Right ventricular outflow tract reconstruction with Medtronic Freestyle valve in the Ross procedure: A systematic review with meta‐analysis
Bibliographic record
Abstract
Cryopreserved pulmonary homografts (PH) are the current gold standard for right ventricular outflow tract (RVOT) reconstruction in the Ross procedure. Unfortunately, their use is limited by a relatively scarce availability and high cost. Porcine stentless xenografts (SX) such as the Medtronic Freestyle SX are increasingly being used, although it is unclear whether the hemodynamic performance and the long-term durability are satisfactory. The present systematic review followed the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement. The pooled treatment effects were calculated using a weighted DerSimonian-Laird random-effects model. We also evaluated the effect of time after RVOT reconstruction on valve gradients using meta-regression. Six studies with a total of 156 patients met the inclusion criteria. The pooled estimates for the pooled follow-up of 37 months were: 1.3% operative mortality, 94.8% overall survival, 7.5% structural valve deterioration, 5.2% reintervention, 73.3% asymptomatic, and 1.5% moderate or severe pulmonary insufficiency. Peak valve gradients were significantly correlated with time after RVOT, increasing during follow-up. Three studies compared PH with SX, one concluded that the SX is an acceptable alternative for RVOT reconstruction, whereas two concluded that this valvular substitute had inferior performance. The Freestyle SX can be considered as an alternative to PH, although it might be associated with more reinterventions, higher peak valve pressure gradients, and pulmonary valve dysfunction.
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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 | 0.007 | 0.015 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.014 | 0.029 |
| Bibliometrics | 0.004 | 0.005 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".