nitinol and Coronary-Thrombosis

The objective of the study was to retrospectively evaluate the long-term clinical outcome after implantation of the self-expandable (SE) STENTYS stent in a large multicenter cohort.. Incomplete stent apposition is known to cause higher rates of myocardial infarction (MI) and stent thrombosis. Because of its self-expanding features, the SE STENTYS stent adapts to the vessel wall and is therefore expected to minimize malapposition and therefore the rates of MI and stent thrombosis.. Treatment with a total of 351 SE coronary stents was attempted in 314 patients of a cohort from three German institutions between 2011 and 2015. Technical success was achieved with 331/351 (94%) stents. Patients treated successfully with SE stents (n=298) were followed up using the primary outcome measure of target lesion failure (TLF), a combined endpoint of cardiac mortality, recurrent target vessel MI, acute stent thrombosis, and clinically driven target lesion revascularization. Follow-up was complete in 268/298 (90%) patients with a median follow-up period of 2.5 (interquartile range: 1.4-3.3) years.. TLF occurred in 54/298 (18%) patients. Event rates were 7.5% for cardiac mortality, 11.6% for target vessel MI, and 5.2% for clinically driven target lesion revascularization. Acute stent thrombosis occurred in 2/298 (0.7%). Overall, stent thrombosis had an incidence of 2.6% within the follow-up period. ST-elevation MI at baseline (P=0.02) and a dual antiplatelet therapy with clopidogrel for only 6 months (P=0.04) were the only clinical factors linked to the absence of TLF.. Technical success of SE coronary stent implantation in an all-comer cohort of patients was high, although the rate of TLF and stent thrombosis during long-term follow-up was also relatively high.

Topics: Acute Coronary Syndrome; Aged; Alloys; Coronary Artery Disease; Coronary Thrombosis; Female; Germany; Humans; Incidence; Kaplan-Meier Estimate; Male; Middle Aged; Non-ST Elevated Myocardial Infarction; Percutaneous Coronary Intervention; Proportional Hazards Models; Prosthesis Design; Quality of Life; Recurrence; Retrospective Studies; Risk Factors; Self Expandable Metallic Stents; ST Elevation Myocardial Infarction; Time Factors; Treatment Outcome

The purpose of this study was to test the feasibility of implanting and retrieving a heat-activated recoverable temporary stent and to determine its effect on the angiographic, gross and histologic appearance of a normal coronary artery wall.. Permanent coronary stenting is associated with a significant incidence of thrombosis, bleeding and vascular complications. These may be avoided by temporarily stenting for a period of hours to several days.. Seventy-eight stents constructed from the shape-memory nickel-titanium alloy nitinol were deployed by balloon expansion in the coronary arteries of 28 dogs and left in place for up to 6 months. Thirty minutes to 1 week after implantation, 70 stents were recovered by flushing the coronary arteries with 3 to 5 ml of 75 degrees C lactated Ringer solution, with collapse of the stent over a recovery catheter and subsequent withdrawal.. All stents were successfully recovered and removed percutaneously. Mean vessel diameter after stenting was 12 +/- 6% (p < 0.05) greater than baseline diameter. Mean vessel diameter after stent removal remained enlarged (6 +/- 3%, p < 0.05). No angiographic or gross evidence of thrombosis, dissection, embolization, migration or spasm was associated with implantation or recovery. Microscopic examination revealed minor intimal injury in 40 segments (51%). Microscopic focal medial necrosis was associated with mural platelet-fibrin thrombus in 23 stented segments (29%) and media was interrupted in 7 (9%).. This study demonstrates the feasibility of a new method of temporary stenting that uses the thermoelastic properties of nitinol to permit reliable recovery of the stent in normal canine coronary arteries.

Topics: Alloys; Animals; Biopsy; Coronary Angiography; Coronary Thrombosis; Coronary Vessels; Dogs; Equipment Design; Feasibility Studies; Hot Temperature; Incidence; Materials Testing; Necrosis; Stents; Thermodynamics; Time Factors; Wounds and Injuries