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At least 19 recordsLinked to original sources
PubMed1996

Mechanisms and immediate and long-term results of adjunct directional coronary atherectomy after rotational atherectomy.

OBJECTIVES: The purpose of this study was to confirm the mechanisms and the immediate and long-term results of rotational atherectomy and adjunct directional coronary atherectomy. BACKGROUND: Rotational atherectomy is best suited for treating calcific stenoses, but the ability of rotational atherectomy alone to optimize lumen dimensions in large vessels is limited; this is only partly improved by adjunct balloon angioplasty. METHODS: We treated 165 lesions in 163 patients by use of rotational atherectomy and adjunct directional coronary atherectomy. Quantitative angiography and intravascular ultrasound were used for lesion analysis. A matched comparison with 208 lesions treated with rotational atherectomy and adjunct coronary angioplasty was performed. Patients were then followed up for at least 9 months, and target-lesion revascularization was assessed. RESULTS: In the 61 lesions imaged sequentially, lumen area increased from 1.7 +/- 0.8 (mean +/- 1 SD) to 3.9 +/- 1.1 mm(2) after rotational atherectomy, owing to a decrease in plaque plus media area from 16.8 +/- 5.0 to 15.2 +/- 5.2 mm(2) (both p < 0.0001). After adjunct directional coronary atherectomy, lumen area increased even more to 6.7 +/- 2.0 mm(2) (vs. 5.1 +/- 1.4 mm(2) after adjunct coronary angioplasty, p < 0.0001) as a result of both vessel expansion (18.8 +/ 5.3 to 20.8 +/- 5.7 mm(2)) and additional plaque removal (to 14.1 +/- 5.0 mm(2), all p < 0.0001). The total arcs of calcium decreased from 207 +/- 107 degrees to 166 +/- 93 degrees after rotational atherectomy and to 145 +/- 87 degrees after directional coronary atherectomy. Overall, procedural success was 96%, and final diameter stenosis was 15 +/- 17%. Target-lesion revascularization was 23%. The only independent predictor of target-lesion revascularization was a larger overall atherectomy index (84% vs. 59%, p = 0.048). CONCLUSIONS: There is a synergistic relationship between rotational atherectomy and directional coronary atherectomy in the treatment of calcific lesions. The immediate results show a high procedural success--lumen dimensions were larger and late target-lesion revascularization was lower in lesions treated with rotational atherectomy and directional coronary atherectomy than in those treated with rotational atherectomy and adjunct balloon angioplasty.

Aged↗
PubMed1993

Transcatheter device synergy: preliminary experience with adjunct directional coronary atherectomy following high-speed rotational atherectomy or excimer laser angioplasty in the treatment of coronary artery disease.

We performed high-speed rotational atherectomy followed by adjunct directional atherectomy in 10 patients and excimer laser angioplasty followed by directional atherectomy in 6 patients and evaluated the results using quantitative coronary arteriography and intravascular ultrasound. Quantitative coronary arteriographic measurements of minimal lumen diameter and % diameter stenosis and intravascular ultrasound measurements of external elastic membrane, lumen, and plaque + media cross-sectional areas; % cross-sectional narrowing; minimal lumen diameter; and target-lesion arc of calcium were made pre-intervention, after rotational atherectomy or excimer laser angioplasty, and after adjunct directional atherectomy. Rotational atherectomy: Using quantitative coronary arteriography, the pre-intervention minimum lumen diameter measured 0.7 +/- 0.4 mm, increased to 1.5 +/- 0.5 mm after rotational atherectomy, and to 2.5 +/- 0.3 mm after adjunct directional atherectomy. The pre-intervention % diameter stenosis measured 78 +/- 15%, decreased to 50 +/- 17% after rotational atherectomy, and to 17 +/- 11% after adjunct directional coronary atherectomy. Intravascular ultrasound showed arcs of target lesion calcification that measured 271 +/- 92 degrees pre-intervention, decreased to 210 +/- 120 degrees after rotational atherectomy, and to 163 +/- 122 degrees after adjunct directional atherectomy, with distinct directional atherectomy cuts into calcium. Pre-intervention, target lesion external elastic membrane area measured 20.4 +/- 2.3 mm2, lumen area measured 1.5 +/- 0.6 mm2, plaque + media are measured 18.9 +/- 2.3 mm2, and % cross-sectional narrowing measured 93 +/- 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Preliminary experience with adjunct directional coronary atherectomy after high-speed rotational atherectomy in the treatment of calcific coronary artery disease.

A high-speed rotational atherectomy was performed followed by adjunct directional atherectomy in 10 patients with symptomatic coronary artery disease and calcified target lesions and the results were evaluated using quantitative coronary arteriography and intravascular ultrasound. Target lesion calcium is common in obstructive coronary artery disease. High-speed rotational coronary atherectomy preferentially abrades noncompliant atherosclerotic plaque material, especially calcium, but often requires adjunct balloon angioplasty to achieve optimal lumen dimensions. Directional coronary atherectomy has limited efficacy in heavily calcified plaque; usually, it is a definitive primary procedure in large arteries with noncalcified target lesions. Neither of these devices alone is effective in treating calcified target lesions in large coronary arteries. Before intervention, after rotational and adjunct directional atherectomy, these measurements were obtained: quantitative coronary arteriographic measurements of minimal lumen diameter and percent diameter stenosis and intravascular ultrasound measurements of external elastic membrane, lumen, and plaque+media cross-sectional areas; percent cross-sectional narrowing; minimal lumen diameter; and target-lesion arc of calcium. With use of quantitative coronary arteriography, the preintervention minimal lumen diameter measured 0.7 +/- 0.4 mm, increased to 1.5 +/- 0.5 mm after rotational atherectomy (p = 0.0013) and to 2.5 +/- 0.3 mm after adjunct directional atherectomy (p < 0.001). The preintervention percent diameter stenosis measured 78 +/- 15%, decreased to 50 +/- 17% after rotational atherectomy (p = 0.0011), and to 17 +/- 11% (p < 0.001) after adjunct directional coronary atherectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Atherectomy, Coronary↗
PubMed1994

Optimal use of directional coronary atherectomy is required to ensure long-term angiographic benefit: a study with matched procedural outcome after atherectomy and angioplasty.

OBJECTIVES: This study was designed to examine whether restenosis is related to the extent or mechanism of lumen improvement and to explore angiographic determinants of optimal atherectomy. BACKGROUND: Directional atherectomy induces a greater extent of immediate gain and late loss but has not been found to yield a better late angiographic lumen than angioplasty in randomized trials. The difference in lumen renarrowing may be related to either the extent or the mechanism of immediate gain. The design of previous studies has precluded the detection of a device-specific effect on restenosis. METHODS: A retrospective analysis was based on matching a prospectively collected series of 80 native coronary arteries successfully treated with atherectomy with a prospectively collected series of 80 native coronary arteries successfully treated with balloon angioplasty. Angiographic analysis was performed in 160 lesions to explore whether a specific device-related effect exists. Multivariate analyses were performed to determine the correlates of minimal lumen diameter at follow-up and late lumen loss and to identify the procedural characteristics for optimal atherectomy. RESULTS: Matching resulted in two comparable groups with equivalent baseline clinical and stenosis characteristics. By study design, atherectomy and angioplasty resulted in similar mean (+/- SD) immediate lumen gain (1.15 +/- 0.44 vs. 1.10 +/- 0.40 mm, p = 0.50). However, lumen loss was more pronounced after atherectomy, and, thus, the minimal lumen diameter at follow-up differed significantly between the two groups (1.78 +/- 0.57 vs. 2.00 +/- 0.56 mm, p = 0.001). Device type was retained in the multivariate analysis as an independent predictor of late minimal lumen diameter and lumen loss. Multivariate analysis identified vessel size and immediate gain as determinants of optimal atherectomy. CONCLUSIONS: Restenosis is a consequence not only of the extent of lumen improvement but also of the mechanism of vessel wall injury (debulking vs. dilating). While performing atherectomy, the operator should strive for an optimal procedural result to accommodate an increased intimal hyperplastic response.

Angioplasty, Balloon↗
PubMed1995

Directional atherectomy versus balloon angioplasty for coronary ostial and nonostial left anterior descending coronary artery lesions: results from a randomized multicenter trial. The CAVEAT-I investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: We hypothesized that atherectomy would be superior to balloon angioplasty for ostial and nonostial left anterior descending coronary artery lesions. BACKGROUND: Balloon angioplasty of ostial coronary artery lesions has been associated with a lower procedural success rate and a higher rate of complications and of restenosis than angioplasty of nonostial stenoses. Directional coronary atherectomy has been proposed as an alternative therapy for ostial lesions. METHODS: In the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I), 1,012 patients were randomized to undergo either procedure; 563 patients had proximal left anterior descending coronary artery lesions, of which 74 were ostial. We compared balloon angioplasty with directional atherectomy for early and 6-month results for ostial as well as nonostial proximal left anterior descending coronary artery lesions. RESULTS: Directional atherectomy led to an initially higher gain in minimal lumen diameter for ostial lesions (1.13 vs. 0.56 mm, respectively, p < 0.001) but a higher rate of adjudicated non-Q wave myocardial infarction (24% vs. 13%, respectively, p < 0.001) than balloon angioplasty and no improvement in restenosis rates (48% vs. 46%, respectively). In the nonostial proximal left anterior descending coronary artery lesions, angiographic restenosis was reduced (51% vs. 66%, p = 0.012), but this was also associated with a higher rate of periprocedural myocardial infarction (8% vs. 2%, p = 0.008 by site and 24% vs. 8%, p < 0.001 by adjudication) and no difference in the need for subsequent coronary artery bypass surgery (7.3% vs. 8.4%, respectively) or repeat percutaneous coronary intervention (24% vs. 26%, respectively). CONCLUSIONS: For ostial left anterior descending coronary artery stenoses, both procedures yielded similar rates of initial success and restenosis, but atherectomy was associated with more non-Q wave myocardial infarction. In this trial the predominant angiographic benefit (increased early gain and less angiographic restenosis) of atherectomy for the left anterior descending coronary artery was in proximal nonostial lesions. However, the tradeoffs for this angiographic advantage were more in-hospital myocardial infarctions and no decrease in clinical restenosis.

Angioplasty, Balloon↗
PubMed1992

Abrupt vessel closure after directional coronary atherectomy. The U.S. Directional Atherectomy Investigator Group.

From October 1, 1986 to December 31, 1989 directional coronary atherectomy was performed during 1,020 procedures (1,140 lesions) at 14 clinical centers. Abrupt vessel closure, defined as a total coronary occlusion or subtotal occlusion associated with clinical evidence of myocardial ischemia, occurred in 43 procedures (4.2%). It developed in the catheterization laboratory in 34 patients, but was delayed 1 to 96 h after directional atherectomy in 9 patients. By univariate analysis the incidence of abrupt closure was higher in directional atherectomy of de novo lesions (p less than 0.001), lesions in the right coronary artery (p = 0.001) and diffuse lesions (p = 0.04). The incidence of abrupt closure tended to be lower in directional atherectomy of saphenous vein grafts as opposed to native coronary arteries (1.6% vs. 4.4%; p = 0.08). Clinical findings during abrupt closure included severe angina in 26 patients, myocardial infarction in 17 patients, hypotension in 5 patients and death in 2 patients. Balloon angioplasty was attempted in 32 patients after abrupt vessel closure. In 16 patients balloon angioplasty resulted in initial resolution of the closure episode, although 1 patient died 96 h after the procedure. Fifteen of 16 patients without initial improvement after balloon angioplasty underwent coronary bypass operation; 9 additional patients with abrupt closure were referred directly for bypass operation. It is concluded that abrupt vessel closure develops relatively infrequently after directional coronary atherectomy. In the absence of severe coronary dissection, abrupt closure after directional atherectomy may be effectively managed with balloon angioplasty in some cases, although coronary bypass operation is often required.

Adult↗
PubMed1994

Peripheral atherectomy with the rotablator: a multicenter report. The Collaborative Rotablator Atherectomy Group (CRAG).

PURPOSE: Our purpose was to evaluate the efficacy and limitations of the Auth Rotablator, an atherectomy device recently approved by the U.S. Food and Drug Administration for general use in treating peripheral arterial occlusive lesions. METHODS: Between August 1987 and December 1990, 72 patients from three medical centers (University of California, Los Angeles, Montefiore, and Stanford) underwent atherectomy with the Auth Rotablator in 79 limbs and 107 arteries: 2 iliac, 45 femoral, 29 popliteal, and 31 tibial. The average age among the 72 patients was 69 years (43 to 91 years), and 67% were men. Indications for atherectomy were claudication in 34 (43%), limb threat in 44 (56%), and asymptomatic in 1 (1%) case. Average ankle-brachial index was 0.47 (0 to 0.81). Average length of lesions was 9 cm (1 to 40 cm); 70 treated arterial segments were less than 10 cm and 37 were greater than 10 cm. All patients underwent arterial pulse examination, vascular laboratory Doppler measurement of ankle-brachial indexes, and arteriography before and after surgery and at follow-up intervals during a period of 15 to 41 months (mean 27 months). RESULTS: Angiographic success (residual lumen < 25% stenosis) was achieved in 70 (89%) of 79 limbs and 82 (77%) of 107 arteries: iliac 1 (50%) of 2, femoral 38 (84%) of 45, popliteal 24 (83%) of 29, and tibial 19 (61%) of 31. In-hospital clinical and hemodynamic success was achieved in 61 (77%) of 79 limbs. The cumulative primary patency rate was 47% at 6 months, 31% at 12 months, and 18.6% at 24 months. Complications included hemoglobinuria in 10 cases (13%), emboli in eight cases (10%), dissection in five cases (6%), perforation in three cases (4%), hematoma in four cases (5%), and infection in one case (1%). There were nine early thromboses (11%) and two device-related amputations (2.5%). CONCLUSION: Peripheral atherectomy with the Auth Rotablator currently has limited application because of frequent early thromboembolic complications and poor late patency rates. Atherectomy is not generally recommended for treating peripheral arterial occlusive lesions until these problems with early thromboemboli, occlusions, and late restenoses are solved.

Adult↗
PubMed1998

Peripheral atherectomy with the Pullback Atherectomy Catheter: procedural safety and efficacy in a multicenter trial. PAC Investigators.

PURPOSE: To report the initial results of a newly designed catheter for percutaneous circumferential atherectomy in patients with lower extremity atherosclerotic occlusive disease. METHODS: The Pullback Atherectomy Catheter (PAC) is an over-the-wire device that circumferentially debulks atherosclerotic lesions in peripheral arteries up to 6 mm in diameter. Pullback atherectomy with or without adjunctive balloon angioplasty was attempted in 190 patients (246 lesions) with lower extremity lesions < or = 7.0 cm in length and a diameter stenosis > 50%. RESULTS: Angiographic success was accomplished in 95% (234/246) of the of the lesions attempted. The baseline ankle-brachial index rose from 0.61+/-0.20 to 0.83+/-0.20 (p < 0.001) at 24 hours after the procedure. There were no major complications (distal emboli, dissection, thrombosis, or perforation requiring surgical correction) attributable to pullback atherectomy. CONCLUSIONS: The acute results of pullback atherectomy demonstrate an extremely high technical success rate and an excellent safety record for lower extremity percutaneous revascularization. The catheter facilitates debulking longer lesions, but it is limited to small-diameter (< or = 6 mm) peripheral vessels.

Arteriosclerosis↗
PubMed1997

Pullback atherectomy with the Arrow-Fischell atherectomy device.

The Arrow-Fischell pullback atherectomy catheter is designed to circumferentially debulk and retrieve coronary atheroma. We performed pullback atherectomy before balloon angioplasty or stenting in 41 patients. The device crossed the target lesion in 38 (93%) and obtained tissue in 36 (88%). All procedures were completed successfully and without myocardial infarction, emergency cardiac surgery, or death. Complications included major spasm in 8 patients, postprocedural abrupt closure in 1, and otherwise uncomplicated arterial perforation in 2. Pullback atherectomy can be performed relatively safely, but is more difficult than balloon angioplasty, obtains less tissue than directional atherectomy, and is associated with significant limitations.

Aged↗
PubMed1993

Results of directional coronary atherectomy during multicenter preapproval testing. The US Directional Coronary Atherectomy Investigator Group.

Between 1988 and 1990, clinical testing was performed at 12 US institutions using the Simpson Coronary AtheroCath under an Investigational Device Exemption. Data on 1,069 lesions (873 patients) were analyzed and presented to the Food and Drug Administration (FDA) advisory panel in the summer of 1990, forming the basis for approval of this device in September 1990. Analysis of these preapproval data shows a primary success rate of 85% (defined as tissue removal, > or = 20% reduction in stenosis, < 50% residual stenosis after directional atherectomy, and no major complication), with somewhat higher primary success in prior restenosis and noncalcified lesions. Including the use of conventional angioplasty performed after atherectomy, the overall success rate was 92%. One or more major complications occurred in 4.9% of procedures, and included death (0.5%), nonfatal Q-wave myocardial infarction (0.9%), and emergency bypass surgery (4.0%). These complications were more frequent in right coronary, de novo, and diffuse (> 20-mm length) lesions. Six-month angiography results were available in 384 (77%) of 498 lesions eligible for follow-up when the registry closed and showed a restenosis rate (late stenosis > 50%) of 42%. The restenosis rate in both native vessels (30 vs 46%) and bypass grafts (31 vs 68%) was lower in primary (de novo) lesions compared with lesions that had developed restenosis after a prior intervention. Despite the use of prototype atherectomy catheters and still evolving procedural technique, this preapproval experience provided an important initial indication of the situations in which directional coronary atherectomy was most useful and helped set clear standards for performance of this procedure following FDA approval.

Atherectomy, Coronary↗
PubMed2000

Directional coronary atherectomy: optimal atherectomy trials and new combined strategies with coronary stents.

Directional coronary atherectomy (DCA) has evolved from its early use as a tool for minimal plaque debulking to its current use of more aggressive lumen enlargement. The trend toward improved lumen results and reduced restenosis following DCA compared to percutaneous transluminal coronary angioplasty (PTCA) in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) was confirmed as a significant improvement in the subsequent Balloon versus Optimal Atherectomy Trial (BOAT). BOAT showed that acute lumen results and late angiographic restenosis could be significantly improved by DCA over PTCA, without any increase in procedural complications or late cardiac events. The role of DCA in conjunction with coronary stents is currently being defined as studies suggest that residual plaque burden after stenting is predictive of late restenosis. The Atherectomy before Multilink Stent Improves Lumen Gain and Clinical Outcomes Study (AMIGO) will help determine whether plaque debulking prior to stenting can reduce restenosis.

Atherectomy, Coronary↗
PubMed2000

Further insights into coronary debulking: the EUROCARE trial of directional atherectomy and the PACT trial of pullback atherectomy.

Although the principle of reducing plaque load in the coronary artery remains very appealing, clinical benefit from debulking devices has not been demonstrated unequivocally. Other approaches to prevent restenosis had been the application of various pharmacological agents. Unfortunately, the majority of clinical studies have not reproduced the promising results observed in the experimental laboratories. New frontiers in improving atherectomy devices and in optimizing concomitant medical treatment are currently being explored. We report on the EUROCARE trial investigating the possible benefit of carvedilol after coronary atherectomy, and the Pullback Atherectomy (PAC) pilot trial using a novel atherectomy device.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Can rotational atherectomy cause thermal tissue damage? A study of the potential heating and thermal tissue effects of a rotational atherectomy device.

PURPOSE: Thermal tissue damage (TTD) is customarily associated with some lasers. The thermal potential of rotational atherectomy (RA) devices is unknown. We investigated the temperature profile and potential TTD as well as the value of fluid flushing of an RA device. METHODS: We used a high-resolution infrared imaging system that can detect changes as small as 0.1 degree C to measure the temperature changes at the tip of a fast RA device with and without fluid flushing. To assess TTD, segments of porcine aorta were subjected to the rotating tip under controlled conditions, stained by a special histochemical stain (picrisirius red) and examined under normal and polarized light microscopy. RESULTS: There was significant heating of the rotating cam. The mean "peak" temperature rise was 52.8 +/- 16.9 degrees C. This was related to rotational speed; thus the "peak" temperature rise was 88.3 +/- 12.6 degrees C at 80,000 rpm and 17.3 +/- 3.8 degrees C at 20,000 rpm (p < 0.001, t-test). Fluid flushing at 18 ml/min reduced, but did not abolish, heating of the device (11.8 +/- 2.9 degrees C). A crater was observed in all segments exposed to the rotating tip. The following features were most notable: (i) A zone of "thermal" tissue damage extended radially from the crater reaching adventitia in some sections, especially at high speeds. This zone showed markedly reduced or absent birefringence. (ii) Fluid flushing of the catheter reduced the above changes but increased the incidence and extent of dissections in the media, especially when combined with high atherectomy speeds. (iii) These changes were observed in five of six specimens exposed to RA without flushing, but in only one of six with flushing (p < 0.05). (iv) None of the above changes was seen in control segments. CONCLUSION: RA is capable of generating significant heat and potential TTD. Fluid flushing reduced heating and TTD. These findings warrant further studies in vivo, and may influence the design of atherectomy devices.

Analysis of Variance↗
PubMed1996

Effect of subintimal resection on initial outcome and restenosis for native coronary lesions and saphenous vein graft disease treated by directional coronary atherectomy. A report from the CAVEAT I and II investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial.

OBJECTIVES: This study was designed to determine whether the depth of tissue resection affected either immediate outcome or subsequent restenosis in patients treated by directional coronary atherectomy (DCA) in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I and II studies. BACKGROUND: The relation between the depth of tissue resection, immediate outcome and subsequent restenosis in lesions treated with DCA has been controversial. METHODS: In CAVEAT I, 412 patients undergoing DCA had tissue samples available for analysis by the core laboratory, whereas in CAVEAT II, 113 patients had vein graft tissue specimens available. RESULTS: Subintimal deep arterial wall resection was demonstrated in 169 patients (41%) in CAVEAT I and 40 (35%) in CAVEAT II. The depth of tissue resection did not affect initial procedural outcome in either CAVEAT I or CAVEAT II, nor did it affect subsequent restenosis rates at 6 months in native coronary lesions (CAVEAT I, 50.8% for intimal resection vs. 51.2% for subintimal resection). In patients treated with vein graft disease (CAVEAT II), restenosis rates varied; when resection was limited to the intima, a restenosis rate of 40.4% was documented, whereas in patients with subintimal resection, the restenosis rate was 57.1%. This difference was not statistically significant (p = 0.144). CONCLUSIONS: This combined randomized series of DCA for treatment of primary native coronary artery and vein graft stenoses with quantitative coronary angiography and core laboratory pathologic assessment resolves the controversy created by previous experimental and clinical data regarding deep vessel wall resection and immediate and longer outcome. Directional atherectomy with deep arterial wall resection as practiced in these studies is safe and does not jeopardize initial success rates. More important, deep wall resection is not associated with significantly increased restenosis rates.

Atherectomy, Coronary↗
PubMed1996

[Percutaneous dynamic atherectomy with the aid of 12-F and 14-F transluminal atherectomy catheters (TEC): initial results].

OBJECTIVE: The presented study reports on the first experience with the large diameter 12 F and 14 F TEC system for percutaneous dynamic atherectomy of peripheral vascular obstructions. METHODS AND PATIENTS: The 12 F and 14 F TEC-extraction catheter was used to recanalize peripheral vascular obstructions in 4 patients. The extracted material was continuously aspirated during the procedure. Three patients with intermittent claudication suffered from chronic arterial occlusion (two cases) or from stenosis of an implanted stent (one case) in the region of the superficial femoral artery. In another patient with long-term dialysis history an insufficient collier shunt was treated by atherectomy. RESULTS: Complete vascular recanalisation was achieved in all cases. Supplementary intervention was not necessary. There were no complications. CONCLUSION: Atherectomy with the large diameter 12 F and 14 F TEC allows a safe and complete recanalisation of complex peripheral vascular occlusions. Further studies must show whether the enlarged vascular intrusion is justified by more favourable results.

Angiography, Digital Subtraction↗
PubMed1993

Evaluation of a new mechanical atherectomy system (TRAC) in normal canine coronary arteries. Transluminal Rotary Atherectomy System.

BACKGROUND: The feasibility and safety of a new mechanical atherectomy device, the Transluminal Rotary Atherectomy System (TRAC), for coronary application was examined in vivo in eight dogs. The system operates over a standard balloon coronary guide wire and excises and removes the atherosclerotic material in a single application. METHODS: The TRAC was introduced percutaneously using routine cardiac catheterization technique in four open-chest dogs (acute experiments) and in four closed-chest dogs (chronic experiments). RESULTS: Coronary angiography at the end of the procedure and 1-3 days later demonstrated normal coronary arteries without evidence of dissection, perforation, spasm, or thrombus formation. Macroscopic examination revealed perivascular bleeding along the treated coronary arteries in two out of eight dogs. Microscopic examination of these arteries demonstrated minimal endothelial peeling. Histology of the other coronary arteries demonstrated normal intact blood vessels without evidence for thrombus formation. CONCLUSIONS: These results demonstrate that it is feasible and relatively safe to introduce and operate the new TRAC mechanical atherectomy system in the normal coronary arteries of a beating dog heart.

Animals↗
PubMed2000

Carvedilol for prevention of restenosis after directional coronary atherectomy : final results of the European carvedilol atherectomy restenosis (EUROCARE) trial.

BACKGROUND: In addition to its known properties as a competitive, nonselective beta and alpha-1 receptor blocker, carvedilol directly inhibits vascular myocyte migration and proliferation and exerts antioxidant effects that are considerably greater than those of vitamin E or probucol. This provides the basis for an evaluation of carvedilol for the prevention of coronary restenosis. METHODS AND RESULTS: In a prospective, double-blind, randomized, placebo-controlled trial, 25 mg of carvedilol was given twice daily, starting 24 hours before scheduled directional coronary atherectomy and continuing for 5 months after a successful procedure. The primary end point was the minimal luminal diameter as determined during follow-up angiography 26+/-2 weeks after the procedure. Of 406 randomized patients, 377 underwent attempted atherectomy, and in 324 (88.9%), a </=50% diameter stenosis was achieved without the use of a stent. Evaluable follow-up angiography was available in 292 eligible patients (90%). No differences in minimal luminal diameter (1.99+/-0.73 mm versus 2.00+/-0.74 mm), angiographic restenosis rate (23.4% versus 23.9%), target lesion revascularization (16.2 versus 14.5), or event-free survival (79.2% versus 79.7%) between the placebo and carvedilol groups were observed at 7 months. CONCLUSIONS: The maximum recommended daily dose of the antioxidant and beta-blocker carvedilol failed to reduce restenosis after successful atherectomy. These findings are in contrast to those of the Multivitamins and Probucol Trial, which raises doubts regarding the validity of the interpretation that restenosis reduction by probucol was via antioxidant effects. The relationship between antioxidant agents and restenosis remains to be elucidated.

Adrenergic Antagonists↗