated. The videodensity over the ROI of both ventricles with peak contrast enhancement was measured in all frames for 3 consecutive cardiac cycles. The peak videodensity of right and left ventricle subtracting the background videodensity of each ventricles was further calculated respectively. The injections caused no change in blood pressure or heart rate. All injections produced right ventricular contrast echo. As much as 85% of peripheral venous and 82.5% of inferior vena cava injections resulted in left ventricular contrast which was 0.68 and 0.65 as bright as that produced in the right ventricle. Pulmonary transit time and left ventricle contrast persistent time of peripheral venous injection was 4.05 +/- 0.53 and 13.67 +/- 4.28 seconds respectively. No difference of these data (3.93 +/- 0.47 and 11.65 +/- 4.66 seconds) from those produced by inferior vena cava injections were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗

PubMedDate not supplied

Assessment of successful valve reconstruction by intraoperative transesophageal echocardiography (TEE).

In 17 patients (10 patients with mitral insufficiency, 5 patients with tricuspid regurgitation, 2 patients with mitral stenosis) the result of valve reconstruction was evaluated by intraoperative two-dimensional transesophageal contrast-echocardiography (TEE). Therefore, 1-2cc of an agitated contrast-medium (Gelifundol) were injected into the left or right ventricle. The result of reconstruction was assessed by the extent of regurgitant microbubbles into the left or right atrium. A successful valve repair could be demonstrated in 15 patients without or with only minimal regurgitation of contrast-fluid. In one patient residual severe mitral insufficiency after valve reconstruction could only be detected when valve function was examined by contrast-TEE in the beating heart. An intraoperative decision for valve replacement was made. In another patient, mild to moderate residual mitral incompetence was shown; no further surgical intervention was done. By TEE the function of reconstructed valves can be examined under physiological conditions in the beating heart. Surgeons can obtain additional intra-operatively information and certainty about the result of reconstruction and an early decision for valve replacement can be made if necessary.

Adult↗

PubMed1998

Reduced release of tissue factor by application of a centrifugal pump during cardiopulmonary bypass.

The application of a centrifugal pump might lead to a reduced release of tissue factor (TF) due to less blood cell damage. This could result in a decrease in activation of the extrinsic pathway of coagulation and embolus formation. In the present study, 60 patients undergoing coronary artery bypass grafting were randomly assigned to a centrifugal or a roller pump. Plasma concentrations of TF, thrombin-antithrombin complex (TAT), and prothrombin fragments F1 + 2 were investigated before, during, and after cardiopulmonary bypass (CPB). Embolus detection was performed at the arterial line of CPB and transcranially by Doppler ultrasound. The centrifugal pump group revealed a lower TF release (area under the curve during CPB) when compared with the roller pump group [5661 (696-10359) vs 12681 (6383-17538) microg x min/l; median (lower - upper quartiles); P = 0.009]. In contrast, TAT and F1 + 2 formation did not differ between the groups, and neither did the total embolus count of both Doppler systems. Embolus counts did not correlate with TAT or F1 + 2 formation. In conclusion, the reduction in TF release by the application of a centrifugal pump seems to have little consequence on total thrombin formation. Since the applied Doppler systems seem to detect mainly microbubbles, conclusions regarding differences between the two pumps in the formation of thrombofibrinous clots cannot be drawn.

Cardiopulmonary Bypass↗

PubMed1992

Initiation of replication in the Chinese hamster dihydrofolate reductase domain.

Two-dimensional (2-D) gel analysis of replication intermediates in the Chinese hamster dihydrofolate reductase domain has suggested that nascent chains can initiate at any of a large number of sites scattered throughout a approximately 50 kb "initiation locus" (although the level of initiation detected at any given site within this region was relatively low). This result contrasts markedly with data from an in vitro strand switching assay suggesting that > 80% of initiations occur within a single 500 bp fragment lying within the initiation locus. In an effort to reconcile these two disparate views of the initiation reaction, we have questioned the validity of our 2-D gel data in several ways. We show here that: 1) the number of replication bubbles detected in the DHFR locus in the early S period is markedly increased when the cells are released from a synchronizing agent that inhibits initiation per se, rather than from aphidicolin, which is a chain elongation inhibitor; 2) initiation in the DHFR domain occurs only during the first 90 min of the S period, as would be expected of an early-firing origin; 3) a pulse of 3H-thymidine moves through the structures observed on 2-D gels with the kinetics expected of bonafide replication intermediates; and 4) preparations of replication intermediates that are subsequently analyzed on 2-D gels appear, by electron microscopy, to represent the typical theta structures and single-forked molecules expected of bidirectional origins of replication; no unusual structures (e.g., microbubbles) were seen.

Animals↗

PubMed1984

Clinical evaluation of the microporous hollow fiber oxygenator.

This report concerns a clinical evaluation for a newly devised hollow fiber oxygenator, Capiox II. It functions on a one-pump system, and is simple to set up and operate. This equipment was used for 118 patients undergoing cardiac surgery at Tokyo University Hospital from February 1982 through February 1983. The gas transfer capacity proved to be satisfactory. The employment of an air-oxygen blender prevented overoxygenation, and reasonable levels of PaO2 and PaCO2 were demonstrated with a FiO2 0.7, V/Q ratio 0.7 at normothermia. The destruction of platelets was much less with the use of this oxygenator, as compared to findings with the BOS-10. Hemolysis by Capiox II appeared to be lower than that by BOS-10, but the difference was not statistically significant. Differences were distinct in the amount of microbubbles; strikingly, no bubble was evidenced in Capiox II by the ultrasound bubble detector, during general procedures. We conclude that Capiox II is of excellent clinical value, and should be used especially for infants as well as adult patients with possible long perfusions. The merits and demerits of this equipment are given attention.

Adolescent↗

PubMedDate not supplied

Extended intraarterial cisplatin infusion for treatment of gynecologic cancer after alteration of intrapelvic blood flow and implantation of a vascular access device.

PURPOSE: Twenty-two patients with advanced gynecologic cancer underwent extended intraarterial cisplatin infusion after alteration of the intrapelvic blood flow and implantation of a vascular access device (VAD). METHODS: To maximize concentrations of cisplatin at the target lesion, the superior and inferior gluteal arteries were embolized with steel coils. The tip of the catheter was inserted into the internal iliac artery; the opposite end of the catheter was connected to the VAD. RESULTS: Intensive radioisotope accumulation was demonstrated in the anterior division of the pelvis, seen by scintigraphy performed with technetium 99m macroaggregated albumin via the VAD. Local perfusion in the tumor was well seen by ultrasonographic angiography with CO2 microbubbles via the VAD. Continuous consecutive infusion of cisplatin at a rate of 12.5 mg/day via the VAD minimized the toxicity. The overall response rate was 73%. Radical surgery was possible in 16 of the 22 patients after this intraarterial infusion. CONCLUSION: This method was useful for treating advanced gynecologic cancer without significant toxicity.

Adenocarcinoma↗

PubMed1993

Visualization of patent foramen ovale by biplanar transesophageal echocardiography.

It is difficult for conventional transthoracic echocardiography (TTE), by which precise and accurate images of interatrial septum (IAS) can not be acquired, to diagnose patent foramen ovale (PFO) clearly. To evaluate the diagnostic value of biplanar transesophageal echocardiography (TEE) for PFO, TTE and biplanar TEE were performed simultaneously in 270 patients. It was found that in 7 patients patent foramen ovale was detected only through longitudinal planes of biplanar TEE. IAS, which consists of primitive septum and membrane of fossa ovalis, can be directly visualized by two-dimensional images of TEE; in patients with PFO, a dull color flow, which shunts from the right atria to the left atria through the gap between primitive septum and fossa ovalis, can be detected by color Doppler flow images. Furthermore, some right-to-left shunting microbubbles through the valve of patent fossa ovalis can be discovered by cardiac acoustic contrast echocardiography. In conclusion, biplanar TEE combined with color Doppler image and cardiac acoustic contrast facilitates a definite diagnosis of patent foramen ovale as the excellent anatomic images of IAS can be obtained from multiple views under this kind of performance.

Adult↗

PubMed1999

[Patency, perfusion and prognosis in acute myocardial infarct].

Early restoration of bloodflow in the infarct-related coronary artery is the principal mechanism by which early reperfusion therapies may improve outcome in patients with acute myocardial infarction. The beneficial effect of reperfusion is independent of the therapy used (thrombolysis or PTCA), but, as shown in many studies, depends very much on the time to reperfusion. The achievement of a normal bloodflow in the infarct vessel, the so called TIMI 3 patency is considered to be the gold standard for the evaluation of the success of reperfusion therapy. However, there is increasing evidence from recent studies, that restoration of epicardial bloodflow does not necessarily indicate perfusion at the myocardial level. As unequivocally shown by contrast echocardiography using intracoronary injections of microbubbles, this is true even for TIMI Grade 3 flow, which correlates most strongly with prognosis and usually is associated with a very low mortality of about 3 to 4%. Angiographic patency not only is a sometimes unreliable indicator of myocardial reperfusion, but also involves an invasive procedure, is expensive and not universally available. A readily available and simple indicator of reperfusion is the early resolution of ST segment elevation. Complete ST resolution at 90 or 180 minutes after the initiation of treatment is associated with an excellent prognosis, even better than TIMI 3 patency. In contrast, no ST resolution indicates an in-hospital mortality which is about 8-fold greater than with complete ST resolution. Since ST resolution may be more closely related with the relief of ischemia than angiographic patency, the prognostic power of the combination of both indicators should be greater than that of either of them alone. Thus, it is evident from many studies that patency of the infarct-related artery is necessary for myocardial salvage in acute myocardial infarction, but it has to be achieved rapidly and has to be complete and sustained. However, even an early and perfect angiographic result achieved by thrombolysis or PTCA, does not consistently indicate myocardial reperfusion, and the mechanisms of the often called no-reflow phenomenon are still poorly understood. The possible contribution of reperfusion injury to poor clinical outcomes after adequate epicardial flow has been restored is also a matter of controversy and deserves further research. Promising results were derived from studies with GP IIb/IIIa inhibitors, in which improved microvascular flow and myocardial reperfusion were observed, when these agents were used as adjunct to thrombolysis and PTCA.

Acute Disease↗

PubMed1999

[Hepatopulmonary syndrome].

ANAMNESIS: We report about a 60-year-old woman with hepatopulmonary syndrome. The patient suffered from progressive dyspnea and liver cirrhosis following viral hepatitis C, acquired through blood transfusion 30 years ago. EXAMINATION RESULTS: Remarkable were clinical signs of chronic liver disease (cutaneous spider naevi, palmar erythema) and signs of chronic respiratory failure (clubbing) with platypnea. Arterial pO2 was 33 mm Hg under 41 O2/min nasal oxygen supplement and improved to 74 mm Hg under 81 O2/min. Arterial pO2 deteriorated in upright position (orthodeoxia). Contrast enhanced two-dimensional transthoracic echocardiography showed a delayed microbubble opacification in the left heart chambers (without atrial or ventricular septal defect), suggesting pulmonary vascular dilatations. Perfusion scan with macroaggregated albumin labelled with technetium-99m showed uptake over thyroid, kidneys, liver, and spleen suggesting an abnormal passage through the pulmonary vascular bed. The radiological examination with chest radiography and high resolution computer tomography revealed no signs of interstitial lung disease. The pulmonary artery angiography showed neither anatomical shunts nor malformations. DIAGNOSIS: The final diagnosis was hepatopulmonary syndrome Type 1. TREATMENT/FOLLOW-UP: The patient underwent liver transplantation with following good function of the liver graft. After 6 months the patient presented in a much better general condition, but with persisting severe hypoxemia whereas the spider naevi disappeared completely. One year after the liver transplantation in the perfusion scan the uptake over thyroid, kidneys, liver, and spleen was absent. The orthodeoxia and hypoxemia improved evidently. From that we conclude that the pulmonary vascular dilatations diminished after liver transplantation.

Diagnosis, Differential↗

PubMed2002

Therapeutic ultrasound in cardiology.

Ultrasound can be exploited to derive therapeutic results by using its bioeffects such as creation of mechanical vibrations, localized cavitations, microstream formation, physicochemical changes and thermal energy. Extensive in vitro and animal investigations during the last 2 decades have laid a foundation for ultrasound energy to be used for treatment purposes in various medical specialties. In the area of cardiovascular diseases, ultrasound could be used for thrombolysis, adjunct to coronary interventions, drug delivery, local gene transfer, and creating therapeutic lesions. The dispensation approaches to therapeutic ultrasound are varied, from the use of low- to medium-range frequency, low to focused high intensity, and catheter-based to external devices. Catheter-based ultrasound could be useful for intracoronary thrombolysis, and external ultrasound instrument with transcutaneous delivery could be of use in applications such as creation of myocardial lesions, peripheral vessel thrombolysis, and drug and gene delivery. Adjunct administration of microbubbles has been found to enhance thrombolysis, and drug and gene therapy. Ongoing studies strongly suggest that therapeutic ultrasound could have an important role in cardiovascular disorders associated with thrombosis, inflammation, atherosclerotic disease, and arrhythmias.

Animals↗

PubMed2000

[Dilated coronary sinus. A preoperative transesophageal echocardiographic diagnosis].

A 36-year old woman was presented to our hospital with congenital ventricular septal defect and one-vessel coronary artery disease (75% proximal left main coronary artery) for CABG and repair of the VSD. After induction, a transesophageal echocardiographic (TEE) baseline examination was performed, showing a severely dilated coronary sinus (CS) measuring approximately 3 cm (abnormal >1 cm). We suggested a persistent left superior vena cava (PLSVC) draining into the CS. PLSVC is a common venous congenital anomaly, with a reported incidence of 0.5% in general population and in 3-5 % of patients with congenital heart defect. Injection of echo-contrast solution in a left arm vein, visualizing microbubbles passing through the PLSVC into the CS confirmed our suspicion. The diagnosis of a PLSVC and dilated CS is a contraindication for retrograde cardioplegia because of the loss of cardioplegia into the PLSVC resulting in a inadequate myocardial protection. It may be difficult to pass a pulmonary artery catheter (PAC) through a left internal or left subclavian vein and it may be associated with arrhythmias. A chest radiograph shows the anomalous course of the PAC along the left heart.

Adult↗

PubMed2003

[The value of ultrasound (US) in the diagnosis of prostate cancer].

The value of ultrasound (US) in the diagnosis of prostate cancer has increased in importance in the past decade, which is mainly related due to the increasing incidence of prostate cancer, the most common malignancy in men. The value of conventional gray-scale US for prostate cancer detection has been extensively investigated. The introduction of US contrast agents has dramatically changed the role of US for prostate cancer detection. Advances in US techniques were introduced to further increase the role of US contrast agents. Although most of these advances in US techniques, which use the interaction of the contrast agent with the transmitted US waves are very sensitive for the detection of microbubbles, are mostly unexplored, in particular for prostate applications. First reports of contrast-enhanced US investigations of blood flow of the prostate have shown that contrast-enhanced US adds important information to the conventional US technique. We present a critical evaluation of the current status of transrectal US imaging for prostate cancer detection. Furthermore, we give background information on US contrast agents and imaging modalities. Early results of contrast-enhanced US suggest the feasibility of the use of US contrast agents to enhance US imaging of the prostate. The application of US contrast agents for the detection and clinical staging of prostate cancer is promising. However, future clinical trials will be needed to determine the promise of contrast-enhanced US of the prostate evolves into clinical application.

Biopsy↗

PubMed1998

[Dynamic assessment of contrast medium enhancement in Doppler ultrasound imaging. Current status].

Findings in previous investigations have indicated that contrast-enhanced colour Doppler can be used to improve the demonstration of characteristic features of neovascularization in malignancies. However, the quantification of the increase in colour Doppler signals after Levovist in the cited study relied only on descriptive criteria defined by the investigator, resulting in a subjective scoring system. A computer-assisted method for quantitative analysis of colour pixel density is a novel approach for objective assessment of colour Doppler signal after contrast media administration. After microbubble contrast medium injection in 47 patients, carcinomas and benign lesions behaved differently regarding degree, onset and duration of Doppler enhancement. However, the high interindividual variability and the temporal variations of the Doppler signal still limit the value of these criteria for prospective diagnosis. Rapid image-acquisition techniques are needed in order to apply the necessary mathematical processing before the contrast kinetics can be used for diagnostic purposes.

Adult↗

PubMed1998

[Diagnosis of vesicoureteral reflux with echo-enhanced micturition urosonography].

AIM: To ascertain the diagnostic efficacy of reflux sonography with the application of the echo-enhancing agent Levovist in comparison with X-ray voiding cystourethrography (VCUG). PATIENTS AND METHODS: Echo-enhanced voiding urosonography (VUS) and VCUG were performed successively in one examination session in 114 children referred for the investigation of possible vesicoureteral reflux (VUR). After sonography of the urinary tract the bladder was filled with normal saline and Levovist was administered. Reflux was diagnosed when hyperechogenic, floating microbubbles appeared in the ureters or renal pelvises. RESULTS: A total of 226 kidney-ureter units were available for analysis. Reflux was diagnosed in 80 units. All grades of reflux were represented. In 15 kidney-ureter units VUR was diagnosed with echo-enhanced VUS but was not seen at VCUG. The contrary was true in 3 units. High sensitivity and specificity in comparison to the VCUG could be attributed to the echo-enhanced VUS. The long imaging window attainable with Levovist makes the documentation of convincing images possible, contributing to the high diagnostic efficacy. CONCLUSION: Echo-enhanced VUS is comparable to VCUG in the diagnosis of reflux.

Adolescent↗

PubMed2002

[Contrast-medium enhanced reflux ultrasound in children. A comparison with radiologic imaging up to now].

Voiding cystourethrography (VCUG) has long been the method of choice for the diagnosis of vesicoureteral reflux (VUR). Especially in the course of conservative treatment, the radiation dose involved might become quite high over the years. Since the development of such ultrasound echo-enhancing agents as Levovist (Schering, Germany), we now have the ability to assess the diagnostic efficacy of this agent in the evaluation of VUR with a view to replacing VCUG with the radiation-free ultrasound methodology. A total of 104 children with a mean age of 5.4 years were examined using echo-enhancing ultrasound after informed consent had been obtained from their parents. For control purposes, all children were examined by standard VCUG as well. The diagnosis of VUR was judged to be positive when microbubbles appeared in the ureter or renal pelvis. Correlations were sought between the sonographic findings and those obtained by standard VCUG. In 76 (37%) of the 208 ureter-kidney units investigated, VUR was detected by both technologies. VUR was diagnosed by ultrasonography only in 5 units and by VCUG only only in 3 units. All reflux grades (I-V) were identified. The specificity and sensitivity of the contrast reflux ultrasound were significantly high. The long contrast time of up to 30 min combined with the high contrast effect resulted in convincing images with high levels of diagnostic confidence. Our results clearly demonstrate that the safety and accuracy of the diagnosis of VUR by means of contrast-enhanced ultrasound is statistically comparable to those of standard radiologic VCUG. Therefore, this methodology is an exceptional approach to reducing the number of children being exposed to ionising radiation especially during conservative follow-up of children with reflux.

Adolescent↗

PubMed2002

[Transrectal ultrasound of the prostate. Current status and prospects].

In recent years the role of ultrasound in the diagnosis of prostate carcinoma has increased in importance. In view of the increasing incidence of prostate cancer, which is the most frequent malignant neoplasm in men, TRUS (transrectal ultrasound) is an important imaging method in the diagnosis of various prostate diseases. This paper provides a basic overview of physical and technical bases of TRUS investigation of the prostate. It concerns technical developments and modern techniques designed to improve its value in diagnosis. Impressive innovations in ultrasound equipment, particularly in the area of colour-coded Doppler sonography in association with microbubble-enhanced colour Doppler ultrasound, have given rise to justifiable hope of improvements in the early diagnosis of prostate cancer.

Diagnosis, Differential↗