Assessment of the results of percutaneous transluminal coronary angioplasty using an integrated ultrasound imaging-angioplasty Catheter

To evaluate the results percutaneous transluminal coronary angioplasty (PTCA), intra-vascular ultrasound imaging was performed in 32 proximal coronary arterial segments and in 16 atherosclerotic lesions after PTCA in 13 patients using a 5 Fr balloon catheter with an ultrasound transducer mounted just proximal to the balloon. Simultaneous angiographic measurements of vessel diameter were also performed using electronic calipers from contrast cine angiograms. There was good correlation between ultrasound and angiographic minimum luminal diameters of the normal proximal vessel (y = 0.59x + 1.49, r = 0.70, P<0.01, n = 32). However, the luminal diameter measured by intravascular ultrasound was significantly greater than when measured by contrast angiography (2.81±0.10 vs. 2.34±0.12mm, n = 16, P<0.001, mean ±SEM). Post-PTCA, there was good correlation between ultrasound and angiographic minimum luminal diameters of the lesion (y = 0.62x + 1.42, r=0.76, P<0.001, n = 16), but again luminal diameters were significantly greater when measured by intravascular ultrasound compared to contrast angiography (2.61±0.08 vs. 1.89 ± 0.10mm, n = 16, P<0.001). Furthermore, residual stenosis was significantly less when determined by intravascular ultrasound than by contrast angiography (7.3±2.0 vs. 18.1 ± 2.1%, n = 16, P<0.001). Intravascular ultrasound was able to detect coronary calcification that was not evident by contrast coronary angiography in 8 of 16 lesions. Post-PTCA, dissection was evident in four lesions by ultrasound, whereas dissection was appreciated in only three lesions by contrast angiography. We conclude that intravascular ultrasound can accurately measure the luminal diameter of coronary arteries both before and after PTCA and reveals more information about the lesion characteristics than does conventional contrast angiography.     

经皮桡动脉冠状动脉造影及冠状动脉成形术的临床应用

目的 :评价经皮桡动脉冠状动脉造影术与冠状动脉腔内成形术 (PTCA)的临床应用价值。方法 :有选择性的对 37例患者行经皮桡动脉途径冠状动脉造影及冠状动脉成形术 ,观察其疗效和血管并发症。结果 :1 桡动脉穿刺成功率为 93 8% (有 2例失败 )。 2 14例冠状动脉造影正常 ,17例冠状动脉造影显示 2 6处存在≥ 70 %的狭窄病变 ,适合行冠状动脉介入手术。 2 6处病变有 4处PTCA疗效满意 ,2 2处行PTCA +支架术 ,植入支架 31只。狭窄从 (81± 12 ) %降低至 (10 6± 7 4 ) % ,最小血管直径由 (0 86± 0 12 )mm增加至 (3 0 8± 0 32 )mm。 6例病人行冠状动脉旁路移植术。 3 所有患者术后即拔导管鞘 ,局部压迫 4h。术后并发症的发生率为 3 3% (1例术后的桡动脉闭塞 )。结论 :经桡动脉途径行冠状动脉造影及冠状动脉成形术安全可行 ,其具有穿刺部位出血少、住院时间短的特点 ,可选择性的应用于某些冠心病患者。     

Rotational atherectomy for in-stent restenosis: acute and long-term results of the first 100 cases

Objectives. This study evaluated the clinical safety and long-term results of rotational atherectomy (RA) followed by low-pressure balloon dilatation (percutaneous transluminal coronary angioplasty [PTCA]) for the treatment of in-stent restenosis (ISR).Background. In-stent restenosis is associated with a high incidence of recurrence after interventional treatment. Because ISR is due to neointimal hyperplasia, rotational ablation may be a more effective treatment than PTCA.Methods. Between November 1995 and November 1996, 100 consecutive patients with first-time ISR were treated by RA. Quantitative coronary angiography and intravascular ultrasound (IVUS) were used to analyze the acute procedural results. The incidence of repeat in-stent restenosis and target vessel revascularization (TVR) at follow-up was determined.Results. Procedural success without any major in-hospital complications was achieved in 100% of cases. Slow flow was observed in 3% and creatine kinase-MB enzyme elevation >3× normal occurred in 2%. The mean burr-to-artery ratio was 0.68 ± 0.18 and adjuvant balloon dilatation was performed at 4.2 ± 2.1 atm. Minimum luminal diameter increased from 0.86 ± 0.28 mm to 1.89 ± 0.21 mm after RA and to 2.56 ± 0.29 mm after adjunct PTCA. Quantitative IVUS analysis showed that 77% of the luminal gain occurred due to rotational ablation of the restenotic tissue and only 23% occurred after adjunct balloon dilation, and further stent expansion did not contribute to the luminal enlargement. At a mean follow-up of 13 ± 5 months, repeat in-stent restenosis occurred in 28% of patients with TVR of 26%. Univariate predictors of repeat restenosis were burr-to-artery ratio <0.6, ISR in <90 days of stenting, ostial lesion, stent for a restenotic lesion and diffuse type ISR.Conclusions. Rotational atherectomy is a safe and feasible technique for treatment of ISR and is associated with a relatively low recurrent restenosis in comparison to historical controls of balloon angioplasty.     

Efficacy and safety of using perfusion dilatation catheter as initial balloon in coronary angioplasty

The efficacy and safety in using a new low-profile perfusion balloon catheter (PBC) as the initial balloon in percutaneous coronary angioplasty (PTCA) was assessed retrospectively in 61 patients: 43 males, mean age 62 ± 12 years. Thirty-three patients (54%) had unstable angina. PTCA was performed using an improved PBC in the following vessels: LAD 40%; CX 21%; RCA 24%. Lesion morphology was: Type A 21%; Type B1 18%; Type B2 40%; Type C 21%. Mean artery size was 3.01 ± 0.53 mm. Mean PBC size was 3.14 ± 0.45 mm. The mean number of inflations used was 2.85 ± 2.0. The mean longest inflation was 415 ± 213 sec and the total inflation time was 663 ± 342 sec to a mean maximum pressure atmosphere of 7.85 ± 2.0 bars. The number of balloons used per procedure was 1.2 ± 0.44. In 50 patients (82%) only one balloon was used during the PTCA. PTCA was successful (<50% diameter stenosis without major complications) in 60 patients (98.4%). Mean diameter stenosis at baseline was 82 ± 9.5% and post-angioplasty 13 ± 10.6%. A mild intimal tear occurred in 6 patients (9.8%). A stent was implanted in 3 patients (4.9%) due to severe dissection. In hospital reocclusion occurred in one patient (1.6%). There were no deaths or emergency bypass surgery. A low profile PBC is safe and effective as an initial balloon in PTCA. It may reduce the number of balloons used and inflations per procedure. © 1994 Wiley-Liss,Inc     

Initial experiences with a miniaturized pressure transducer during coronary angioplasty

A newly constructed pressure sensor with a diameter of 0.45 mm was evaluated in 15 patients undergoing balloon coronary angioplasty (PTCA). The sensor and an optic fiber were mounted on a 0.018″ guide wire, which was used in the balloon catheter. Pressure gradients were recorded before and after PTCA, respectively. The pressure tracings were of satisfactory quality in all cases. The mean systolic and diastolic gradients before PTCA were 32 ± 20mm Hg and 44 ± 26mm Hg, respectively. Pressure gradients were also obtained with the balloon placed in the lesion in order to simulate the conventional way of pressure measurement through the balloon catheter. In this setting, the systolic and diastolic gradients were 77 ± 32mm Hg and 59 ± 25mm Hg, respectively. Following balloon dilatation, the systolic pressure gradient decreased to 14 ± 12mm Hg, and the diastolic gradient to 13 ± 11 mm Hg. In conclusion, this new pressure sensor delivers recordings of good quality and may be especially of interest during angioplasty due to its small diameter.     

Coronary angioplasty of bifurcational stenoses: a new approach utilizing a single-guide, double-probe technique: case reports

The authors describe a new approach to percutaneous transluminal coronary angioplasty (PTCA) of bifurcational lesions with a single-guide, "kissing balloon" technique, utilizing two probe dilatation systems, inserted simultaneously into the guiding catheter and across both diseased branches. The versatility of the probe dilatation system in complex angioplasty is portrayed, both for simultaneous or alternate balloon inflations, and the low-profile characteristics of the system are highlighted, which allow a double-probe introduction into a single guiding catheter, good visualization still being retained by guide injections.     

Angioplasty of coronary bifurcation stenoses: Immediate and long-term results of the protecting branch technique

Percutaneous transluminal angioplasty (PTCA) of coronary stenoses involving major bifurcations carries a small but significant risk of side branch occlusion which can be avoided by simultaneously using multiple dilatation systems. Among 1,275 PTCA procedures performed between 1984 and 1988 in 1,035 consecutive patients, 42 double wire procedures were applied (4%) to protect and/or dilate major coronary side branches. A total of 80 coronary stenoses were attempted of which 76 were located on a bifurcation and 4 on other segments. In the first 11 patients (group A), 2 guiding catheters were used and PTCA of each vessel was successfully performed by means of separate double lumen over-the-wire balloon catheters. In the next 31 patients (group B), 2 guidewires were advanced through a single guiding catheter and PTCA was attempted using “Monorail” balloon catheters sequentially advanced over the wires. In group B, a successful PTCA was obtained in 29 patients (93%) but twisting of the wires hampered balloon progression in 5 cases, such that dilatation could only be performed by stepping back to a single wire technique. The procedure time in group B was significantly shorter than in group A: 144 ± 30 versus 230 ± 52 minutes (p = .01). Repeat angiography was performed in 35 out of 40 patients (87%) after a mean of 180 ± 46 days following successful PTCA. Angiographic restenosis was present in 37% (24/65) of bifurcation segments which, in our experience, is not significantly different from the angiographic restenosis rate in less complex lesions (248/740; 34%; NS). It is concluded that 1) the need for using a protecting branch technique in PTCA practice is uncommon (4%); 2) among other approaches, the use of a “Monorail” system allows successful dilatation in 93% of cases with a shortened procedure time; 3) the restenosis rate at repeat angiography is similar to that of non-bifurcated lesions.     

血管内超声的冠状动脉腔内成形术的机制研究

目的应用血管内超声的方法研究病人经皮冠状动脉(冠脉)腔内成形术(PTCA)前后冠脉内的粥样斑块和血管壁的变化,进一步明确PTCA的机制。方法择期行PTCA的病人50例,共68支血管于球囊扩张前后行冠脉内超声(ICUS)检查。记录病变部位粥样斑块的特性,最小管腔面积,弹力内膜面积和斑块面积。结果PTCA球囊扩张前后病变部位的内弹力膜面积(IELA)分别为(6.67±1.45)mm2和(8.14±1.13)mm2,术后有明显的扩大(P＜0.05)。脂质斑块,纤维斑块,钙化斑块,混合斑块各组PTCA手术前后IELA之差(ΔIELA)分别为1.84,1.52,0.40,1.23mm2,钙化斑块球囊扩张前后内弹力膜面积无明显扩大,P＜0.05。斑块的撕裂程度及管壁变化根据Honye分类法记录A型10例,B型20例,C型16例,D型12例,E1型5例,E2型5例。68个病变中有58个（85%）病变出现不同程度的斑块撕裂。12个D型撕裂中有11个是钙化的斑块,1个是混合斑块。结论粥样斑块的撕裂和管壁的牵伸在冠脉球囊扩张术的管腔增大方面同时起关键作用,较硬的斑块如钙化的斑块球囊扩张时易出现大的夹层,而血管牵伸的程度较差,用旋磨或旋切的方法处理可能会得到更好的结果。     

Excimer Laser Angioplasty with Adjunctive Balloon Dilatation Versus Balloon Dilatation Alone for the Treatment of In-Stent Restenosis: Results of a Randomized Single-Center Study

Background: Laser ablation of neointimal tissue prior to balloon dilatation has been shown to be a potential treatment modality for restenosis within previously implanted stents. It remains controversial whether this treatment provides superior acute and long-term results compared to conventional balloon dilatation. Methods and Results: Between November 1995 and November 1996, 96 patients with significant (≥ 50%) in-stent restenosis were randomized to receive excimer laser angioplasty with adjunctive balloon dilatation (ELCA + PTC A, n = 47) or PTCA alone (n = 49). Both groups did not differ with regard to gender, clinical history, location of the lesion, reference diameter, or lesion length. Angiographic success was achieved in 46 patients with ELCA + PTCA (98%) and in 48 patients with PTCA alone (98%). In-hospital complications included acute closure in one patient of each group, one CABG, one repeat PTCA, and one non-Q wave MI with ELCA + PTCA, versus two bleeding and one death with PTCA. Clinical follow-up was obtained in all patients, while angiographic follow-up was available in 35 of 47 (ELCA+PTCA) versus 35 of 49 (PTCA) patients with a mean follow-up time of 163 ± 81 days. With ELCA+PTCA, MLD increased from 0.82 ± 0.38 to 1.99 ± 0.33 mm versus 0.81 ± 0.39 mm to 2.07 ± 0.60 mm with PTCA (P = NS). At follow-up, MLD was 1.32 ± 0.60 mm with ELCA + PTCA versus 1.45 ± 0.75 mm with PTCA (P = NS). Late adverse events included nine repeat PTCA with ELCA +PTCA (19%) versus 12 with PTCA (24%), three CABG with ELCA +PTCA (6%) versus two with PTCA (4%), and one death (2%) with PTCA (P = NS). Angiographic restenosis rate was 52% with ELCA + PTCA versus 47% with PTCA alone (P = NS). Conclusion: Our data suggest that excimer laser angioplasty with adjunctive balloon dilatation for the treatment of in-stent restenosis provides similar acute results as plain balloon dilatation and may offer no advantage over PTCA alone with regard to intermediate-term outcomes.     

The Falconª Eccentric Coronary Balloon Angioplasty Catheter: A Randomized Safety and Efficacy Study

Percutaneous coronary angioplasty (PTCA) is usually performed using concentric shaped balloon catheters with the guidewire passing through the center of the shaft. The Falcona balloon catheter features a guide wire lumen on the outside of the balloon so that an eccentric balloon catheter profile is obtained concentrating the dilating force on the wire supported side, allowing lower inflation pressures and potentially causing less vessel injury. The aim of this study was to evaluate the safety and efficacy of this new balloon catheter in patients with stable and unstable angina. In 95 prospectively randomized patients, 57 lesions were dilated with a concentric balloon and 51 with the eccentric balloon. Technical success in the two groups was similar (73.3% vs. 74.5% control vs. Falcon respectively). Procedural success was 96.5% vs. 96.1% in the control and Falcon groups respectively. The mean increase in minimum luminal diameter (MLD) was 1.01 +/- 0.41 mm in the control vs 0.85 +/- 0.45 mm in Falcon (p = 0.053). There was an increase in type A dissections in the Falcon group 18 (36.75%) vs. 10 (19.23%) in the control group (p = 0.07) with no difference in stent implantation, myocardial infarction, CABG or death between the two groups. All patients with a technically successful PTCA were followed up. Seventeen (43.6%) in the control and 11 (32.4%) in the Falcon had repeat coronary angiography (p = 0.38), 12 (30.8%) vs. 7 (20.6%) had repeat PTCA (p = 0.37) and time to PTCA was 116 +/- 70 days vs. 154 +/- 103 days respectively (p = 0.36). The Falcon performed technically as well as the concentric balloons. Despite a smaller MLD and increase in Type A dissections there was no associated increase in complications or reintervention for restenosis. Further investigation is required to evaluate the role of this mechanism of dilatation in restenosis.     

Excimer laser angioplasty vs. balloon angioplasty in saphenous vein bypass grafts: Quantitative angiographic comparison of matched lesions

Technologies which ablate or debulk tissue may result in better angiographic outcomes by altering the elastic properties of the vessel wall. Accordingly, the procedural outcomes of 88 vein graft lesions treated by either excimer laser angioplasty with adjunct balloon angioplasty (PELCA + PTCA, n = 44) (Spectranetics CVX-300, 1.4-, 1.7-, or 2.0-mm catheters) or balloon angioplasty alone (PTCA, n = 44) were analyzed by quantitative angiography (Cardiac Measurement System). Lesions were individually matched for vessel position, reference diameter (RD), and minimal luminal diameter (MLD). Matching was deemed adequate as the preprocedure MLD (PELCA + PTCA, 1.14 ± 0.48 mm; PTCA, 1.20 ± 0.47 mm) and RD (PELCA + PTCA, 3.23 ± 0.56 mm; PTCA, 3.25 ± 0.57 mm) were not significantly different. There were also no significant differences between PELCA + PTCA- and PTCA-treated lesions with respect to patient age, graft age, lesion length, symmetry, and plaque area. Balloon diameter at maximal inflation was 2.77 ± 0.55 mm (PELCA + PTCA group) and 2.84 ± 0.59 mm (PTCA group), P = NS. Final MLD postprocedure was 2.17 ± 0.54 mm and 2.19 ± 0.55 mm for PELCA + PTCA- and PTCA-treated lesions (P = NS), respectively. Vessel stretch [(balloon diameter − MLD pre)/RD], elastic recoil [(balloon diameter − MLD post)/RD], and acute gain [(MLD post − MLD pre)/RD] were calculated and normalized for vessel size (RD). Vessel stretch (PELCA + PTCA, 0.60 ± 0.22; PTCA, 0.59 ± 0.24; P = NS), elastic recoil (PELCA + PTCA, 0.28 ± 0.18; PTCA, 0.26 ± 0.16), and acute gain (PELCA + PTCA, 0.34 ± 0.24; PTCA, 0.31 ± 0.23; P = NS) were not significantly different between the two treatment groups. In a matched population of successfully treated vein graft lesions, PELCA + PTCA did not reduce elastic recoil or improve immediate angiographic outcome, as compared with PTCA alone. © 1996 Wiley-Liss, Inc.     

Exaggerated luminal loss a few minutes after successful percutaneous transluminal coronary angioplasty in patients with recent myocardial infarction compared with stable angina: An intracoronary ultrasound study

This study investigates the mechanisms of exaggerated acute luminal loss after successful coronary angioplasty in patients with recent myocardial infarction compared with stable angina by angiography and intracoronary ultrasound (ICUS). We studied 15 consecutive patients (group 1) who, after a successful thrombolysis for myocardial infarction, underwent delayed (8 ± 2 days after the myocardial infarction) successful balloon coronary angioplasty. Group 1 patients were individually matched with 15 stable angina patients (group 2). The percentage of stenosis and acute luminal loss were measured by quantitative coronary analysis. The ultrasound characteristics of lumen pathology were described as soft, hard, calcified, eccentric, concentric, thrombotic, and dissection lesions. Matching by stenosis location, reference diameter, sex, and age resulted in 2 comparable groups of 15 lesions with identical baseline characteristics. Immediately after percutaneous transluminal coronary angioplasty (PTCA), the minimal luminal diameter increased from 0.5 ± 0.3 mm to 2.4 ± 0.3 mm and from 0.5 ± 0.2 mm to 2.4 ± 0.3 mm in groups 1 and 2, respectively. Similar balloon sizes were used in both groups. The acute luminal loss (the difference between the maximal dilated balloon diameter and the minimal luminal diameter) immediately after PTCA was 0.4 ± 0.2 mm and 0.3 ± 0.3 mm (14 ± 8% and 10 ± 11% of balloon size) (P = not significant [NS]) in groups 1 and 2, respectively. After ICUS (mean 24 min after the last balloon deflation), the acute luminal loss was 0.9 ± 0.3 mm and 0.5 ± 0.4 mm (29 ± 11% and 17 ± 8% of balloon size) (P = 0.01) in groups 1 and 2, respectively. There was a significantly higher prevalence of intracoronary thrombus formation as detected by ICUS in group 1 compared with group 2 (80% vs. 20%; P < 0.001). In matched groups of successfully treated coronary angioplasty, patients with recent myocardial infarction had a similar magnitude of acute gained luminal loss immediately after the procedure. However, an exaggerated luminal loss a few minutes after the last balloon deflation in patients with recent myocardial infarction was noted because of mural thrombus formation compared with patients with stable angina. Cathet. Cardiovasc. Diagn. 41:32–39, 1997. © 1997 Wiley-Liss, Inc.     

Probe “balloon on a wire” ultra-low-profile coronary catheter: Results of ptca in 107 patients

A new low-profile “balloon-on-a-wire” angioplasty catheter, the Probe? (USCI), was used in 107 patients over a 4-month period. Twenty-nine patients had stable angina, 59 had unstable angina, and 19 had had myocardial infarction (Ml) 3 to 15 days prior to the procedure; 71 patients had single-vessel and 36 had multi-vessel disease. In this series, 57 lesions were defined as complex. Successful dilatation was defined as a residual stenosis of <30%. Of 132 non-total obstructions, 127 (97%) were successfully dilated. Two distal lesions could not be reached, two lesions could not be crossed by the balloon, and a distal lesion dilatation resulted in acute closure in one case. Of 19 total obstructions, 16 (84%) were successfully dilated (mean residual stenosis 23%). The wire tip was unable to cross the lesion in the three unsuccessful procedures. Seven complications occurred in the series, all involving non-total obstructions: closure of a distal vessel and a side branch caused no clinical symptoms or EKG changes; three local dissections were tacked back with repeat dilatation; and two longitudinal dissections caused no apparent reduction in luminal diameter. The Probe's low-profile and exceptional trackability enabled it to cross very tight lesions with minimal trauma to the vessel wall. The high degree of conformability of the PET balloon minimizes vessel straightening or sheer forces and appears to reduce the potential for dissection. The device may therefore extend the indications and ease of PTCA while reducing complications of the procedure.     

Initial clinical experience with the new EBI (BARD-XT) flexible coronary stent: Acute results and follow-up

The EBI (BARD-XT, C.R. Bard, Murray Hill, NJ) stent is a new radiopaque balloon expandable coronary stent with high resistance to external radial forces. It does not shorten significantly with expansion and allows stent implantation in bifurcation lesions. A total of 28 EBI stents were implanted in 23 lesions in 21 patients. Indications for stent implantation were acute closure in 1, threatened closure in 15, and electively in 7 lesions. In 2 cases, the lesion involved a bifurcation where a stent was implanted in both vessels. All patients received aspirin and ticlopidine. No anticoagulant therapy was given. The stenting procedure was successful in 22 of 23 lesions. No complications occurred with the exception of 1 patient with a thrombotic reocclusion within 1 hr after stent implantation and 1 patient with a temporary occlusion of a side branch. The mean minimal luminal diameter (MLD) increased from 0.74 ± 0.46 mm before balloon dilatation to 1.27 ± 0.62 mm before stent implantation and 2.32 ± 0.57 mm after stent implantation. Percent stenosis decreased from 71 ± 19% before angioplasty to 46 ± 25% after angioplasty to 5 ± 8% after stent implantation. MLD at the time of follow-up angiography after 4 months was 1.98 ± 0.77 mm and percent stenosis was 26 ± 21%. Restenosis of more than 50% occurred in 2 lesions. In these lesions, a second percutaneous transluminal coronary angioplasty was performed. Advantages of this stent are its flexibility together with an acceptable radial strength as well as enabling radiopacity without obscuring the arterial lumen. Stenting of bifurcation lesions is possible. Cathet. Cardiovasc. Diagn. 43:159–162, 1998. © 1998 Wiley-Liss, Inc.     

Rotational coronary atherectomy with adjunctive balloon angioplasty for the treatment of ostial lesions

Conventional balloon angioplasty (PTCA) of ostial lesions (OL) is associated with suboptimal results and a higher complication rate. Partial plaque ablation with rotational atherectomy (RA) before PTCA might improve results. This approach was used in 63 patients (pts) (mean age 64±10 yrs; 44 men, 19 women) with 69 OL. There were 15 aorto-OL and 54 branch-OL. Calcification was more frequent in aorto-OL than in branch-OL (67% vs. 35%, P< 0.05). Mean burr size was 1.8±0.3 mm. Burr-artery ratio was 0.74±0.10. Adjunctive PTCA was systematically performed. Procedural success was achieved in 58 pts (92%): 14 aorto-OL (93%) and 50 branch-OL (93%) were successfully treated; major complications occurred in 1 (7%) aorto-OL and 1 (2%) branch-OL. Uncomplicated failure occurred in three cases. Minimal lumen diameter (MLD) increased from 0.69±0.31 mm before RA to 1.43±0.28 mm after RA (P<0.001) and 2.16±0.29 mm after PTCA (P<0.001). Diameter stenosis (DS) decreased from 75±13% before RA to 32±12% after RA (P<0.001) and 14±10% after PTCA (P<0.001). All successfully treated pts underwent repeat angiography 24 h later and exercise testing or repeat cardiac catheterization >6 mo later. At 24 h repeat angiography, DS was 17±15% (P=NS vs. after PTCA); no lesion had a DS ≥ 50%. Follow-up coronary angiography was performed in 30 pts (52%) who had abnormal stress testing: 13 pts (43%) showed angiographic restenosis in at least one successfully treated OL. In conclusion, RA with adjunctive PTCA is a safe and effective treatment of OL. It is associated with higher success and lower major complications rates when compared with conventional PTCA. Restenosis remains a major limitation of all percutaneous approaches. © Wiley-Liss, Inc.     

Primary angiographic success rates of percutaneous transluminal coronary angioplasty

Three distinct periods in catheter design have been identified since the advent of percutaneous transluminal coronary angioplasty (PTCA) in 1977. In the first period PTCA was performed using a double-lumen balloon catheter that had a fixed, flexible guidewire at the tip. In the second period, an independent, steerable guidewire and the steerable catheter system were used. In the third period, low-profile catheters were introduced. A total of 2,969 patients who had single-vessel PTCA of a native coronary artery was separated into groups according to the period during which PTCA was performed. Introduction of the steerable catheter system was accompanied by improvement in primary success rate in PTCA attempts on the right coronary artery (78% vs 88%, p less than 0.005). Introduction of the low-profile catheter was accompanied by improved primary success in PTCA attempts on the left anterior descending coronary artery (LAD) (90% vs 94%, p less than 0.005). The percentage of PTCA attempts on the LAD decreased over the 3 periods (70% to 60% to 56%), while the percentage of attempts on the left circumflex artery increased (7% to 12% to 16%). Before steerable and low-profile catheters were used, there were significant differences in ability to reach and cross stenoses among the 3 major coronary arteries. These differences no longer exist. These results indicate that technical improvements and operator experience have made stenoses in all 3 major coronary arteries equally accessible to dilatation catheters and that primary success rates and reasons for failure in these arteries are now similar.     

Probe "balloon on a wire" ultra-low-profile coronary catheter: results of PTCA in 107 patients

A new low-profile "balloon-on-a-wire" angioplasty catheter, the Probe (USCI), was used in 107 patients over a 4-month period. Twenty-nine patients had stable angina, 59 had unstable angina, and 19 had had myocardial infarction (MI) 3 to 15 days prior to the procedure; 71 patients had single-vessel and 36 had multi-vessel disease. In this series, 57 lesions were defined as complex. Successful dilatation was defined as a residual stenosis of less than 30%. Of 132 non-total obstructions, 127 (97%) were successfully dilated. Two distal lesions could not be reached, two lesions could not be crossed by the balloon, and a distal lesion dilatation resulted in acute closure in one case. Of 19 total obstructions, 16 (84%) were successfully dilated (mean residual stenosis 23%). The wire tip was unable to cross the lesion in the three unsuccessful procedures. Seven complications occurred in the series, all involving non-total obstructions: closure of a distal vessel and a side branch caused no clinical symptoms or EKG changes; three local dissections were tacked back with repeat dilatation; and two longitudinal dissections caused no apparent reduction in luminal diameter. The Probe's low-profile and exceptional trackability enabled it to cross very tight lesions with minimal trauma to the vessel wall. The high degree of conformability of the PET balloon minimizes vessel straightening or sheer forces and appears to reduce the potential for dissection. The device may therefore extend the indications and ease of PTCA while reducing complications of the procedure.     

Intravascular ultrasound imaging after excimer laser angioplasty

To help elucidate the mechanism of excimer laser coronary angioplasty (ELCA), intra-vascular ultrasound (IVUS) imaging was performed in 19 of 29 patients who were treated with ELCA. The results were compared with a non-randomized control group of 18 patients who had IVUS studies both before and after PTCA alone. After ELCA alone, lumen diameter (1.9 × 1.7 mm) and lumen cross-sectional area (CSA) (2.9 mm²) by IVUS were not significantly different from baseline values in the patients before PTCA alone (2.1 × 1.8 mm, 3.2 mm²). After balloon dilatation in the laser treated group, lumen diameter (2.5 × 2.1 mm) and lumen CSA (4.9 mm²) were significantly greater than those post ELCA alone. However, there was no difference in lumen CSA or atheroma CSA in the group treated with excimer laser plus balloon dilatation vs. these measurements in the group treated with PTCA alone. ELCA does not ablate a large amount of atheroma (9% reduction) but creates a pathway to permit easier passage of a PTCA balloon. These quantitative and morphologic results may help explain why the restenosis rate with ELCA is similar to PTCA alone. © 1994 Wiley-Liss,Inc..     

Reduction of restenosis by vessel size adapted percutaneous transluminal coronary angioplasty using intravascular ultrasound

Restenosis following percutaneous transluminal coronary angioplasty (PTCA) remains a serious problem in interventional cardiology. Recent trials using stent implantation have proposed a reduction in restenosis, presumably due to a higher initial luminal gain. This study was conducted to evaluate if the short- and long-term results following conventional PTCA may be favorable, if balloon dilation was performed according to measurements gained by intravascular ultrasound (IVUS) (vessel size adapted PTCA). The use of intracoronary stents might be omitted if comparable long-term results could be achieved by this modified technique of balloon angioplasty. This unicenter and nonrandomized pilot trial was initiated in January 1995 with 252 patients who had 271 lesions. IVUS was performed before and after intervention to determine the external elastic membrane (EEM) diameter at the lesion site. The balloon catheter was sized according to the EEM diameter measured by IVUS (EEM 10%). The mean balloon diameter was 4.1 +/- 0.5 mm, the dilation time 130 +/- 60 seconds with a balloon pressure of 7.0 +/- 2.0 atm. Clinical acute and 1-year long-term follow-up were obtained for all patients and follow-up angiography in 71% of patients. Acute events occurred postinterventionally in 5 patients (2%). The cumulative event rate during long-term follow-up was 14%. The angiographic restenosis rate (diameter stenosis >50%) after 1 year was 19%. Vessel size adapted PTCA using IVUS led to favorable acute and long-term results with a low restenosis rate and a low 1-year clinical event rate. Despite dissections that occur frequently using large balloon sizes, an increased rate of major complications did not occur, indicating a safe procedure and substantiating the philosophy of "therapeutic dissections." The results need to be verified in a randomized trial.     

Excimer laser ablation before autoperfusion balloon inflation: A novel therapeutic approach to high grade stenoses in vessels supplying substantial myocardium at risk

The utility of a novel approach employing excimer laser ablation to form a channel for subsequent autoperfusion balloon angioplasty is presented. Two important advantages of this strategy are highlighted: (1) applicability to severe stenoses in vessels supplying substantial myocardium at risk and (2) ability to allow prolonged inflation time to minimize procedure related ischemia and optimize revascularization of the heart. We prospectively selected and studied five patients and performed excimer laser coronary angioplasty using either a 1.3 mm or 1.6 mm laser catheter followed by autoperfusion balloon dilatation. Procedural success was documented by a significant reduction in mean percent diameter stenosis from 89 ± 4% (S.D.) to 53 ± 4% after laser angioplasty (p<0.0001) and subsequently to 20 ± 4% after autoperfusion balloon angioplasty (p<0.0001). Clinical success was attained and characterized by resolution of anginal symptoms for at least 4 weeks after hospital discharge. There were no major acute complications encountered; however, restenosis has occurred in 2 out of 5 patients. We therefore recommend this novel pre-dilation strategy with excimer laser followed by autoperfusion balloon angioplasty in selected patients with an extensive amount of myocardium at risk.