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Increased expression of monocyte chemoattractant protein-1 in atherectomy specimens from patients with restenosis after percutaneous transluminal coronary angioplasty.

The plasma concentration of monocyte chemoattractant protein-1 (MCP-1) antigen is higher in patients with restenosis after coronary angioplasty than in those who do not restenose. In this study the MCP-1 expression of coronary atherectomy specimens was investigated by immunohistochemistry. Samples were obtained from 12 patients with restenosis and 15 with de novo lesions by directional coronary atherectomy. MCP-1 immunoreactivity was found in all patients in the restenosis group and in 8 of the de novo group. The frequency of macrophage expression was higher in the restenosis group than in de novo group. These results indicate that local expression of MCP-1 may be associated with the mechanisms of vascular remodeling after coronary angioplasty.

Adult↗

Pretreatment with Intracoronary Diltiazem Reduces Non-Q-Wave Myocardial Infarction Following Directional Atherectomy.

The Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) reported a greater risk of non-Q-wave myocardial infarction (MI) with directional atherectomy (DCA), although the specific mechanism was unclear. To assess the possible role of microvascular spasm in creatinine phosphokinase (CPK) elevation (> 2x normal) following DCA, 193 consecutive patients were given intracoronary diltiazem (2-6 mg) prior to DCA. These patients were compared with a retrospective control group of 400 consecutive patients who underwent DCA without diltiazem (all 593 procedures performed by a single operator). The groups were similar with respect to age, gender, clinical presentation and lesion morphology. Comparative analysis revealed that clinical success and the need for emergency bypass surgery was similar for each cohort. For patients who received intracoronary diltiazem prior to DCA, there was a significant decrease in the incidence of non-Q-wave myocardial infarction (2.7 vs. 6.8%, p =.04) and abrupt closure (2.5 vs. 6.2%, p = 0.05). These findings suggest that intracoronary diltiazem prior to DCA may result in a significant decrease in the rate of abrupt closure and non-Q-wave MI. Adjunctive intracoronary diltiazem should be considered in patients undergoing DCA.

Journal Article↗

The Efficacy of Directional Atherectomy Prior to Stent Implantation.

Coronary stents have improved the short- and long-term outcomes of patients undergoing catheter-based coronary interventions. However, the use of these devices in complex coronary lesions has also created an incessant form of in-stent restenosis that still defies treatment. Plaque burden has been consistently and reproducibly recognized as an important factor that may incite neointimal proliferation after stent implantation. Prospective nonrandomized experience has shown that plaque removal prior to stent implantation using directional atherectomy is a promising approach to reduce restenosis in selected patients. However, the proof of concept awaits the results of the randomized trials. Ultimately, the clinical use (safety and efficacy) of this approach will depend on 1) further improvements on the current directional atherectomy device to make it user friendly; 2) minimizing the incidence of non-Q-wave myocardial infarction with selective use of IIb-IIIa platelet receptor antagonists or distal protection devices; and 3) targeting patients at high risk for restenosis in whom efficient debulking is feasible. This would include patients who have noncalcified lesions in vessels greater than 2.75 mm but less than 3.5 mm in diameter that require a long stent or multiple stents, aorto-ostial lesions, bifurcational lesions, and chronic total occlusions.

Journal Article↗

[Guided coronary atherectomy: preliminary results].

Coronary atherectomy implies removing atheromatous material from the diseased coronary arterial wall. This technique has emerged as an attractive alternative to conventional percutaneous transluminal coronary angioplasty procedures, in an attempt to diminish both initial procedural failure and restenosis rate. Among different technologies, the Simpson's atherotome provides a means of performing directional (i.e. selective) coronary atherectomy (DCA). This device implements a coaxial catheter which is advanced into the lesion over a steerable guidewire. Its distal tip includes a hollow metallic cylinder with a lateral window. Removal of the material is accomplished by a rotating cutter which can be moved distally, once the device's window has been orientated facing the lesion. We have performed 14 DCA in 14 patients. Mean age was 58 years and 12 patients were male. The technique was indicated for unstable angina (7 patients), stable angina (4 patients) and silent myocardial ischemia (3 patients). Fifteen lesions were attempted (13 original and two with restenosis), located as follows: nine in the left anterior descending coronary artery, three in the right coronary artery and three in the left circumflex artery. Eleven lesions were proximal and four were located in mid coronary segments. Twelve lesions (80%) were eccentric, and five (33%) were irregular. Initial angiographic success (residual stenosis less than 50%) was obtained in all 15 lesions (100%). Pre-DCA stenosis was 84 +/- 5% and post-DCA stenosis was 16 +/- 6%. There was no need for urgent coronary artery by-pass surgery and no patient developed an acute myocardial infarction in relation to the procedure. A 82-year-old woman died after the procedure in cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Percutaneous transluminal atherectomy in the treatment of occlusive peripheral vascular disease].

Percutaneous transluminal atherectomy (ATH) can remove the obstructing atheromatous material and may overcome the limitations of balloon angioplasty for the treatment of occlusive peripheral vascular disease. This is the first case reported in China using the Simpson rotational atherectomy device in a patient with total occlusion of left superficial femoral artery. The significant improvement in lumen was achieved by removing a tissue specimen of 14 x 4 x 3 mm3 followed by a balloon angioplasty, which reduced the residual luminal narrowing further from 50% to 20%. No acute complication was found and the patient was discharged from hospital one week after the procedure. Our results suggests that the ATH might be an effective and safe treatment for occlusive peripheral vascular disease.

Angioplasty, Balloon↗

[Directional coronary atherectomy; initial Dutch experiences with a new percutaneous revascularization procedure].

Acute complications and restenosis in the first few months after a successful procedure remain the two major limitations of coronary balloon angioplasty. New devices have been developed in order to avoid these limitations. We tested the directional atherectomy catheter clinically and compared the immediate quantitatively analysed results with two other recently developed devices and conventional balloon angioplasty. A gain in luminal diameter of 1.7 mm after atherectomy was observed in 7 patients. This is far more than could be accomplished by balloon angioplasty, stenting and rotablation. Furthermore, the size of the device in relation to the size of the obstructed vessel suggests that a Dotter effect is partly responsible for the gain in luminal diameter. Whether this large gain can prevent restenosis remains to be confirmed. Preliminary literature data suggest that this is not the case.

Adult↗

Preliminary results of percutaneous transluminal atherectomy.

Percutaneous transluminal atherectomy with the Simpson atherectomy catheter was performed in 5 patients with severe atheromatous stenoses of the femoropopliteal arteries. In all patients plaque material was removed with successful restoration of vessel patency. Further clinical follow-up will have to determine whether recurrence rate of stenosis will be lower with this method than with conventional balloon angioplasty.

Arteriosclerosis↗

PTCA, thrombolysis or atherectomy: rational treatment of recently occluded saphenous vein grafts.

Recently occluded saphenous vein grafts (SVG) contain abundant thrombus. Distal embolization and myocardial infarction often occur when recanalization of such SVG is attempted. In 80 patients with occluded SVG, we employed transcatheter devices to lyse, compress or extract thrombus. Primary treatment for these SVG was performed in the following manner; PTCA 29, intragraft urokinase 12, TEC atherectomy 39. Following urokinase or atherectomy, adjunctive PTCA was performed to diminish the residual stenosis. All patients had class III or IV angina. Clinically, SVG occlusions were 3 days to 3 months old. TIMI flow was grade 0, and occlusion length was greater than 6 cm for all SVG. Each strategy resulted in a similar procedure success rate. However, when used as a primary treatment, TEC may be associated with lower rates of distal embolization and myocardial infarction.

Angioplasty, Balloon, Coronary↗

Surgical management of complications of percutaneous coronary rotational atherectomy interventions.

Percutaneous coronary interventions have progressed from angioplasty and intracoronary stents to the more aggressive rotational atherectomy devices. These technically complex procedures are typically performed on the more diseased anatomy, which causes the likelihood of complications to be more common. In this report, we present our experience with three unusual complications and their surgical management.

Aged↗

Vascular repair mechanisms after directional atherectomy or percutaneous transluminal coronary angioplasty in atherosclerotic rabbit iliac arteries.

Although directional atherectomy (DA) reduces the plaque burden, successful revascularization is not associated with a reduced restenosis rate when compared with percutaneous transluminal coronary angioplasty (PTCA). The purpose of this study was to compare and contrast the vascular response to DA-induced and PTCA-induced injury. Six to 8 weeks after induction of atherosclerosis, PTCA (n = 34) was performed in one iliac artery and DA in the other (n = 30). Arteries were obtained at 6 time points: 1, 3, 5, 7, 14, and 28 days. Eleven arteries that did not undergo an intervention acted as controls. Radiograms obtained before and after intervention and at euthanization were compared. Morphometric, histologic, and immunohistochemical analyses were performed. Both PTCA and DA resulted in an immediate increase in luminal diameter that subsequently decreased over the ensuing month. PTCA caused deep dissection (7 of 8 arteries), often extending to the adventitia, whereas stand alone DA resulted in deep cleft formation (4 of 5). Of the 30 arteries that underwent DA, 4 exhibited an increase in luminal diameter in the absence of tissue retrieval. Thrombus was observed in both the dissection planes and the clefts within the first 7 days, and cellular ingrowth was appreciated at 5 to 7 days. By 7 days the artery was repaired, and the histologic appearance of the arteries that had undergone PTCA could not be differentiated from the arteries that had undergone DA. Increased intimal and medial collagen and elastin was noted at 14 and 28 days. An increase in the area bordered by the external elastic lamina was observed in both groups. Although successful DA results in tissue removal and the production of a deep tissue cleft and PTCA causes a dissection, both produce a condition in which the arterial injury exposes the arterial media to blood, causing thrombus formation and inflammation with subsequent cellular accumulation into the thrombotic framework.

Aortic Dissection↗

Enhanced manipulation of directional coronary atherectomy and coronary angioplasty guide catheters.

Manipulation of thin-walled coronary guiding catheters, especially directional coronary atherectomy guides, may sometimes be difficult. This is particularly so in patients with tortuous or ectatic aorto-iliac arterial systems. To improve torque transmission and eliminate kinking, the introducer catheter or a smaller caliber diagnostic catheter is advanced to within 1.5 cm of the distal guide tip. Connecting the rotating hemostatic valve to the introducer hub or diagnostic catheter proximally allows distal contrast injections and pressure monitoring via this inner catheter. Other methods of enhancing guide catheter manipulation are also discussed.

Atherectomy, Coronary↗

Short- and long-term clinical effects of primary directional coronary atherectomy for acute myocardial infarction.

We performed primary directional coronary atherectomy (DCA) without antecedent thrombolytic therapy in 21 of 67 patients with acute myocardial infarction within 24 hr of onset between June 1993-March 1994. Reperfusion with primary DCA was successful in 18 patients (85.7%, group D). Results were compared with those of primary balloon angioplasty patients treated between June 1992-May 1993 (group P). Minimum lumen diameter (MLD) values both immediately after reperfusion and in predischarge angiograms were significantly larger in group D than in group P, but were similar in late follow-up angiograms. Although a larger MLD in group D than in group P contributed to the prevention of reocclusion of the coronary artery before discharge in DCA patients, a high rate of restenosis at late follow-up canceled the beneficial effects of primary DCA.

Aged↗

Plaque rupture as a cause of apparent coronary aneurysm formation following directional coronary atherectomy.

Late coronary aneurysm formation was observed following treatment by directional coronary atherectomy. Intravascular ultrasound disclosed that the mechanism involved was plaque rupture. The cause of coronary aneurysm may be multifactorial after coronary interventions. Intravascular ultrasound imaging is useful for understanding the pathologic mechanism of coronary aneurysm production.

Aortic Dissection↗

Treatment of in-stent restenosis with high speed rotational atherectomy and IVUS guidance in small <3.0 mm vessels.

The management of in-stent restenosis remains a subject for debate because no one revascularization option is considered the most appropriate. Since a high restenosis rate still occurs after repeat balloon angioplasty, new techniques are attempted in order to reduce this rate. A combination of high speed rotational atherectomy (HSRA) and adjunctive balloon angioplasty is likely to achieve good results. In small (<3.0 mm diameter) vessels, the risk of interaction between the burr and the stent increases. We thus used intravascular ultrasound (IVUS) guidance in the treatment of in-stent restenosis with HSRA in small <3.0 mm small diameter vessels. Nine patients with in-stent restenosis in small vessels were referred for repeat angioplasty. Initial IVUS examination was used to assess the minimal stent struts diameter and to guide the burr size selection. A combination of HSRA and additional balloon angioplasty was performed under IVUS and angiographic guidance. Mean angiographic reference diameter was 2.25 +/- 0.35 mm and mean stent struts diameter was 2.38 +/- 0.20 mm. Burr size was selected approximately 0.5 mm smaller than stent struts diameter and ranged from 1.75 to 2.5 mm, with a 0.88 +/- 0.12 mean burr/artery ratio (range 0.71, 1.08). In two patients, a second larger burr was used. In 4/9 patients, the burr size chosen under IVUS guidance was close to angiographic MLD at stent implantation and thus larger than what would be used without IVUS guidance. Additional balloon angioplasty was decided in all cases, using a 1.1 +/- 0.15 balloon/artery ratio. No complication occurred. Mean relative gain in minimal lumen diameter (MLD) was 94 +/- 90% after HSRA and 54 +/- 34% after balloon angioplasty (total relative gain 180 +/- 100%). IVUS guidance allowed safe management of in-stent restenosis in small vessels using combination of HSRA and balloon angioplasty. Long-term follow-up and comparison with other techniques are necessary to assess whether this technique should be used routinely.

Adult↗

Comparison of quantitative coronary angiographic results after directional coronary atherectomy and balloon angioplasty of protected left main coronary stenosis.

We compared the angiographic and clinical outcomes after directional coronary atherectomy (DCA, 13 patients) with those after conventional balloon angioplasty (BA, 21 patients) in patients with protected left main coronary artery stenosis. The initial success rate was 100% in the DCA group and 81% (17 of 21) in the BA group. Restenosis was present in 2 of 11 patients in the DCA group and 9 of 16 patients in the BA group (18% vs. 56%, P < 0.05). DCA and BA improved a minimal lumen diameter. The initial gain after DCA was greater than that after BA. At follow-up, the minimal lumen diameter was larger and the percentage diameter stenosis was smaller in the DCA group than in the BA group. The late loss and loss index were equivalent in both groups. Compared with conventional BA, DCA in protected left main coronary artery stenosis is associated with a higher angiographic success rate and provides a wider luminal diameter with reduced incidence of restenosis.

Angioplasty, Balloon↗

Analysis of heat generation during rotational atherectomy using different operational techniques.

Rotational atherectomy can generate heat from the friction of the burr as it ablates atherosclerotic plaque. The objective of this study is to correlate Rotablator technique and heat generation using two experimental models. First, 2.0 mm burrs were advanced through a lesion model derived from bovine bone implanted with thermal probes. Intermittent ablation with minimal decelerations resulted in a smaller temperature increase than continuous ablation with maximal decelerations (2.6 +/- 1.3 vs. 13.9 +/- 1.0 degrees C, respectively, P < 0.01). The second model used porcine femoral arteries cradled in constricting polyethylene grafts with thermal probes in contact with the adventitia. As the burr advanced through the segment, RPM decreases of 5-7 k resulted in a temperature rise of 4.1 +/- 1.2 degrees C, whereas decelerations of 10-20 k resulted in a 11.3 +/- 6.2 degrees C temperature increase. We conclude that excessive drops in speed and aggressive advancement of the burr are related to significant increases in temperature and potential thermal injury.

Animals↗

Acute directional coronary atherectomy prior to stenting in complex coronary lesions: ADAPTS Study.

The purpose of this study was to determine the results of directional coronary atherectomy (DCA) combined with stenting in a high-risk patient population. The use of stenting or DCA alone for aorto-ostial lesions, total chronic occlusions, long lesions, and lesions containing thrombus is associated with lowered success and a relatively high restenosis rate. Between July 1993 and October 1996, we treated 89 lesions with the combined approach of DCA and stenting in 60 consecutive patients. Thirty-one (51.7%) patients were treated because of unstable angina, 11 (18.3%) for post-myocardial infarction (MI) angina, 3 (5.0%) for acute MI, and 15 (25.0%) patients for stable angina. A total of 43 (71.7%) patients had multivessel disease, 19 (31.7%) had undergone previous coronary artery bypass graft (CABG), and 17 (28.3%) patients had undergone multivessel revascularization. The procedure was successful in all patients; and no postprocedural deaths or emergent CABG occurred. Two patients (3.3%) had non-Q-wave MI after the procedure and 1 patient (1.7%) experienced Q-wave MI due to subacute stent closure 7 days after the procedure. During follow-up ranging from 6 months to 3 years, 2 (3.3%) patients died, 2 (3.3%) required CABG surgery, 1 (1.7%) patient had an MI, and 6 patients (10.0%) required target vessel revascularization. By the quantitative coronary angiography, the initial minimal luminal diameter (MLD) averaged 0.91+/-0.45 mm (74.7+/-11.8% stenosis) increasing to 3.80+/-0.44 mm (-6.7+/-12.1%) after the combined approach procedure. Thirty patients (50.0%) met criteria for late (> or =6 months) angiographic follow-up. Late MLD loss averaged 1.13+/-1.07 mm, for a mean net gain of 1.61+/-1.23 mm. Available angiographic follow-up evaluation showed a restenosis rate of 13.3%. A combined approach, defined as the use of both DCA and stenting, is safe and yields a low restenosis rate in high-risk patients who have lesions known to respond less favorably to stenting or DCA alone.

Aged↗