Leaflet opening and closing dynamics of stentless bioprostheses.
Bibliographic record
Abstract
BACKGROUND AND AIM OF THE STUDY: Stiffening of the aortic root may entail asynchronous aortic leaflet movement, and result in enhanced flexion-stress in specific areas of the cusps. As stentless prostheses are more flexible than their stented counterparts, they are more likely to exhibit physiologic leaflet movements. The study aim was to compare leaflet movement dynamics in stented versus non-stented aortic valves implanted in pigs. METHODS: Aortic bioprostheses were implanted surgically into adult pigs as follows: stented Mitroflow (n = 6), stentless Solo (n = 5), and stentless Toronto SPV (n = 4). In five control animals, the native aortic valve leaflets were untouched. Postoperatively, the aortic valve was displayed by epicardial echocardiography. M-mode display of the non-coronary leaflet was applied to assess rapid valve-opening velocity (V(open)) and rapid valve-closing velocity (V(close)). RESULTS: The mean V(open) values were 29.2, 25.5, 37.8, and 31.9 cm/s, respectively, for the native, Toronto SPV, Solo, and Mitroflow valves. The mean V(close) values were 23.2, 21.9, 34.1, and 34.3 cm/s, respectively. A comparison of V(open) values showed no statistically significant difference between the valves. The Mitroflow and Solo valves yielded significantly higher V(close) values than the native and Toronto SPV valves. The Toronto SPV exhibited marked systolic leaflet folding. CONCLUSION: The stent of a bioprosthetic valve does not appear to affect leaflet velocities when compared to the stentless bioprosthetic valve. The Solo and Mitroflow valves closed more abruptly than the porcine native aortic valve; however, the Toronto SPV valve displayed diverging systolic leaflet movement patterns.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| 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) | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".