Acute and long-term outcome of narrowed saphenous venous grafts treated by endoluminal stenting and directional atherectomy.

Angioplasty of the narrowed saphenous vein bypass grafts remains a difficult challenge. Over a 37-month period at this institution, 119 of 176 interventions (68%) on saphenous vein grafts (average age 8.3 years from bypass surgery to graft intervention) were performed using either directional coronary atherectomy (n = 35) or Palmaz-Schatz intracoronary stents (n = 84), representing 37% of all stents and 15% of all atherectomies during the study period, respectively. Of the 57 saphenous vein graft lesions treated with conventional balloon angioplasty during this period, 49 (86%) had 1 or more contraindications to stenting or directional atherectomy (thrombus, total occlusion, reference vessel less than 3 mm in diameter). The acute success rate was 99% for stents (1 failure to dilate) and 94% for directional atherectomy (2 failures to cross the lesion with the atherectomy device). Lumen diameter increased from 0.9 to 3.6 mm (reference vessel 3.6) for stents, and from 0.9 to 3.5 mm (reference 3.8) for atherectomy (for all comparisons, p = not significant), with no major complications (abrupt or subabrupt closure, emergent coronary bypass surgery, death, or Q-wave myocardial infarctions). During the same time period 50 of 57 vein grafts (88%) rejected for stenting or atherectomy were dilated successfully by conventional balloon angioplasty, with 3 patients (5%) requiring emergent coronary bypass surgery. Angiographic follow-up was available for 50 of 64 eligible patients (78%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Angiographic outcome after intracoronary X-Sizer helical atherectomy and thrombectomy: first use in humans.

The objective of this study was to evaluate the early angiographic outcome in the first human subjects who underwent intracoronary atherectomy and thrombectomy using the X-Sizer helical cutting and aspiration system. Percutaneous coronary interventions in patients with thrombo-occlusive disease or friable degenerative saphenous vein grafts are associated with considerable periprocedural morbidity and mortality, predominantly related to microscopic distal embolization. X-Sizer catheter system is a novel atherectomy and thrombectomy device that consists of a helix cutter connected to a handheld motor drive unit and a vacuum collection chamber for aspiration of excised atheroma, thrombus, and debris. Quantitative coronary angiography was obtained in 14 patients before and after X-Sizer extraction atherectomy with adjunctive balloon angioplasty and stenting. Thirteen native coronary arteries and one saphenous vein graft were treated. Mean preprocedural reference vessel diameter was 3.06 +/- 0.66 mm. There were 71.4% AHA/ACC type B2 and C lesions. Preprocedural thrombus was present in nine patients and total occlusion in 64% of cases. Minimal luminal diameter was increased from 0.29 +/- 0.47 mm to 1.32 +/- 0.64 mm, a gain of 1.04 +/- 0.69 mm after atherectomy. Final total gain was 1.47 +/- 0.61 mm. Mean diameter stenosis was reduced from 89.3% to a final residual stenosis of 14.4%. Postatherectomy distal embolization occurred in one patient who had heavy preprocedural thrombus burden. No episodes of perforation, distal coronary spasm, abrupt closure, or slow/no-reflow occurred. The angiographic analysis of the first cohort of human subjects suggests that X-Sizer helical atherectomy is a feasible method of removing occlusive tissue or thrombus in coronary artery disease with a low angiographic complication rate. A large-scale randomized phase II clinical trial is underway to determine the ultimate safety and efficacy of this device in thrombo-occlusive native coronary arteries and saphenous vein grafts.     

Reduced distal embolization with transluminal extraction atherectomy compared to balloon angioplasty for saphenous vein graft disease

Extraction atherectomy utilizes suction aspiration as an attempt to limit distal emboll during atherectomy. We sought to test the hypothesis that extraction atherectomy produces less distal embolization than balloon angioplasty when treating saphenous vein grafts. Among 163 consecutive, nonrandomized patients, 103 patients underwent transluminal extraction catheter (TEC)^® atherectomy with or without adjunctive balloon angioplasty, and 60 patients had conventional balloon angioplasty. Both groups showed comparably high procedural success rates (TEC 90.3%, angioplasty 83.3%, P = NS). TEC cases had a significantly lower incidence of angiographic distal embolization, compared with angioplasty (3.9% vs. 16.7%, P = 0.005). In cases with angiographic evidence of thrombus in the grafts, TEC maintained a significantly lower incidence of distal embolization than angioplasty (5.6% vs. 31.8%, P = 0.004). There were no statistical differences between the two groups regarding the incidence of other procedure-related complications, including death, myocardial infarction, or emergency coronary artery bypass grafting. TEC atherectomy appears to have a significantly lower incidence of distal embolization than balloon angioplasty when treating saphenous vein grafts, particularly in the presence of angiographically apparent thrombus. © 1996 Wiley-Liss, Inc.     

Acute results and long-term outcome of transluminal extraction catheter atherectomy for saphenous vein graft stenoses

Distal embolization of atheroma and thrombus is a major concern when performing balloon angioplasty in coronary saphenous vein grafts (SVGs). The transluminal extraction catheter (TEC) is designed to remove this material and may improve the safety of percutaneous treatment of SVG disease. We assessed the acute results and long-term outcome of 67 patients (mean age 65.6 ± 8.1 years; range 47–83 years) who underwent 73 separate TEC atherectomy procedures. Eighty-eight SVG lesions were treated (mean age 8.7 ± 3.8 years from bypass surgery). Procedural success (< 50% final diameter stenosis and absence of major complications) was obtained in 63 patients (86%). Adjunctive balloon angioplasty and/or directional coronary atherectomy was required in 69 of the procedures (95%). Major complications, occurring in 8 patients (ll%), were acute closure in 4 (5%), resulting in Q-wave myocardial infarction in 3 and urgent bypass surgery in 1, and distal embolization in 4 (5%; 1 associated with Q-wave myocardial infarction). Angiographic follow-up was available for 50 patients and restenosis was present in 26 (52%). These data suggest TEC atherectomy can be performed in SVGs with an acceptable procedural risk, but restenosis remains a significant limitation which will require other strategies to overcome. o 1994 Wiley-Liss, Inc.     

Role of glycoprotein IIb/IIIa inhibitors in the treatment of degenerated aortocoronary saphenous vein grafts

Treatment of degenerated vein grafts is a large, growing portion of interventional procedures. Because the operative risk of repeat bypass surgery is substantially increased, percutaneous transluminal coronary angioplasty has been accepted as a less invasive treatment in symptomatic patients with significant stenoses of vein grafts. Stent placement has been established in the randomized SAVED trial as a safe and efficient treatment strategy of degenerated saphenous vein grafts, enhancing acute success, reducing the incidence of subsequent angiographic restenosis, and improving event-free survival. Despite coronary stents and new technological innovations like directional and transluminal extraction atherectomy distal embolization is still a frequent occurrence, with a reported incidence of 10-15% associated with an increased in-hospital mortality. Blockade of the platelet surface glycoprotein IIb/IIIa receptors has been convincingly demonstrated to reduce the ischemic complications of angioplasty in native coronary arteries. In degenerated vein grafts the efficacy of glycoprotein IIb/IIIa inhibitors in reducing distal embolization is uncertain. Major clinical events could not be reduced by glycoprotein IIb/IIIa antagonists administered periprocedurally. But prospective randomized trials are lacking. Protection devices could reduce the incidence of distal embolization during interventions in degenerated saphenous vein grafts. The relative role of these devices compared to pharmacologic interventions will require careful assessment in future clinical trials.     

Percutaneous intervention of old degenerated saphenous vein grafts

The treatment of failing bypass grafts is difficult because repeat surgery carries a higher mortality rate than a first operation. Percutaneous intervention is more difficult because mechanical manipulation of these soft, friable atherosclerotic plaques have been associated with a significant rate of distal embolization, myocardial infarction, late restenosis and death. Balloon angioplasty alone has proven to have serious limitations in the treatment of older degenerated saphenous vein grafts (SVG). Although directional atherectomy yielded a higher angiographic success in a randomized trial, the restenosis rate was similar, and the procedural complications higher. The transluminal extraction catheter (TEC) has also shown significant limitations for the treatment of degenerated or thrombotic vein grafts with a significant procedural complication rate. A randomized trial comparing stenting versus balloon angioplasty in focal SVG lesions showed a higher freedom from major adverse cardiovascular events in the stent group, but there was no significant difference in the angiographic restenosis rates. More recently, rheolytic thrombectomy and mechanical thrombolysis have proven useful in treating thrombotic lesions in SVG. In addition, the recent development of distal protection devices appears very promising and will probably contribute to decreased distal embolization during percutaneous revascularization of these conduits.     

Covered stent graft for primary PTCA of an aortocoronary vein graft

Covered stent graft by entrapping the thrombus between the vessel wall and stent might be helpful in preventing distal embolization and "no reflow" in a high-risk patient cohort. We here present a case with successful restoration of coronary flow in a highly thrombogenic milieu (acute myocardial infarction) with implantation of two covered stent grafts which by entrapping the thrombus avoided the distal embolization and "no reflow" in a totally occluded saphenous vein graft (SVG). However, stent length should be longer than the measured lesion length since choosing the exact diameter will not cover the plaque elongification secondary to the dilation process which is specifically significant in SVGs because of the softness of the plaque.     

Plaque removal prior to stent implantation in native coronary arteries: why? When? And how?

Coronary stenting has significantly reduced restenosis in focal de novo coronary lesions, but its impact in complex lesions has been less pronounced. Recent data suggest a possible role for pre-intervention plaque burden in exacerbating neo-intimal hyperplasia after stent implantation. These observations formed the basis for the hypothesis that plaque removal prior to stent implantation, using directional atherectomy in non-calcified lesions and rotational atherectomy in calcified lesions, may reduce restenosis. The currently available non-randomized experience that used this approach has shown its feasibility and favourable long-term outcome when applied in selected patients. However, the incidence of non-Q-wave myocardial infarction is increased with both rotational and directional atherectomy compared to PTCA or stent alone. The utilization of potent antiplatelet agents and/or the development of new atherectomy devices that produce lower embolization rate may decrease the incidence of these ischaemic complications. In addition, considering the increased procedural time and cost, this approach will have to be applied in selected patient subsets where debulking or stenting as a stand-alone strategy is associated with a high restenosis rate. Randomized clinical trials testing the usefulness of this approach, with both rotational and directional atherectomy, are currently in progress.     

Histololfic analysis of directional coronary atherectomy samples: A review of findings and their clinical relevance

Histologic analysis of atherectomy samples from >400 patients who received directional coronary atherectomy at 3 separate institutions disclosed 2 major categories of tissue: atherosclerotic plaque (with or without thrombus) and intimal proliferation (hyperplasia, with or without thrombus). The predominant tissue type in atherectomy samples from native, primary, or de novo coronary artery stenoses was atherosclerotic plaque. The predominant tissue type in atherectomy samples from restenosis lesions (prior balloon angioplasty, atherectomy, or both) was intimal proliferation with variable amounts of atherosclerotic plaques (with or without thrombus). Deep vessel wall components (media, adventitia) were identified at varying frequencies. The clinical relevance of atherectomy tissue is reviewed.     

Adjunctive abciximab improves outcomes during recanalization of totally occluded saphenous vein grafts using transluminal extraction atherectomy

Degenerative disease of aortocoronary saphenous vein grafts is a major cause of late morbidity and mortality in patients after coronary bypass surgery. We previously described a technique for recanalization of totally occluded grafts using extraction atherectomy (TEC) as a primary modality. While success was comparable to overnight urokinase, distal embolization, no-reflow, and non-Q myocardial infarction were common. Recently, abciximab has been used adjunctively in angioplasty and stenting with a reduced incidence of periprocedural complications. In order to determine whether abciximab can reduce the incidence of distal embolization, no-reflow, and myocardial infarction during TEC in totally occluded saphenous vein grafts, we compared patients treated with adjunctive abciximab with control subjects not receiving the drug. Male patients with previous coronary bypass surgery, class III–IV angina, and totally occluded saphenous vein grafts serving a vascular territory with ischemia not approachable by standard catheter-based techniques underwent TEC with or without adjunctive abciximab. Recanalization of the graft was achieved in 8/10 (80%) of subjects without abciximab, but complete success was achieved in only 5/10 (50%). In contrast, all procedures in the abciximab group were completely successful, without embolization or no-reflow. Our results suggest that TEC with adjunctive abciximab may be a highly effective approach for management of totally occluded saphenous vein grafts. Cathet. Cardiovasc. Intervent. 46:107–110, 1999. © 1999 Wiley-Liss, Inc.     

Atherosclerotic saphenous vein grafts treated with different interventional procedures assessed by intravascular ultrasound.

Intravascular ultrasound imaging of saphenous vein grafts may enhance the angiographic interpretation of results following transcatheter interventions. We used intravascular ultrasound to study 18 patients with stenotic vein grafts following balloon angioplasty, atherectomy, or stent placement. In real-time imaging the three-layer appearance was rarely seen, calcification was infrequent (11% of patients), and atheroma were usually mildly echogenic ("soft"). Despite excellent angiographic results (reduction in percent diameter stenosis from 90 +/- 8% to 17 +/- 8%) and concordant improvement in lumen area by ultrasound regardless of the intervention, there was usually significant retained atheroma at the treatment site. Following balloon angioplasty, ultrasound showed multiple superficial fissures and fractures without discrete dissections. Atherectomy caused a smooth lumen surface without deep dissections or resections, but significant retained atheroma was observed with each one of the atherectomy procedures. Endovascular stents were concentric in the vein with reflective struts above compressed atheroma and an outer echogenic adventitia. Stent expansion was asymmetric axially and longitudinally and evidence of stent recoil was present. Thus intravascular ultrasound may be an important adjunct to angiography in characterizing postintervention results in saphenous vein grafts.     

Thrombus aspiration as definitive mechanical intervention for ST-elevation myocardial infarction: a report of five cases

Thrombus aspiration is an effective adjunctive therapy to prevent distal embolization during primary percutaneous coronary intervention (PCI). In some patients, thrombus aspiration results in complete restoration of flow without significant residual stenosis or plaque rupture at the site of occlusion. It is currently unclear if additional angioplasty with balloon or stenting is necessary in these patients. We present 5 cases in which thrombus aspiration was performed without additional angioplasty as treatment for ST-elevation myocardial infarction. During follow up, no patient had an adverse cardiac event. These cases indicate that thrombus aspiration can be performed safely and effectively as definitive treatment in selected patients.     

Rheolytic thrombectomy during percutaneous revascularization for acute myocardial infarction: experience with the AngioJet catheter

BACKGROUND: Although balloon angioplasty and stenting are effective in the treatment of acute myocardial infarction (MI), reduced coronary flow and distal embolization frequently complicate interventions when thrombus is present. Adjunctive treatment with mechanical thrombectomy devices may reduce these complications. METHODS AND RESULTS: We evaluated the angiographic and clinical outcomes of 70 patients with acute MI (16% with cardiogenic shock) and with angiographically evident thrombus who were treated with AngioJet rheolytic thrombectomy followed by immediate definitive treatment. Procedure success (residual diameter stenosis <50% and Thrombolysis in Myocardial Infarction [TIMI] flow > or =2 after final treatment) was achieved in 93.8%. Clinical success (procedure success without major in-hospital cardiac events) was achieved in 87.5%, with an in-hospital mortality rate of 7.1%. Final TIMI 3 flow was achieved in 87.7%. AngioJet treatment resulted in a mean thrombus area reduction from 73.2 +/- 64.6 mm(2) at baseline to 15.5 +/- 30.1 post-thrombectomy (P <.001). Subsequent definitive treatment included stenting in 67% and balloon angioplasty alone in 26% of patients. Procedural complications included distal embolization in six patients and perforation in two patients. There were no further major adverse events during 30-day follow-up. CONCLUSION: Rheolytic thrombectomy can be performed safely and effectively in patients with acute MI, allowing for immediate definitive treatment in thrombus-containing lesions.     

Mechanisms of balloon angioplasty and directional coronary atherectomy as assessed by intracoronary ultrasound.

OBJECTIVE. This study was designed to use intracoronary ultrasound imaging to elucidate the physical effects of balloon angioplasty and directional coronary atherectomy in vivo in humans. BACKGROUND. The proposed mechanisms of coronary artery interventions such as balloon angioplasty and directional atherectomy are based on animal studies or pathologic findings and these data may not be applicable to living patients. Intracoronary ultrasound findings correlate highly with pathologic results and may allow in vivo assessment of the mechanisms of such interventions in humans. METHODS. Intracoronary ultrasound imaging was performed in 45 patients after a successful coronary intervention (balloon angioplasty in 30, directional coronary atherectomy in 15). Ultrasound images obtained at the treatment site and at an adjacent angiographically normal references site were analyzed quantitatively for minimal lumen diameter, cross-sectional lumen area, are enclosed by the internal elastic lamina, plaque area (internal elastic lamina area--lumen area) and percent area stenosis (plaque area/internal elastic lamina area). Qualitative analysis included assessment of presence of dissection, plaque composition and plaque topography. RESULTS. The results of the two procedures were similar with respect to minimal lumen diameter (angioplasty 2.6 +/- 0.5 vs. atherectomy 2.6 +/- 0.3 mm, p = NS), lumen area (0.07 +/- 0.03 vs. 0.07 +/- 0.02 cm2, p = NS) and percent area stenosis (59 +/- 14% vs. 51 +/- 21%, p = NS). However, after angioplasty, the internal elastic lamina area was significantly larger at the treated site than at the reference site (delta = +0.03 +/- 0.04 cm2, p = 0.01). There was no significant difference between the two sites after atherectomy (delta = -0.01 +/- 0.05 cm2, p = NS). In addition, dissection was seen significantly more often after balloon angioplasty than after atherectomy (50% vs. 7%, p less than 0.01). The results were similar when stratified for plaque composition and morphology. These data were confirmed in six additional patients who underwent ultrasound imaging before and after the intervention. CONCLUSIONS. Thus, the improvement in lumen dimensions after coronary balloon angioplasty is a result of both vessel stretch, demonstrated by a larger internal elastic lamina area at the treated site, and dissection. Both vessel stretch and dissection are uncommon after atherectomy, a finding consistent with plaque removal as the major mechanism for improved lumen area after this procedure.     

Directional atherectomy for treatment of restenosis within coronary stents: clinical, angiographic and histologic results.

OBJECTIVES. The safety and long-term results of directional coronary atherectomy in stented coronary arteries were determined. In addition, tissue studies were performed to characterize the development of restenosis. METHODS. Directional coronary atherectomy was performed in restenosed stents in nine patients (10 procedures) 82 to 1,179 days after stenting. The tissue was assessed for histologic features of restenosis, smooth muscle cell phenotype, markers of cell proliferation and cell density. A control (no stenting) group consisted of 13 patients treated with directional coronary atherectomy for restenosis 14 to 597 days after coronary angioplasty, directional coronary atherectomy or laser intervention. RESULTS. Directional coronary atherectomy procedures within the stent were technically successful with results similar to those of the initial stenting procedure (2.31 +/- 0.38 vs. 2.44 +/- 0.35 mm). Of five patients with angiographic follow-up, three had restenosis requiring reintervention (surgery in two and repeat atherectomy followed by laser angioplasty in one). Intimal hyperplasia was identified in 80% of specimens after stenting and in 77% after coronary angioplasty or atherectomy. In three patients with stenting, 70% to 76% of the intimal cells showed morphologic features of a contractile phenotype by electron microscopy 47 to 185 days after coronary intervention. Evidence of ongoing proliferation (proliferating cell nuclear antigen antibody studies) was absent in all specimens studied. Although wide individual variability was present in the maximal cell density of the intimal hyperplasia, there was a trend toward a reduction in cell density over time. CONCLUSIONS. Although atherectomy is feasible for the treatment of restenosis in stented coronary arteries and initial results are excellent, recurrence of restenosis is common. Intimal hyperplasia is a nonspecific response to injury regardless of the device used and accounts for about 80% of cases of restenosis. Smooth muscle cell proliferation and phenotypic modulation toward a contractile phenotype are early events and largely completed by the time of clinical presentation of restenosis. Restenotic lesions may be predominantly cellular, matrix or a combination at a particular time after a coronary procedure.     

Early ostial vein graft stenosis: management by atherectomy

During the initial perioperative period (1 mo to 1 yr) after saphenous vein coronary grafting, early stenosis and occlusion occurs in 5-8% of grafts due to intimal hyperplasia. We report a patient who developed ostial stenosis within 4 mo of bypass surgery at the aortotomy site of two vein grafts. Balloon angioplasty of the elastic stenoses did not provide significant luminal enlargement, but successful treatment of the lesions was obtained using directional atherectomy. Histological examination demonstrated intimal hyperplasia. Directional atherectomy may be an excellent technique for treatment of elastic ostial vein graft stenoses in lieu of conventional balloon dilatation.     

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.     

The whole nine yards: multiple cardiac surgical and percutaneous interventions in a patient during 30 years of care

A 38-year-old man underwent coronary artery bypass graft surgery for angina pectoris following myocardial infarction. During the following 28 years, he required two repeat coronary artery bypass graft surgical procedures, nine percutaneous coronary interventions and 17 coronary angiograms. His treatment included saphenous vein, left internal mammary artery and gastroepiploic artery grafting, percutaneous transluminal coronary angioplasty and intragraft thrombolytic therapy, directional coronary atherectomy, cutting balloon angioplasty, intracoronary stenting with bare-metal and drug-eluting stents, treatment for in-stent restenosis, stenting of the left main and circumflex coronary arteries and saphenous vein graft as well as intracoronary pressure wire diagnostics. In addition to his statin therapy, antiplatelets and angiotensin-converting enzyme inhibitors, he also underwent biventricular automatic implantable cardioverter-defibrillator implantation and atrioventricular node radiofrequency ablation for his impaired left ventricular function, ventricular tachycardia and rapid atrial fibrillation. The present unusual case represents almost 'the whole nine yards' of treatment that has become available to patients with coronary artery disease during the past 30 years of technological development.     

The benefit of abciximab in percutaneous coronary revascularization is not device-specific

Abciximab has been shown to decrease adverse outcomes after percutaneous coronary interventions, but it is unclear whether this beneficial effect is more or less pronounced with specific devices. This study sought to determine the relative magnitude of the benefit of abciximab among different interventional devices. Data from the 5 placebo-controlled trials of abciximab during coronary intervention were pooled. Patients were divided into groups based on whether they received balloon angioplasty alone, elective stenting, bailout stenting, or directional coronary atherectomy. In the patients undergoing balloon angioplasty, the 30-day hazard ratio for death or myocardial infarction (MI) in the group randomized to abciximab versus the placebo-treated group was 0.52 (p <0.001), for elective stenting the hazard ratio was 0.51 (p <0.001), for bailout stenting the hazard ratio was 0.38 (p <0.001), and for directional coronary atherectomy the hazard ratio was 0.38 (p = 0.007). A Cox proportional-hazards model revealed that overall, the use of abciximab decreased the composite end point of 30-day death or MI rates (hazard ratio 0.55, 95% confidence interval 0.43 to 0.69, p <0. 001). However, bailout stenting and directional coronary atherectomy were associated with increased rates of death or MI compared with balloon angioplasty, as was elective stenting in women compared with men. There was no significant increase in major bleeding episodes associated with abciximab in any of the device categories. These findings from all the controlled coronary revascularization trials using abciximab demonstrate that a decrease in death and MI is achieved with abciximab regardless of the type of device used, without an increase in significant bleeding complications.     

Mechanisms of luminal enlargement and quantification of vessel wall trauma following balloon coronary angioplasty and directional atherectomy: A study using intracoronary ultrasound, angioscopy and angiography

Objectives: The purpose of this study was to assess the dualaction of lumen enlargement and vessel wall damage followingeither balloon angioplasty or directional atherectomy, usingintracoronary ultrasound, and angioscopy. Background: Differences in the mechanisms of action of balloonangioplasty and directional atherectomy may have a significantbearing on the immediate outcome and the restenosis rate at6 months. Methods: A total of 36 patients were studied before and aftereither balloon angioplasty (n=18) or directional atherectomy(n=18). Ultrasound measurements included changes in lumen area,external elastic membrane area and plaque burden. In addition,the presence and extent of dissections were assessed to derivea damage score. Angioscopic assessment of the dilated or atherectomizedstenotic lesions was translated into semi-quantitative dissection,thrombus and haemorrhage scores. Results: Atherectomy patients had a larger angiographic vesselsize compared with the angioplasty group (3.55±0.46 mmvs 3.00±0.64 mm, P<0.05); however, minimal lumen diameter(1.18±0.96 mm vs 0.85±0.49 mm) and plaque burden(17.04±3.69 vs 15.23±4.92 mm²) measurements didnot differ significantly. As a result of plaque reduction, atherectomyproduced a larger increase in luminal area than the angioplastygroup (5.80±1.78 mm² vs 2.44±1.36 mm², P<0.0001).Lumen increase after angioplasty was the result of ‘plaquecompression’ (50%) and wall stretching (50%). Additionally,in both groups there was indirect angioscopic evidence of thrombus‘microembolization’ as an adjunctive mechanism oflumen enlargement. Angioscopy identified big flaps in six andsmall intimal flaps in 11 of the atherectomized patients ascompared with five and 12 patients in the angioplasty group.Changes in thrombus score following both coronary interventionswere identical (0.72±3.42 points atherectomy vs –0.38±3.27points balloon angioplasty, ns). Conclusions: Lumen enlargement after directional atherectomyis mainly achieved by plaque removal (87%), whereas balloondilation is the result of vessel wall stretching (50%) and plaquereduction (50%). Despite the fact that the luminal gain achievedby directional atherectomy is twice that achieved with balloonangioplasty, the extent of trauma induced by both techniquesseems to be similar.