Carpentier-Edwards Perimount Valves?Morphological Findings in Surgical Explants
Bibliographic record
Abstract
Valvular heart disease is a growing medical problem in the 20th century, with an increasing number of patients undergoing valve repair and replacement surgery. 1 Worldwide, more than 55% of implanted prosthetic heart valves (PHV) are mechanical heart valves (MHV) and 45% are bioprosthetic heart valves (BHV). 2 BHV more closely resemble native valves in design than do mechanical valves, and are, therefore, better able to mimic normal blood flow patterns through a three-cusp valve. 1 BHV may comprise porcine aortic tissue or bovine pericardium.The Carpentier-Edwards Perimount (CEP) bioprosthesis is a second-generation pericardial valve made of bovine (calf) pericardial tissue. 1 The tissue is cut from selected regions of bovine pericardium and mounted on a lightweight Elgiloy frame covered with a porous, knitted polytetrafluoroethylene (PTFE) fabric.The sewing ring is made of molded silicone rubber covered with PTFE cloth, which enables the surgeon to sew the valve into place.Few studies have examined the postimplantation morphological changes in a series of explanted CEP.Herein, we describe such changes in 23 CEP valves, explanted at our institution since the start of their use in 1981. MATERIALS AND METHODSFrom 1981 to 2005, a total of 1042 Carpentier-Edwards bovine pericardial bioprostheses (CEP) were implanted in our hospital by one group of surgeons.CEP bioprostheses explanted at surgery or autopsy were examined at the Toronto General Hospital Department of pathology by one pathologist (JB) with an interest in cardiovascular pathology and prosthetic heart valves.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".