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Biomedical subjects

D D Do

Publications and source records attributed to D D Do.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Special technics for angioplasty of the brachiocephalic vessels].

PURPOSE: Description of special techniques for retrograde angioplasty of cerebral arteries with protection of the brain. MATERIAL AND METHOD: During the last 3 years, 51 dilatations of cerebral vessels were carried out in 45 patients; in 8, special techniques were required. In cases with particular operative risks, angioplasty of cerebral vessels can be performed using various techniques (double catheter [8 cases], retrograde PTA [8 cases], kissing balloon technique [3 cases]). RESULTS: All stenoses were successfully dilated, using a local anaesthetic. One patient with a double stenosis of the common carotid artery developed severe headache and visual disturbances in the ipsilateral eye following dilatation of a tight stenosis with total remission of all symptoms within 24 hours. CONCLUSION: Stenoses of cerebral arteries where surgery would be difficult and associated with a high risk can be dilated by retrograde PTA using a double catheter technique with a low complication rate.

Aged↗
PubMed1997

Adventitial cystic disease of the popliteal artery: percutaneous US-guided aspiration.

PURPOSE: To evaluate percutaneous ultrasound (US)-guided aspiration as an alternative therapy for adventitial cystic disease. MATERIALS AND METHODS: Between September 1993 and June 1996, seven patients (six men, one woman; age range, 42-62 years; mean age, 48 years) presented with symptomatic adventitial cystic disease of the popliteal artery (one patient with subacute foot paresthesia, six patients with chronic calf claudication). Color Doppler sonography showed stenosis due to eccentric cysts. Five of the patients also underwent digital subtraction angiography, and four patients underwent magnetic resonance imaging. With real-time sonographic guidance, a 14-gauge needle was forwarded percutaneously into the cysts for aspiration. The aspiration procedure was performed on an outpatient basis with local anesthetics. RESULTS: The procedure was technically and clinically successful in all cases. No complications were noted. Follow-up color duplex sonography performed between 1 and 32 months (mean, 14.8 months) after the procedure showed no relevant recurrent stenosis. CONCLUSION: Percutaneous US-guided aspiration is an easy, safe, efficacious method for treating adventitial cystic disease. In symptomatic patients who do not have thrombotic occlusion, it may be considered the treatment of choice.

Adult↗
PubMed1997

Acute inflammatory reaction associated with endoluminal bypass grafts.

PURPOSE: Nonspecific inflammatory reactions characterized by local tenderness, fever, and flu-like discomfort have been seen in patients undergoing endoluminal graft placement in the abdominal aorta or the femoral arteries. We undertook a study to assess the clinical and laboratory parameters of this inflammation. METHODS: Ten patients with femoropopliteal artery (n = 9) or aortic (n = 1) lesions were treated with EndoPro System 1 stent-grafts made of nitinol alloy and covered with a polyester (Dacron) fabric. Eleven patients implanted with a bare nitinol stent served as the control group. RESULTS: In the stent-graft group, four patients showed clinical signs of acute inflammation manifested by fever and local tenderness. Three of these patients suffered thrombosis of the stent-grafts during the first month of follow-up. Plasma levels of interleukin-1 beta and interleukin-6 in all stent-graft patients were markedly increased 1 day after intervention (7.3 +/- 2.8 versus 90.2 +/- 34.1 pg/mL and 15.6 +/- 5.8 versus 175.5 +/- 66.3 pg/mL, respectively; p < 0.01). This was followed by an increase in fibrinogen (3.0 +/- 0.2 versus 5.0 +/- 0.2 g/L; p < 0.05) and C-reactive protein (14.6 +/- 3.3 versus 77.5 +/- 15.0 mg/L; p < 0.01) at 1 week. No direct correlation between the inflammatory markers and symptoms could be found. In vitro analysis showed that individual components of the stent-graft did not activate human neutrophils, whereas the intact stent-graft itself induced a marked neutrophil activation. CONCLUSIONS: The component of the self-expanding stent-graft responsible for the nonspecific inflammatory reaction was not identified in this study. It is likely that the stent-graft itself or some as yet unrecognized element of the device other than the Dacron fabric or metal alloy may be a potent in vivo inducer of cytokine reaction by neutrophils.

Aged↗
PubMed1997

Blue toes due to floating plaque of the abdominal aorta: endovascular repair with stent.

A 60 year old male patient was admitted with so-called blue toes on both sides. Investigation, including real-time ultrasound, revealed a floating plaque on the dorsal side of the abdominal aorta as the most probable cause of the blue toes. By means of simultaneous fluoroscopy and ultrasound guided implantation of a stent it was possible to restore a free lumen of the aorta. The patient had an uncomplicated recovery. Post-operative colour coded Doppler ultrasound showed normal flow in the aorta. Follow-up examination one year after the procedure demonstrated no evidence of further embolic events and a patent aorta.

Aorta, Abdominal↗
PubMed1996

Ultrasound-guided compression repair for treatment of femoral artery pseudoaneurysm: acute and follow-up results.

Femoral artery pseudoaneurysm is a significant problem in patients undergoing arterial diagnostic or therapeutic catheterization. The aim of this investigation was to report the incidence of pseudoaneurysm after arterial catheterization and the success rate of ultra-sound-guided compression repair. During a 3-year period (11/91-11/94) 9,051 patients underwent 7,312 cardiac catheterizations and 1,739 peripheral percutaneous transluminal coronary angioplasty procedures. Patients suspect of pseudoaneurysm were referred for a color Doppler ultrasound examination. All patients with pseudoaneurysm were considered for ultrasound-guided compression repair. Pseudoaneurysm occurred more frequently after interventional procedures with new devices (valvuloplasty 2.3%, stent 3.2%) than after conventional catheterization diagnostic cardiac catheterization 0.2%, electrophysiology 1.3%, percutaneous transluminal coronary angioplasty 0.2%). The incidence of pseudoaneurysm after peripheral percutaneous coronary transluminal angioplasty, including intra-arterial lysis and stent, was 1%. Ultrasound-guided compression repair was successfully performed in 37 of 41 cases with pseudoaneurysm (90%). Ultrasound-guided compression repair was successfully performed in 30 of 31 patients (97%) without anticoagulation and in 7 of 10 patients (70%) receiving anticoagulants (P < 0.05). There was no correlation between mean diameter of the pseudoaneurysm, age of the lesion, or antiplatelet therapy. Color Doppler ultrasound re-examination at up to 3 months indicated successful treatment in all patients. The use of complex interventional catheterization procedures leads to an increased frequency of pseudoaneurysms compared with conventional angiography and percutaneous transluminal coronary angioplasty. Ultrasound-guided compression repair is a non-invasive, efficient, safe and cost-effective therapy for post-catheterization pseudoaneurysm.

Adult↗
PubMed1996

Ultrasonic-pathologic comparison of postangioplasty myointimal hyperplasia and primary atheroma of the superficial femoral artery.

The purpose of this study was to characterize postangioplasty myointimal hyperplasia as compared to primary atheroma of superficial femoral arteries using color-coded duplex sonography (CCD), and to correlate sonographic findings with the histopathology of samples obtained from these lesions by catheter atherectomy (Redha-cut device). Preinterventionally, homogeneity, echogeneity, and the surface of plaques were described using CCD in nine cases with secondary stenoses after percutaneous transluminal angioplasty and in seven cases with primary atheroma. Myointimal hyperplasia of femoral restenoses showed a homogeneous (7 of 9 vs. 1 of 7) and hypoechogenic (7 of 9 vs. 0 of 7) wall thickening compared to primary atheromas (p < 0.05). Primary atherosclerotic plaques showed a rather heterogeneous, hypo- and hyperechogenic ultrasonic appearance with or without echo shadowing in six of seven cases. The surface of restenoses was more often regular than that of primary atherosclerotic lesions, but this finding did not reach statistical significance (6 of 9 vs. 2 of 7, p = 0.14). Thrombotic material appeared homogeneous and hypoechogenic in three of five cases and could not be discriminated from intimal hyperplasia. In summary, postangioplasty intimal hyperplasia is characterised by a hypoechogenic, homogeneous, rather regularly confined vessel wall thickening and can be differentiated from primary atheroma at CCD.

Aged↗
PubMed1996

[Assessment of deep venous thrombosis].

Deep vein thrombosis (DVT) is a frequent disorder, which should not be missed diagnostically because of the associated morbidity and mortality due to pulmonary embolism and the postthrombotic syndrome. Clinical diagnosis is unreliable. Because of the possible risks a treatment by anticoagulation should not be undertaken without objective confirmation of DVT. Venography is generally considered as the gold standard for the diagnosis of DVT, but is invasive and associated with side effects. Noninvasive cw-Doppler ultrasound and the plethysmography are simple methods, but the accuracy is sufficient only for symptomatic proximal DVT and not for isolated DVT of the calf. In the past few years (color-coded) venous duplex imaging gained increasing importance. It is a noninvasive test with an accuracy comparable to that of venography. In addition to vascular changes perivascular structures can be investigated. B-mode compression sonography has a comparable accuracy for symptomatic proximal DVT.

Humans↗
PubMed1996

[Initial clinical results in the treatment of peripheral arterial occlusive diseases using new percutaneous atherectomy equipment (REDHA-CUT)].

In 11 female and 13 male patients 29 symptomatic femoropopliteal occlusions were treated with a novel intraluminal endarterectomy device (REDHA-CUT). The pre-existing stenoses (71 +/- 9%) could be reduced to 29 +/- 18% (means +/- s.d.). The arteriectomy procedure with this device took on average 5 +/- 3 min. Neither perforations nor dissections nor distal embolisms or any other complications were observed. In comparison with other percutaneous transluminal angioplasty procedures the clinical use of the novel REDHA-CUT device is safe, simple and fast and allows for the retrieval of plaque biopsies.

Aged↗
PubMed1995

[Results in stent implants in pelvic arteries: follow-up with color-coded duplex ultrasonography].

Thirty-one patients (26 males, 5 females), treated with percutaneously inserted endoprostheses (stents) in the iliac artery were followed up a mean 1 year (2-60 months) with regard to clinical and non-invasive results, by color duplex ultrasound and (8 cases) angiography. With one exception self-expandable stents (Wallstents) were applied. The indications for stent implantation were PTA-resistant lesions in 78% and treatment of acute complications after PTA in 22%. Primary technical success with an open stent was achieved in all patients. The ankle-arm systolic pressure index (ASPI) increased from mean 0.67 +/- 0.14 to 0.88 +/- 0.17 (p < 0.001). Early stent occlusion occurred in 1 patient (3%), and 9 (24%) further complications (thrombosis, distal embolization, puncture site problems) were treated either by conservative or interventional procedures, and only once by surgical revision. Color duplex ultrasound showed all stents open without stenosis of hemodynamic significance. Angiography demonstrated intimal hyperplasia in 2 patients with stenosis of about 20-25%. At follow-up 61% of the patients were asymptomatic, 32% were improved. Remaining symptoms were due to lesions of the distal arteries and not to obstructions of the stents. Stenting of iliac arteries is a safe and effective treatment for recurrent and/or complex iliac lesions and has become a valuable adjunct in catheter interventions. We conclude that color duplex ultrasound is not only applicable in native arteries but also in stents, and gives reliable results with regard to hemodynamically relevant obstructions.

Aged↗
PubMed1995

Severe symptomatic vasospasm after rupture of an arteriovenous malformation.

A 31-year-old woman had intracerebral and intraventricular hemorrhage from an arteriovenous malformation. Vasospasm of the internal carotid arteries developed and was treated with angioplasty. On initial CT scans, only traces of blood were seen in the basal cisterns; thus, the development of symptomatic vasospasm was an unexpected complication.

Adult↗
PubMed1994

Low-dose aspirin combined with dipyridamole versus anticoagulants after femoropopliteal percutaneous transluminal angioplasty.

PURPOSE: To investigate whether anticoagulation or platelet inhibition treatment provides better prevention of reobstruction after percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: In a controlled study, 160 patients received either oral anticoagulants or a combination of low-dose acetylsalicylic acid (25 mg) and dipyridamole (200 mg) (ASAD) twice daily for 1 year after successful femoropopliteal PTA. Compliance was comparable. The patients in the two groups had similar clinical and angiographic characteristics. Patency was assessed with noninvasive methods 1 day and then 3, 6, and 12 months after PTA and was confirmed at angiography at the end of the study in 112 patients. RESULTS: Patency in patients who received anticoagulants was 53% and was not statistically significantly different from 69% in patients who received ASAD (P = .18). With anticoagulants, there were four bleeding complications (one was fatal); with ASAD, only five minor complications occurred. CONCLUSION: ASAD is at least as effective as anticoagulants for secondary prevention of obstruction after PTA but has less severe side effects.

Administration, Oral↗
PubMed1994

Fibrin formation and degradation in patients with arteriosclerotic disease.

BACKGROUND: The blood coagulation cascade was reported to be activated in patients with arteriosclerotic disease of the lower limbs (peripheral arterial disease, PAD). There is more thrombin and fibrin formation compared with healthy control subjects. In many studies, however, the presence of arteriosclerotic disease had not been thoroughly ruled out in the control group. Therefore, markers of the activation of the blood coagulation cascade were measured in patients with PAD and in a carefully defined control group, both groups being subjected to an exercise test. METHODS AND RESULTS: Twenty-two patients with angiographically documented PAD of grade II (Fontaine classification) and 13 control subjects in whom the presence of arteriosclerotic lesions was ruled out by noninvasive means in the carotid arteries, abdominal aorta, leg arteries, and coronary arteries took part in the study. Before and immediately after a treadmill stress test, the concentrations of prothrombin fragment F1 + 2 (F1 + 2), thrombin-antithrombin III complexes (TAT), fibrinopeptide A (FPA; this peptide was measured in spot urine also), and D-dimers were measured. Before exercise, the concentrations of F1 + 2 (1.0 +/- 0.6 versus 0.7 +/- 0.3 nmol/L), TAT (2.9 +/- 2.1 versus 1.9 +/- 0.8 micrograms/L), and D-dimers (318.2 +/- 270.1 versus 150.0 +/- 91.4 micrograms/L) were significantly higher in the patients with PAD compared with the healthy control subjects. FPA concentrations in plasma (1.9 +/- 1.0 versus 1.4 +/- 0.6 micrograms/L) and spot urine were not different, however. F1 + 2, FPA, and D-dimer concentrations correlated with the severity of the PAD as assessed by the ankle systolic blood pressure index (ABPI). The symptom-limited stress test did not lead to further activation of the blood coagulation cascade. However, concentrations of F1 + 2 (P < .001) and TAT (P < .01) after exercise correlated with the presence of ischemic changes in the stress-test ECG. CONCLUSIONS: There is evidence of enhanced thrombin formation in patients with PAD compared with an age- and sex-matched control group without clinical and sonographic evidence of arteriosclerosis. The thrombin formed, however, appears to be almost completely neutralized by antithrombin III. No direct evidence of fibrin formation was obtained, since the FPA concentrations were not different. In the patients with PAD, the higher concentrations of D-dimers are indicative of in vivo fibrinolysis. Thus, some fibrin formation must be postulated to occur in patients with arteriosclerosis.

Aged↗
PubMed1993

[Color-coded Doppler sonography in iatrogenic spurious aneurysms in the groin].

Pseudoaneurysm of the femoral artery occurred in five patients (aged between 61 and 82 years) after catheterization of the artery, four times after percutaneous transluminal angioplasty of the leg arteries and once after left-heart catheterization. The pseudoaneurysms were correctly diagnosed by colour-coded duplex Doppler sonography by demonstrating turbulence within the aneurysm and a connection to the femoral artery with bidirectional shunting. Enough pressure was exerted with the instrument head to stop flow in the aneurysm and its connection to the artery without, however, significantly reducing arterial flow. After 30-35 min flow into the aneurysm had ceased even when the compression was released. Re-examination up to 11 months later (mean of 7.6 months) indicated that the treatment had been successful in all.

Aged↗
PubMed1992

Femoropopliteal artery occlusion: clinical experience with the Kensey catheter.

In 25 patients, 12 with acute-subacute and 13 with chronic extensive femoropopliteal artery occlusions (mean length, 8 cm), a prospective study was performed after application of the Kensey catheter and subsequent performance of percutaneous transluminal angioplasty (PTA). Passage through the occlusion with the Kensey catheter failed in five patients because of the presence of dissections. As confirmed at angiography, free flow through the obstruction and the runoff bed could be restored with the Kensey catheter, guide wires, balloon dilation, and thrombus aspiration and/or thrombolysis in 24 of the 25 patients (96%). In five patients, peripheral embolisms occurred after application of the Kensey or balloon catheter. Cumulative patency rates, according to findings of a noninvasive examination, were 80% at 3 days, 59% at 6 months, and 38% at 12 months after performance of the combined interventions. Thus, the results obtained with use of this new device have not proved superior to previously reported results with conventional PTA.

Aged↗
PubMed1992

Interventional angiology.

Percutaneous transluminal angioplasty in peripheral artery occlusive disease by balloon catheters is the standard method in interventional angiology. For almost twenty years it has been recommended in the aorto-iliac region for arterial stenoses, and in the femoro-popliteal arteries for stenoses and short occlusions. Due to progress in technology of catheters and guide wires, a primary success rate of more than 90% is to be expected with favourable angiographic conditions. The long-term patency rate of some 90% on the aorto-iliac level exceeds that of 70-90% on the femoro-popliteal level. The patency rate decreases with increasing complexity of the lesions. Subacute/acute occlusions of the femoro-popliteal arteries by thrombosis or embolism are treated successfully in 80% of cases by catheter-thrombolysis and/or thrombus aspiration combined with percutaneous transluminal angioplasty if necessary. Several new techniques are under clinical evaluation, such as laser angioplasty, rotational catheters, atherectomy catheters and stents. Their application in clinical routine has up to now not been justified except for special situations such as obtaining biopsy material by Simpson catheter or maintenance of patency in balloon resistant lesions by stents.

Angiography↗
PubMed1991

[Mapping of superficial veins for vascular replacement using duplex ultrasound].

With regard to surgical vascular reconstruction, we evaluated the saphenous veins of 110 patients as potential substitute vessels by duplex ultrasound. The technique is analogous to the one used for diagnosis of varicose veins. Finally 74 patients underwent a surgical intervention with exploration or removal of veins. The comparison between the 74 operative findings available for analysis and the results of duplex ultrasound showed agreement in 93%. The duplex technique informs not only about the permeability and morphology of the veins but also by direct skin marking about their precise position. In comparison with phlebography, it is in experienced hands at least as reliable, without morbidity and virtually without inconvenience to the patient. In our opinion, the non-invasive duplex ultrasound method is quite adequate for the preoperative judgement of veins destined for vessel replacement.

Aged↗