In-stent Restenotic Lesions Research Articles

Totally occluded in-stent restenotic lesions treated with intracoronary radiation: six-month clinical and anglographic follow-up

Totally occluded in-stent restenotic lesions treated with intracoronary radiation: six-month clinical and anglographic follow-up

Intracoronary brachytherapy: Initial Australasian experience with the Novoste Beta-Cath system

Background: Coronary artery stenting is now performed in the vast majority of percutaneous interventional procedures worldwide. In-stent restenosis remains the major limitation of this technology and responds poorly to conventional interventional therapies. The only available treatment shown to impact upon this unfavourable response is endovascular radiation. In this paper we describe the initial Australasian experience with the Novoste Beta-Cath device, designed specifically for the delivery of beta radiation to the coronary artery. Methods: Patients were considered eligible for intracoronary brachytherapy if they had symptomatic diffuse in-stent restenosis, or restenosis within a vessel that was not suitable for stenting. Brachytherapy was provided as a clinical procedure following successful percutaneous transterminal coronary angioplasty (PTCA). Clinical and procedural details were collected at hospital admission, and patients were contacted a median of 9 months following the procedure. Information was collected on recurrent hospital presentations and details verified by retrieving patient records. Results: From June 1999 to July 2000, intracoronary brachytherapy was performed in 17 vessels in 16 patients and was technically successful in all cases. A single late stent thrombosis occurred 80 days following brachytherapy. This patient died of a subarachnoid haemorrhage 186 days later. There were three presentations with chest pain during the follow-up period, one associated with scintigraphic abnormality consistent with clinical restenosis. There was no documented angiographic restenosis. Conclusions: Intracoronary brachytherapy with the Beta-Cath device is simple to apply and has yielded promising intermediate term results in our patient cohort. Its application appears most appropriate to diffuse in-stent restenotic lesions in vessels ranging from 2.5 to 3.5 mm in diameter. In these patients, adjunctive brachytherapy currently provides the best available option for ensuring an enduring result following repeat percutaneous revascularisation.

Effects of 32P radioactive stents on in-stent restenosis in a double stent injury model of the porcine coronary arteries

Background: The major limitation of coronary stenting remains in-stent restenosis, due to the development of neointimal proliferation. Radioactive stents have demonstrated the ability to reduce this proliferation in the healthy nonatherosclerotic porcine animal model. However, inhibition of tissue proliferation in the in-stent restenotic lesion in a porcine model is not well characterized. The objective of this study was to examine the efficacy and safety of the 32P radioactive stent for the treatment of in-stent restenosis in a double stent injury model of the porcine coronaries.Methods and Materials: Eighteen coronary arteries in 9 pigs underwent nonradioactive stent (8 mm in length) implantation. Thirty days after the initial stent implantation, a 32P radioactive stent (18 mm in length) with an activity of 0 and 18 μCi was implanted to cover the initial stent. The swine were killed 30 days after the second stent implantation. Histomorphometric analysis was performed for vessel area (VA), stent strut area (SSA), intimal area (IA), and lumen area (LA).Results: Injury scores, VA, SSA, and LA were similar among the control and radiated groups. Neointimal formation was significantly reduced after placement of radioactive stents as compared to control in both the overlapped (0.93 ± 0.12 vs. 1.31 ± 0.51 mm2, p < 0.05) and nonoverlapped segments (1.14 ± 0.21 vs. 1.91 ± 1.04 mm2, p < 0.05). The smooth muscle cell index in the neointima was reduced. Intimal fibrin was increased in the radiated group as compared to the control (p < 0.01 respectively).Conclusions: 32P radioactive stents may be safe and effective in reducing neointimal formation leading to in-stent restenosis. Longer follow-up will be required to examine whether these positive findings can be maintained.

Intracoronary gamma radiation for patients with totally occluded in-stent restenotic lesions: 6 Months clinical and angiographic follow-up: Han-Soo Kim, Andrew E. Ajani, Lowell F. Satler, Roxana Mehran, Alexandra J. Lansky, Gary S. Mintz, Kenneth M. Kent, Augusto D. Pichard, Luis Gruberg, Rosanna C. Chan, Ron Waksman. Washington Hospital Center, Washington, DC

Intracoronary gamma radiation for patients with totally occluded in-stent restenotic lesions: 6 Months clinical and angiographic follow-up: Han-Soo Kim, Andrew E. Ajani, Lowell F. Satler, Roxana Mehran, Alexandra J. Lansky, Gary S. Mintz, Kenneth M. Kent, Augusto D. Pichard, Luis Gruberg, Rosanna C. Chan, Ron Waksman. Washington Hospital Center, Washington, DC

Types of In-Stent Restenosis and Predictive Factors for Diffuse Type In-Stent Restenosis

Background and Objectives：Coronary stents have been used increasingly in the field of coronary intervention. However, in-stent restenosis (ISR remains a therapeutic challenge. The subsequent response to repeat intervention in the restenotic lesion may be predicted by the angiographic pattern of ISR. In particular, the restenosis rate following re-intervention in this lesion is higher. This study evaluated the incidence of restenosis types and the predictors for diffuse type ISR. Subjects and Methods：The study population included 66 patients with in-stent restenotic lesions after stent implantation. Angiographic restenosis was defined as a diameter stenosis of ≥50% at follow-up coronary angiography. Patterns of ISR were defined as focal type (<10 mm in length and diffuse type (≥10 mm in length. The patients were divided into two groups according to the angiographic patterns of ISR. Clinical characteristics, pre-stenting angiographic features, and stenting procedure related factors were analyzed. A multivariate logistic regression analysis was performed in order to identify the independent predictors for diffuse-type ISR. Results：Angiographic analysis of 66 restenotic lesions showed diffuse type in 29 lesions (44% and focal type in 37 (56%. Most of the focal in-stent restenoses occured in the proximal and mid portions of the stents. The reference diameter (3.02±0.37 mm vs 3.25±0.46 mm, p＝ 0.046 and post-stenting minimal luminal diameter (2.89±0.36 vs 3.19±0.39 mm, p＝0.002 were significantly smaller in the diffuse type as compared to the focal type, whereas other parameters were significantly different. Using multivariate logistic regression analysis, the only predictive factor for diffuse type ISR was post-stenting MLD (OR＝4.74, p＝0.025. Conclusion：Small post-stenting MLD (<3 mm has a high risk for diffuse type INR. Therefore, new therapeutic strategies are required for these lesions. (Korean Circulation J 2001;31( ( ( (11 :1135-1141

The Early Loss Index: Interesting observations comparing balloon angioplasty and stenting in the instent restenotic lesion in the SCRIPPS Gamma Radiation Trial

The Early Loss Index: Interesting observations comparing balloon angioplasty and stenting in the instent restenotic lesion in the SCRIPPS Gamma Radiation Trial

Clinical Follow-up of Excimer Laser Coronary Angioplasty for In-stent Restenosis

Background and Objectives:Previous studies have shown a high restenosis rate after balloon angioplasty for diffuse in-stent restenosis. Debulking strategy has been expected to be helpful to reduce the restenosis rate. This study evaluated the safety and long-term clinical event rate after excimer laser coronary angioplasty (ELCA) and adjunctive balloon angioplasty for in-stent restenosis. Materials and Method:We included 29 in-stent restenotic lesions treated in 28 patients (18 men, 10 women, mean age 60±2 years) admitted to Samsung Medical Center between June 1997 and August 1998. Quantitative coronary angiography was performed and clinical characteristics, acute complications, 30-day and 8-month major cardiac adverse event rate was analyzed. Results: Initial success rate was 97%. We stopped the ELCA procedure in one lesion located in the proximal left anterior descending artery due to bradycardia and hypotension. In the 28 lesions successfully treated with ELCA and adjunctive balloon angioplasty, the minimal luminal diameter increased from 0.7±0.1 mm before ELCA to 1.9± 0.1 mm after ELCA and to 2.7±0.1 mm after adjunctive balloon angioplasty (p<.0001). The acute luminal gain after ELCA was 60%. The diameter stenosis decreased from 75±2% before ELCA to 36±2% after ELCA and to 15±2% after adjunctive balloon angioplasty (p<.0001). There was no in-hospital death, Q wave acute myocardial infarction (AMI), emergency coronary artery bypass graft (CABG), but non-Q AMI was noted in 1 case (3%). During the followed-up period of 8 months, there were 1 death (4%) due to congestive heart failure, 1 nonQ-AMI (4%) and 7 target lesion revascularization (26%) among the successfully treated 27 patients, but there was no CABG, Q-AMI. Combined event rate at the 8-month follow-up was 33% and target lesion revascularization rate at 8-month follow-up was 26%. Conclusion:The ELCA and adjunctive balloon angioplasty seems to be safe and effective for the treatment of in-stent restenosis. A prospective randomized trial comparing ELCA versus other ablative technique is required. (Korean Circulation J 1999;29(9):891-897)

Immediate and long-term outcomes of rotational atherectomy versus balloon angioplasty alone for treatment of diffuse in-stent restenosis

This study was performed to compare the effects of rotational atherectomy (RA) plus balloon angioplasty (BA) with those of BA alone for treatment of diffuse in-stent restenosis. RA+BA or BA alone was performed in a consecutive, prospective (not randomized) manner in 81 patients with 81 diffuse in-stent restenotic lesions (lesion length >10 mm): 36 patients underwent RA+BA, and 45 patients BA. Clinical recurrence was the primary end point of this study, and was defined as angina associated with objective evidence of myocardial ischemia on stress testing. Mean follow-up duration was 277 ± 109 days. In the BA group, acute lumen gain after repeat intervention was significantly lower than that of the original stenting procedure (1.94 ± 0.63 vs 2.37 ± 0.51 mm, p <0.05). In the RA + BA group, however, acute lumen gain of repeat intervention was similar to that of the original stenting procedure (2.16 ± 0.52 vs 2.26 ± 0.66 mm). Clinical recurrence rate at 6 months follow-up was significantly lower in the RA+BA group than in the BA group (25% vs 47%, p <0.05). Clinical events (death, myocardial infarction, repeat intervention) occurred in 6.7% (3 of 45) of patients in the BA group, but in no patient in the RA+BA group during the follow-up period. The long-term angina-free survival rate was significantly higher in the RA+BA group than in the BA group (72% vs 49%, p = 0.02). In conclusion, RA+BA seems to be a more effective therapeutic modality than BA alone for treatment of diffuse in-stent restenosis.

Clinical and angiographic results of balloon-expandable intracoronary stents in right coronary artery stenoses

Balloon-expandable stents were placed successfully in 35 (95%) of 37 patients whose right coronary artery lesion was believed to have a poor short- or long-term prognosis with conventional balloon angioplasty because of prior restenosis or adverse lesion morphology. Quantitative angiography showed a reduction in stenosis diameter from 83 ± 14% to 42 ± 14% after conventional balloon dilation, with a further reduction to − 3 ± 12% after stent placement (p < 0.001). There were no acute stent thromboses, but one patient (with two stents and unstented distal disease) developed subacute thrombosis on day 8 after self-discontinuation of warfarin and was treated with thrombolytic therapy and reflation.Follow-up angiography was performed at 4 to 6 months in 25 patients, demonstrating restenosis (83 ± 13%) in 4 (57%) of 7 patients with multiple stents, but only 3 (17%) of 18 patients with a single stent (p < 0.05). Six of the seven in-stent restenotic lesions were subtotal (80 ± 12%) and were subjected to repeat conventional balloon angioplasty (postdilation stenosis 13 ± 21%). The 18 patients without restenosis had a maximal in-stent diameter stenosis of 29 ± 15%, corresponding to a maximal focal neointimal thickness of 0.68 ± 0.26 mm within the stented segment. These preliminary results suggest that the Schatz-Palmaz stent may be a useful adjunctive device in the performance of coronary angioplasty.