Effects of envelopes on CIED pocket healing: a head-to-head preclinical evaluation
Bibliographic record
Abstract
Abstract Background The body's natural immune response to cardiac implantable electronic device (CIED) implantation results in capsule formation with healthy surrounding tissue. Alternatively, chronic inflammation and infection can disrupt healing, cause pocket instability, and increase morbidity and cost, while complicating future interventions. Two envelopes are currently available to provide CIED stabilization: the TYRX absorbable antibacterial envelope and the CanGaroo envelope derived from porcine extracellular matrix (ECM). Effects of these envelopes on CIED pocket healing are not well known. Purpose To compare TYRX, ECM, and no envelope on CIED pocket healing. Methods An ovine model was used for time-course evaluation of pocket healing. CIEDs were implanted with TYRX or ECM per manufacturer's instructions or with negative control (no envelope) to allow for direct comparison. Envelope type was rotated across animals to minimize localized effects associated with implant location. At least one control was implanted in each animal. Across 18 sheep, a total of 50 CIED pockets were evaluated (TYRX=16, control=20, ECM=14). Morphometric and histopathologic analyses were completed for pockets at 3 days, 7 days, 4 wks, and 12 wks post-implant. An independent pathologist completed blinded histopathology assessment of all tissue blocks using ISO 10993–6:2016 scoring standards. For capsule thickness comparisons, a mixed effects model with a random subject (sheep) effect and fixed time and treatment effects was used. Results The TYRX inflammatory response was low, as indicated by scoring measurements of neutrophils, fibrin, and macrophages (Figure 1). Neutrophil infiltration scores with TYRX and control declined from moderate (≤2) at 3 days to absent (score = 0) at 4 and 12 wks, whereas ECM scoring showed an elevated response at 3 days (3.2) and 7 days (2.2). A lower rate of fibrin deposition was observed with TYRX at 3 days compared to control and ECM (0.8 vs 1.6 vs 2.0). Macrophage scoring was lower at 7 days for TYRX compared to control and ECM (2.2 vs 2.8 vs 3.0). Rapid tissue repair with TYRX was evidenced by increased fibrosis at 7 days compared to control (1.8 vs 1.0), with substantial resolution by 12 wks. Tissue granulation and neovascularization progressed similarly for pockets with TYRX and control over time. Capsule thickness peaked at 4 wks for all groups (TYRX 1.3±0.4, control 0.9±0.4, ECM 2.3±0.1), was reduced at 12 wks (TYRX 0.7±0.2, control 0.7±0.2, ECM 1.2±0.2), and ECM was significantly different compared to TYRX and control (p<0.01, Figure 2). There was no evidence of fat infiltration or calcification in any sample. Conclusion The TYRX absorbable antibacterial envelope was associated with a more rapid natural healing response with less inflammation and thin uniform capsule formation compared to ECM. These healing conditions can foster development of a well-healed pocket that may ease secondary procedures when required. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.
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 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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 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".