-
[show abstract]
[hide abstract]
ABSTRACT: Laser-induced fluorescence may be used to guide laser ablation of atherosclerotic lesions. This study was performed to evaluate arterial autofluorescence spectroscopy in vitro using a single XeCl excimer laser (308 nm) for simultaneous tissue ablation and fluorescence excitation. The laser beam was coupled to a 600-microns silica fiber transmitting 40-50 mJ/mm2 per pulse. The fluorescence radiation emanating retrogradely from the fiber was collected by a concave mirror spectroscopic analysis over a range of 321-657 nm. The arterial media (n = 26), lipid plaques (n = 26), and calcified lesions (n = 27) of aortic specimens from ten human cadavers were investigated in air, saline, and blood. Whereas the spectrum of calcified lesions changed with the surrounding optical medium, the other spectra remained constant. In air and blood, the spectra of arterial media, lipid plaques, and calcified lesions could be differentiated qualitatively and quantitatively (P < 0.0001). In saline, there was no clearcut spectroscopic difference between lipid plaques and calcified lesions. However, normal arterial media and atherosclerotic lesions (lipid plaques plus calcified lesions) could still be discriminated. Thus spectroscopy and plaque ablation can be combined using a single XeCl excimer laser. These encouraging results should stimulate further studies to determine the potential use of this approach to guide laser angioplasty in humans.
Lasers in Surgery and Medicine 02/1994; 14(3):238-48. · 2.75 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The success of percutaneous transluminal coronary angioplasty is limited by acute occlusion and late restenosis. In 25 patients (20 men, 5 women, age range 36-81 years) coronary angioplasty was performed using a new cutting balloon into which 3-4 longitudinally orientated blades are incorporated so as to reduce the rate of severe dissections. In 12 patients stenoses were reduced from 83.9 +/- 7.8% to 28.4 +/- 10.7% (mean +/- SD) by the cutting balloon alone, using predilatation with a small conventional balloon in two cases. Thirteen other patients were additionally dilated with a conventional balloon because of a residual stenosis > 50% after cutting balloon angioplasty. Here the stenoses could be reduced from 78.1 +/- 8.7% to 29.1 +/- 11.3%. Six months follow-up angiography in 14 patients showed > 50% restenosis in two of seven patients dilated with a conventional balloon in addition to the cutting balloon, and in one of seven patients dilated with the cutting balloon alone but predilated with a small conventional balloon. These results show that coronary angioplasty by the new cutting balloon results in a stenosis reduction comparable with conventional balloons at a low complication rate. Available 6 months follow-up data show three restenoses in patients either pre- or postdilated by a conventional balloon and none in stand-alone cutting balloon cases.
Clinical Cardiology 10/1993; 16(9):660-4. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A recently developed cutting balloon was used for coronary angioplasty in 21 patients (4 women, 17 men; mean age 57.6 [36-81] years) with coronary heart disease (angioplasty of the right coronary artery in 4, of the circumflex branch in 4, and of the anterior interventricular branch in 13 patients). The balloon contains 3-4 longitudinally arranged metal cutters to prevent uncontrolled vessel tears. An average stenosis reduction from 84 +/- 8.6% to 30 +/- 10.6% was achieved in ten patients. In the eleven others a second dilatation with a conventional balloon was necessary because of a residual stenosis of over 50% after the first dilatation with the cutting balloon. This reduced the original stenosis from 78.6 +/- 9.4% to 30.4 +/- 9.9%. Complete occlusion at the place of previous dilatation occurred in one patient 14 hours after the procedure, due to a dissection which required a stent implantation. These preliminary results suggest that the cutting balloon can achieve a stenosis reduction similar to that with a conventional balloon.
DMW - Deutsche Medizinische Wochenschrift 07/1993; 118(24):887-92. · 0.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Acute thrombocytopenic purpura temporally related to the oral administration of ibuprofen developed in a patient with ankylosing spondylitis. Clinical manifestations, with sudden onset occurring within 12 h of drug ingestion and rapid increase of platelet counts following discontinuation of the drug, were characteristic of an antibody-mediated immune pathomechanism. Immunological studies demonstrated IgM and IgG antibodies in the patient's serum that were capable of binding to allogenic platelets in the presence of a metabolite preparation. This finding suggested that an ibuprofen metabolite, rather then the drug itself, was the antigenic agent responsible for the immune reaction. Despite its widespread therapeutic use, ibuprofen has not been described previously as causing immune-mediated thrombocytopenia.
The Clinical Investigator 06/1993; 71(5):413-5.
-
[show abstract]
[hide abstract]
ABSTRACT: Directional atherectomy represents one potential approach for the treatment of restenosis in stented coronary arteries. In this case report we demonstrate an important pitfall of this angioplasty technique for stent restenosis--inadvertent entanglement of the stent wire in the device. While cutting and removal of part of the wire was achieved in the case presented, this potential adverse event limits the applicability of directional atherectomy for restenosis in coronary stents.
Clinical Cardiology 06/1993; 16(5):450-2. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Strut fractures followed by disk escape of Björk-Shiley convexo-concave valve prostheses are a well-known problem. This article discusses the case of a successfully treated patient who was admitted to our institution with extreme and prolonged cardiogenic shock. The strut was dislodged into the main stem of the left coronary artery and the disk into the iuxtarenal abdominal aorta. The intent of this report is, in particular, to illustrate the management problems. Immediately after diagnosis, circulation and oxygenation were ensured by use of a portable cardiopulmonary bypass support (CPS) system whose circulation lines were introduced subcutaneously. Thus the transfer to the operating room and the surgical intervention were able to start under controlled conditions. The disk was removed by Fogarty catheter manoevre without any problems during the same operation, using a transpericardial access to the descending thoracic aorta. In our opinion, the primary insertion of the CPS and the avoidance of an additional laparotomy in disk removal help promote the survival of such critically ill patients.
The Thoracic and Cardiovascular Surgeon 03/1993; 41(1):77-9. · 0.88 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report the first documented case of an iatrogenic aorto-coronary artery to coronary vein fistula secondary to an aortocoronary saphenous vein jump bypass graft inadvertently anastomosed to a coronary vein. Angiographic and oximetric results of left and right cardiac catheterization--including direct catheterization of the anastomosed coronary vein--as well as clinical data with a four-year follow-up are presented. The role of surgery, percutaneous transcatheter embolization, and conservative treatment is discussed in this unique case with the potential of a coronary steal phenomenon.
European Journal of Cardio-Thoracic Surgery 02/1993; 7(8):441-2. · 2.55 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The present study was designed to test the hypothesis that the direct thrombin hirudin is more efficient than heparin in reducing thrombus formation after coronary stenting.
Despite aggressive anticoagulation, subacute thrombosis of coronary stents is a major complication associated with these new devices.
In 19 minipigs indium-111-labeled thrombocytes and iodine-125-labeled fibrinogen were injected 14 to 19 h before coronary implantation of tantalum balloon-expandable stents. In group 1 (n = 6, seven stents), a bolus of heparin (100 U/kg body weight) was given before stenting. Group 2 (n = 6, 11 stents) received both dextran (500 ml) and heparin (a 100-U/kg bolus followed by a continuous infusion of 50 U/kg per h). In group 3 (n = 7, 13 stents), hirudin (recombinant desulphatohirudin HV 1 [CGP 39393] [1 mg/kg]) was given before stent implantation, followed by an infusion of 1 mg/kg per h. All animals were pretreated with aspirin (250 mg intravenously).
Activated partial thromboplastin time was prolonged to > 1.8 times control values in groups 2 and 3. Histologic examination after perfusion fixation 12 h after stenting showed a variable extent of thrombus on all stents. Medial tear was observed in three stents in group 1, six stents in group 2 and six stents in group 3. The number of platelets on all stents averaged 116.2 (range 22 to 522) x 10(6) in group 1, 64.3 (range 11 to 169) x 10(6) in group 2 and 19.7 (range 9 to 38) x 10(6) in group 3 (p < 0.05 vs. group 1 and vs. group 2). The increase in platelet deposition, associated with medial tear in all groups, was lowest in the hirudin group. Similarly, fibrin deposition was lowest on stents in hirudin-treated animals.
Recombinant hirudin significantly reduces platelet and fibrin deposition on coronary stents compared with the reduction achieved with combined heparin, dextran and aspirin.
Journal of the American College of Cardiology 01/1993; 21(1):249-54. · 14.16 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Intracoronary stents have been suggested as a method of reducing the restenosis rate after balloon angioplasty. Proliferation of vascular smooth muscle cells is a major contributing factor to the restenosis process. Heparin and some of its derivatives have been shown to inhibit smooth muscle cell proliferation. We investigated the effect of low-molecular-weight heparin on the proliferative response after implantation of a balloon-expandable tantalum stent in previously deendothelialized coronary artery segments of hypercholesterolemic minipigs.
Minipigs were fed a diet containing 2% cholesterol, starting 1 month before balloon denudation of the endothelium in a coronary artery. One month later, a stent was implanted at this site. Animals were killed after 4 weeks (group 1, n = 6) or 3 months (group 2, n = 6). Animals in group 3 (n = 6), also followed for 4 weeks after stenting, received subcutaneous low-molecular-weight heparin at a dose of 200-300 units/kg anti-factor Xa activity per day in addition to the chronic acetylsalicylic acid (100 mg/day) also administered to groups 1 and 2. Eighteen of 22 animals survived to the end of the study. Angiography revealed patent stents in all surviving animals. In group 1, histological analysis showed extensive neointimal proliferation around stent struts. Maximal neointimal thickness seen in group 1 averaged 0.93 +/- 0.11 mm, was lower after 3 months (0.8 +/- 0.14 mm) in group 2, but was significantly reduced (0.44 +/- 0.18 mm, p less than 0.01) in group 3.
These data show a significant reduction of the neointimal proliferative response to coronary stent implantation by low-molecular-weight heparin.
Circulation 09/1992; 86(2):531-7. · 14.74 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Between 1982 and 1990, in 134 patients with prior coronary artery bypass grafting and recurrent angina, repeat coronary angiography and balloon angioplasty of stenoses in grafts or native arteries were attempted. Mean age of grafts was 45.6 months, range three days to twelve years. At the time of angioplasty, 6 patients had one-vessel-disease, 33 had two-vessel-disease, and 95 had three-vessel-disease. A total of 182 lesions were dilated: 55 venous grafts, 3 internal mammary artery grafts, and 124 native vessels. Forty-nine of 55 (89%) venous grafts could be successfully dilated, and in 3 internal mammary artery grafts, a stenosis reduction greater than 50% was achieved. In 65 of 88 (74%) grafted native arteries, dilation success was achieved. Twenty-seven of 36 (75%) patients with prior bypass surgery to other arteries had successful angioplasty of nongrafted native arteries. Three patients underwent emergency bypass surgery after dissection and acute occlusion: one of them died in cardiogenic shock secondary to acute myocardial infarction. The angiographic success rate in grafts was slightly higher than in native arteries (90% vs 74%). These data indicate that percutaneous transluminal coronary angioplasty in patients after bypass surgery is possible at a low risk (3%) and constitutes an effective therapy in symptomatic patients.
Angiology 09/1992; 43(8):653-60. · 1.51 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In an open clinical study, a xenon-chloride excimer laser was used for angioplasty of coronary stenoses (n = 48) and chronic total occlusions (n = 56) in 104 patients. Multifiber catheters (4.0F to 5.5F) transmitted 37 to 120 mjoules/mm2 of fiber surface. Excimer laser angioplasty was successful in 43 patients with a stenosis (89%), followed by percutaneous transluminal coronary angioplasty in 21 patients (49%) to reduce the stenosis to less than 50% luminal narrowing. In 39 patients (70%) with a chronic occlusion (age 1 to 14 months), recanalization by means of excimer laser angioplasty was successful, with subsequent percutaneous transluminal coronary angioplasty performed in 23 patients. Major complications included one perforation, one acute occlusion, and two severe dissections. Six-month angiographic follow-up examinations after successful angioplasty were completed in 40 patients (98%) with stenoses and 34 (94%) with occlusions. Restenosis (greater than 20% decrease in luminal diameter) occurred in 13 patients (33%) with stenoses and in 16 patients (47%) after angioplasty of a chronic occlusion. These long-term results indicate that restenosis after excimer laser angioplasty of coronary stenoses and chronic total occlusions is similar to reported results of conventional balloon angioplasty.
American Heart Journal 05/1992; 123(4 Pt 1):878-85. · 4.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An intravascular ultrasound catheter system was used in patients to assess the effect of percutaneous transluminal coronary angioplasty. In 14 out of 16 patients, the intravascular ultrasound catheter could be successfully advanced to the site of a previous dilatation. Qualitative assessment of the cross-sectional images revealed intimal thickening and an increase of ultrasound reflectance and calcification at atherosclerotic coronary arteries. A disruption of the obstructing plaque and evidence for local dissections (11 of 14 cases) were observed after angioplasty. The quantitative comparison between angiography and the ultrasound measurement showed a close correlation for vessel sites distant to the dilatation (r = 0.91 for vessel diameter; r = 0.86 for luminal area; p less than 0.001). After angioplasty, the quantitative evaluation of the dilated area was possible in 11 cases. The correlation of angiographic and sonographic measurements of these segments was good for the assessment of the vessel diameter (r = 0.82, p less than 0.001), but poor for the determination of the luminal area (r = 0.48, p = 0.10). This difference reflected the complex morphology of the vessel lumen after angioplasty, which would be better assessed by the cross-sectional sonographic technique than by contrast angiography. The intravascular imaging of coronary arteries provides a new and unique method to obtain information on the plaque morphology and composition, and to assess the local effects of interventional procedures and their complications.
American Heart Journal 08/1991; 122(1 Pt 1):212-20. · 4.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The Wiktor stent, a new coronary balloon-expandable tantalum stent, was implanted in 17 patients for other wise nonmanageable occlusion after balloon angioplasty (n = 11) and for recurrent restenosis (n = 6). Stents of 3.0 to 4.0 mm were implanted (right coronary artery: n = 10, left anterior descending artery: n = 4, left circumflex artery: n = 2, venous graft: n = 1). All patients were fully anticoagulated initially with heparin followed by coumadin for 3 months and were treated with acetylsalicylic acid indefinitely. Due to its good radiopacity, the device could be placed easily without complications. Early occlusion occurred in one patient after 8 h probably due to friable atheromatous material prolapsing between the meshes of the stent. Late occlusion occurred in another patient who was admitted in cardiogenic shock after pre-hospital reanimation and was stented after occlusive disection following balloon angioplasty of an occluded right coronary artery. In this patient with severe hypoxic brain damage, reocclusion and reinfarction to which the patient finally succumbed occurred following cessation of anticoagulation. Histology demonstrated occlusive thrombosis without evidence of a neointimal covering of the stent. Another thrombotic occlusion due to inadvertent omission of anticoagulation occurred in another patient two weeks after stenting. Control angiography after 6 months in 12 patients revealed restenosis in two patients (50% and 80%). The patient with 80% restenosis of the right coronary artery and pathologic results during stress testing underwent surgical revascularization. The other patient with a 50% restenosis of the right coronary artery was managed medically as he was asymptomatic and without evidence of ischemia during stress testing.(ABSTRACT TRUNCATED AT 250 WORDS)
Clinical Cardiology 06/1991; 14(5):374-9. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Beginning at October, 14th, 1981 until March, 10th, 1989 2015 PTCA-treatments on 1673 patients were performed in Göttingen. 2357 coronary lesions were treated, indicating an average of 1.17 lesions per treatment. During the observation period 1981 to 1986 versus 1987 to 1989 the subgroup of patients greater 65 years increased from 13.5% to 18.4% (p less than 0.01), while those patients with multivessel disease increased from 37% to 56% (p less than 0.001). During the compared observation periods the clinical success rate (all stenoses attempted greater than or equal to 20% reduced, no untowards events) was almost unchanged with 69%, versus 72%, respectively (p = n.s.). However, the rate of untowards events such as bypass grafting during the first 48 hours period decreased from 9.9% to 4.9% (p less than 0.001), the myocardial infarction rate decreased from 4.6% to 3.3% while the lethality rate stayed steadily low at 0.4%. Those nine years experience demonstrate in spite of older and sicker patients that the complication rate of PTCA procedures decreased while the success rate remained unchanged, a trend opposed to the development in coronary bypass grafting, where the complication rate increases due to older and sicker patients.
Medizinische Klinik 04/1991; 86(3):121-7. · 0.34 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The inspiration against a closed airway, the Mueller manoeuver, leads to a negative intrathoracic pressure. It is controversially discussed whether this is causing an augmentation of right heart murmurs. There is only limited knowledge on the temporal relationship of the negative intrathoracic pressure with right and left ventricular filling and stroke volume. To investigate this relationship, the flow through the mitral, aortic, tricuspid and pulmonary valves was studied continuously by Doppler echocardiography during a standardized Mueller manoeuver in 15 healthy subjects (age 45 +/- 10 years). Five heart beats after the initiation of the manoeuver, flow through the mitral and aortic valve decreased 12.2 +/- 7.2% (P less than 0.001) and 10.1 +/- 6.6% (P less than 0.001), respectively. A transient increase of 15.1 +/- 9.2% (P less than 0.001) in tricuspid flow was followed by a 14.3 +/- 9.8% (P less than 0.005) increase of flow through the pulmonary artery. Ten heart beats after the initiation of the Mueller manoeuver, flow through the pulmonary artery again reached baseline, while tricuspid flow remained below baseline values. In contrast to previous studies, our results indicate that the Mueller manoeuver causes a small and transient increase in right ventricular stroke volume which is unlikely to cause a marked augmentation in right heart murmurs.
European Journal of Clinical Investigation 03/1991; 21(1):72-6. · 3.02 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Intravascular ultrasound imaging was performed in 15 patients (three women and 12 men; mean age 55 [48-70] years) after percutaneous balloon angioplasty of the right coronary artery (7 patients), the anterior interventricular branch (6) or the circumflex branch of the left coronary artery (2). The catheter, external diameter 4.8 F, was advanced over a 0.014--in coronary wire to the area of the previously balloon-dilated stenosis. Vessel diameter measured by ultrasound correlated closely with that by angiography (r = 0.93; P less than 0.001). Ultrasound imaging distinguished between concentric and eccentric intimal thickening and made it possible to assess the consistency and degree of calcification of the wall changes. The success of angioplasty was evaluated in 10 patients. In eight, local dissection was revealed, but only three of them had been diagnosed angiographically. In one patient a vessel spasm was recorded during ultrasound imaging; it regressed after the intracoronary injection of 0.2 mg nitroglycerin. There were no other complications. The method made it possible to assess in vivo the extent and consistency of atherosclerotic plaques, and it adds to the angiographic monitoring of treatment results and of complications after angioplasty.
DMW - Deutsche Medizinische Wochenschrift 02/1991; 116(3):81-6. · 0.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The results of coronary excimer laser angioplasty were evaluated in 70 patients. Forty-five patients had laser angioplasty of coronary stenoses. Twenty-five patients in a total of 35 attempts had wire-guided laser recanalization of chronic coronary occlusions, resulting in a success rate of 71%. Immediate results in both groups demonstrated the efficacy of this technique without serious side-effects. Stenoses were reduced from 90 +/- 5% to 48 +/- 18% diameter reduction (mean +/- standard deviation) by excimer laser angioplasty. Residual stenosis in recanalized vessels after laser angioplasty was 52 +/- 19%. In slightly more than half of the patients with a residual stenosis greater than 50% after excimer laser angioplasty, subsequent balloon angioplasty was performed for further stenosis reduction. While satisfactory immediate results were achieved by excimer laser angioplasty intermediate follow-up revealed a restenosis rate in the same range as with balloon angioplasty.
European Heart Journal 02/1991; 12(1):24-9. · 10.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A low primary success and high restenosis rate after recanalization of chronic total occlusions by conventional coronary angioplasty have encouraged the application of new interventional techniques like excimer-laser angioplasty. In 39 patients with a coronary occlusion for 1 to 12 months, recanalization was attempted by laser angioplasty through a multifiber-catheter coupled to a pulsed XeCl excimer laser. After successful passage of the occlusion by a standard guidewire in 27 patients (69%), the laser catheter was advanced over the central guidewire and crossed the occlusion in 25 patients (64%). In 2 patients with unsuccessful passage of the laser catheter, the subsequent attempt with a low profile balloon catheter also failed. In 19 of the 25 patients with successful laser recanalization, the residual stenosis exceeded 50% and was therefore followed by additional balloon angioplasty. The average residual stenosis after laser was 61 +/- 17% of the vessel diameter, and after balloon angioplasty 28 +/- 9% (n = 19), whereas after laser angioplasty alone it was 38 +/- 5% (n = 6). No complications associated with the laser application were observed. Angiographic control after 24 hours showed a reocclusion of 2 (8%) recanalized vessels. In this pilot study, laser angioplasty proved to be a safe and feasible method for the treatment of chronic total coronary occlusions. Because it was necessary to guide the catheter by a central wire, the primary success was limited by a successful passage of the wire of the occlusion. The rate of stand-alone laser angioplasty has to be increased by future improvements of the technique to enable a comparative evaluation of this method with conventional angioplasty.
The American Journal of Cardiology 01/1991; 66(20):1445-50. · 3.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Ten patients, two women and eight men, were treated with the new balloon-expandable Wiktor Stent for acute coronary occlusion after PTCA. Two patients presented with an acute myocardial infarction. Stents with a diameter of 3.0 or 3.5 mm were implanted into the right coronary artery (n = 7), the left anterior descending (n = 2) artery, and the left circumflex coronary artery (n = 1). Stent implantation in the target segment was successful in all cases. Afterwards, patients received coumadine for 3 months and 100 mg acetylsalicyclic acid per day. We observed one acute occlusion after 8 h. Late occlusion occurred in two patients after cessation of anticoagulation within 3 weeks. Control angiography after 6 months in seven patients revealed stenosis within the stent in two cases.
Zeitschrift für Kardiologie 01/1991; 79(12):837-42. · 0.97 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A 28-year-old male patient suffering from Wegener's granulomatosis died suddenly with signs of cardiac failure after clinical symptoms had basically subsided under chemotherapy. Autopsy revealed pulmonary granulomata, necrotizing vasculitis of the lungs and kidneys, focal and segmental necrotizing glomerulonephritis, and diffuse granulomatous and necrotizing giant cell myocarditis. Histological confirmation of inflammation of the heart in Wegener's disease has rarely been reported. Although cardiac involvement in Wegener's granulomatosis sometimes is suspected, it is usually thought to have no major impact on the course of the disease. By its dramatic clinical and morphologic presentation this case illustrates that the heart, in addition to the lungs and kidneys, may determine the outcome of the idiopathic granulomatous vasculitis of Wegener.
Klinische Wochenschrift 10/1990; 68(17):880-5.
