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Clinical and angiographic outcome of directional atherectomy followed by stent implantation in de novo lesions located at the ostium of the left anterior descending coronary artery.

BACKGROUND: Lesions located at the ostium of the left anterior descending coronary artery (LAD) are considered an ideal target for directional atherectomy (DCA), but few data are available about the value of using this strategy before stenting in comparison with stenting alone. OBJECTIVES: To investigate the immediate and mid term clinical and angiographic results of DCA followed by stent implantation for ostial LAD lesions. DESIGN: Retrospective comparison of the immediate and mid term angiographic and clinical results of a series of 117 consecutive patients with de novo lesions located at the ostium of the LAD. Of these, 46 underwent DCA before stenting and 71 were treated with stenting alone. RESULTS: Technical success in the two groups was similar at around 98%. DCA plus stenting provided a larger minimum lumen diameter at the end of the procedure than stenting alone (3.57 (0.59) mm v 3.33 (0.49) mm, p = 0.022). There were no differences for in-hospital major adverse events (MACE) (7.5% for atherectomy plus stenting, and 5.3% for stenting alone; p = 0.41). All patients had clinical follow up at a mean of 7.9 (2.7) months. Angiographic follow up was done in 89 patients (76%) at a mean of 5.9 (2.2) months. The atherectomy plus stenting group had a larger minimum lumen diameter than the stenting group (2.79 (0.64) mm v 2.26 (0.85) mm, p = 0.004) and a lower binary restenosis rate (13.8% v 33.3%, p = 0.031). Six month MACE were reduced in the atherectomy plus stenting group (8.7% v 23.9%, p = 0.048). CONCLUSIONS: Debulking before stenting in de novo lesions located at the ostium of the LAD is safe and is associated with a high rate of technical success. Follow up data show that DCA plus stenting results in a significantly larger minimum lumen diameter and a lower incidence of restenosis than stenting alone.

Angioplasty, Balloon, Coronary↗

Directional atherectomy facilitates the interventional procedure and leads to a low rate of recurrent stenosis in left anterior descending and left circumflex artery ostium stenoses: subgroup analysis of the FLEXI-CUT study.

OBJECTIVES: To examine by retrospective analysis of data from the FLEXI-CUT monocentre registry whether atherectomy can effectively simplify complex stent implantation in ostial bifurcation lesions by reducing the procedure to stenting of the left anterior descending (LAD) or left circumflex (LCX) artery ostium alone. PATIENTS AND METHODS: All patients who had been enrolled in the prospective FLEXI-CUT study (directional atherectomy with adjunctive balloon angioplasty) were retrospectively analysed on the basis of significant LAD or LCX ostial stenosis (>or= 70% stenosis) deriving from an undiseased left main stem. The primary combined end point was the rate of target lesion revascularisation (TLR) and binary restenosis; secondary end points were procedural success and major adverse cardiac events (MACE) at the six-month follow up. RESULTS: Of 30 patients enrolled with significant LAD or LCX ostium stenosis, 29 were effectively treated with directional atherectomy (96.7% procedural success). All patients underwent single-vessel stenting procedures of solely the LAD or LCX ostium. At follow up, binary stenosis was 25% (6 of 24), TLR (angiographic plus clinical) 10.3% (3 of 29) and total MACE 6.9% (2 of 29). CONCLUSIONS: Directional atherectomy with single-vessel stenting procedures facilitates the interventional treatment of LAD and LCX ostium stenosis, and leads to remarkably low TLR and binary stenosis at follow up.

Aged↗

Expression of tumour necrosis factor alpha and accumulation of fibronectin in coronary artery restenotic lesions retrieved by atherectomy.

BACKGROUND: The formation of coronary artery neointima experimentally induced in piglets after cardiac transplantation is related to an immune-inflammatory reaction associated with increased expression of T cells and inflammatory mediators (tumour necrosis factor alpha and interleukin 1 beta) and upregulation of fibronectin. In vivo blockade of tumour necrosis factor alpha in rabbits after cardiac transplantation results in reduced neointimal formation. The objective of this study was to investigate the hypothesis that coronary restenosis after atherectomy or percutaneous balloon angioplasty is associated with a similar inflammatory cascade initiated by mechanical injury. METHODS: Specimens taken at coronary atherectomy were analysed from 16 patients. Nine had had the procedure performed twice, firstly, to remove a primary lesion, and secondly, to remove a restenotic lesion. Seven had percutaneous balloon angioplasty after removal of restenotic tissue. Coronary atherectomy specimens were analysed by immunohistochemistry for the presence of T cells, macrophages, major histocompatibility complex II, interleukin 1 beta, tumour necrosis factor alpha, fibronectin, and the receptor for hyaluronan mediated motility. RESULTS: The groups were clinically and angiographically similar with equivalent lumens before and after atherectomy. Restenotic lesions had increased expression of tumour necrosis factor alpha and fibronectin compared with the primary lesions (P < 0.05 for both). There was also a trend towards a greater number of T cells and increased expression of interleukin 1 beta. CONCLUSIONS: Restenosis is associated with increased expression of tumour necrosis factor alpha and fibronectin, suggesting that an immune-inflammatory reaction probably contributes to neointimal formation and may represent a form of wound healing and repair secondary to mechanical injury.

Angioplasty, Balloon, Coronary↗

The importance of acute luminal diameter in determining restenosis after coronary atherectomy or stenting.

BACKGROUND: We evaluated native coronary arteries treated by directional coronary atherectomy or balloon-expandable stent placement in an effort to derive a quantitative geometric model relating the luminal diameter immediately after intervention to that present 6 months later. The minimal luminal diameter of each lesion was measured before and immediately after intervention in 102 single Palmaz-Schatz stents and 134 directional atherectomies, 192 (81%) of which had repeat angiographic measurement of minimal luminal diameter 6 months after the intervention. The immediate enlargement in luminal diameter produced by the intervention (acute gain) and the subsequent reduction in luminal diameter from the time of intervention to 6 months of follow-up (late loss) were calculated. METHODS AND RESULTS: Luminal diameter increased from 0.69 +/- 0.40 mm to 3.11 +/- 0.64 mm (acute gain, 2.41 +/- 0.64 mm) after intervention, providing an immediate postprocedure residual stenosis of 1 +/- 14% relative to a reference diameter of 3.13 +/- 0.65 mm. At 6-month follow-up, the late luminal diameter was 1.97 +/- 0.92 mm (late loss, 1.13 +/- 0.89 mm), yielding a late diameter stenosis of 36 +/- 26%. The restenosis rate (according to the traditional definition of diameter stenosis > or = 50%) was 30%. Multivariable analysis demonstrated that late luminal diameter (p = 0.02), late percent stenosis (p = 0.04), and restenosis (according to a > 50% definition, p = 0.04) were each strongly associated with the luminal diameter present immediately after the procedure. Whereas late luminal diameter was also influenced by reference artery size and the vessel treated (left anterior descending versus right coronary artery), reference vessel size was rejected by the multivariable models of late percent stenosis and binary restenosis after they were adjusted for the effect of postprocedure luminal diameter. Once adjusted for postprocedure luminal diameter, neither late luminal diameter nor late loss was found to be independently determined by which device was used (atherectomy versus stents). Rather, late loss was determined independently by the immediate postprocedure luminal diameter (p = 0.005) and the postprocedure percent stenosis (p = 0.02). Although late loss thus increased with acute gain, the net beneficial effect of increased acute gain was maintained: Late loss was only a fraction (0.47) of acute gain, so the ability of a larger postprocedure luminal diameter to reduce the probability of subsequent restenosis was preserved. CONCLUSIONS: This quantitative model demonstrates that the late coronary lumen diameter and the probability of restenosis after Palmaz-Schatz stenting or directional atherectomy are influenced strongly by the lumen diameter present immediately after the procedure rather than by the specific device used. Although the influence of a larger acute result on reduced restenosis appears to be well established in this treatment population, the interplay among the multiple other biological influences on restenosis limits the ability to predict the probability of restenosis for the individual patient based on a large acute result alone. Future studies of restenosis, however, can further refine this multivariable quantitative model by adjusting for the effects of other clinical variables, mechanical interventions, or drug therapies in addition to the clear effect of postprocedure luminal diameter.

Atherectomy, Coronary↗

Proliferation in primary and restenotic coronary atherectomy tissue. Implications for antiproliferative therapy.

On the basis of animal models of arterial injury, smooth muscle cell proliferation has been posited as a dominant event in restenosis. Unfortunately, little is known about this proliferation in the human restenotic lesion. The purpose of this study was to determine the extent and time course of proliferation in primary and restenotic coronary atherectomy-derived tissue. Primary (n = 118) and restenotic (n = 100) coronary atherectomy specimens were obtained from 211 nonconsecutive patients. Immunocytochemistry for the proliferating cell nuclear antigen (PCNA) was used to gauge proliferation in the atherectomy specimens. The identity of PCNA-positive cells was then determined using immunohistochemical cell-specific markers. Eighty-two percent of primary specimens and 74% of restenotic specimens had no evidence of PCNA labeling. The majority of the remaining specimens had only a modest number of PCNA-positive cells per slide (typically < 50 cells per slide). In the restenotic specimens, PCNA labeling was detected over a wide time interval after the initial procedure (eg, 1 to 390 days), with no obvious proliferative peak. Cell-specific immunohistochemical markers identified primary and restenotic PCNA-positive cells as smooth muscle cells, macrophages, and endothelial cells. In conclusion, the findings were as follows: (1) Proliferation in primary and restenotic coronary atherectomy specimens, as indicated by PCNA labeling, occurs infrequently and at low levels. (2) The response to injury in existing animal models of angioplasty may follow a very different course of events from the clinical reality in human atherosclerotic coronary arteries and may help explain why current approaches to restenosis therapy have been ineffective.

Adult↗

Intravascular ultrasound imaging of peripheral arteries as an adjunct to atherectomy: preliminary experience.

12 atherosclerotic lesions in nine patients, including four restenoses after balloon angioplasty, were treated by atherectomy under the guidance of intravascular ultrasound (US). Echogenicities of the plaques and morphological alterations in the arterial walls produced by atherectomy were evaluated. The two-layered appearance of post-angioplasty restenoses was found to be inner fibrous intimal thickening with proliferation of smooth muscle cells and outer residual collagen-rich plaque. The deep cut surfaces were shown as concave U-shaped defects. Medial tissues were present in all cases where intravascular US demonstrated the disruption of a thin hyperechoic layer of the internal elastic lamina. Intravascular US imaging may provide valuable information on the degree, eccentricity and histological type of stenosis, the presence of calcification before atherectomy, and on the extent of excision and the morphological changes in the arterial wall after atherectomy.

Aged↗

Acute outcome of directional coronary atherectomy vs standard balloon angioplasty in de novo left anterior descending stenoses.

To assess the immediate outcome of directional coronary atherectomy (DCA) versus standard balloon angioplasty (PTCA) in de novo left anterior descending coronary stenoses, 25 consecutive atherectomies (22 men, 3 women) performed at The Toronto Hospital, between July 1990 and March 1991 were compared with 25 (14 men, 11 women) temporally matched successful angioplasties. Coronary stenoses were analyzed by quantitative arteriography, using the Coronary Measurement System (Leiden, The Netherlands), with estimation of transstenotic hemodynamics by fluid dynamic equations. Before and after procedure qualitative blood flow (TIMI criteria) was also evaluated, as was intimal haziness and coronary dissection. In comparison to PTCA, coronary atherectomy produced less residual minimum stenotic diameter (DCA, 2.75 +/- 0.55 vs PTCA, 1.70 +/- 0.44 mm, p < 0.001), and relative percent diameter stenosis (DCA, 17.9 +/- 10.7 vs PTCA, 34.4 +/- 10.7 percent, p < 0.001), with less transstenotic obstructive gradient (DCA, 0.2 +/- 0.2 vs PTCA, 1.0 +/- 1.5 mm Hg, p < 0.05), and greater estimated stenotic flow reserve (DCA, 4.86 +/- 0.15 vs PTCA, 4.50 +/- 0.48 x baseline, p < 0.05). Coronary atherectomy "normalized" TIMI flow patterns in virtually all patients (DCA, 2.96 +/- 0.20 vs PTCA, 2.72 +/- 0.45, p < 0.05), while creating less intimal haziness (DCA, 10/25 [40 percent] vs PTCA, 23/25 [92 percent], p < 0.01), and coronary dissection (DCA, 6/25 [24 percent] vs PTCA, 16/25 [64 percent], p < 0.05). Therefore, when compared with standard balloon angioplasty, DCA produces less residual stenosis, better transstenotic hemodynamics, while decreasing the frequency of coronary artery damage, in de novo left anterior descending stenoses.

Adult↗

High speed rotational atherectomy for diffuse in-stent restenosis: short- and mid-term follow-up results.

Between January 1997 to May 1998, 37 consecutive patients underwent high speed rotational atherectomy with adjunctive balloon angioplasty for the management of first-time diffuse variety of in-stent restenosis in the native coronary arteries. Their age ranged from 38 to 71 years (mean 54.3 +/- 9.7 years). All the patients underwent initial stent implantation at moderate to high pressure. Patients were either symptomatic or demonstrated significant ischaemia by non-invasive testing. The median time from the index procedure to in-stent restenosis was 20 weeks (range 9-40 weeks). Majority (78.1%) of lesions were in the territory of left anterior descending coronary artery. The mean lesion length was 24.3 +/- 8.3 mm (range 12-42 mm). Five lesions each (12.2%) were total occlusion and ostial in location. High speed rotational atherectomy was performed using stepped burr technique in majority (90.2%) with the largest burr corresponding to approximately 70 percent of the reference vessel diameter. The initial burr size ranged from 1.5-2.0 mm, final burr was 1.75-2.25 mm and the average number of burrs used per target vessel was 2.2 +/- 0.3 (range 1-3). Adjunctive balloon angioplasty was performed in all (100%) cases using a semi-compliant oversized balloon (balloon-to-artery ratio 1.1:1) inflated at a pressure of 6.5 +/- 2.1 atmospheres (range 4-10). The procedure was successful in all cases without any major complications (death, Q-MI, CABG or repeat PTCA). Over a median follow-up of 10 months, 27 (73%) patients were asymptomatic. Recurrence of clinical events occurred in 10 (27%) patients at median interval of 16 weeks after rotational atherectomy. Angina was controlled on drug therapy in six (16.2%) and target vessel revascularisation was required in three (8.1%) cases. By the Kaplan-Meier estimate, an event-free survival (absence of death, Q-MI, recurrence of angina, target vessel revascularisation) was 97.3, 94.6, 75.7 and 72.6 percent at 1, 3, 6 and 12 months, respectively. Thus, rotational atherectomy using a stepped burr approach for adequate debulking, followed by adjunctive balloon angioplasty is safe with excellent in-hospital results for the treatment of diffuse in-stent restenosis. Although recurrence of symptoms develops in approximately one-fourth of patients on follow-up, it is much less than reported with balloon angioplasty in this subgroup of patients.

Adult↗

Directional coronary atherectomy: from therapeutic device to research tool in coronary artery disease.

Directional coronary atherectomy (DCA) was introduced as a new percutaneous revascularization modality in 1990, and was initially applied to large vessels without tortuosity or calcification, with overall results including a 95% procedural success, 94% clinical success and 4.6% major complications (urgent bypass surgery in 3.8%, Q wave myocardial infarction in 1.7%, and hospital mortality in 0.3% of patients). In addition to its established efficacy for eccentric lesions, newer applications emerged such as treatment of saphenous vein grafts, thrombus-associated lesions, aorto-ostial lesions, failed or suboptional coronary angioplasty results, bifurcation lesions and use as a part of multi-vessel intervention. Comparative studies with coronary angioplasty such as CAVEAT I and II and CCAT showed better success rates with DCA vs coronary angioplasty, but failed to demonstrate benefit in restenosis rates. OARS and BOAT studies helped define optimal atherectomy techniques, which led to better acute angiographic results and to the "debulking plus stenting" concept. A spin-off of those clinical applications has been the opportunity to study the histology of tissue excised by DCA in vivo in different clinical settings. Such studies, investigating plaque ulceration, thrombosis and inflammation are reviewed, with special emphasis on new insights into unstable angina; the future of atherectomy research is also outlined with a categorization of various possible protocols to be applied utilizing coronary atherectomy specimens from live patients.

Angioplasty, Balloon, Coronary↗

Effects of rotational atherectomy with a reduced burr-to-artery ratio on coronary no-reflow.

AIM: The use of rotational atherectomy in addition to standard percutaneous coronary interventional procedures, although it improves coronary blood flow dynamics by improving vessel geometry, is often associated with distal embolization and the no-reflow phenomenon. We sought to evaluate the safety and effectiveness of a burr size/reference artery diameter (RAD) ratio <0.7 in rotational atherectomy in order to reduce the distal embolization and then to analyze the procedural and peri-procedural no-reflow phenomenon. METHODS: Between March 1999 and May 2003, 50 consecutive patients with a chronic stable angina lasting more than 3 months underwent rotablator atherectomy, adjunctive stent im-plantation (primary coronary stenting, PCS) or plain old balloon angioplasty (POBA) in case of de novo lesions or in stent restenosis, respectively. We analyzed the target vessel myocardial blush grade and the troponin I, creatine kinase and CK-MB values at 1.6 and every 8 h during the first day and then daily until discharge. RESULTS: Procedural success was achieved in all 50 patients (mean age 55+/-11 years; 45 males, 5 females). Quantitative angiography revealed, in the group treated with PCS, an increase in minimal lumen diameter (MLD) from 0.88+/-0.39 mm at baseline to 1.4+/-0.63 mm after rotablator (p<0.01) to 2.85+/-0.9 mm after stent implantation (p<0.01). On the other hand, for the group treated with POBA, the MLD changed from 1.8+/-0.32 mm at baseline to 2.2+/-0.54 mm after rotablator (p=0.6) to 3.28+/-0.91 mm after adjunctive balloon angioplasty (p<0.01). No statistically significant changes have been observed between myocardial blush grade and enzymes between baseline and after the procedure. CONCLUSION: Rotablator atherectomy with a reduced burr size/RAD ratio is a safe and effective interventional procedure without any peri-procedural no-reflow phenomenon.

Adult↗

Intravascular ultrasound predictors of subacute vessel closure after balloon angioplasty or atherectomy.

BACKGROUND: Factors leading to subacute vessel closure after percutaneous coronary intervention (PCI) have not been well established in lesions treated with balloon angioplasty or atherectomy. METHODS AND RESULTS: We used intravascular ultrasound (IVUS) to determine the pre- and post-PCI characteristics involved in subacute vessel closure after PCI. Of 3,403 patients undergoing IVUS imaging during coronary balloon angioplasty or atherectomy, 8 patients (0.2%) developed angiographically documented subacute vessel closure within 1 week post-PCI and were compared to a group matched by procedure date (within 6 months), age, gender, stable or unstable angina, lesion location and treatment (balloon angioplasty or atherectomy). IVUS identified at least one cause for subacute vessel closure in 87% of patients (vs 25% in matched lesions, p < 0.01). Causes were all procedure-related and included inadequate final lumen (60%), dissection (50%) and thrombus (25%). Pre-procedure lesion characteristics were not different from matched lesions. CONCLUSIONS: Subacute vessel closure after balloon angioplasty or atherectomy is mostly related to insufficient post-procedure lumen dimension or dissection.

Aged↗

[Rationale for coronary recanalization using transluminal atherectomy].

Although balloon angioplasty represented a significant advance in the treatment of coronary artery disease, this procedure is limited by acute occlusion and late restenosis. Among the new devices proposed to overcome the limitations of balloon catheters, Simpson's atherocath has the unique property of removing the atherosclerotic plaques from the coronary wall. Size and stiffness of the terminal portion limit the use of the atherocath to the proximal, non tortuous portion of coronary vessels more than 2.5 mm in size. Studies comparing atherectomy with balloon angioplasty have demonstrated a greater acute luminal gain with atherectomy but have failed to prove a clinical advantage from this better initial results. Atherectomy however is a rapidly evolving technology: better devices and more aggressive dilating strategies could significantly modify the conclusions of the earlier studies. In the meantime atherectomy is providing a unique opportunity to study vascular wall pathology.

Angioplasty, Balloon, Coronary↗

Magnetic resonance angiographic imaging of angioplasty and atherectomy sites.

UNLABELLED: Magnetic resonance angiography (MRA) provides detailed morphologic and flow information that demonstrates complex changes at sites of percutaneous transluminal angioplasty (PTA) and atherectomy. The purpose of this study is to examine the appearance of the vessel by MRA in the initial post-procedural and early follow-up periods. METHODS: MRA was performed to evaluate 35 infrainguinal endovascular procedures (20 patients), including PTA (20), atherectomy (4), and combination PTA/atherectomy (11). MRA imaging was performed within 24 hours of the procedure and at a mean follow-up interval of 3.5 months (range 1-8). RESULTS: Abnormalities in the immediate post-procedural MRA were seen in 55% of the PTA group and 93% of the atherectomy group (p = 0.04). Importantly, three of 35 lesions (9%) were shown by MRA to harbor > 50% stenoses despite angiographically "successful" procedures. Follow-up MRA showed abnormalities in 25% of those undergoing PTA, and in 67% of those with atherectomy (p = 0.01). At the time of follow-up MRA, four areas showed > 50% stenosis and four areas showed occlusion, revealing unfavorable outcomes in 22%. CONCLUSIONS: MRA provides a detailed noninvasive image of the sites of endovascular interventions and reveals vessel wall abnormalities not appreciated by conventional arteriography. Continued observation may allow prediction of segments at increased risk for restenosis.

Aged↗

Early experience with directional coronary atherectomy: documentation of the learning curve.

OBJECTIVE: To evaluate evolving selection criteria and angiographic outcome ('learning curve') for directional coronary atherectomy. SETTING: Tertiary referral, university-based hospital. PATIENTS: Initial 50 subjects undergoing directional coronary atherectomy of de novo left anterior descending stenoses at The Toronto Hospital from July 1990 to April 1991. INTERVENTIONS: Directional coronary atherectomy according to standard interventional techniques, with pre- and post procedure qualitative evaluation and quantitative coronary arteriography (Cardiac Measurement System; Leiden, The Netherlands) to define angiographic outcome. RESULTS: Comparing 'early' (group 1) versus 'late' (group 2) subjects, baseline demographics and clinical parameters were similar. Later subjects demonstrated increased coronary tortuosity (group 1, 1.40 versus group 2, 1.64, P < 0.01) and major side branch involvement within the stenosis (group 1, seven of 25 [28%] versus group 2, 18 of 25 [72%], P < 0.01). Regardless of experience, post procedure residual minimum stenotic diameters were equal (group 1, 2.75 +/- 0.55 versus group 2, 2.49 +/- 0.42 mm) in progressively longer lesions (group 1, 11.4 +/- 4.9 versus group 2, 13.3 +/- 5.5 mm, P < 0.1), with increased symmetry (group 1, 0.60 +/- 0.28 versus group 2, 0.73 +/- 0.19, P < 0.05). Analysis of consecutive pentiles (10 subjects per group) indicated gradual increases in post procedure residual lumen during early experience (the first 30 subjects), with an abrupt deterioration in outcome (fourth pentile), secondary to qualitative changes in coronary anatomy, before a return to satisfactory residual minimum stenotic diameters (fifth pentile). CONCLUSIONS: This study defines a distinct 'learning curve' during the initial 30 patients undergoing directional coronary atherectomy, with subtle changes in case selection, predominantly reflected by qualitative indices (eg, tortuosity, dystrophic calcification), resulting in a transient deterioration in final outcomes (patient 31 to 40). Subsequently, optimal results were re-established after defining appropriate case selection criteria, in conjunction with progressive expertise.

Adult↗

[Directional coronary atherectomy in ostial lesions of the anterior descending coronary artery].

INTRODUCTION AND OBJECTIVES: Coronary stenoses at ostial level, when treated by balloon angioplasty, show a primary success rate much lower than those located in other parts of the coronary tree. Balloon dilation of lesions located at the left anterior descending ostium is associated with a high degree of restenosis, elastic recoil and the possibility of retrograde dissection to the left main coronary artery. Simpson atherectomy may be considered a percutaneous alternative in this particular location, since this technique produces fewer incidents of elastic recoil than balloon dilation. The purpose of the present study is to evaluate directional atherectomy in the treatment of patients with symptoms deriving from severe to stenosis at the origin of the left anterior descending artery. MATERIAL AND METHODS: From a total number of 302 patients treated by Simpson atherectomy, we have analyzed 45 with severe stenosis at the left anterior descending ostium (less than 3 mm from its origin). The mean age was 54 +/- 12 years. Eighty two percent of the patients were male. The clinical condition was stable in unstable in 34; eleven had had a previous myocardial infarction. Six had multivessel coronary disease, all of them underwent combined balloon angioplasty of other segments. The treated lesion was native in 41 patients and previously dilated by balloon (restenosis) in 4. Two patients needed balloon predilation with 2 and 2.5 mm to facilitate the pass of the atherocatheter. The size of the Simpson atherocatheter was mainly 7F (78%). The weight of the resected arteriosclerotic material was 11 +/- 7 mg. RESULTS: Primary success (residual stenosis < 40% without major complications) was obtained in 42 out of 45 patients (93%); 3 patients (7%) had major complications (1 death, 1 emergency surgery, and 1 non-Q wave myocardial infarction). A follow-up angiography study was available in 31 patients 7 +/- 8 months later. Restenosis was evidenced in 12 (39%). CONCLUSIONS: Simpson atherectomy for left anterior descending artery ostial lesions is an effective transluminal alternative in selected patients providing a high rate of primary success (93%) and an acceptable restenosis rate (39%).

Adult↗

Immunohistochemical characterization of immune cell composition and cytokine receptor expression in human coronary atherectomy tissue.

BACKGROUND: Prior histologic studies have examined smooth muscle cell, macrophage and thrombus constituents of atherosclerotic coronary atherectomy specimens. Lymphocytes and mononuclear leukocytes are also detectable in atherosclerotic surgical pathology specimens utilizing immunocytochemical techniques. METHODS: In order to quantify the histological contribution of cytokine receptor-expressing immunocompetent cells to human coronary artery stenoses, 30 directional atherectomy catheter biopsy specimens (wet weight < or = 10 mg) from 16 patients were snap frozen (-70 degrees C) for quantitative immunocytochemical studies. Following computer-assisted quantification of total intimal nuclei per tissue section (mean 297 +/- 177; cell density 7 +/- 5/10(4) microns 2), monoclonal antibody cytochemistry was used to identify the percentage of these cells expressing antigenic clusters of differentiation (CD) characteristic of T-lymphocytes, B-lymphocytes and monocytes. Identification of alpha (low affinity) and beta (intermediate affinity) interleukin-2 receptors on intimal cells was accomplished using a three-step streptavidin-biotin method. RESULTS: A significant percentage of intimal cells were of lymphocytic (11 +/- 13%) or monocytic (12 +/- 14%) origin, with helper T-cells (9 +/- 12%) outnumbering both suppressor T-cells (2 +/- 4%) and B-lymphocytes (1 +/- 2%). Interleukin-2 receptors were noted on 9 +/- 12% of intimal cells, including cells with a vascular smooth muscle phenotype. CONCLUSIONS: These quantitative immunocytochemical data conclusively demonstrate that lymphocytes and monocytes account for over 20% of coronary plaque cells obtained by in-vivo atherectomy, and that helper (CD4) T-cells predominate over suppressor (CD8) T-cells and B-lymphocytes. Variable interleukin-2 receptor subtype expression occurs in mononuclear leukocytes infiltrating chronic human atheroma. By applying these techniques, the therapeutic effects of cytotoxic agents on selectively targeted cytokine receptor-expressing cells may now be evaluated in vivo in small human directional coronary atherectomy specimens.

Adult↗

Coronary physiology of percutaneous rotational atherectomy.

Integration of coronary blood flow velocity measurements into interventional procedures has enhanced our understanding of coronary flow dynamics. The coronary physiology of rotational atherectomy, with and without adjunctive coronary angioplasty, has not been well-defined. This review describes the coronary physiology induced by rotational atherectomy. Serial coronary blood flow and translesional hemodynamics, measured following rotational atherectomy and again after adjunctive balloon angioplasty, indicate that coronary blood flow and flow reserve may not be normalized despite significant angiographic improvements after rotational atherectomy alone and after adjunctive balloon angioplasty.

Aged↗

[Directional coronary atherectomy in coronary dissection?].

Significant local dissection at the site of angioplasty remains the most common cause of complications at balloon dilatation. In the past, the only solution was to transfer the patient for emergency coronary artery bypass grafting. Recent improvements in equipment and increasing experience mean that alternative instrumental methods are now available to manage dissection; in particular, by directional atherectomy and stent implantation, thus possibly avoiding surgery. In this article, the use of atherectomy as management for acute local dissection will be discussed, with special reference to the potential difficulties which may be encountered. Data showing that excellent immediate results and good long-term success can be achieved with atherectomy for acute dissection using careful selection criteria will be presented, indicating that atherectomy is a valid alternative instrumental treatment for the management of such dissection.

Aortic Dissection↗