"Occlusion angioplasty". Light at the end of the tunnel or dead end?
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Angioplasty, Balloon, Coronary↗
Biomedical subjects
B Meier
Publications and source records attributed to B Meier.
Isolation of a high-molecular mass glycoprotein from culture supernatant of an arthritogenic strain of the bacteria Erysipelothrix rhusiopathiae reacting with "inductive" monoclonal antibodies derived from rats with erysipelas polyarthritis.
A glycoprotein exhibiting a relative molecular mass of about 1000 kDa was purified to homogeneity from culture supernatant of arthritogenic bacteria (Erysipelothrix rhusiopathiae, strain T28) by ultrafiltration, ammonium sulfate precipitation, molecular mass exclusion, and ion exchange chromatography. Fractions obtained were analysed for their antigenic content by an enzyme linked immunosorbent assay (ELISA) using rabbit immune serum raised against this strain of Erysipelothrix rhusiopathiae. Distinct monoclonal antibodies obtained from rats suffering from erysipelas polyarthritis display a unique property by inducing very efficiently protective and regulatory mechanisms while being unable to generate classical "passive immunity". These "inductive" monoclonal antibodies recognize most likely linear epitopes on the purified glycoprotein. This makes it a prime source for analysing the target structure of these in vivo "inductive" antibodies.
Animals↗
Percutaneous transluminal coronary angioplasty through six French catheters.
We present the results of 221 coronary angioplasty (PTCA) procedures in which a 6 French diagnostic catheter was chosen as a guiding catheter. A total of 218 were done through a femoral and 3 through an axillary approach. Total occlusion PTCA was done in 9 (4%) and multivessel PTCA in 19 procedures (9%). In 191 (86%) procedures a fixed-wire system was used (ACE Scimed, Probe USCI, Orion Cordis), and in 30 (14%) a monorail system (Speedy Schneider, Express Scimed). The mean nominal inflated balloon diameter was 2.9+/-0.3 mm (range 2.0-4.0), and the catheter internal lumen varied between 0.041 and 0.055 inch. In 186 procedures (84%) all targeted lesions could be successfully dilated through the 6 French catheter. In 30 (14%) patients, the guiding catheter was changed to a 7 or 8 French, for an overall success rate of 95%. Results with 6 French catheters were significantly better in our late experience (success rate of 92% for the last 110 procedures compared to 77% for the first 111 procedures) (p less than 0.01). There were no new Q-wave myocardial infarctions, but 6 patients (2.7%) had moderate CK elevation, 1 required emergent bypass surgery, 1 underwent emergent coronary stenting, and there was 1 in-hospital death. The overall major complication rate was 3.2%. In selected patients, PTCA can be safely and effectively done through a diagnostic 6 French guiding catheter.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
PTCA at first sight: angioplasty based on video only.
The results of 326 coronary angioplasties (PTCAs) performed during a first diagnostic angiography and based on video images only (PTCA at first sight, Group I) are compared with those of 756 PTCAs done during the same time period in patients with a previous cine-film and therefore a known or predictable coronary anatomy (Group II). Group I patients had more single vessel disease (74% versus 58%, p less than 0.001), single vessel PTCA (93% versus 84%, p<0.001), unstable angina (54% versus 28%, p less than 0.001), recent myocardial infarction (66% versus 37%, p less than 0.001), and total occlusion PTCA (29% versus 19%, p<0.01). On the other hand, they had less severe stable angina (mean New York Heart Association class 1.3+/-1.2 versus 1.8+/-1.4, p less than 0.001), less advanced disease (average of 1.3+/-0.5 versus 1.5+/-0.7 diseased vessels, p less than 0.001) and worse left ventricular ejection fraction (61+/-12% versus 63+/-12%, p less than 0.01). The angiographic and clinical success rates were 90% and 84% in Group I and 92% and 87% in Group II respectively, (p=NS). Complication rates were not statistically different between the groups (Q-wave myocardial infarction 2% versus 3%, non Q-wave myocardial infarction 4% in both groups, emergency surgery 0.3% versus 0.8% and inhospital mortality 0.9% for both groups). In selected patients, coronary angioplasty can be performed safely and effectively during a first coronary angiography based on video images exclusively.
Adult↗
Randomized evaluation of 5 French catheters for coronary angiography with or without the CO2 powered Hercules syringe.
To evaluate the CO2 power-assisted hand-held Hercules syringe (Cordis) for diagnostic coronary angiography using 5 French catheters (Judkins number 4 exclusively), 200 consecutive patients (excluding patients with valve disease and prior bypass surgery) were randomized to conventional manual or Hercules injections. The angiography was done through a femoral artery with or without a sheath. Total duration and fluoroscopy time from the end of the ventriculogram to the end of the procedure, quantity of contrast medium required, length of cinefilm, quality of film (good, satisfactory, or bad), streaming, technical ease [scale 1 (easy) to 6 (difficult)], and need for larger catheters were analyzed. Adequate quality angiograms were obtained in 193 patients (97%). Crossover to a larger catheter was required in 7 patients due to difficulty in engaging coronary ostia (right 6, left 1). No significant differences between manual or Hercules injections were seen in total duration of the procedure (12.0 +/- 4.6 versus 12.9 +/- 8.5 min), fluoroscopy time (4.0 +/- 3.1 versus 4.2 +/- 4.8 min), quantity of contrast medium (81 +/- 28 versus 89 +/- 29 ml), and length of the film (1.1 +/- 0.6 versus 1.3 +/- 0.7 min). The conventional method was found to be easier (facility scale: conventional 1.7 +/- 0.5, Hercules 2.3 +/- 1.2, p less than 0.05) because there was significantly less dislodgement of the catheter from the coronary ostia during contrast injections. Five French number 4 Judkins catheters permit adequate diagnostic coronary angiograms in 97% of routine coronary patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Coronary angioplasty without surgical standby: a prospective study].
In 811 out of 1000 consecutive patients submitted to coronary angioplasty we elected not to arrange for surgical standby. All patients were informed, and accepted that in case of vessel occlusion an infarction might ensue, for which a conservative management was planned. This choice was made on the basis of a clinical and angiographic estimate of the possible consequences of vessel occlusion, or dictated by sound inoperability of the patient. Primary success was achieved in 700 patients (86%) and in 933/1026 lesions (91%). Fifty-six patients (6.9%) had an acute vessel occlusion (within 24 hours of the procedure), with Q or non Q-wave infarction in 24 cases (2.9% of patients). Emergency coronary stenting was performed in 9 patients. One patient had emergency bypass surgery 1 hour after the procedure, and another had urgent bypass surgery 24 hours after the procedure because of left main stem dissection: the former died despite surgery, the latter was discharged uneventfully. The remaining 7 in-hospital deaths (total mortality 1%) could not have been prevented by surgical standby: one patient died from electromechanical dissociation during the procedure, due to rupture of a ventricular pseudoaneurysm; another died after an uncomplicated procedure, due to an anaphylactic reaction to protamine; two others died suddenly 3 and 20 days, respectively, after a successful procedure; finally, three patients were "a priori" inoperable. Our data suggest that surgical standby is not necessary for a large number of angioplasty candidates, who can be identified on the basis of preliminary clinical and angiographic evidence.(ABSTRACT TRUNCATED AT 250 WORDS)
Angioplasty, Balloon, Coronary↗
Recanalization of chronically occluded coronary arteries.
A chronic coronary occlusion consists of an atherosclerotic plaque and one or several thrombi. It clinically imitates a tight stenosis but is exempt from the risk of truly unstable angina or myocardial infarction. Hence, quality of life is at stake and not longevity. This holds true for balloon angioplasty as well as for surgery. Indications for angioplasty are based on an estimate of technical difficulties and clinical risks balanced against potential subjective benefit and amount of viable myocardium concerned. An occlusion flush at the orifice of the vessel, tapering into a small sidebranch, with bridging collaterals, or devoid of collaterals is no target for angioplasty. Primary success is around 65% and complications are extremely rare. Abrupt vessel closure is common but harmless. No Q-wave infarctions have been reported in that context. The need for emergency bypass surgery may arise from acute closure of a vessel proximal to the occlusion in an exceptional case. Duration and length of occlusion are the most important predictors of success. Recurrence averages 62% (17% reocclusion and 45% restenosis). An important factor for the high recurrence rate is the competitive pressure exerted by the collaterals on standby. Recurrence happens almost exclusively within the first six months. It is innocuous but produces symptoms prompting further interventions (repeat angioplasty or bypass surgery). The conventional technique uses a stiff guidewire and advances the balloon catheter close to the tip of the guidewire for additional rigidity. New technologies are under investigation but no breakthrough has happened so far. They encompass blunt mechanical instruments (e.g., Magnum wire), drills of various velocities, laser energy applied directly to the tissue (some angioscopically guided, some triggered by on-line spectral tissue analysis), catheters dispersing laser energy through a sapphire or converting it into heat (hot tip), and electrical or radiofrequency heat applicators. As low-yield procedures had better be low-risk and low-cost, there are definite limits to how sophisticated, complicated, risky, and expensive tools and techniques for percutaneous coronary recanalization can become. Close relatives of conventional gear such as the Magnum system offer themselves as first choice equipment complemented, in case of need, by mechanical drills.
Angioplasty, Balloon, Coronary↗
Dreaming and anaesthesia: total i.v. anaesthesia with propofol versus balanced volatile anaesthesia with enflurane.
Sixty consecutive ASA Grades I and II patients scheduled for elective ear, nose and throat surgery were randomly assigned to receive either total i.v. anaesthesia with propofol ('propofol group') or 'balanced technique' with thiopentone induction followed by N2O and enflurane. Patients were asked whether they had experienced dreams immediately after extubation when verbal communication was established, in the recovery room and in the ward on the evening of the day of surgery. Thirteen patients in the propofol group (43%) and three patients in the enflurane group (10%) reported dreaming (P less than 0.05) when asked as soon as verbal communication was established. In the recovery room and in the ward only three patients of the propofol group (10%) and one patient in the enflurane group (3%) remembered that they had been dreaming (NS). To avoid underestimating the frequency of peri-operative dreaming, post-operative interviews should take place as soon as possible after conversing is possible.
Adult↗
[Prevalence and significance of ant-HCV-antibodies in ambulatory patients with raised transaminases].
From November 1989 to April 1990 we analyzed prospectively the prevalence of anti-hepatitis C virus antibodies and the possible mode of infection in 90 outpatients with repeatedly elevated alanine-aminotransferase levels. The clinical and serological course of these patients was evaluated after 1, 3 and 6 months. Initially, 24 patients (26.6%) were positive for anti-HCV antibodies, but subsequently only 14 of these patients (15.5%) were positive in the follow-up tests. 9 patients (10%) showed no antibodies against HCV in control evaluations and one patient dropped out of the investigation. The 9 patients with a negative result in the control tests had median relative anti-HCV concentrations of 2.0 (range 1.2-4.1) in contrast to 5.5 (range 1.6-256.5) in the 14 patients with a confirmed anti-HCV test (p less than 0.001). None of those 9 patients had received blood transfusions, 7 had consumed drugs intravenously and only 2 had no specific risk for HCV infection. The consistently anti-HCV positive patients had median alanine-aminotransferase levels between 115 and 200 U/l, whereas the levels in initially anti-HCV positive and subsequently negative patients ranged from 75-90 U/l. The initial prevalence of anti-HCV antibodies in 26.6% of our patients is related to the high rate of either false positive results or sero-conversion in 38% of this group. We recommend cautious interpretation of anti-HCV test results with relative anti-HCV concentrations less than or equal to 2 in equivocal clinical situations.
Adult↗
Identification of a superoxide-generating NADPH oxidase system in human fibroblasts.
Human fibroblasts have the capacity to release superoxide radicals upon stimulation of an electron transport system similar to the NADPH oxidase of leukocytes. Two components of the NADPH oxidase system, (1) a flavoprotein of 45 kDa which binds diphenylene iodonium (a compound described as a specific inhibitor of the leukocyte NADPH oxidase), and (2) a low-potential cytochrome b, are present in fibroblast membranes. Fibroblasts exhibit these compounds at lower concentrations than do polymorphonuclear leukocytes or B-lymphocytes. The superoxide-generating system is rather uniformly associated with the outer cell membrane, as shown by light and electron microscopy. Superoxide release upon stimulation with various agents was prevented by the addition of micromolar concentrations of diphenylene iodonium, making an NADPH oxidase a likely source.
Calcimycin↗
Intravascular ultrasound for diagnosis of aortic dissection.
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Aortic Dissection↗
Angiographic follow-up after placement of a self-expanding coronary-artery stent.
BACKGROUND: The placement of stents in coronary arteries after coronary angioplasty has been investigated as a way of treating abrupt coronary-artery occlusion related to the angioplasty and of reducing the late intimal hyperplasia responsible for gradual restenosis of the dilated lesion. METHODS: From March 1986 to January 1988, we implanted 117 self-expanding, stainless-steel endovascular stents (Wallstent) in the native coronary arteries (94 stents) or saphenous-vein bypass grafts (23 stents) of 105 patients. Angiograms were obtained immediately before and after placement of the stent and at follow-up at least one month later (unless symptoms required angiography sooner). The mortality after one year was 7.6 percent (8 patients). Follow-up angiograms (after a mean [+/- SD] of 5.7 +/- 4.4 months) were obtained in 95 patients with 105 stents and were analyzed quantitatively by a computer-assisted system of cardiovascular angiographic analysis. The 10 patients without follow-up angiograms included 4 who died. RESULTS: Complete occlusion occurred in 27 stents in 25 patients (24 percent); 21 occlusions were documented within the first 14 days after implantation. Overall, immediately after placement of the stent there was a significant increase in the minimal luminal diameter and a significant decrease in the percentage of the diameter with stenosis (changing from a mean [+/- SD] of 1.88 +/- 0.43 to 2.48 +/- 0.51 mm and from 37 +/- 12 to 21 +/- 10 percent, respectively; P less than 0.0001). Later, however, there was a significant decrease in the minimal luminal diameter and a significant increase in the stenosis of the segment with the stent (1.68 +/- 1.78 mm and 48 +/- 34 percent at follow-up). Significant restenosis, as indicated by a reduction of 0.72 mm in the minimal luminal diameter or by an increase in the percentage of stenosis to greater than or equal to 50 percent, occurred in 32 percent and 14 percent of patent stents, respectively. CONCLUSIONS: Early occlusion remains an important limitation of this coronary-artery stent. Even when the early effects are beneficial, there are frequently late occlusions or restenosis. The place of this form of treatment for coronary artery disease remains to be determined.
Angiography↗
Coronary balloon angioplasty through diagnostic 6 French catheters.
We investigated the use of ultralow profile balloon catheters (Scimed ACE, USCI Probe, Cordis, Orion) for coronary angioplasty through 6 French diagnostic catheters (Schneider, Cordis). Contrast injection was assisted with a Hercules pump (Cordis) in all cases. During 21 procedures, angioplasty of 27 lesions in 20 selected patients was attempted (1.3 lesion/procedure). Twelve lesions were in the right, 10 in the left anterior descending, and 5 in the left circumflex coronary artery. Balloon size varied between 2.5 and 3.5 mm. Twenty lesions could be successfully dilated (74%) through the 6 French catheter and 7 lesions required an exchange to a 7 French angioplasty guiding catheter. For 5 cases, another balloon was also necessary to complete the procedure. The final overall success rate was 100% per patient and per lesion and there were no major complications. Despite the small internal catheter lumen (1.22 mm) coronary visualization was adequate, and mechanical support was good. Failures of 6 French catheters were attributed to insufficient torque control and excessive friction when the balloon crossed the tapered end of the diagnostic catheter. Coronary angioplasty through a diagnostic 6 French catheter is feasible and may represent a reasonable alternative for simple cases that are done during the same session as the diagnostic angiography. Once available, 6 French high flow angioplasty guiding catheters without a tapered tip should improve success while retaining the advantage of a small femoral puncture site.
Angiography↗
Coronary collateral flow reversal.
Coronary collaterals demonstrated angiographically are expected to be usable both ways and to remain on standby even if they are no longer used after flow improvement through the physiological pathway. Evidence of these hypotheses is provided by two case reports, one showing spontaneous reversal of collaterals and one showing recruitable reversed collaterals.
Aged↗
Coronary angioplasty with 7F guiding catheters.
The performance of 7F guiding catheters for percutaneous transluminal coronary angioplasty (PTCA) was investigated in 300 patients. A total of 233 patients had single-vessel PTCA and 67 had multivessel PTCA. Angioplasty was attempted for 371 lesions (141 [38%] in the left anterior descending, 124 [33%] in the right coronary artery, and 95 [26%] in the left circumflex coronary artery or their branches; 10 [3%] in a bypass graft, and one in the left main stem). The mean degree of stenosis was 86 +/- 11% (range 60% to 100%). The monorail technique was used in 83%, and balloon-on-a-wire devices were used in 6% of cases. The balloon sizes varied between 2.0 and 4.25 mm. There was a 98% technical success rate for the 325 nontotal lesions. Five could not be crossed with the wire. Exchange to an 8F guiding catheter was done in four cases (1.2%) and yielded success in two of them. In 46 occlusions the success rate was 72%. Nine were failures due to an inability to cross the wire, another two were balloon failures, and in two cases the residual stenosis was greater than 50%. The mean residual stenosis of successful cases was 24 +/- 18%. Overall, the primary success rate was 95%. The complications were: in-hospital death in five patients (1.7%); infarction in 12 (4%); emergency bypass surgery in one; and significant inguinal hematoma in five (1.7%). Coronary angioplasty through 7F guiding catheters yields a high success rate with less coronary wedging and a smaller puncture hole.
Angioplasty, Balloon, Coronary↗
Coronary angioplasty with second generation Monorail catheters.
The Monorail system (Schneider) consists of a balloon catheter in which the guidewire passes through the balloon itself, exits the catheter proximal to the balloon, and runs alongside its small shaft (3 French) through the length of the guiding catheter. It offers distinct advantages over conventional systems of coronary angioplasty. It facilitates contrast injections and permits rapid balloon exchanges. This system was used for coronary angioplasty in 273 unselected consecutive patients (age 59 +/- 10, mean 35 to 73 years). There were 216 patients (84%) undergoing single-vessel and 57 patients (16%) with multi-vessel coronary angioplasty. A total of 335 coronary stenoses were dilated, which included 35 total occlusions. The size of balloon used ranged from 2.0 to 4.25 mm (3.0 +/- 0.5 mm) and the severity of stenosis was 85 +/- 11%. Technical success was defined as a residual stenosis of less than 50% as determined angiographically. Clinical success was defined as technical success, and absence of a major inhospital complication defined as absence of myocardial infarction, lack of need for coronary arterial bypass surgery, and survival. The Monorail system was technically successful in 294/300 stenotic lesions (98%). It was clinically successful for 281 lesions (94%). Of the 35 total occlusions, technical success was obtained in 25 (71%). The residual stenosis of successful cases was 26 +/- 21%. The Monorail system was also successful in 5 patients with stenosis of more than 90% in whom conventional systems failed. The complications included acute occlusion causing acute myocardial infarction in 13 cases (5%), emergency coronary arterial bypass surgery in 1 patient (0.4%), and death in 4 patients (1.5%).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Total coronary occlusion: a different animal?
Provided collateralization is adequate, a chronic total coronary occlusion clinically imitates a 90% stenosis but is exempt from the risk of myocardial infarction. For angioplasty of vessels with chronic total coronary occlusion, technical difficulties and clinical risks are balanced against projected subjective benefit and amount of viable myocardium concerned. The primary success rate is approximately 65% and complications are rare because abrupt vessel reclosure may be common but is harmless. New Q wave infarction in that context has not been reported. The duration of occlusion is the most important predictor of success. The length of the occluded segment is also important. Recurrence averages 68% (21% reocclusion and 47% restenosis) and happens typically within 6 months. The high recurrence rate is due to competitive pressure exerted by collateral vessels and an often suboptimal local result. Even if the primary success rate of angioplasty in vessels with chronic total coronary occlusion can be improved by advanced technology and skill, the clinical yield will remain low compared with that of angioplasty of stenoses. Because low yield procedures must be low risk and low cost, there are definite limits to how sophisticated, risky and expensive new techniques can become. Derivatives of conventional balloon systems are likely to remain the equipment of first choice, perhaps complemented by mechanical drills. Although chronic total coronary occlusions are no clinical menace in contrast to stenoses, they frequently deserve revascularization and are the reason to select bypass surgery over angioplasty. These factors justify endeavors to improve recanalization techniques that help to refine coronary angioplasty of nontotal lesions, because total occlusion, albeit a different animal, is of the same species.
Angioplasty, Balloon, Coronary↗
[Treatment of fallopian tube pregnancies with prostaglandins].
In a study, the clinical use of prostaglandin F2 alpha in local and systemic application in women with ectopic pregnancies were studied (1, 9). Two different treatment schedules were defined and applied. In group A, patients with a diagnosed ectopic and beta-HCG level lower than 850 mIU/ml were treated with prostaglandin F2 alpha i.m. injected only. In group B, prostaglandin F2 alpha were injected in the chorionic cavity of the ectopic by laparoscopy after localisation with a thin needle. In spite of prostaglandin F2 alpha treatment, 6 of 30 patients (20.0%) had to be operated by microsurgery because of increasing serum beta-HCG levels. A control of tubal patency 6 month later showed one closed tube only (4.5%). Up to now, 8 spontaneous intrauterine pregnancies occurred in our study groups after successful prostaglandin F2 alpha treatment; one pregnancy was seen in a women with a single fallopian tube. The conserving treatment of one ectopic pregnancy using prostaglandin F2 alpha yields positive results, if serum beta-HCG levels are below 2000 mIU/ml.
Abortifacient Agents, Nonsteroidal↗