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Biomedical subjects

S G Fransson

Publications and source records attributed to S G Fransson.

At least 19 recordsLinked to original sources

A comparison of analogue and digital techniques in upper gastrointestinal examinations: absorbed dose and diagnostic quality of the images.

This study was performed to investigate whether patient exposure and diagnostic quality of the image is significantly influenced by the introduction of digital image acquisition techniques. Evaluation was performed for three different techniques (analogue, analogue fluoro + digital radiography, digital) in examination of the upper gastrointestinal tract. The evaluation was done from data acquired in three different departments. Patient exposure was recorded as KERMA-area product (KAP) and the individual patient readings were normalised to a standard size patient. Image quality was assessed using visual grading with a reference image. The recorded KAP values were significantly higher (22.3 Gycm2) for the fully digital technique compared to the others (analogue 6.8 Gycm2, analogue + digital 3.6 Gycm2). This was due mostly to an increased number of exposures. The diagnostic quality of the image was, however, also regarded to be slightly lower for the technique giving the lowest patient dose with the smallest number of exposures (analogue + digital). The digital examination technique, as used in this study, thus resulted in significantly higher patient dose without any significant gain in diagnostic quality of the image.

Esophagus↗

Patient radiation exposure during coronary angiography and intervention.

PURPOSE: To prospectively register fluoroscopic and cine times in a random fashion, and to measure patient radiation exposure from routine coronary angiography and coronary balloon angioplasty. We also evaluated an optional dose reduction system used during interventions. MATERIAL AND METHODS: The incident radiation to the patient was measured as kerma area product (KAP) in Gycm(2), obtained from an ionisation chamber mounted on the undercouch tube during 65 coronary angiography procedures and another 53 percutaneous transluminal coronary angioplasties (including 29 stent procedures), mostly directly following complete coronary angiography. RESULTS AND CONCLUSION: The values from coronary angiography were comparable to other reports with a mean fluoroscopic time of 4.4 min and a mean KAP value of 62.6 Gycm(2). The corresponding figures from coronary balloon angioplasty without stenting were lower than otherwise reported, with 8.2 min and 47.9 Gycm(2), respectively. The use of coronary stents did prolong the mean fluoroscopic time (10.5 min) but did not significantly enhance the patient mean radiation dose (51.4 Gycm(2)). The dose reduction technique resulted in a significant KAP value reduction of 57%. In conclusion, with regard to radiation exposure, coronary angiography and balloon angioplasty are considered safe procedures.

Angioplasty, Balloon, Coronary↗

Clinical evaluation of a diagnostic strategy for deep venous thrombosis with exclusion by low plasma levels of fibrin degradation product D-dimer.

Clinical research studies have indicated the possibility of diagnostic strategies for deep venous thrombosis (DVT), strategies which include a step where the diagnosis is excluded by low or undetectable plasma levels of fibrin degradation product D-dimer. In collaboration with two local hospitals in Sweden, three implementations of such a strategy are evaluated in this study. Procedures 1, 2 and 3 differed in the method for D-dimer determination, i.e. latex agglutination, immunofiltration and both, respectively. The evaluated procedures were performed in parallel and compared with the current procedure in the different hospitals. At both hospitals, the current procedure stipulated mandatory phlebography and laboratory analysis of acute coagulation status and routine haematology with report-back time of 2 h. Within the 2 h the hospitals' clinical chemistry laboratories also determined plasma D-dimer by the two methods. Of 180 patients enrolled in the study, phlebography was successful in 155 and unsuccessful in 25. The phlebographies revealed 47 proximal DVT, 13 distal DVT and 95 no DVT. With Procedure 1, 53 patients (29%) were excluded in the D-dimer step. For these patients, 47 successful phlebographies revealed one proximal DVT and two distal DVT. With Procedure 2, 71 patients (39%) were excluded. For these patients, 65 successful phlebographies revealed two proximal DVT and four distal DVT. With Procedure 3, 44 patients (24%) were excluded. For these patients, 41 successful phlebographies revealed two distal DVT. The negative predictive values of the D-dimer exclusion step, with 95% confidence intervals given within parentheses, were 96% (88-100%), 91% (84-98%) and 95% (89-100%) for Procedures 1, 2 and 3, respectively. The evaluation demonstrated that the diagnostic potential of D-dimer revealed in research studies can be achieved in clinical practice. The study also indicated that the positive diagnostic value of high levels of D-dimer may be of use in finalizing the diagnosis in the 14% of patients for whom phlebography is unsuccessful.

Enzyme-Linked Immunosorbent Assay↗

Femoral artery haemostasis with a pneumatic compression device versus a clamp after coronary angiography.

To evaluate the safety and efficacy of a new pneumatic compression device for achieving haemostasis after femoral artery catheterization, 1,017 patients undergoing selective coronary angiography by a 5F unilateral femoral route were prospectively randomised to pneumatic or the routinely used clamp compression technique. All initial bleedings could be controlled in the pneumatic group, whereas in 38 patients (8%) of the clamp group the initial positioning of the clamp was unsuccessful or was not tolerated by the patient (p < 0.05). Ultrasound Doppler study of the puncture site because of suspected postcatheterization vascular complication revealed two haematomas which needed no further measure and two pseudoaneurysms which were successfully treated with ultrasound-guided compression or surgical repair. The rate of complications requiring treatment (pseudoaneurysms) was 0.2% overall, 0.5% in the clamp group and nil in the pneumatic compression group (NS). We conclude that the pneumatic compression device is effective, convenient and at least as safe as the clamp and, by shortening the time in the catheterization laboratory, offers time for further angiograms.

Aged↗

[Initial experience with the use of abciximab in the salvage treatment of acute coronary thrombosis in the Hemodynamics Laboratory].

The optimal treatment of acute thrombotic complications in the Catheterization Laboratory has not been defined yet, due to the limited efficacy shown by various pharmacological regimens, even when associated to coronary angioplasty (PTCA). The aim of our study was therefore to evaluate the effects of abciximab (ReoPro), a new potent inhibitor of the platelet glycoprotein IIb/IIIa, when administered as a "rescue" treatment for acute thrombotic coronary occlusion during diagnostic or interventional procedures. Sixteen patients (12 males, 4 females, mean age 59.3 +/- 9.2 years, range 43-77 years), with unstable angina and consecutively treated with abciximab due to clinical instability attributable to coronary thrombosis angiographically proven during PTCA (9 cases) or diagnostic angiography (7 cases), were identified. The individual angiographic films and medical records were then reviewed in order to evaluate the effects of treatment on coronary flow, thrombus size and occurrence of in-hospital adverse events: death, non-fatal acute myocardial infarction (AMI), need for urgent myocardial revascularization and hemorrhage. The administration of abciximab, in association with PTCA (associated in turn with stent implantation in 8 cases), induced a significant increase of coronary TIMI flow grade (0.3 +/- 0.6 vs 2.4 +/- 0.9; p < 0.05) and a significant decrease of thrombus "score" (size) 2.4 +/- 0.9 vs 1.3 +/- 0.6; p < 0.01). No deaths nor need for urgent myocardial revascularization were observed; in 31% of cases (5 patients) evolution towards AMI occurred, while however 94% of cases (15 patients) had a coronary occlusion before treatment. No major hemorrhagic complications were observed, while in 12% of cases (2 patients) a groin hematoma associated with moderate hemoglobin drop, developed. In conclusion, the administration of abciximab, associated with the common "rescue" interventional procedures, in patients with acute thrombotic coronary occlusion in the Catheterization Laboratory, appears to be effective in restoring adequate coronary flow and reducing the thrombus size (limiting therefore the evolution towards AMI), and safe, not having been associated with significant hemorrhagic complications.

Abciximab↗

Olof Rudbeck.

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Cardiology↗

Mortality related to coronary angiography.

Coronary angiography is in general regarded as a safe investigation with a low risk of serious complications. Unfortunately, a risk of serious complications exists, especially in patients with left main coronary artery disease or 3-vessel disease. The mortality rate ranges in different studies between 0.10% to 0.25%. The present series, reflecting nine years experience, shows an overall mortality of 0.16%. This figure is influenced by the relatively high mortality rate in the first year of the study. The recent mortality rate of 0.07% has not changed in the last 3 years and almost all deaths occurred in the patients known to be at higher risk.

Aged↗

Immediate and late adverse reactions in coronary angiography. A comparison between iodixanol and ioxaglate.

PURPOSE AND METHODS: In 120 patients in a double-blind, randomized, pa rallel study, iodixanol (Visipaque), a nonionic dimer isotonic with blood, was compared with ioxaglate (Hexabrix), an ionic low-osmolar dimer, in coronary angiography regarding early and late adverse reactions. Haemodynamic and electrophysiologic parameters were also analyzed. RESULTS: Visipaque resulted in significantly fewer early adverse contrast medium-related reactions (p<0.05). Visipaque also demonstrated significantly fewer effects on electrophysiologic parameters. Both contrast media reduced systolic and diastolic blood pressures at the 1st injection in the left coronary artery. Late adverse reactions were unusual with both contrast media and occurred only as urticaria with a frequency of 1.7%, which is lower than reported in i.v. studies. One serious adverse reaction, a myocardial infarction in a male patient with severe cardiovascular disease, occurred in the Visipaque group. This event was considered to be procedure- and disease-related rather than related to the type of contrast medium used. CONCLUSION: We found Visipaque safe for coronary angiography, causing fewer early adverse reactions than Hexabrix and also fewer effects on electrophysiologic parameters. Late adverse reactions seemed to be unusual with intra-arterial administration of contrast media.

Contrast Media↗

Intra- and postoperative cerebral complications of open-heart surgery.

A consecutive series of 1400 patients who had undergone open-heart surgery was retrospectively reviewed concerning postoperative cerebral dysfunction. The 30-day mortality was 1.6%. Forty-one patients (2.9%) showed signs of cerebral dysfunction, which proved fatal in seven cases. Neurologic symptoms were observed immediately after surgery in 14 patients, suggesting intraoperative damage. In 20 others there was an interval between surgery and the onset of cerebral symptoms, which in 12 cases were preceded by supraventricular tachycardia. Computed tomographic scans were performed on 27 patients and showed recent brain infarction in 22. No bleeding was found. At follow-up 34 of the 41 patients were alive, 21 of them with neurologic sequelae and 13 reporting complete recovery. Nineteen of the 34 survivors experienced no diminution of quality of life. Since half of the cerebral complications occurred postoperatively, more aggressive prevention and management of supraventricular tachyarrhythmia and anticoagulation therapy should be considered.

Adolescent↗

AMBER chest radiography and patient dose measurements.

PURPOSE: Improved chest imaging has been reported with the usage of AMBER (advanced multiple-beam equalization radiography) equipment but with a higher patient radiation dose compared with conventional chest radiography. Most studies, however, describe dose measurements from phantoms. This study presents a comparison of radiation dose measurements in 57 patients for p.a. projections from an AMBER unit with and without an extra Cu filtration and from a formerly used conventional Siemens chest stand. MATERIAL AND METHODS: Dose measurements were performed with thermoluminescence dosimetry. Entrance surface doses were recorded from 5 dosimeters, placed on the patient's back. Four were placed over the upper and lower lung fields, respectively, and 1 over the mediastinal area. The dose values were then compared with the values obtained from the conventional chest stand and from the measurements with the extra filtration on the AMBER system. RESULTS: The mean entrance dose for the mediastinal area was 0.25 mSv (range 0.15-0.49). With the extra Cu filtration it was 0.16 mSv (0.07-0.29). For the lung fields the values were 0.19 mSv (0.07-0.44) and 0.10 mSv (0.02-0.31), respectively. For the conventional chest stand the entrance dose to the patient was 0.23 mSv. CONCLUSION: AMBER entrance surface doses for the p.a. projection without extra Cu filtration were comparable to the doses obtained with the formerly conventional Siemens chest stand and were well within European recommendations. With extra Cu filtration the AMBER entrance surface doses were reduced by a factor of almost 2.

Adult↗

Vascular injury following cardiac catheterization, coronary angiography, and coronary angioplasty.

All vascular injuries occurring at this hospital department over a 5-year period (1987-91) as a result of cardiac catheterization, coronary angiography, or coronary angioplasty (PTCA) and requiring transfusion, surgical consultation, or repair, are reviewed. Such complications may occur late and, to detect cases not apparent from the protocol accompanying every examination, a questionnaire was sent to all surgical clinics in the region asking for details of vascular surgical intervention after angiography. The present review of 4879 examinations disclosed 18 patients with 19 vascular injuries (0.39%); four of them were detected by the questionnaire. The types of injury were: pseudoaneurysm (12), thrombembolic episode (4), and excessive bleeding (3). Of the patients with a vascular complication 11 (61%) were receiving anticoagulation treatment, compared to 10% in the whole series; two others suffered from a coagulopathic state. Catheterization was difficult or severe atherosclerosis was present in three, inadvertent mobilization occurred in one, and unintentional puncture distal to the common femoral artery occurred in two patients. With the increasing use of invasive diagnostic and interventional procedures in cardiovascular diseases, knowledge of the type and frequency of possible complications is important, especially of those that may occur late. In the present study anticoagulation, coagulation disorders, and cardiac catheterization combined with brachial puncture and angiography all predisposed to a vascular complication.

Adult↗