Transluminal Extraction Catheter Research Articles

Thrombo-atherectomy: hope for pesky thrombus-containing lesions?

Angiographic lesion morphology remains an important predictor of acute and long-term clinical outcomes after percutaneous coronary interventional (PCI) procedures even in the current era of the stent. Chronic total occlusions and thrombus-containing lesions present perhaps the greatest risk for failed PCI due to technical issues or procedural-related clinical events such as noflow or distal embolization [1]. These lesion subsets may indeed benefit form a novel mechanical solution to address the technical limitations of existing devices applied to the treatment of these pesky lesion subsets. Thrombus-containing lesions represent a subset of lesions with a high risk for procedural-related thrombotic or flow-mediated complications. Thrombolytic and anticoagulant therapies have generally proven unreliable in preventing procedural-related thrombotic events and improving clinical outcomes. Antiplatelet therapies with GP IIb/IIIa inhibitors (abciximab, eptifibatide, tirofiban) have been shown to improve clinical outcome with PCI in patients with acute coronary syndromes by reducing procedural-related myocardial infarctions. Only anecdotal evidence supports the use of GP IIb/IIIa inhibitors for PCI of thrombus-containing lesions [1]. Several mechanical solutions have been proposed for intracoronary thrombectomy. The transluminal extraction catheter (TEC) was the first device developed for the purpose of cutting and aspirating thrombus [2]. The physical properties (profile and flexibility) of the TEC catheter, however, substantially limited clinical adoption of the device and caused a high frequency of dissections as well as distal embolic events. The incompatibility of the TEC catheter with contemporary-sized (6–8 Fr) guide catheters and guidewires also impacted negatively on the clinical integration of this device. The POSSIS Angiojet rheolytic thrombectomy system has been developed for peripheral vascular and selected coronary arterial lesion subsets [3]. The POSSIS catheter utilizes a unique high-pressure fluid jet and aspiration system to remove thrombus. The device is well proven for the treatment of thrombotic occlusion of peripheral vascular grafts and native vessels. The device, however, has limited application for intracoronary thrombus due to profile and a high probability for bradyarrhythmias as well as adverse hemodynamic consequences. The X-Sizer (EndiCor Medical, San Clemente, CA), as described by Kwok et al. [4], is an 8 Fr–compatible excisional thrombo-atherectomy catheter with 2.0 and 2.3 mm tip sizes. The X-Sizer removes thrombo-embolic debris by cutting with a rotating helical cutter (2,100 rpm) while aspirating the material away from the lesion through the central catheter lumen into a vacuum bottle. This excisional atherectomy device, unlike the TEC, is compatible with off-the-shelf 0.014 guidewires. Kwok et al. [4] report a retrospective angiographic analysis of the initial clinical application of the X-Sizer for the treatment of 14 complex noncalcified and thrombus-containing lesions as part of an 85-patient international multicenter phase I clinical trial [5]. Patients treated with GP IIb/IIIa inhibitors were excluded from this retrospective study. The report of Kwok et al. [4], unfortunately, reminds one of past experiences with similarly designed thrombo-atherectomy devices. The acute gain after thrombo-atherectomy with the X-Sizer was approximately 1 mm, which equates to 50% or less of the cutter dimensions (2.0 or 2.3 mm). The cut-and-suck approach effectively removed the entire thrombus in four of nine patients (40%), while three patients (33%) had persistent thrombus after the X-Sizer and adjunctive therapy with PTCA or stenting. Distal embolization occurred in only one of 14 patients; unfortunately, periprocedural CPK data and the incidence of myocardial infarction were not reported in this angiographic study. Kwok et al. [4] identify yet another potential mechanical approach for dealing with complex or thrombus-containing lesions. These feasibility data must be supported by clinical efficacy documented in the randomized multicenter trial comparing the X-Sizer with PTCA while employing contemporary mechanical (stents, embolic protection) and pharmacological therapies (GP IIb/IIIa inhibitors). An approach harmonizing mechanical and pharmacological therapies will likely prove more efficacious than simply aspirating thrombus. Catheterization and Cardiovascular Interventions 55:140–141 (2002)

Effectiveness of transluminal extraction atherectomy for debulking saphenous vein graft in-stent restenosis

Treatment of in-stent restenosis in saphenous vein grafts often requires initial debulking, but transluminal extraction catheter (TEC) atherectomy is seldom used for this purpose, and most discussions omit this option. Our experience with 6 episodes of TEC used successfully for saphenous vein graft in-stent restenosis and review of 7 other reported cases suggests TEC may be safe and effective for debulking saphenous vein graft restenosis lesions.

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.

Clinical experiences with the PercuSurge GuardWire--a new system for prevention of peripheral embolisms in catheter interventions on degenerated coronary artery venous bypasses

Peripheral embolization is a typical complication of catheter interventions in degenerated aortocoronary saphenous vein grafts. Alternative techniques, such as transluminal extraction catheter (TEC), directional coronary athrectomy (DCA) and eximer laser angioplasty (ELCA) were not able to reduce the risk of peripheral vessel occlusion or "no-reflow". For the protection from peripheral embolisation we used the PercuSurge GuardWire Temporary Occlusion & Aspiration System (PercuSurge Inc., Sunnyvale, USA) in 55 patients with 58 stenosis in degenerated saphenous vein grafts. The primary endpoint of this consecutive series was to access the efficacy of the system by post-interventional TIMI flow and determination of serial CK/CK-MB. The intervention was primarily successful in 55 of 58 cases (94.8%), with a reduction in stenosis from 87.6% (range 75-100%) to 4.5% (range 0-40%). TIMI flow improved from a mean of 2.1 +/- 1.4 to 2.9 +/- 0.4 after intervention. CK/CK-MB levels were 24/5, 27/7 and 26/6 U/l (mean values) before, 8 hours, 16 hours and 24 hours after intervention, ruling out myocardial ischemia. Three (5.2%) non-q wave infarctions occurred in this series, twice caused by a peripheral embolization during the crossing of the lesion with the wire und once because of "no-reflow". In the latter case the occlusion balloon had to be deflated before the aspiration could be performed. In 80 of 92 aspirates (86.9%) macroscopic embolic debris was visible. The PercuSurge GuardWire Temporary Occlusion & Aspiration System is a safe and effective device for the protection of distal embolization during interventions in degenerated aorto-coronary saphenous vein grafts.

Elevated levels of pro-inflammatory cytokines in coronary artery thrombi

To validate the hypothesis that artery sites occluded with thrombi release pro-inflammatory cytokines, we measured concentrations of interleukin (IL)-6 and IL-8 in infarct-related coronary artery thrombi and atherosclerotic plaque specimens obtained with a transluminal extraction catheter (TEC) from cases of acute myocardial infarction (MI). Fifteen patients (group I) were enrolled in the study and four sets of samples were obtained (taken from the right atrium both before and after angioplasty, from infarct-related coronary artery thrombi and atherosclerotic plaque aspirated with a TEC and from the thoracic aorta aspirated with a TEC). Ten patients undergoing elective TEC served as controls (group II). IL-6 and IL-8 were measured in all patients by means of an enzyme-linked immunosorbent assay. Both IL-6 and IL-8 levels of infarct-related coronary artery samples in group I were significantly higher than in group II (mean ± SEM, 15.3 ± 4.5 vs. 3.8 ± 1.2 pg/ml; P < 0.01 and 44.0 ± 2.4 vs. 15.6 ± 0.6 pg/ml; P < 0.001, respectively). The results suggest that pro-inflammatory cytokines originate from occluded coronary arteries in acute MI.

Acute Intraoperative Embolic Peroneal Artery Occlusion: Treatment with Suction Embolectomy, Angioplasty, and the Transluminal Extraction Catheter

Acute Intraoperative Embolic Peroneal Artery Occlusion: Treatment with Suction Embolectomy, Angioplasty, and the Transluminal Extraction Catheter

Laser angioplasty and recanalization

Percutaneous transluminal coronary balloon angioplasty (PTCA) still is the most frequently applied interventional technique for treatment of coronary artery disease. Plastic deformation of the obstructive plaque with creation of splits, intimal tears and dissections is the main mechanism of PTCA for lumen widening. As a result, acute complications due to flow limiting dissections and acute vessel closure can unpredictably occur resulting in myocardial infarction, urgent bypass surgery and death. Furthermore, long-term success of PTCA is limited by restenosis. In order to overcome these limitations of PTCA, alternative interventional techniques were developed, which instead of deforming the obstructive plaque ablate this tissue. These techniques include high and low speed rotational angioplasty, directional atherectomy, the transluminal extraction catheter, ultrasound angioplasty and laser (Light Amplification by Stimulated Emission of Radiation) angioplasty. 308 nm XeCl excimer laser angioplasty today is the laser technique of choice for clinical application. This pulsed laser requires direct contact to the obstructive plaque. It creates fast (< 200 microseconds) expanding gas bubbles which induce plaque ablation. Main indications for 308 nm XeCl excimer laser angioplasty are diffuse and long coronary lesions and total coronary occlusions. Despite promising initial results this technique showed no better acute and long-term results in comparison to PTCA for the treatment of these types of lesions ("Amsterdam-Rotterdam" Study, "Excimer Rotational Balloon Angioplasty Comparison" Study). As a result, this interventional technique was rarely applied for patient treatment. More recently, the concept of plaque ablation by 308 nm XeCl excimer laser angioplasty was renewed for the treatment of in-stent restenosis. This indication is being investigated in the "Laser Angioplasty of Restenosed Stents" trial. First results document the practicability and safety of this approach. Long-term results are awaited. With ongoing miniaturization, laser guidewires were developed for the recanalization of chronic total occlusions. The randomized multicenter "Total Occlusion Trial with Angioplasty assisted by Laser guidewire "Study documented a success rate of laser wire recanalization in up to 66% in contrast to 47.5% for mechanical wires only. Long-term results are still awaited. Technical and procedural progress including saline flush during laser application, homogeneous light distribution and the concept of smooth laser ablation is pushed foreward to make excimer laser angioplasty safer, more predictable and more effective.

Predictors of Acute and Long-Term Outcome With Transluminal Extraction Atherectomy: The New Approaches to Coronary Intervention (NACI) Registry

The New Approaches to Coronary Intervention (NACI) registry was established to define the role of new coronary devices in overcoming the limitations of balloon angioplasty. The purpose of the present study was to evaluate the acute and long-term efficacy of the transluminal extraction catheter (TEC) device utilizing data from the NACI registry and identify clinical and anatomic patient subsets who may benefit from this device. From 1990–1994, >4,300 patients from 39 clinical sites enrolled consecutive patients treated with one of the 7 new devices to the NACI registry. The study population consists of 331 patients (385 lesions) treated with planned TEC as the sole new device. Of these patients, 243 (292 lesions) were treated for saphenous vein graft (SVG) disease and 88 (93 lesions) for native disease. Patients undergoing SVG treatment were older and more likely to be male. They had lower ventricular function, more unstable angina, and a higher incidence of congestive heart failure. Multivessel disease was more prevalent in the SVG cohort, as was evidence of thrombus before treatment. Although device success was achieved in 50% of SVG lesions and 41% of native lesions, lesion success was achieved in 90% and 78%, respectively, after adjunctive balloon angioplasty, and procedure success rates were 86% and 79%, respectively. The in-hospital major complication (death/Q-wave myocardial infarction/emergency coronary artery bypass graft [CABG] surgery) rate was higher in the SVG cohort (6.2% vs 2.3%), mainly due to higher mortality rate (5.3% vs 1.1%). Multivariate analysis showed that SVG was not an independent predictor for either an in-hospital major complication or clinical failure. The risk factors for major in-hospital complications were history of congestive heart failure (odds ratio = 3.17) and thrombus (odds ratio = 3.36). For clinical failure the risk factors were diabetes (odds ratio = 1.88), thrombus (odds ratio = 2.08), and calcium (odds ratio = 3.09). One-year rates of death, Q-wave myocardial infarction, or any repeat revascularization were 51% in the SVG cohort and 41% in the native cohort. Following adjustment, patients treated for SVG disease did not have a higher risk when compared with those treated for native disease. The factors significantly associated with this composite event at 1 year are male (relative risk = 1.41), patients with history of congestive heart failure (relative risk = 1.56), and total occlusions (relative risk = 1.52). This study shows that for both SVG and native cohorts, device success rates were low with TEC alone, but acceptable lesion success rates were achieved when adjunctive PTCA was used. In-hospital as well as 1-year major complications were higher in the SVG cohort. However, after adjusting for other risk factors, SVG attempt was not significantly associated with either in-hospital or 1-year events.

Clinical and vascular laboratory determinants for outcome after infrainguinal atherectomy

Three surgeons performed 180 atherectomy procedures in 161 patients using the Transluminal Extraction Catheter in 144 and the Auth Rotablator in 36. The primary patency rate was 55% at 1 year and 46% at 2 years, and failure was caused by stenosis in 28 (15.6%) and occlusion in 61 (33.7%) limbs. Multivariate Cox regression analysis showed significantly better outcome if the indication was claudication, the lesion was short or there was associated stenting. Vascular laboratory surveillance was performed in 93 limbs in 83 patients. Cox regression analysis in this subgroup also showed a significant relationship between outcome and the maximum peak systolic velocity from a duplex scan at the last study performed. Receiver operating characteristics curves showed that a raised maximum peak systolic velocity best predicted late failure (sensitivity 84%, specificity 66% for >200 cm/s; sensitivity 72%, specificity 84% for >250 cm/s); the velocity ratio at the stenosis to that in the segment above or the resting ankle/brachial pressure index were less predictive. For 50 procedures studied in the vascular laboratory which remained successful to the end of the study, maximum peak systolic velocities were >250 cm/s from the first postoperative study, suggesting residual stenosis in 6%, or increased to become >250 cm/s by the last study, suggesting recurrent stenoses in 12%. For 43 procedures which were studied and later failed, velocities were >250 cm/s from the first test in 26% or increased to >250 cm/s by the last test before failure in 40%. Vascular laboratory surveillance helps to predict outcome after atherectomy. Failure may be a result of residual disease from the time of the procedure or from restenosis. The apparent high incidence of clinically manifest or developing stenoses raises doubts as to the benefit of atherectomy over balloon dilatation alone. Copyright © 1996 The International Society for Cardiovascular Surgery.

Prospective Study of Extraction Atherectomy in Patients With Acute Myocardial Infarction

Although percutaneous transluminal coronary angioplasty (PTCA) has been an effective treatment for primary reperfusion in acute myocardial infarction, patients with thrombolytic ineligibility, thrombolytic failure, cardiogenic shock, and vein graft occlusion remain at high risk for complications with PTCA treatment. The transluminal extraction catheter may be useful for treatment of such patients owing to its ability to aspirate thrombus. At 2 clinical centers, extraction atherectomy was prospectively evaluated in 100 patients (age 62 ± 10 years). High-risk features included thrombolytic failure in 40%, postinfarct angina in 28%, presence of angiographic thrombus in 66%, presence of cardiogenic shock in 11%, and a saphenous vein graft occlusion in 29%. Procedural success, defined as a final residual stenosis <50% and Thrombolysis in Myocardial Infarction 2 or 3 grade flow, was seen in 94%. Events during the hospitalization included death in 5%, bypass surgery in 4%, and blood transfusion in 18%. In a substudy, patients enrolled at William Beaumont Hospital (n = 65) underwent elective predischarge angiography, which revealed a patent infarct-related vessel in 95%. These patients were also followed for 6 months with angiographic follow-up in 60%. Target vessel revascularization was necessary in 38%, and 6-month mortality was 10%. Although long-term vessel patency was 90%, angiographic restonosis occurred in 68%. Acute myocardial infarction patients can be treated with extraction atherectomy with a high technical success rate and a low week and 6 months was excellent; however, angiographic restenosis remains a problem. Extraction of thrombus in this high-risk group of patients is associated with low in-hospital mortality and a high rate of vessel patency at 6 months.

Percutaneous bailout therapy of a perforated vein graft using a stent‐autologous vein patch

A 74-yr-old man with two prior coronary bypass surgeries experienced perforation of an occluded aortocoronary vein graft during a transluminal extraction catheter (TEC) procedure for unstable angina. The perforation was successfully closed using a Palmaz 154 stent covered with a short segment of autologous antecubital vein. © 1996 Wiley-Liss, Inc.

Comparative results of transluminal extraction coronary atherectomy in saphenous vein graft lesions with and without thrombus

Objectives. The purpose of this retrospective study was to compare the results of transluminal extraction coronary atherectomy in saphenous vein graft lesions with and without angiographic thrombus.Background. Percutaneous interventions in lesions with thrombus are associated with reduced procedural success and increased risk of complications. Use of the transluminal extraction catheter, which cuts and aspirates atheroma and thrombus, has been advocated as a potential revascularization strategy for lesions with thrombus.Methods. Baseline patient characteristics, lesion morphology, immediate angiographic results, in-hospital complications and follow-up were prospectively entered into an interventional cardiology data base. The results of transluminal extraction coronary atherectomy in saphenous vein bypass grafts with angiographic thrombus were compared with results in similar grafts without angiographic thrombus.Results. Transluminal extraction coronary atherectomy was performed in 175 patients with 183 vein graft lesions, including 59 lesions (32%) with thrombus (Group 1) and 124 (68%) without thrombus (Group 2). Compared with lesions in Group 2, lesions in Group 1 were associated with a higher incidence of baseline total occlusion, diffuse disease and abnormal Thrombolysis in Myocardial Infarction (TIMI) grade flow (p < 0.05); more severe diameter stenosis at baseline, after atherectomy and after final angiography (p < 0.05); a lower rate of clinical success (69% vs, 88%, p < 0.01); and more angiographic and clinical complications, including no reflow (p < 0.05), vascular repair (p < 0.05) and Q wave myocardial infarction (p = 0.09).Conclusions. In transluminal extraction coronary atherectomy of saphenous vein bypass grafts, the presence of thrombus is associated with more baseline lesion complexity, reduced clinical success and increased risk of no reflow, Q wave myocardial infarction and vascular repair.

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

To evaluate the efficacy, safety, and long-term results of atherectomy using the Transluminal Extraction catheter (TEC), patients with diseased saphenous vein grafts were enrolled in a prospective nonrandomized trial. Patients were followed to hospital discharge for acute complications and underwent routine 6-mo reevaluation with repeat cardiac catheterization to assess restenosis. Atherectomy was performed on 650 graft lesions in 538 consecutive patients (male 81%; mean age 66 yr; range 37-81). Mean graft age was 8.3 yr; (range 0.3-20) with 85% of grafts > 3 yr of age. Complex lesion morphology included thrombus (28%), ulceration (13%), and eccentricity (50%). Lesion success was achieved in 606 lesions (93%) with clinical success in 479 patients (89%). Lesion success was achieved in 90% of thrombus containing lesions, 97% of ulcerated lesions, and 97% of grafts > 3 yr. Complications included nonfatal myocardial infarction in 4 (0.7%) of patients, emergency bypass surgery in 2 (0.41%), and in-hospital death in 17 patients (3.2%). Angiographic follow-up at 6 mo was obtained from 268 lesions in 227 patients. The overall lesion angiographic restenosis rate was 60%. TEC atherectomy can be performed in patients with diseased saphenous vein grafts with high primary success and low complication rates. It is suitable for use in aged grafts, particularly in the presence of thrombus and ulcerations, and may be superior to balloon angioplasty alone in this group of patients.

Fortnightly Review: New methods of making blocked coronary arteries patent again

The use of percutaneous transluminal coronary angioplasty is limited by procedural complications and the serious drawback of restenosis, but some new techniques have been developed in an attempt to lower the complication rate for difficult lesions and reduce the rate of restenosis. These include devices to physically remove atheromatous plaque, such as the Simpson Coronary AtheroCath and the transluminal extraction catheter, as well as devices to ablate the plaque in situ, including the Rotablator and the excimer laser catheter. Although each device may have advantages in certain types of lesion, few data on their use have been reported in properly controlled randomised trials. The data available so far do not suggest that these devices will be safer than balloon angioplasty or that they will reduce restenosis. However, using metallic stents to support coronary arteries after balloon angioplasty seems to reduce acute complications and to lower the rate of restenosis, and the use of stents is likely to increase.

New guiding catheter configuration for aortocoronary vein graft angioplasty

A new family of four guiding catheters (8 French and 9 French) has been developed for angioplasty of aortocoronary vein grafts and native coronary arteries beyond vein graft insertions. In 67 consecutive grafts and native vessels dilated through the grafts in 54 patients, the procedural success rate was 97%. The G-1 standard catheter was employed for the majority of the procedures (66%), but the G-3 catheter was better for high anterior grafts and the G-4 catheter was better for high left grafts. The G-2 catheter was better for lower right grafts, especially in dilated aortas. Balloon angioplasty alone using 8 French catheters was performed in 60 procedures, and excimer laser with adjunctive balloon angioplasty using 9 French catheters was performed in 7 procedures. These unique guiding catheters provide an attractive alternative to existing vein graft guides by their improved seating and backup support. They may be the primary choice for vein graft angioplasty and may have future application in stent deployment and transluminal extraction catheter (TEC) atherectomy.

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 (11%), 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.

Baseline characteristics and therapeutic goals in the New Approaches to Coronary Intervention (NACI) registry.

The New Approaches to Coronary Intervention (NACI) voluntary registry was designed to study the use, safety, and efficacy of new percutaneous transluminal interventional devices including directional coronary atherectomy, the transluminal extraction catheter, the rotablator, the Palmaz-Schatz stent, the Gianturco-Roubin stent, the Advanced Interventional Systems (AIS) laser, and the spectranetics laser. To date, more than 3800 consecutive patients treated for the first time with a new device at 41 centers have been entered into the registry. Complete detailed information about the patient, lesions, device characteristics, reasons for device selection, and procedural data, such as adjunctive use of conventional balloon angioplasty (PTCA), was available for the first 2835 patients. The registry shows that 88% of the 3233 attempts with a new device were intended as a definitive treatment of target lesions, frequently in combination with adjunctive PTCA. The remaining 12% of attempts with a new device were unplanned, prompted by unexpected complications, unsuccessful attempts, or suboptimal results with PTCA. Although there was some overlap in the indications for selecting a given interventional device, the variation from device to device was sufficiently large to caution users against any direct comparison of either safety or efficacy between devices without careful attention to the differences in baseline patient and lesion characteristics, treatment plans, and the circumstances of device use. This report provides the first comprehensive overview of how new interventional devices are currently being used in the treatment of coronary artery lesions at the 41 centers participating in the NACI registry.

Results of coronary angioplasty using the transluminal extraction catheter

To assess the procedural results after coronary angioplasty using the transluminal extraction catheter (TEC) in patients with complex lesion anatomy, experience with 51 patients undergoing this procedure was reviewed. One or more adverse lesion morphologic features were present in 45 patients (88%) and ≥2 adverse features were present in 38 (74%). Procedural success (<50% final diameter stenosis and the absence of major complications) was obtained in 42 patients (82%); major complications occurred in 7 patients (death, 3; Q-wave myocardial infarction, 4; emergency bypass operation, 2). Distal embolization was noted in 5 patients with thrombus-containing saphenous vein graft stenoses. Only lesion thrombus correlated with an unsuccessful outcome. After TEC use, diameter stenosis was reduced from 76 ± 13 to 50 ± 22% (p < 0.001). Adjunct balloon angioplasty was used in 44 procedures (86%), further reducing the diameter stenosis to 32 ± 22% (p < 0.001 compared with post-TEC). High-frequency intracoronary ultrasound was performed in 11 patients after TEC use. Plaque fissuring was present in all lesions and intraluminal dissection was noted in 4 (36%). Residual plaque after TEC use was found in virtually all lesions. During the 5.2 ± 2.8-month follow-up period, 17 patients (40%) developed recurrent symptoms. Coronary bypass surgery was performed in 4 patients and repeat coronary angioplasty was required in 3. In addition, 3 patients died from cardiac causes. It is concluded that coronary angioplasty using the TEC may be a useful alternative to balloon angioplasty in patients with complex coronary anatomy, although distal embolization may still occur in thrombuscontaining saphenous vein graft lesions.

Thromboembolectomy with the Transluminal Extraction Catheter (TEC) as an Adjunct to Thrombolysis

Multiple surgical and percutaneous interventional radiologic techniques have been used to restore blood flow in an acutely ischemic extremity. The transluminal extraction catheter (TEC) system was used as a mechanical thromboembolectomy device to supplement pharmacologic thrombolysis in one patient. In this case, 40 hours of direct intraarterial infusion of urokinase into the occluded vascular segments of a threatened lower extremity resulted in incomplete thrombolysis. Therefore, a 7-F TEC system was advanced percutaneously through the occluded vessels with restoration of luminal patency in all vessels treated. No distal embolization occurred. The TEC system facilitated prompt recanalization of vessels occluded by acute thrombus superimposed on atherosclerotic disease.

New technologies for the treatment of obstructive arterial disease

The well-known limitations of balloon angioplasty include unpredictable abrupt closure, chronic total occlusion, diffuse disease, and restenosis, among other factors. These limitations have prompted the development of new technologic approaches to angioplasty including laser applications for plaque ablation, mechanical device applications for plaque removal/debridement, and stent devices for structural maintenance of vascular lumen patency. Devices which directly apply laser energy for ablation of plaque material include a balloon-centered laser angioplasty system, excimer laser ablation catheter systems, and a fluorescence-guided spectral feedback laser system. Experience with these devices indicates that plaque can be successfully ablated by using laser energy. Vessel perforation and dissection are complications reported with these devices and the effects of laser angioplasty on restenosis remain unclear. Indirect application of laser energy has been tested by using a "hot tip" catheter and a laser balloon angioplasty system. Although the hot tip device has received FDA approval for use in peripheral arteries, it appears to have very limited applications in the coronary arteries. Laser balloon angioplasty appears to be beneficial in the setting of threatened acute closure; the device continues to be evaluated for potential beneficial impact on restenosis. Mechanical atherectomy catheters are designed to remove atherosclerotic plaque from the arterial system and include the AtheroCath, the Transluminal Extraction Catheter (TEC), and the Pullback Atherectomy Catheter (PAC). The Rotablator is an atheroablation device which debrides the obstructing plaque material with distal embolization of the particulate debris. Successful removal/debridement of atherosclerotic plaque has been demonstrated with the AtheroCath, Rotablator, and the TEC device. Pre-clinical studies demonstrate successful removal of plaque material with the PAC device. Despite the theoretic advantage of removing plaque material when performing angioplasty with these devices, there has been little or no reduction in restenosis rates based on a significant experience with the AtheroCath and the Rotablator. Intravascular stent devices including one self-expanding device design and two balloon-expandable device designs have been employed successfully in the elective setting to treat recurrent restenosis lesions. Two of the devices have been successfully tested in the setting of threatened acute closure. Early follow-up studies suggest some improvement in restenosis rates in certain clinical settings following intravascular stenting. Acute and subacute thrombosis remain substantial problems for stent devices and very aggressive anticoagulation regimens are necessary to minimize the adverse events. In summary, a number of a new technologic approaches for treatment of atherosclerotic lesions have been developed and are undergoing significant clinical evaluation.(ABSTRACT TRUNCATED AT 400 WORDS)