Immediate Results of Manually Crimped NIR Stent

BACKGROUND: The several kinds of coronary stents have proven successful in their role to treat acute or subacute closures after balloon angioplasty as well as to reduce the restenosis rate in de novo lesions. However, investigations continue in order to develop an ideal stent with a strong, highly flexible, radial force, especially useful in cases of tortuous vessels, lesions at bends, and lesions distal to previously deployed stents. The NIR stent is a recently developed balloon-expandable, stainless-steel, slotted tube stent; it is designed for improved flexibility with a higher radial force when compared with the traditional Palmaz-Schatz stent. We report the immediate results of our experience with the NIR stent. The purpose of the present study was to assess the feasibility, safety and efficacy of the deployment of manually crimped NIR stents in patients with complex coronary anatomy as well as the clinical outcomes within the first month. METHODS: Between January and July 1997, 143 NIR stents were implanted in the coronary arteries of 124 patients (male 76%, mean age 56+/-10 years). Sixty-one patients had UAP, 43 had SA, and 20 patients had AMI. RESULTS: 1)Indications of stenting were de novo lesions in 123 (95%) and restenosis lesion in 6 (5%). 2)Frequency of used stent length was 16mm in 65 cases (46%), 32mm in 60 cases (42%), 25 mm in 12 cases (8%), and 9mm in 6 cases (4%). 3)Single stents were implanted in 115 (89%) lesions, and overlapping stenting with 2nd NIR stents in 14 (11%) lesions. 4)Procedural success rate (defined as the angiographically residual stenosis of <30% immediately after the procedure with no major clinical events within 4 weeks after the procedure) was 95.2% (118/124 pts). Angiographic success rate (defined as a residual stenosis of <30% without major dissection) was 96.1% (124/129 lesion). The procedural success rate and the angiographic success rate in calcified lesions and/or thrombi containing lesions were 100%. The procedural success rate and the angiographic success rate in cases of tortuous proximal vessels to the lesion were 91% and 91%, respectively. The procedural success rate and the angiographic success rate in more than 45 degrees angulated lesions were 98% and 94%, respectively. 5)The mean lumen diameter of target lesions was increased from 0.6+/-0.4mm to 3.1+/-0.5mm (p<0.001) after stent implantation. The percent of diameter stenosis was decreased from 82+/-12% to -1+/-13% (p<0.001) after stent implantation. The mean diameter of the reference artery was 3.1+/-0.6mm. 6)Incidence of peristent dissection after stenting was 6.2% (8/129 lesion). 7)The rate of stenting failure was 4.8% (6 pts). There were 2 cases of stent migration, 2 cases of failure to cross the lesion and 2 cases of procedure-related emergency CABG. CONCLUSION: There is a higher tendency for stent migration with manually crinped stents compared with that of premounted stents. However, coronary stenting with manually-crimped NIR stents can be safely performed and may be particularly useful in patients with unfavorable clinical and angiographic characteristics for percutaneous coronary intervention. Follow-up data is needed to assess long term patency of this stent.

Immediate Results of AVE Micro-II Stent

BACKGROUND: Several kinds of stents have shown their safety and efficacy to treat acute or subacute closure after balloon angioplasty as well as to reduce restenosis rate. However, one of the limitations of stents is difficult to deploy especially in tortuos vessels, lesions at a bend, and distal to previously deployed stents. The Micro stent II, which was one of the most recently developed stents, ia a rapid-exchage balloon expandable stainless steel stent with a zigzag design connected with a continuous single weld in each 3mm segments. It scores over excellent trackability and optimum radio-opacity. Therefore, it is easy to operate and feasible in tortuous, distal lesions and variety of lesion lengths. We report our experiences with Micro-II stent implanatation in the first 76 patients at Tonsei cardiovascular center to assess its safety and efficacy in patients with complex coronary anatomy and clinical results in the first months. METHODS: Between January 1996 and July 1996, eighty-six Micro-II stent were implanted in the coronary arteries of 76 patients(male 65.8%, age 59+/-10 year). Forty-five patients had unstable angina, the others had stable angina(17pts), acute myocardial infarction(14pts). RESULTS: 1) Indication of stenting was de novo 51(59.3%), suboptimal result 25(29.1%), restenosis 1(1.2%) and 9(10.4%) of lesions were stented in bail out situation. 2) Single stent were implanted in 76(88.4%)lesions, overlapping stent in 10(11.6%)lesions. Among overlapping stents, the second stent with Micro-II stent and with another kind of stent were 4.6%, 7.0%, respectively. 3) Procedure related complication including a subacute closure was occurred in 1(1.2%) patient who had distal dissection and 45% residual stenosis. In 12(14%) lesions, preistent dissection has been noticed after stent impantation. 4) Angiographic success(defined as a residual stenosis of <30% without major dissection) was achieved in 82 of 86 attempts(95.3%). The procedual success rate(defined as a residual stenosis of <30% without occurrence of major clinical events within 4 weeks after procesure) was 96.1%(73/76 patients). Angiographic success and procedural success rate in calcified lesion were 100% and 100%, respectively. Angiographic success and procedural success rate in more than 45` angulated lesion were 97% and 100%, respectively. 5) The mean minimal luminal diameter of the target lesions was increased from 0.42+/-0.40mm before stent implantation to 2.93+/-0.50mm(p<0.001). The percentage of diameter stenosis was reduced from 86.49+/-13.04% to 1.40+/-7.11%(p<0.001) after stent implantation. CONCLUSION: Coronary stenting with AVE Micro-II stent can be safety performed and is particularly beneficial in tortuous and calcified arteries. There was a high tendency for peristent dissection which need to special consideration to avoid. Follow-up data is needed to assess mid and term patency. Coronary artery disease . AVE Micro-II stent . Immediate results.

Coronary Less Shortening Wallstent in the Long Lesion of Coronary Disease : Immediate Results

BACKGROUND: Although the first coronary Wallstent implantation ushered in a new era in interventional cordiology with the purpose of circumventing the two major limitations of coronary balloon angioplasty, early acute occlusion and late restenosis, the previous investigators have reported a high rate of subacute occlusion after Wallstent implantation. However, recent studies have reported a low incidence rate of subacute closure and restenosis using the newly modified coronary Less Shortening in aortocoronary vein grafts. The present study reports the immediate results of the Less Shortening Wallstent Implantation for 21 diffuse native coronary lesions in 20 patients. METHODS: Twenty patients were enrolled at the Yonsei Univ. Cardiovasular Center of medical College, Yonsei University in Seoul, Korea from March 1996 through May 1996. The specific angiographic criteria for enrollment included at least 75% diameter stenosis, according to the estimate of two investigatior ; a lesion that was 20mm or more in lenght and a vessel diameter of at least 2.5mm. Bail-out procedure was performed in the case of abrupt closure or threatened closure, defined as a dissection and over 50% residual stenosis of the artery. RESULTS: The coronary Less Shortening Wallstents were successfully implanted in the 21 diffuse coronary lesions(more than 20mm in length) of the 20 patients(pts), including 7 pts of acute myocardial infarction, 11 pts of unstable angina, and 2 pts of stable angina. Angiographic results after Less Shortening Wallstent were 3.0+/-0.3mm in minimal luminal diameter(MLD), 6.7+/-10.8% diameter stenosis(DS) comparing with pre-stent implantation MLD and DS, respectively, 0.3+/-0.4mm and 89.9+/-8.4%. During the in-hospital phase, no major cardiac event occurred except 2 cases of transmural myocardial infarction, including one of stent thrombosis and one of side branch occlusion, despite of inclusion of 7 cases of threatened occlusion in the long lesion. The peristent spasms were observed in 11 among 21 lesions, although long term significance of peristent spasm is not defined. The relative risk for peristent spasm were 10 times higher when larger stents(expanded stent diameter/reference artery diameter>1.7) were implanted. There was no peristent spasm when stents of which expanded stent diameter 1.4 times smaller than reference artery size ware used. CONCLUSION: The results of this introductory study suggest that new Less Shortening Wallstent may reduce the requirement of multiple stent in the long lesion and a lower rate of thrombotic occusion in comparison to its prototype. Further large scale long term follow-up study is needed to evaluate the role of new Less Shortening Wallstent.