Randomized study to compare balloon angioplasty and elective stent implantation in venous bypass grafts: the Venestent study.

The aim of the study was to compare acute and long-term angiographic and clinical outcome of balloon angioplasty and elective stenting in de novo lesions in the body of a saphenous vein graft (SVG). A total of 150 patients, with de novo lesions in SVG, were randomly assigned to balloon angioplasty or elective Wiktor I stent implantation. The angiographic restenosis rate at 6-month follow-up was 32.8% in the balloon group and 19.1% in the stent group (P = 0.069). At 1-year follow-up, target vessel revascularization rate was 31.4% vs. 14.5% (P < 0.05), and event-free survival was 60.0% vs. 76.3% (P < 0.05) for the balloon and stent group, respectively. Elective stent implantation in de novo SVG lesions is associated with a significant lower target vessel revascularization rate and a significant higher event-free survival at 1-year follow-up as compared to balloon angioplasty.     

Differences in restenosis propensity of devices for transluminal coronary intervention: A quantitative angiographic comparison of balloon angioplasty, directional atherectomy, stent implantation and excimer laser angioplasty

With the increasing clinical application of new devices forpercutaneous coronary revascularization, maximization of theacute angiographic result has become widely recognized as akey factor in maintained clinical and angiographic success.What is unclear, however, is whether the specific mode of actionof different devices might exert an additional independent effecton late luminal renarrowing. The purpose of this study was toinvestigate such a difference in the degree of provocation ofluminal renarrowing (or ‘restenosis propensity’)by different devices, among 3660 patients, who had 4342 lesionssuccessfully treated by balloon angioplasty (n=3797), directionalcoronary atherectomy (n= 200), Palmaz-Schatz stent implantation(n= 229) or excimer laser coronary angioplasty (n= 116) andwho also underwent quantitative angiographic analysis pre- andpost-intervention and at 6-month follow-up. To allow valid comparisonsbetween the groups, because of significant differences in coronaryvessel size (balloon angioplasty=2.62±0.55 mm, directionalcoronary atherectomy= 3.28±0.62 mm, excimer laser coronaryangioplasty= 2.51±0.47 mm, Palmaz-Schatz=3.01±0.44mm;P<0.0001), the comparative measurements of interest selectedwere the ‘relative loss’ in luminal diameter (RLoss=losslvessel size) to denote the restenosis process, and the‘relative lumen at follow-up’ (RLfup=minimal luminaldiameter at follow uplvessel size) to represent the angiographicoutcome. For consistency, lesion severity pre-intervention was representedby the ‘relative lumen pre’ (RLpre=minimal luminaldiameter prelvessel size) and the luminal increase at interventionwas measured as ‘relative gain’ (relative gain=gainl vessel size). Differences in restenosis propensity betweendevices was evaluated by univariate and multivariate analysis.Multivariate models were constructed to determine relative lossand relative lumen at follow-up, taking account of relativelumen pre-intervention, lesion location, relative gain, vesselsize and the device used. In addition, model-estimated relativeloss and relative lumen at follow-up at given relative lumenpre-intervention relative gain and vessel size, were comparedamong the four groups. Significant differences were detectedamong the groups both with respect to these estimates, as wellas in the degree of influence of progressively increasing relativegain, on the extent of renarrowing (relative loss) and angiographicoutcome (relative lumen at follow-up), particularly at higherlevels of luminal increase (relative gain). Specifically, lesionstreated by balloon angioplasty or Palmaz-Schatz stent implantation(the predominantly ‘dilating’ interventions) wereassociated with more favourable angiographic profiles than directionalatherectomy or excimer laser (the mainly ‘debulking’interventions). Significant effects of lesion severity and location,as well as the well known influence of luminal increase on bothluminal renarrowing and late angiographic outcome were alsonoted. These findings indicate that propensity to restenosis afterapparently successful intervention is influenced not only bythe degree of luminal enlargement achieved at intervention,but by the device used to achieve it. In view of the clinicalimplications of such findings, further evaluation in largerrandomized patient populations is warranted.     

Neointimal response following rotational atherectomy compared to balloon angioplasty in a porcine model of coronary in-stent restenosis

In-stent restenosis remains a clinical therapeutic challenge. Rotational atherectomy (RA) is an attractive treatment option as it may cause less vascular injury than balloon angioplasty (BA) and, therefore, limit further neointimal response. In an animal model of coronary in-stent restenosis, thermal injury and stenting created neointima (old NI). The treatment of in-stent restenosis with either BA (n = 9) or RA (n = 11) also generated neointima (new NI). The average areas (mm²) of old NI in the BA and RA groups were similar (3.77 ± 0.40 vs. 3.67 ± 0.53; P = 0.32). However, new NI formed after treatment of in-stent restenosis was significantly less in the RA as compared to the BA group (0.33 ± 0.12 vs. 0.73 ± 36, P < 0.01). In this porcine coronary artery model of in-stent restenosis, treatment with rotational atherectomy resulted in significantly less recurrent neointimal hyperplasia than balloon angioplasty. This animal study, thus, provides a rationale for the clinical use of rotablation in the treatment of in-stent restenosis. Cathet. Cardiovasc. Diagn. 45:332–336, 1998. © 1998 Wiley-Liss, Inc.     

Coronary stent strut avulsion in aorto-ostial in-stent restenosis: potential complication after cutting balloon angioplasty.

We report a case of stent strut avulsion by the cutting balloon during the withdrawal of the deflated balloon catheter in aorto-ostial in-stent restenosis, which was managed successfully by another stent. The proposed mechanisms and recommendations to avoid this rare complication are provided.     

Effects of increasing balloon pressure on mechanism and results of balloon angioplasty for treatment of restenosis after Palmaz-Schatz stent implantation: An angiographic and intravascular ultrasound study

Repeat balloon angioplasty is a widely used therapeutic option for in-stent restenosis, but the optimal balloon inflation pressure has not yet been determined. We used angiography and intravascular ultrasound imaging to assess the mechanism and results of lumen enlargement at various inflation pressures. Thirteen consecutive patients with restenosis post–Palmaz-Schatz stent implantation were submitted to a four-step balloon angioplasty using increasing balloon pressure of 2, 4, 8, and >12 atm. As a global result, the lumen size was only 80% of that observed at stent implantation. Significant changes in angiographic minimal lumen diameter, minimal lumen cross-sectional area, and lumen volume were observed after each step except after the highest-pressure inflation. At low inflation pressure (<8 atm), the decrease in neointimal tissue and the stent over expansion explained the lumen enlargement, whereas after further high inflation pressure (>8 atm), only additional stent over expansion was observed. These results suggest that only moderate balloon inflation pressure (up to 12 atm) is needed for angioplasty of post–Palmaz-Schatz stent restenotic lesions. Cathet. Cardiovasc. Intervent. 46:314–321, 1999. © 1999 Wiley-Liss, Inc.     

Bare-metal stent outcomes in an unselected patient population

BACKGROUND: Randomized trials have shown that drug-eluting stents (DES) substantially reduce in-stent restenosis compared with bare-metal stents (BMS). HYPOTHESIS: Revascularization event rates related to BMS restenosis may be higher in the trials setting than in real-world experience, calling into question the extent of benefit possible with widespread DES use in regular practice. METHODS: Between December 1998 and March 2003, 17,102 patients with BMS registered in the Goodroe Healthcare Solutions Data Warehouse met the inclusion criteria for this retrospective study of catheterization laboratory data. We examined the database for evidence of diagnostic angiography or percutaneous coronary intervention (PCI) readmission within 1 year after stenting. RESULTS: Repeat PCI was documented for 2070 patients, and 232 were referred for coronary artery bypass graft surgery (CABG)-in sum, 13.5% of the cohort. Stented region revascularization was observed in 8.4%: 1350 patients underwent subsequent PCI, and 84 of the patients referred for CABG had in-stent lesion recurrence. Only 1207 (7.1%) patients required stent-related PCI after 30 days, the time frame consistent with restenosis. CONCLUSIONS: In this "real-world" series, reintervention of a stented region after the first follow-up month was documented in fewer than 8% of patients in a large cohort that had received BMS. The rate of clinical events potentially related to BMS in-stent restenosis in this large, unselected patient population is substantially lower than that in the control arms of some DES trials. The incremental benefit of widespread conversion from BMS to DES may be smaller in some patient populations than is suggested by the results of those trials.     

Transluminal extraction atherectomy and adjunctive balloon angioplasty for restenosis after palmaz-schatz coronary stent implantation

Two patients who developed restenosis after implantation of Palmaz-Schatz coronary stents were successfully treated by transluminal extraction atherectomy and there has been no recurrence on follow-up angiograms. The optimum strategy for managing restenosis after coronary stenting remains unclear, but transluminal extraction atherectomy appears to be a safe and effective option. © 1993 Wiiey-Liss, Inc.     

Distortion of Palmaz-Schatz stent geometry following side-branch balloon dilation through the stent in a rabbit model

The compromise of side-branches following coronary angioplasty of the parent vessel remains a limitation of the procedure. Reports of dilation through a Palmaz-Schatz stent to salvage a compromised side-branch covered by the stent have been made. We examined the distortion of stent geometry which occurs following this procedure in a rabbit model. Palmaz-Schatz stents were placed at the aortoiliac bifurcation in 7 rabbits and the contralateral iliac artery was dilated through the stent. Despite good angiographic results, varied degrees of stent distortion were noted on gross pathologic analysis. Most distortion occurred when the arteries were dilated through the ends of the struts or through the “diamonds,” and least distortion occurred during dilation through the mid-articulation site. While good stent deployment is thought to be necessary for improved outcomes, the distortion of stents after balloon dilation through the stent, despite good angiographic results, may have negative implications for both short- and long-term outcomes. Cathet. Cardiovasc. Diagn. 40:422–426, 1997. © 1997 Wiley-Liss, Inc.     

兔髂动脉球囊成形及支架术后血管壁超微结构的观察

目的 :比较兔髂动脉球囊成形及支架术后血管壁超微结构的变化 ,探讨支架内再狭窄与球囊血管成形术后再狭窄的不同机制。方法 :10支兔 ,分别于左髂动脉行 NIR支架置入术 （S组 ） ,右髂动脉行球囊成形术 （B组 ）。术前3d始予阿司匹林 2 5 mg· d- 1 ,直至处死动物。术后皮下注射肝素 2 5 0 0 U· d- 1 ,连续 7d。术后 7d和 30 d处死动物。用光镜、透射电镜及免疫组化染色技术观察损伤部位血管壁变化。结果 :术后 30 d光镜检查发现 S组新生内膜平滑肌细胞 （SMC）的增生程度明显高于 B组 （P<0 .0 5 ）。电镜检查 ,术后 7d,S组较 B组可见较多从外膜向中膜及内膜迁移的肌纤维母细胞 ,中膜及内膜大量以合成型为主的 SMC,细胞外基质 （ECM）以胶原及弹性纤维为主。30 d时 B组内膜下 SMC已转化为收缩型 ,ECM以胶原及弹性纤维为主 ;而 S组内膜下大量 SMC仍为典型合成型表现 ,周围 ECM以氨基聚糖及糖蛋白为主。结论 :球囊成形术及支架术后 ,新生内膜组成成分不同 ,支架术后新生内膜增生以 SMC增生为主 ,ECM以氨基聚糖及糖蛋白为主而球囊成形术后新生内膜增生 SMC较少 ,ECM以胶原及弹性纤维为主     

Restenosis following coronary angioplasty

Restenosis is the most important problem limiting the success of coronary angioplasty. Clinically, restenosis is seen in approximately one-third of patients undergoing percutaneous transluminal coronary angioplasty. Several clinical and angiographic risk factors have been identified which may contribute to the development of restenosis. Histopathologic studies indicate that restenosis is characterized by intimal proliferation of smooth muscle cells in a loose connective tissue matrix. These intimal lesions are associated predominantly with the nonatheromatous portion of the vessel wall. Thinning of the media of the plaque-free wall and marked fragmentation of the internal elastic lamina are also seen. Traumatic injury of the vessel wall during angioplasty probably triggers a series of cellular and subcellular events which may ultimately lead to myointimal proliferation and restenosis. Although the exact mechanism by which this occurs is unknown, several factors may enhance smooth muscle cell growth and therefore may play a role in the development of restenosis. These include platelet deposition, mechanical stretching of the media, inflammation of the vessel wall, the activity of growth factors, and alterations in vessel geometry. These possible mechanisms of restenosis suggest several potential ways to limit the proliferative response to vascular injury. Anticoagulants and platelet antagonists, direct inhibitors of smooth muscle proliferation, anti-inflammatory agents, growth factor inhibitors, and new devices which improve final vessel geometry are currently being tested as methods to curb restenosis. Unfortunately, no treatment has yet been shown to reduce significantly the rate of restenosis following angioplasty. The problem of restenosis will most likely be solved by better understanding of the basic molecular and biologic phenomena involved in vascular injury and repair.     

Immediate and chronic results of cutting balloon angioplasty: A matched comparison with conventional angioplasty

Background: At the initial stages of percutaneous transluminal coronary angioplasty (PTCA), several studies reported on the feasibility of coronary artery incision and dilatation leading to the extension of the PTCA technique. Hypothesis: This study was designed to determine the immediate and chronic results of cutting balloon (CB) angioplasty. Methods: This procedure was performed on 127 lesions in 110 patients (male 83%, age 61.8 ± 9.3 years). Results: The overall procedural success rates for the CB were 93.7% (119 lesions) and 92.7% (102 patients), while solitary CB without pre- and/or postdilatation was 76.4% (91 lesions). There was one major in-hospital complication (Q-wave myocardial infarction, 0.9%), but there were no deaths or emergency coronary artery bypass graftings. Significant angiographic dissections (≥ grade C) occurred in four patients, and coronary perforation occurred in one. The successfully treated CB group (95 lesions) was matched with the successful conventional angioplasty group (PTCA group) for chronic result assessment in regard to reference vessel size and lesion characteristics. In the CB group, postprocedural minimal luminal diameters were significantly larger and the percentage of stenosis at the stenotic site was significantly lower compared with the PTCA group. Restenosis occurred in 22 lesions (23.1%). This showed a significantly lower restenosis rate compared with the PTCA group (42.1%). In addition, the restenosis rate of the CB without inclusion of the pre- and/or postdilatation-treated lesions was 19.7%. Conclusions: (1) Cutting balloon angioplasty procedures can be performed with high success rates with few major in-hospital events. (2) The restenosis rate in the CB group was significantly lower compared with the PTCA group.     

Local drug-delivery balloon for proliferative occlusive in-stent restenosis after drug-eluting stent

Drug-coated balloon has been developed as an alternative to drug-eluting stents for in-stent restenosis but the performance of drug infusion balloon in such setting has not been previously described. We present a case of particularly aggressive in-stent restenosis after drug eluting stent implantation treated with a new kind of drug infusion balloon developed in order to overcome the impossibility to inflate regular drug-coated balloon for several dilatation.     

Acute and six-month clinical outcome after Helistent stent implantation in coronary arteries: results of the French Helistent multicenter registry.

The purpose of our study was to determine the feasibility, safety, and efficacy of the new tubular (Helistent) stent (Hexacath, France) in patients with coronary artery disease. Patients were prospectively included in a multicenter French registry: acute results and 6-month target lesion revascularization rate were assessed. A total of 628 stents were implanted in 527 patients (616 lesions). Mean age was 64 +/- 11 years. Predilatation was performed in 77% of cases. The stent was successfully deployed in 99.4% of attempted lesions. Three patients died during the hospital stay and 10 patients developed myocardial infarction. Angiographic stent thrombosis rate was 1.1%. There was no need for urgent cardiac surgery during hospital stay. Six-month clinical follow-up was obtained in 95% of patients; target lesion revascularization rate was 8.3%. Eight patients (1.6%) (extracardiac death in three patients) died and three patients (0.6%) developed myocardial infarction. In conclusion, the Helistent stent appears safe and effective in minimizing acute complications of elective coronary interventions. Six-month major cardiac events were rare and clinical restenosis was low (< 10%).     

球囊预扩张充盈压对冠脉支架植入术临床疗效的影响

目的 :评估球囊低压力预扩张对冠脉内支架术后临床疗效的影响。方法 :依据不同球囊预扩张压力将入选的91例冠心病患者分为低压力组 （最大扩张压力≤ 12 atm ）、高压力组 （>12 atm ） ,观察住院期间严重临床事件率和术后 6～ 18个月无心脏事件存活率。结果 :低压力组球囊最大预扩张压力为 8.3± 1.6 atm ,高压力组为 13.9± 0 .3atm （P<0 .0 5 ） ,144个支架均成功置入。低压力组和高压力组在术中的血管夹层及撕裂的发生率分别为 8.2 %和19.0 % （P<0 .0 5 ） ,住院期间低压力组发生死亡为 0例 ,高压力组为 1例 ;6 8例患者接受了术后 6～ 18个月的临床随访 ,无心脏事件存活率低压力组为 74% ,高压力组为 6 1% ,其中 13例在随机冠状动脉造影随访中发现支架内再狭窄 ,低压力组为 6例 ,高压力组为 7例。结论 :低压力球囊预扩张可减少支架术中的急性血管并发症 ,不影响支架置入的远期疗效。     

Successful excimer laser angioplasty following unsuccessful primary balloon angioplasty

We report five patients where excimer laser coronary angioplasty facilitated successful balloon dilatation of heavily calcified lesions that could not be dilated by conventional angioplasty techniques alone. In each case, the lesion was crossed successfully with a guide wire. Conventional angioplasty failed because of inability to cross the lesion with a balloon (four lesions) or inability to dilate the lesion with balloon inflation (two lesions). These cases illustrate an indication for excimer laser coronary angioplasty as an adjunctive procedure in heavily calcified coronary stenoses. © 1993 Wiley-Liss, Inc.     

Coronary stenting with the half (disarticulated) Palmaz-Schatz stent: Immediate results and six-month follow-up

Coronary stenting with the half disarticulated Palmaz-Schatz stent is particularly suitable for ostial stenoses, diaphragm stenoses, stenoses distal to tortuous segments or coronary bends and localized dissections after balloon angioplasty. Nevertheless very few data regarding the half stent exist and follow-up data are nonexistent. From January of 1994 to December of 1995 a total of 207 half stents were implanted in 175 patients. Most patients had stable or unstable angina and in the majority of cases the stent was implanted due to localized dissection or to suboptimal result. The procedural success rate was 98%. After stent implantation, 82 patients were treated with acetylsalicylic acid (ASA) and oral anticoagulant (group A), whereas 93 were treated with ASA and ticlopidine (group B). Seven patients had subacute thrombosis (5, group A; 2, group B), and six patients had major bleeding (5, group A; 1, group B). Overall, patients in group A had more cardiovascular complications than patients in group B (10, group A; 3, group B; p = 0.047). After 6-mo follow-up, 1 patient had died and 27 patients had symptoms of angina (16%). Thirteen patients underwent a second PTCA (7%) and four patients (2%) were referred for coronary artery bypass. In conclusion, coronary stenting with half Palmaz-Schatz stent appears to be a safe and effective procedure. In selected cases, the half Palmaz-Schatz stent is easier to handle than the complete stent, it is associated with a low rate of clinical restenosis, and it lowers procedural costs. Cathet. Cardiovasc. Diagn. 41:371–376, 1997. © 1997 Wiley-Liss, Inc.     

Extensive intramural hematoma as the cause of failed coronary angioplasty: Diagnosis by intravascular ultrasound and treatment by stent implantation

Dissections after coronary angioplasty are the major cause of ischemic events following percutaneous transluminal coronary angioplasty (PTCA) and may require additional measures such as intravascular stent deployment to relieve or prevent acute vessel closure. We describe a rare type of dissection after PTCA which caused a severe obstruction of the vessel segment proximal to the dilatation site without a visible dissection flap. Intravascular ultrasound was used to elucidate the morphology of the proximal vessel obstruction, which revealed an intramural hematoma extending into the proximal vessel segment as underlying mechanism. A Palmaz-Schatz stent was placed at the entry site of this hematoma, which led to the relief of the proximal vessel obstruction. After 3 months of anticoagulation therapy the repeat coronary angiography showed no significant restenosis. This demonstrates the unique insight into the underlying morphology of failed PTCA by intravascular ultrasound, which can help to manage even rare and unusual complications. © 1995 Wiley-Liss, Inc.     

Focal stent collapse in a patient with systemic sclerosis

We report a patient with systemic sclerosis having implantation of a 35 mm beStent with immediate success but developing angina at follow-up. A focal stent collapse with focal hyperplasia in and outside the stent was documented by ultrasound after 2 mos. A 14mm Palmaz-Schatz stent was successfully deployed into the collapsed beStent, with good 6-mo angiographic result. The stent collapse was probably due to unequal distribution of radial forces and possibly reactive hyperplasia in this unique patient with systemic sclerosis. Cathet. Cardiovasc. Diagn. 44:57–60, 1998. © 1998 Wiley-Liss, Inc.