Corrosive behaviour of Amplatzer® devices in experimental and biological environments
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
PURPOSE: Nitinol, a nickel-titanium alloy, is a valuable material in the construction of interventional endoluminal devices because of its biocompatibility, super elasticity, high resiliency and shape memory. The possibility of nickel toxicity has been raised with devices constructed of Nitinol. Our investigation examines the long-term corrosive behavior of this alloy in experimental and biological environments. METHODS: We performed three levels of study. Microscopic examination was made of 64 devices of various sizes, randomly selected from 240 Amplatzer Septal Occluders that had been exposed to saline solution at 37 degrees C for fourteen months. All samples were studied by electron microscopy ranging from 50 to 5000 times magnification. We also studied microscopically 3 Amplatzer devices explanted 18-36 months after implantation in dogs, and 2 Amplatzer Septal Occluders removed from patients 18 months (cardiac transplant) and 19 months (died of causes unrelated to device placement) after implantation, which were examined grossly and by electron microscopy up to 5000 times magnification. We then measured the levels of nickel in the blood using inductive plasma mass spectroscopy in 19 patients with implanted Amplatzer devices, making measurements before and 6 months after implantation. RESULTS: Electron microscopy showed an intact titanium oxide layer with no evidence of corrosion in vitro and in vivo. One explanted device in direct contact with the platinum leads of a pacemaker for eighteen months showed minor pitting of the titanium oxide layer believed to be galvanic in nature. No wire fractures were found in vitro after cycle testing with 400 million cycles, nor in devices taken from the animals and humans. Biochemical studies showed no significant elevation of levels of nickel levels after implantation. CONCLUSION: Nitinol wire of Amplatzer septal occlusion devices is resistant to corrosion when exposed to physiologic saline solution, and in experimental animals as well as humans. A device in contact with a platinum pacemaker electrode developed minimal pitting of the titanium oxide layer, believed to be galvanic in nature and of no structural or clinical significance. There is no increase of concentrations of nickel in the blood of patients who have received Amplatzer nitinol devices. These favorable testing results reveal that nickel-titanium is an inert, corrosion resistant alloy.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it