Bibliographic record
Abstract
The introduction of the Toronto stentless porcine valve (SPV) (St. Jude, Minneapolis, MN), recently approved by the Food and Drug Administration following a 6-year multi-institutional clinical trial from 1991 to 1997, reflects an evolutionary pursuit of an ideal valve substitute, namely, low thrombogenicity, freedom from anticoagulation, durability, easy availability, resistance to infection, and easy implantability. Currently, four different types of valve replacement have been time tested: mechanical valves, cryopreserved aortic homograft, stented heterograft, and pulmonary autograft (Ross procedure), and none of the available valve substitutes meet all the criteria of an ideal valve. The mechanical valve's favorable properties of durability and easy implantability are susceptible to thrombus formation, which requires lifelong anticoagulation. Although the aortic homografts are durable, with low incidence of infection and thrombogenicity, their widespread application has been limited by the lack of availability. The pulmonary autograft, with its native aortic valve properties, has been shunned by some surgeons because it requires a demanding technical expertise in implantation and needs an allograft in the pulmonary position. Stented xenografts are characterized by "off-the-shelf" availability, freedom from anticoagulation, easy implantability, and low incidence of infection. Its major drawback has been its limited durability. Another limitation is its residual transvalvular gradient. A modified version, a stentless xenograft, has been introduced to improve hemodynamic profiles in the hope of subsequent superior structural durability and patient survival. Two valves have been approved by the Food and Drug Administration, the Toronto SPV and the Freestyle valve (Medtronic, Minneapolis, MN). At The Methodist Hospital and the Baylor College of Medicine, the Toronto SPV stentless valve has been our stentless xenograft valve of choice. We therefore review the historical evolution, design advantages, surgical techniques, and clinical outcomes of this valve.
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.
How this classification was reachedexpand
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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.004 | 0.004 |
| Bibliometrics | 0.001 | 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 | 0.001 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".