[Changes in left ventricular dP/dt during transluminal coronary angioplasty]. / Modifications de la dP/dt ventriculaire gauche au cours de l'angioplastie transluminale coronaire.

The authors studied changes of LV dP/dt during transcutaneous coronary angioplasty (TCA). The aim of the study was to detect the alterations of LV function during coronary occlusion and to evaluate the immediate effects of PCA on myocardial function. Six patients with incapacitating angina and isolated left anterior descending disease were successfully treated by TCA using Gruntzig's technique. The study protocol included several recording sequences per patient during the phases of balloon inflation at progressively increasing pressures from 2 to 10 hours. Each sequence comprised a recording under basal conditions and every 5 seconds during inflation (20 seconds) and deflation (45 seconds) of the following parameters: heart rate, aortic and LV pressures, positive and negative peaks of LV dP/dt, and the intracoronary pressure gradient at the beginning and the end of each sequence. The first part of the results based on 27 recorded sequences analysed the bad effects of myocardial ischaemia; coronary occlusion induced a significant fall (p less than 0.01) in the positive and negative peak dP/dt values and on elevation (p less than 0.01) in LV end diastolic pressure, without affecting LV systolic pressure or heart rate. These changes have the following characteristics: they are early, occurring within seconds of coronary occlusion; they affect LV contraction and relaxation simultaneously, but the effects are more marked on LV relaxation; the severity is proportional to the duration of occlusion; they are totally reversible; the disturbances of relaxation return to normal more quickly than those of contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

[Coronary aneurysm after transluminal angioplasty. Report of 13 cases]. / Anévrysmes coronaires après angioplastie transluminale. A propos de 13 observations.

The aim of this study was to determine the incidence, angiographic characteristics, clinical consequences, therapeutic implications and evolution of coronary arterial aneurysms after percutaneous transluminal coronary angioplasty (PTCA) based on a series of 13 cases out of a total population of 752 patients undergoing balloon dilatation. Before BTCA, 10 patients had unstable angina and 3 had stable angina. The stenoses were of type A in 6 cases and, more complex, type B, in 7 cases. The results of PTCA were good except in 1 case in which the procedure was complicated by a rudimentary infarct due to an extensive intra mural rupture. The frequency of coronary aneurysms evaluated in a series of 150 patients dilated and controlled systematically was 4 p. 100. This complication was observed relatively late, 2 to 13 months after PTCA. The length of aneurysm ranged from 2 to 13 mm (3.9 +/- 2.9 mm). Nine aneurysms were sacciform and 4 were fusiform. They were isolated in 6 cases and associated with restenosis in 7 cases. The predisposing role of an oversized angioplasty balloon was a probable etiological factor; the balloon/artery ratio was over 1.1 in 4 cases and over 1.2 in 3 cases. Intramural rupture observed at the time of PTCA (8/13 cases) did not seem to be a predisposing factor as the incidence of coronary aneurysm was not significantly different in patients without this complication in the group of 150 patients dilated and controlled systematically by angiography (5.8% vs 3%; NS). In the 6 cases of isolated coronary aneurysm the patients were asymptomatic and were followed up with medical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative results of coronary angioplasty performed at the time of coronarography and at a later time]. / Résultats comparés de l'angioplastie coronaire pratiquée dans le même temps ou à distance de la coronarographie.

Between January 1986 and December 1988, 558 patients underwent percutaneous transluminal coronary angioplasty (PTCA) of whom 40 per cent were dilated at the time of diagnostic coronary arteriography. In order to assess the value of this therapeutic strategy we compared the results of 221 patients dilated at the time of diagnostic coronary arteriography (Group 1) with those of 337 patients who underwent deferred PTCA. In Group 1, the incidence of stable angina was lower (26.7% vs 46.3%, p less than 10-5), that of thrombolysed myocardial infarction was higher (24% vs 2.7%, p less than 10-9) and a higher proportion of patients had previously undergone PTCA (29.4% vs 3.2%, p less than 10-9). The proportion of patients with single vessel disease was higher in Group 1 (84.6% vs 74.7%, p less than 0.01) as was that of angioplasty of a single lesion (97.7% vs 88.1%, p less than 10-4). There were fewer dilations of the left circumflex artery in Group 1 (17.2% vs 27.3%, p less than 0.05) which was compensated by a higher number involving the right coronary artery (26.1% vs 15.5%, p less than 0.01). The immediate results were comparable in the two groups with 87.8 per cent primary successes, 3.6 per cent of myocardial infarcts and 1.3 per cent of coronary bypass operations with no fatalities in Group 1. These favorable results encourage the development of PTCA at the time of diagnostic coronary arteriography in the following indications: unstable angina, thrombolysed myocardial infarction and restenosis irrespective of the patient's symptomatology.(ABSTRACT TRUNCATED AT 250 WORDS)

[Coronary intramural ruptures caused by transluminal angioplasty. Incidence, significance and development controlled by coronary angiography]. / Les ruptures intramurales coronaires induites par l'angioplastie transluminale. Incidence, signification et évolution contrôlée par coronarographie.

The authors report their experience of coronary intimal rupture (CIR) observed at control angiography performed at the end of transluminal angioplasty in a series of 150 cases. This lesion was observed in 34 p. 100 of cases. Two subgroups were established according to the presence (Group I: 51 cases) or absence of CIR (Group II: 99 cases) in order to try and identify any predisposing factor. The following features were compared in each group: age, sex, number of risk factors, duration of the disease, its severity, the site and morphology of the lesions (calcification, length, excentric or concentric) on the artery dilated and the technique used (number of inflations, maximal pressure, guidable catheter). The only significant feature associated with CIR was the morphology of the stenosis. Intimal rupture was statistically more frequent when the stenosis was long, calcific and excentric (p less than 0.05). The excentric character was highly predictive of CIR +/- 0.02) and even of complicated CIR (p less than 0.01). The CIR was complicated in 10 cases (19.6 p. 100) with a higher incidence than in the rest of the population (p less than 0.05). These complications were immediate presenting as attacks of angina leading on to 4 myocardial infarctions (7.8 p. 100) but no deaths. The treatment consisted in an attempt to redilate the artery with effective angioplasty in 3 out of 4 cases. Medical therapy alone was sufficient in 2 cases and 4 patients underwent coronary bypass. There were no complications in cases of initially asymptomatic intimal rupture. The 6 months outcome was controlled by coronary angiography in 131 angioplasties.(ABSTRACT TRUNCATED AT 250 WORDS)

[Gamma-angiography in the diagnosis of akinesia and dyskinesia after myocardial infarction]. / Apport de la gamma-angiographie au diagnostic des akinésies et des dyskinésies après infarctus du myocarde.

A one year prospective double blind trial included all patients with myocardial infarction and clinical, electrocardiographic or radiographic signs of left ventricular aneurysm. All 36 patients underwent ventriculography and radionuclide angiocardiography in the same projections: right anterior oblique, antero-posterior, left anterior oblique and left lateral. The angiographic diagnosis of left ventricular aneurysm was based on the finding of a deformation of the ventricular contour persisting in diastole; 22 patients were classified as having a left ventricular aneurysm and the 14 others had akinesia alone. The radionuclide diagnosis of left ventricular dyskinesia was based on the finding of the following 3 criteria in at least one projection: crossing of the systolic and diastolic isocontours; over 4 p. 100 of LV pixels having a negative ejection fraction; the dephased infarcted region having a movement separate from that of the remaining healthy myocardium. None of the clinical criteria of inclusion allowed diagnosis of LV aneurysm when compared with the results of ventriculography. The results of radionuclide and conventional ventriculography correlated 100 p. 100 in the diagnosis of severe contractile abnormalities. When compared with ventriculography, radionuclide angiocardiography had a specificity of 95 p. 100 and a sensitivity of 86 p. 100 for the diagnosis of aneurysm. The only false negative was a non-surgical septal aneurysm. The multiplication of the incidences of examination increases the sensitivity of the results of radionuclide angiography.

[Comparison of magnetic resonance imaging, echocardiography and catheterization in the diagnosis of congenital heart diseases]. / Evaluation comparée de l'IRM, de l'échocardiographie et du cathétérisme pour le diagnostic des cardiopathies congénitales.

The authors compared the diagnostic value of magnetic resonance imaging (MRI), echocardiography and cardiac catheterisation with angiography in 66 patients with congenital heart disease, to determine a diagnostic strategy in the use of these methods of cardiac imaging. The patients were 8 days to 44 years old. The congenital cardiac malformations were classified in three groups: 29 isolated vascular malformations (Group 1), 17 isolated intracardiac malformations (Group 2) and 20 complex malformations (Group 3). MRI was performed in all patients using a high field (1.5 tesla) magnet and spin-echo sequences in multiple incidences. The results were compared with those of echocardiography in 60 patients and/or cardiac catheterisation in 39 cases. Technical evaluation of MRI showed images of diagnostic quality in 62/66 cases (93.9%). MRI provided a diagnostic contribution in 56 cases (85%) which was less important in intracardiac malformations than in the other groups (p less than 0.05). In comparison with other imaging techniques, globally, the diagnostic value of MRI was lower than that of cardiac catheterisation (p less than 0.005) but there was no significant difference between MRI and echocardiography. When the type of malformation was taken into account, MRI was not as useful as catheterisation and echocardiography for the diagnosis of isolated intracardiac malformations (p less than 0.01) but gave comparable results in other malformations. On the other hand, MRI associated with echocardiography was more useful (p less than 0.05) than catheterisation in the diagnosis of complex congenital lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

[Percutaneous aortic valvuloplasty. Long-term outcome apropos of 85 patients with successful dilatation]. / Valvuloplastie aortique percutanée. Evolution à long terme à propos de 85 patients dilatés avec succès.

The outcome at 2, 6, 12, 18 and 24 months in terms of clinical status and Doppler echocardiographic parameters of 85 patients successfully dilated out of 116 patients undergoing percutaneous aortic valvuloplasty is reported. The objectives were to determine the survival rate, degree of clinical remission, the restenosis rate and its predictive factors. The 31 patients considered to be primary failures were excluded from the study. The global survival rates were 90 +/- 2% at 2 months, 84 +/- 4% at 6 months, 78 +/- 5% at 12 months, 69 +/- 6% at 18 months and 60 +/- 8% at 2 years. Patients in clinical remission and with clinical relapse were compared at the 6th month: relapse was significantly, related to prevalvuloplathy, low cardiac output (p = 0.05), low ejection fraction (p less than 0.03) and low fractional shortening (p less than 0.01), but the clinical relapse was independent of aortic valve surface area before and dilatation. In the relapse group, 14 patients (12%) were operated without complications in the first month of follow up, 6 patients underwent repeat valvuloplasty with 4 immediate failures and 2 improvements. The other patients were treated medically. The restenosis rate (loss of greater than 50% of initial gain in surface area or return of pre-valvuloplasty maximal pressure gradient +/- 25%) increased up to the 12th month in both groups (remission and relapse) and reached 78% at 12 +/- 3 months and seemed more pronounced in the less severe aortic stenosis. The incidence of restenosis was independent of gain in surface area after valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

[Beneficial effects of coronary transluminal angioplasty on resting left ventricular systolic function]. / Effets bénéfiques de l'angioplastie transluminale coronaire sur la fonction systolique ventriculaire gauche de repos.

Resting left ventricular systolic function was studied by cardiac catheterisation before and 6 months after effective transluminal coronary angioplasty (TCA) to evaluate the myocardial effects of this procedure. The global left ventricular systolic function was assessed by measuring ventricular volumes, the ejection fraction, the mean velocity of circumferential fibre shortening (m VCF) and mean normalised systolic ejection rate (MNSER). The regional function was studied by dividing the left ventricle into 8 regions using the Stanford radial model and measuring the percentage shortening and velocity of circumferential fibre shortening (VCF). These parameters were obtained from selective left ventriculography filmed at 100 frames/second in the RAD plane. Left ventricular function was analysed from the whole of systolic ejection and then sequentially during each third of systole (early-mid-and end systole). The 10 patients studied had an average age of 45 years. Coronary angiography was performed for unstable angina (6 cases), stable angina (3 cases) and post-infarction angina (1 case). Except for 1 patient with associated LAD and right coronary disease they all had single vessel disease. TCA was performed on the LAD artery in 8 cases, on a dominant left circumflex artery in 1 case and on a right coronary artery in 1 case. The efficacy was demonstrated by angiographic reduction of the degree of stenosis (85 to 25 p. 100 immediately after TCA, and 30 p. 100 at control angiography at 6 months), and by a reduction of more than 40 p. 100 in the average transstenotic pressure gradient.(ABSTRACT TRUNCATED AT 250 WORDS)

[Detection of residual myocardial ischemia by Thallium-201 myocardial scintigraphy after myocardial infarction. Apropos of 53 patients treated with thrombolytic agents during the acute phase and with coronary transluminal angioplasty]. / Appréciation de l'ischémie résiduelle par scintigraphie myocardique au thallium-201, après infarctus du myocarde. A propos de 53 patients traités par thrombolytiques à la phase aiguë et par angioplastie transluminale coronaire.

The prognosis of silent ischemia after myocardial infarction is similar to that of post-infarction angina. In order to detect this condition two stress myocardial scintigraphies were performed: three weeks after hospital admission for myocardial infarction treated by thrombolytic therapy without any complications or recurrence of chest pain; one month later, after percutaneous transluminal coronary angioplasty on the infarct-related artery in 24 patients or after medical therapy alone when this procedure was not possible (29 patients). Silent ischemia, initially present in two thirds of patients, was less frequently observed in the patients undergoing angioplasty (p < 0.05). In the remaining one third of patients with no silent ischemia, myocardial scintigraphy was unchanged at the follow-up procedure whether or not angioplasty had been performed. These results show that silent ischemia is commonly observed during stress myocardial scintigraphy after acute myocardial infarction treated by thrombolysis, but that this condition can be significantly reduced by coronary angioplasty. When no silent ischemia is observed, coronary angiography and angioplasty do not seem to be indicated.

[Long-term evaluation, physical and sports activities after correction of Fallot's tetralogy]. / Evaluation à long terme et activités physiques et sportives après corrections de tétralogie de Fallot.

The aim of this study was to assess the result of surgical repair of Fallot's tetralogy (FT) and to advise physical and sporting activities. Thirty-two patients (20 boys and 12 girls) underwent correction of FT either before 4 years of age (14 cases) or after (18 cases). The patients were assessed on average 7.5 years postoperatively (range 4 to 13 years). All but one were class I of the NYHA classification. Radiological cardiomegaly was observed in 3 cases (CTI greater than 0.55). Sinus rhythm was present in all cases: 27 out of 30 had complete right bundle branch block without bifascicular block. Holter monitoring was performed in 22 cases: occasional monomorphic VES (1 to 15/hour) were observed in 7 cases. Frequent polymorphic VES were observed during exercise in one adult. Echocardiography and cardiac catheterization revealed pulmonary regurgitation and right ventricular dilatation in over half the cases, with an infundibular aneurysm in 2 cases and a residual pressure gradient of 55 and 66 mmHg in 2 other cases requiring reoperation. Left ventricular function was satisfactory in all cases. Treadmill exercise testing was performed in 28 patients. However, for statistical analysis 12 boys aged 7 to 15 years were compared with 11 controls of the same age. There was a significant decrease in maximal O2 consumption, of CO2 excretion, of ventilation, of heart rate, of work developed and total work in the operated patients. Clinical assessment and complementary investigations are essential 5 to 10 years after correction of FT to detect latent abnormalities and to better advise patients on physical and sporting activities.

[Diagnostic angiography of antero-apical ventricular aneurysms. Contribution of multiple projections. Apropos of 42 cases]. / Diagnostic angiographique des anévrysmes ventriculaires antéro-apicaux. Apport des incidences multiples. A propos de 42 cas.

The wide variety of definitions covering the term, left ventricular aneurysm, at the present time suggests the need for a radiological description based on pathological findings. The presence of the aneurysm on angiographic images is shown by a persistent left ventricular deformity during diastole causing a pocket separated from the contractile left ventricle by an annular constriction. A study of 42 cases of anterior apical ventricular aneurysms selected according to these criteria and investigated by multiple ventriculographic projections (LAO, RAO, anteroposterior and profile) demonstrated that the right anterior oblique projection alone is insufficient to ensure the diagnosis. An indirect sign suggestive of the diagnosis is a double outline due to the superimposition of aneurysmal and contractile zones. A complementary LAO projection, with or without a profile film, should be performed in order to confirm diagnosis and determine extent of lesion, this conditioning the result of surgery.

[The new LEM caval filter in the prevention of pulmonary embolism. Preliminary results of a French multicenter study]. / Le nouveau filtre cave LEM(1) préventif de l'embolie pulmonaire. Résultats préliminaires d'une étude multicentrique française.

Preliminary results are reported of a prospective multicenter trial of a new caval filter (LEM*) implanted by the percutaneous jugular route in 100 patients, 55 men and 45 women, mean age 67 +/- 13 years, to produce partial interruption of inferior vena cava (IVC). Of the 100 attempts to insert the LEM* filter, 2 failures to catheterize the jugular vessel were reported, 98 filters being placed in the IVC with 82 implantation considered adequate. Of the remaining 16 cases, the filter was inclined (7 cases) or incompletely open (9 cases) with total lack of success in 3 cases. Overall efficacy was obtained therefore in 95 cases. Follow up included 94 patients seen after one week, 63 after 3 months and 10 after 6 months: 3 embolic recurrences were noted (3.2%) of cases. None of the 8 deaths reported was related to the thromboembolic disease. Standard frontal abdominal radiographic images showed migration of filter in 13 cases (13.7%) not exceeding the height of a vertebral body: 9 were caudal and 4 proximal, the LEM* filter remaining within the IVC. Phlebocavography in 90 cases showed the IVC to be permeable in 84 cases (93.3%). Incomplete opening or inclination of filter had no effect on the course. These findings demonstrate that the advantages of the LEM* filter include: a percutaneous introduction allowing rapid, certain insertion, and a form studied for limitation of inclination and avoidance of perforation of the IVC.(ABSTRACT TRUNCATED AT 250 WORDS)

[Transluminal coronary angioplasty at the same time as or separate from coronarography. Comparative results]. / Angioplastie transluminale coronaire dans le même temps ou à distance de la coronarographie. Résultats comparatifs.

Frequency of PTCA performed at the time of initial coronary angiography has increased to 47% of all PTCA performed in 1988. The aim of this study is to assess the efficacy and safety of this strategy by comparing the results in 2 groups of patients: in group 1 (179 patients), PTCA was performed at the time of initial coronary angiography and in group 2 (549 patients) PTCA was performed, 15 to 30 days after initial coronary angiography. Clinical differences between the two groups concerned: stable angina (25.1% vs 41%; p less than 0.001) and myocardial infarction treated with thrombolytic therapy (23.7% vs 7.7%; p less than 10(-9)). The extent of coronary artery disease was similar in the two groups but the incidence of single vessel PTCA was higher in group 1 (96% vs 90%; p less than 0.01). The immediate results of PTCA were similar and led us to develop this strategy for unstable angina, myocardial infarction treated with thrombolytic therapy, as well as total coronary obstruction and restenosis whatever their symptoms and signs. This strategy requires high quality fluoroscopic and video replay images, and allows a reduction in hospital costs.

Long-term follow-up of Vena Tech-LGM filter: predictors and frequency of caval occlusion.

PURPOSE: To report the frequency of caval occlusion after Vena Tech-LGM filter placement and identify related factors and their potential clinical significance. MATERIALS AND METHODS: The filter was inserted into 243 patients, 142 of whom met inclusion criteria for this prospective study. Follow-up examinations performed every 2 years included clinical evaluation, plain frontal radiography of the abdomen, duplex scanning of the inferior vena cava (IVC), and/or phlebocavography. RESULTS: A progressive decrease in IVC patency was observed, reaching 66.8% at 9 years of follow-up. Complete caval occlusion occurred in 28 patients and was significantly (P < 10(-6)) associated with retraction in 24 cases. Caval occlusion was not related to age, sex, pulmonary embolism (PE), deep venous thrombosis level, underlying conditions predisposing to a thromboembolic disease before filter insertion, the level of filter placement, use of anticoagulant therapy, and death during follow-up. PE with anticoagulation failure was a predictive factor (P = .016) of subsequent filter occlusion during follow-up as compared to all other clinical indications for filter placement. Filter patency at 9 years of follow-up was 35.2% in the PE group with anticoagulation failure and 80% for other patients (odds ratio, 2.5; 95% confidence interval 1.16-5.4). CONCLUSION: PE with anticoagulation failure was the only factor predictive of subsequent caval occlusion observed in patients after Vena Tech-LGM filter placement. Caval occlusion was also related to Vena Tech-LGM filter retraction, which usually occurred at the time of occlusion.

Evaluation of the LGM Vena-Tech infrarenal vena cava filter in an ovine venous thromboembolism model.

PURPOSE: To validate a new percutaneous model of venous thrombosis in sheep and evaluate the use of the LGM Vena-Tech vena cava filter with use of this model. MATERIALS AND METHODS: After implantation of a LGM Vena-Tech filter in the infrarenal vena cava (IVC), thrombus was obtained by blocking the iliac vein with an inflated balloon (Wedge catheter) for 15 minutes and simultaneously injecting 20 mL of fresh thrombus into the femoral vein. Clot migration of the thrombus was induced by balloon deflation and injection of contrast medium. Migration and capture of the thrombus by the filter were filmed under fluoroscopy at 1 frame/sec. Euthanasia followed by pathologic examination of the IVC, heart, and lungs was performed immediately after the procedure in five sheep (group 1). Sheep in groups 2, 3, and 4, (five in each group), were killed at 2, 4, and 8 weeks, respectively, after vena cavography. Histologic examination was performed to analyze the evolution of the thrombus captured, the incorporation of the filter in the caval wall, and the physical and mechanical effects of captured thrombi on the filter. RESULTS: The Vena-Tech filter captured a large amount of thrombus in all cases except one, in which the filter captured a small strand of thrombus, related to incomplete occlusion of the iliac vein during the clot formation procedure. In the 15 animals in which follow-up was performed, fibrous evolution of the thrombus was observed at gross examination in 14, leading to the formation of fibrous webs between the filter and the IVC wall in eight. These observations were not related to the incidence of filter retraction (n = 4), caudal migration (n = 2), tilt (n = 2), or caval perforation (n = 1). Heart and lung thrombi were present in six animals. Histologic results confirmed the fibrous evolution of the thrombus and its organization during follow-up. Neointima increases significantly (P <.02) during follow-up, from 135.7 microm +/- 13.4 at 2 weeks to 192.2 microm +/- 125.7 at 4 weeks and 334.2 microm +/- 144.1 at 8 weeks. CONCLUSION: The model used is suitable for the formation of a large amount of venous thrombus and analysis of its migration and capture by the LGM Vena-Tech filter. Fibrous evolution of the thrombus, including development of webs and changes in filter shape and position, were the main outcomes observed.

[Aortic valvuloplasty in the elderly. Immediate and medium-term results]. / La valvuloplastie aortique du sujet âgé. Résultats immédiats et à moyen terme.

Between January 86 and February 88 we attempted percutaneous aortic valvuloplasty in 100 patients. 68 patients could be dilated with hemodynamic success: the aortic valve area increased from 0.52 +/- 0.17 cm2 to 0.78 +/- 0.27 cm2 (p less than 0.001). Cardiac output did not change significantly (4 +/- 1.1 l/mn). In the remaining 32 patients: 8 patients (8%) died in hospital and the morbidity rate was 11%: arterial injury (9), stroke (1) and major cardiac event (1). Sixty patients regarded as initial success were followed for 6 months: 3 patients (5%) died without cardiac events, functional improvement persisted in 41 patients (68%) and clinical failure was observed in 16 patients (27%): 4 patients died and in the remaining 12 patients, the recurrence of symptoms required medical treatment (5), surgery (5) or repeat percutaneous valvuloplasty (2). Echo-Doppler maximum aortic valve gradient was significantly less in improved patients (55 +/- 21 mmHg) than in deteriorated patients (78 +/- 36 mmHg) (p less than 0.02). One year after valvuloplasty: actuarial survival was 74 +/- 6%, clinical improvement was 53 +/- 7% and clinical recurrence was 41 +/- 7%. Thus percutaneous aortic valvuloplasty may be proposed only to non surgical patients.

Vena Tech-LGM filter: long-term results of a prospective study.

Efficiency and tolerance of the Vena Tech-LGM filter were assessed in 142 patients prospectively studied during a 2-6-year follow-up period. No patients were lost to follow-up, and 137 (91.3%) scheduled control examinations were performed. Fifty-three patients died of causes unrelated to thromboembolic disease. Pulmonary embolism was suspected in five surviving patients (3.5%). Sixteen retractions (18.4%), 16 intracaval migrations (18.4%), and one tilt were observed. Filter patency studied at Doppler ultrasonography, with or without phlebocavography, gave the following results according to the Kaplan-Meier actuarial method: 92% patency after 2 years of follow-up, 80% after 4 years, and 70% after 6 years. Vena Tech-LGM filter obstruction was related to retraction (P < 10(-6)) or distal migration (P < .004). Occurrence of trophic disease in the lower limbs during the follow-up period was related to the initial level of deep venous thrombosis (P = .03) and had no relation to the patency of the filter. The filter was effective in preventing pulmonary embolism, with 70% demonstrating long-term patency, and no deleterious effects were imputed to obstructions observed during follow-up.

Plasma treatment effects on the tantalum Strecker stent implanted in femoral arteries of sheep.

PURPOSE: To evaluate the effects of plasma treatment, a cleaning process for removal of organic contaminants from the knit-wire surface of tantalum Strecker stents, on biocompatibility and thrombogenicity. METHODS: A treated or untreated stent was randomly implanted in both femoral arteries of 15 sheep studied for periods of 4 (group 1), 15 (group 2), or 42 (group 3) days. Patency, histological changes, and mechanical effects were compared by means of radiologic and pathologic controls. RESULTS: Plasma treatment did not influence overall patency (93.3% vs 86.7%), maximal neointimal hyperplasia in groups 2 and 3 (801 +/- 123 vs 733 +/- 179 microns), or media thinning in any group (254 +/- 92 vs 285 +/- 72 microns), but modified the elastic properties of the stents by limiting (p = 0.01) shortening at implantation. CONCLUSION: Plasma treatment does not affect the biocompatibility and thrombogenicity of Strecker stents implanted in normal femoral arteries of sheep but modifies their elastic properties. Further studies are needed to account for this effect.

Caval incorporation of the LGM Vena Tech filter: an experimental study.

PURPOSE: To analyze LGM Vena Tech filter incorporation and the rapidity of the process. MATERIALS AND METHODS: A filter was inserted into the infrarenal inferior vena cava (IVC) of 15 ewes assigned to one of three groups depending on the length of follow-up (2, 4, or 8 weeks). Radiologic data concerning IVC diameter and filter patency, stability, and incorporation were obtained before and after insertion and before euthanasia. Histopathologic analysis concerned wall thickness and smooth muscle cell area (SMCA) at three levels of the filter and at one point outside the filter. RESULTS: All filters remained patent during follow-up. Incorporation of struts was dependent on time (P = .006), level of the filter (P = .0001), and strut surface (P < .0001). Neointimal thickness increased during follow-up (P = .0002), being more marked in the midportion of the filter (P = .0037). Adventitial thinning was observed (P = .0001), corresponding to a significant decrease in SMCA (P < .0001) above the struts as a function of the length of the follow-up period (P = .0021). CONCLUSIONS: The LGM Vena Tech filter was well tolerated and is suitable for incorporation into the IVC wall of normal animals without risk of any deleterious reactions due to biological incompatibility.