THE ROLE OF PLASTIC STENTS, ADJUVANT THERAPY AND METAL STENTS IN DISTAL MALIGNANT BILIARY OBSTRUCTION. A SYSTEMATIC REVIEW AND SERIES OF META-ANALYSES
Bibliographic record
Abstract
Purpose: The use of stents for palliation of malignant biliary obstruction is frequently complicated by occlusion. To determine the effect of differing plastic and metal stent technologies and the use of adjuvant therapy on duration of stent patency and survival in this patient population. Methods: Randomized clinical trials published in English (1980–2004) were assessed for extractable statistical information and methodological quality. Outcomes were stent patency and patient survival. Results: A meta-analysis of 4 randomized trials and 379 patients with malignant strictures treated with polyethylene stents did not show any benefit in terms of median stent patency versus Tannenbaum or hydrophilic polymer coated polyurethane [estimate of overall ratio 1.070, p = 0.787, 95% CI 0.655, 1.748]. A meta-analysis of 3 of these 4 trials with 258 patients did not show any difference in median patient survival [overall ratio 1.025, p = 0.869, 95% CI 0.762, 1.380]. A meta-analysis of 5 trials with 478 patients treated with Tannenbaum stents did not show any difference in terms of stent patency versus plastic (polyethylene, Cotton-Leung, Cotton-Huigbretse, or polyurethane) [ratio 1.150, p = 0.615, 95% CI 0.666 to 1.987]. A meta-analysis of 3 of these 5 trials with 271 patients did not show any survival advantage [ratio 0.922, p = 0.652, 95% CI 0.647, 1.313]. A meta-analysis of 4 trials with 182 patients treated with adjuvant therapies versus stent insertion alone did not show a significant treatment effect on median stent patency (ratio 1.65, p = 0.352, 95% CI 0.574 to 4.745). A meta-analysis of 3 of these 4 trials with 184 patients did not show a survival benefit [1.057, p = 0.8, 95% CI 0.692 to 1.612]. A meta-analysis of 3 trials with 324 patients treated with plastic stent insertion vs. metal stent insertion showed a significant benefit for metal stents in terms of median patency (ratio 0.44, p = 0.03, 95% CI 0.205 to 0.943). A meta-analysis of these same 3 trials also showed a survival advantage which favored metal stent insertion (0.69, p = 0.03, 95% CI 0.486 to 0.968). Conclusions: No single plastic stent design can be favored or addition of adjuvant therapy recommended based on available randomized trial data. The use of metal stents provides an advantage in terms of both median stent patency and patient survival.
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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 | 0.020 | 0.045 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.018 | 0.035 |
| Bibliometrics | 0.009 | 0.010 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".