Transluminal extraction catheter for the treatment of diseased saphenous vein grafts: a multicenter experience

Percutaneous coronary intervention of or through saphenous vein grafts or internal mammary arteries: the impact of stents, adjunctive pharmacology, and multicomponent distal protection

We hypothesized that the use of stents and aggressive adjunctive pharmacotherapies has been associated with lower rates of complicating myocardial infarction (MI) and improved long-term outcomes compared to either previous balloon-only percutaneous coronary intervention (PCI) or atheroablative intervention for lesions of or through saphenous vein grafts (SVGs) and/or internal mammary arteries (IMAs). PCI of SVG has been complicated by relatively high rates of procedural MI and less favorable long-term outcomes than native vessel PCI, stimulating the development and application of an array of technologies. This study was based on retrospective review of stent-era (1999-2004) 5-year experience of a single center with 95 SVG procedures in 85 patients and 20 IMA procedures in 20 patients. These cases were compared with the previously published experience of one of the operators during the balloon-only period and literature review of the application of multiple technologies to SVG intervention, as well as consideration of the reoperation alternative. There was one in-hospital death each in the SVG cohort (1%) and in the IMA cohort (5%). There were SIX procedural MIs (6%), defined by total CK > normal, and 19 procedural MIs (20%) based on troponin-I > 1.0. Follow-up has been from 4 months to 5 years (average, 2.5 years), with 91% survival and one late CABG in the IMA group. SVG PCI with stents and adjunctive pharmacotherapies is associated with relatively low rates of procedural MI and favorable long-term outcomes.

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.

Retrieval and analysis of particulate debris after saphenous vein graft intervention

OBJECTIVES

This study was designed to evaluate the composition and quantity of particulate debris resulting from vein graft intervention.

BACKGROUND

Distal embolization and "no reflow" are frequent and important complications resulting from angioplasty of diseased saphenous vein grafts. Little is known about the composition and quantity of embolic particulate debris associated with vein graft intervention, and no intervention has been shown to protect against its clinical consequences.

METHODS

A catheter system, designed to contain, retrieve and protect against distal embolization of this material, was evaluated during 27 percutaneous interventional saphenous vein graft procedures. Clinical, angiographic and pathologic analyses were performed.

RESULTS

The duration of distal graft occlusion required to allow intervention and subsequent debris removal was 150 +/- 54 s, decreasing as experience was gained. Thrombolysis in Myocardial Infarction trial (TIMI) flow grade increased from 2.6 +/- 0.8 to 3.0 +/- 0.0. Creatine kinase (CK) rose above normal in three patients (11.1%) exceeding 3x normal in one (3.7%) resulting in the diagnosis of non-Q-myocardial infarction. Particulate material was identified following 21 of 23 procedures suitable for analysis. Particle size was 204 +/- 57 microm in the major axis and 83 +/- 22 microm in the minor axis. Particles consisted predominantly of soft acellular atheromatous material, such as that typically found under a fibrous cap. Semiquantitative analysis suggested that the quantity of particulate material was less following stenting than following balloon dilation.

CONCLUSIONS

Particulate matter is commonly present following routine angioplasty and stenting of saphenous vein grafts. Containment, retrieval and analysis of this particulate debris are all feasible. Comparison to prior clinical experience is limited by small sample size. However, to the extent that these particles may contribute to distal embolization, no-reflow and infarction, such a system may contribute to the reduction of complications following vein graft intervention.

Risk of distal embolization and infarction with transluminal extraction atherectomy in saphenous vein grafts and native coronary arteries. NACI Investigators. New Approaches to Coronary Interventions

Lower success rates have been reported when treating high-risk lesions in saphenous vein grafts (SVGs) and native coronary arteries with balloon angioplasty. The transluminal extraction atherectomy catheter (TEC) has been proposed to reduce the incidence of distal embolization (DE) in subsets of high-risk lesions. To define the utility of TEC in reducing the incidence of DE, all patients who were enrolled in the New Approaches to Coronary Interventions (NACI) Registry and had TEC planned as the sole treatment were studied (329 patients with 381 lesions). Of the lesions treated, 75.9% were in SVGs; 37.5% were thrombotic; and 15% were total occlusions. Adjunctive percutaneous transluminal coronary angioplasty (PTCA) was performed in 87.4% of lesions. Multivariate predictors of DE were: noncardiac disease, stand alone TEC, thrombus, and larger vessel size. DE was associated with an 18.5% in-hospital mortality vs. 3.0% without DE (P < 0.01) and a 25.9% MI rate vs. 5.0% without DE (P < 0.01). In conclusion, in this high-risk subset of patients, TEC is associated with an 8.3% incidence of DE with thrombotic and SVGs lesions. DE associated with TEC appears to carry high morbidity and mortality. Additional techniques to control DE are needed to reduce the frequency of complications in these patients.

Treatment of thrombus containing lesions in diseased native coronary arteries and saphenous vein bypass grafts using the AngioJet Rapid Thrombectomy System

The occurrence of fresh thrombus during percutaneous coronary interventions, especially in patients with diffusely diseased saphenous vein bypass grafts is associated with an increased incidence of procedural complications and clinical events. The AngioJet Rapid Thrombectomy Catheter was designed to remove thrombus via a Bernoulli effect induced vacuum. Here we report on the technical aspects of the device and the AngioJet thrombectomy procedure. Indications and potential complications, both procedure- and device related are discussed.

Transluminal extraction catheter atherectomy followed by immediate stenting in treatment of saphenous vein grafts

OBJECTIVES

The purpose of this study was to evaluate the effectiveness of transluminal extraction catheter (TEC) atherectomy followed by immediate Palmaz-Schatz coronary stenting of coronary bypass vein grafts.

BACKGROUND

Degeneration of saphenous vein coronary bypass grafts has become a common problem. Repeat bypass surgery is associated with greater risk and a poorer outcome than the initial operation. Moreover, percutaneous interventional procedures in vein grafts have been associated with high procedural complication rates, including distal embolization, and high restenosis rates. TEC atherectomy may reduce distal embolization, and stenting may reduce restenosis rates.

METHODS

We evaluated the procedural, hospital and clinical outcomes of TEC atherectomy followed by immediate Palmaz-Schatz coronary stenting of 53 vein grafts in 49 consecutive patients. The strategy was to limit instrumentation to extraction debulking and to stabilizing the site with stent deployment before using balloon dilation for optimal gain in lumen diameter.

RESULTS

Results are shown as mean value (95% confidence interval [CI]). The mean graft age was 9.2 years (95% CI 7.9 to 10.5), and 1.0 (95% CI 1 to 1) TEC cutter (2.2 mm [95% CI 2.1 to 2.3]) and 1.7 (95% CI 1.4 to 2.0) Palmaz-Schatz coronary stents/ vein graft were used. The procedural success rate was 98%, with a minimal lumen diameter at baseline of 1.3 mm (95% CI 1.1 to 1.5), increasing to 3.9 mm (95% CI 3.6 to 4.2) (p < 0.05) after the TEC-stent procedure. Procedural complications occurred infrequently: graft perforation in 1 (2%) of 53 patients and distal embolization in 1 (2%) of 53 (same patient). In-hospital complications included non-Q wave myocardial infarction in two patients and death after a successful procedure in three (6%) (n = 1 each: massive bleeding from the catheter site; sepsis; and acute myocardial infarction with asystole in the distribution of the stented vessel). The event-free survival rate to hospital discharge was 90%. Clinical follow-up (13 months [95% CI 11 to 15]) was available for all patients. There were five (11%) revascularization procedures (three bypass grafts and two percutaneous transluminal coronary interventions), four (9%) nonfatal myocardial infarctions and five (11%) deaths, for a cumulative rate of 28% for any adverse outcome occurring in 13 of 46 patients.

CONCLUSIONS

TEC atherectomy followed by immediate Palmaz-Schatz coronary stenting of stenoses in old (> 9 years) saphenous vein grafts can be successfully performed, with a low incidence of procedural and hospital complications. Clinical restenosis rates are low and less than those previously reported; however, late morbid cardiac events are still frequent in this high risk group of patients. These observational findings suggest that this technique may improve percutaneous management of vein graft disease, but optimal long-term management strategies remain to be determined.

Abrupt vessel closure: changing importance, management, and consequences

Percutaneous coronary interventions have been performed for 20 years. Despite the success and progress of these interventions, abrupt vessel closure has been a dramatic adverse event of coronary interventions. Closure has frequently led to the major complications of death, myocardial infarction, and emergency coronary artery bypass. Because of the fear of this adverse event and its subsequent complications, the applicability of coronary interventions is sometimes limited. The pathologic characteristics of abrupt vessel closure have been recognized as predominantly caused by dissection, with vessel recoil and thrombus formation playing important secondary roles. The recognition of the lesions at risk for abrupt vessel closure has led to a strategy of lesion-specific device therapy to reduce complications. Similarly the role of antiplatelet and antithrombotic therapies have reduced complications. The earliest methods of dealing with abrupt closure was emergency coronary artery bypass surgery with significant rates of morbidity and mortality. With the advent of second-generation devices and techniques, particularly stents, the management of abrupt vessel closure has been simplified and alternatives to emergency coronary bypass are more available. This article will review the history and current status of the prevention and management of abrupt vessel closure and demonstrate that anticipation and management of this complication have been facilitated with reduction of subsequent complications and increased applicability of coronary interventions.

A profile of candidates for repeat myocardial revascularization: implications for selection of treatment

OBJECTIVES

It is not known whether the results of randomized trials comparing coronary artery bypass grafting to percutaneous transluminal coronary angioplasty for initial revascularization apply to repeat revascularization in patients with prior bypass grafts. We studied the differences between the patients with prior bypass grafts referred for surgery or angioplasty to identify the clinical and angiographic characteristics that correlated best with either choice and to find clues that might aid in selecting one treatment over the other.

METHODS

Between 1992 and 1994, 870 patients underwent first isolated reoperation and 793 patients underwent first balloon angioplasty after a previous operation. A jeopardy score (0 to 8 points) was derived for each patient on the basis of the relative size of the ischemic territory. Clinical and angiographic data were analyzed for association with the revascularization strategy.

RESULTS

The following characteristics were more prevalent in the reoperation group: male sex, diabetes, hypertension, valvular disease, normocholesterolemia, and severe left ventricular systolic dysfunction; fewer functioning venous and arterial grafts; and a higher jeopardy score (p < 0.01 for all) than in the angioplasty group. A higher jeopardy score, diabetes, and a lower number of functioning arterial or venous grafts were strong, independent predictors of referral for reoperation (p < 0.01 for all). In hospital death and Q-wave infarction (p < 0.01 for both) were more frequent in the reoperation group.

CONCLUSIONS

Reoperation was the revascularization procedure of choice when larger regions of myocardium were in jeopardy. Angioplasty was more frequently chosen in the presence of a patent arterial graft to the left anterior descending coronary artery or multiple functioning bypass grafts. Reoperation was associated with a higher risk of in-hospital complications than angioplasty.

Improving the results of coronary angioplasty

Coronary angioplasty has changed dramatically in the past three years with major reductions in suboptimal results and restenosis rates, and improvements in safety, efficacy and cost-effectiveness. Intracoronary stent implantation with optimisation of strut expansion and the abandonment of anticoagulants after deployment, have led to less entry-site complications, facilitated early hospital discharge, virtually abolished subacute stent thrombosis and resulted in a 50% reduction in target vessel revascularisation. Adjuvant medical treatment with anti-platelet agents, including glycoprotein IIb/IIIa receptor inhibitors, improves the safety of angioplasty and may further reduce the restenosis rate. Selective use of debulking devices has extended the indications for angioplasty. High resolution fluoroscopy, quantitative coronary angiography and intracoronary ultrasound leading to improved diagnosis, equipment selection and treatment have contributed to better outcomes. Further clinical trials will compare angioplasty and stent implantation with coronary bypass surgery in patients with multivessel coronary disease, and may extend the indications for percutaneous transluminal coronary angioplasty (PTCA) to selected patients with three vessel disease.

A new thrombosuction catheter for coronary use: initial results with clinical and angiographic follow-up in seven patients

The presence of thrombus in a coronary vessel during percutaneous revascularisation can prevent adequate restoration of flow; it is also associated with an increased risk of distal embolization. We report the acute results and longer-term outcome of seven patients who underwent treatment with a new hydrodynamic thrombectomy catheter (Hydrolyser), designed for the rapid removal of acute, non-organised thrombus from coronary vessels. Three patients demonstrated total thrombotic occlusion of a coronary saphenous vein bypass graft (SVBG), whereas in four patients thrombus was present in a native coronary artery (NCA). In all seven patients, Hydrolyser thrombectomy resulted in removal of thrombus and restoration of flow through the occluded segment. Adjunctive balloon angioplasty or stent placement to treat residual stenosis was performed in five of the patients. Distal embolization of a free-floating thrombus mass occurred in one patient, without clinical sequelae. There were no procedure-related complications in any of the patients. One patient with a degenerated SVBG reoccluded after five days. The other six patients underwent angiographic follow-up after an interval of 3 to 8 months: A wide patent coronary artery, without restenosis, was seen in three of these patients, and the other three patients (two with treatment of an SVBG) underwent re-PTCA for restenosis. These data suggest that the Hydrolyser procedure, as reported in our experience, is safe and effective for the removal of acute thrombus in selected patients.

Comparison of stenting and balloon angioplasty for narrowings in aortocoronary saphenous vein conduits in place for more than five years

To compare the 1 year outcome of Palmaz-Schatz stent implantation versus balloon angioplasty for treatment of obstructive lesions in saphenous vein grafts, we combined databases from the Palmaz-Schatz vein graft stent registry and the coronary angioplasty arm of the Coronary Angioplasty Versus Excisional Atherectomy Trial II (CAVEAT II) for comparison of baseline characteristics, procedural variables, in-hospital events and 1-year composite end point of death, Q-wave myocardial infarction, and repeat target vessel revascularization. De novo graft lesions not involving the ostia were treated with stent implantation in 377 patients and with coronary angioplasty in 156 patients. The patients were comparable in age, coronary risk profile, interval from bypass surgery (9 +/- 4 years), and reference vessel diameter. The in-hospital composite end point of death, myocardial infarction, and emergency revascularization was lower in the stent group (10%) than in the angioplasty cohort (17%) (p = 0.059). At 1 year, the patients in the stent group had a markedly lower incidence of the composite end point of death, myocardial infarction, or revascularization (23% vs 45%, p <0.001). In this nonrandomized comparison with balloon angioplasty, the treatment of lesions in saphenous vein grafts appears to be favorably influenced by Palmaz-Schatz stent implantation, in terms of in-hospital events and clinical restenosis at 1 year follow-up.

Percutaneous revascularization of an extensively diseased saphenous vein bypass graft with a saphenous vein-covered Palmaz stent

A 68-year-old man developed unstable angina 12 years following coronary artery bypass surgery. Angiography revealed an extensive area of severe stenosis and diminished distal flow in a right coronary artery vein bypass graft. Given the high distal embolism rate associated with conventional catheter-based treatment of old degenerated vein grafts, the diseased area was "relined" with a composite autologous saphenous vein-covered stent. The procedure was performed using modifications of standard PTCA methods and resulted in a widely patent, smooth lumen. This initial case demonstrates that a degenerated saphenous vein graft can be successfully revascularized with an autologous saphenous vein-covered stent in an attempt to minimize the potential complications of standard catheter-based revascularization methods.

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 emboli 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.

Three-year follow-up of the Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Artery Bypass Surgery in Multivessel Disease (ERACI)

OBJECTIVES

The purpose of this study was to report the 3-year follow-up results of the ERACI trial (Argentine Randomized Trial of Percutaneous Transluminal Coronary Angioplasty Versus Coronary Artery Bypass Surgery in Multivessel Disease).

BACKGROUND

Although coronary angioplasty has been used with increased frequency in patients with multivessel coronary artery disease, its value, compared with bypass graft surgery, has not been established. Thus, controlled, randomized clinical trials such as the ERACI are needed.

METHODS

In this trial 127 patients who had multivessel coronary artery disease and clinical indication of myocardial revascularization were randomized to undergo coronary angioplasty (n = 63) or bypass surgery (n = 64). The primary end point of this study was event-free survival (survival with freedom from myocardial infarction, angina and new revascularization procedures) for both groups of patients at 1, 3 and 5 years of follow-up.

RESULTS

Freedom from combined cardiac events (death, Q-wave myocardial infarction, angina and repeat revascularization procedures) was significantly greater for the bypass surgery group than the coronary angioplasty group (77% vs. 47%; p < 0.001). There were no differences in overall (4.7% vs. 9.5%; p = 0.5) and cardiac (4.7% vs. 4.7%; p = 1) mortality or in the frequency of myocardial infarction (7.8% vs. 7.8%; p = 0.8) between the two groups. However, patients who had bypass surgery were more frequently free of angina (79% vs. 57%; p < 0.001) and required fewer additional reinterventions (6.3% vs. 37%; p < 0.001) than patients who had coronary angioplasty.

CONCLUSIONS

1) Freedom from combined cardiac events at 3-year follow-up was greater in patients who had bypass surgery than in those who had coronary angioplasty. 2) The coronary angioplasty group had a higher incidence of recurrence of angina and the need for repeat revascularization procedures. 3) Cumulative cost at 3-year follow-up was greater for the bypass surgery group than for the coronary angioplasty group.