Randomized, Single-Blind Comparison of Sidehole and End-Hole v End-Hole Ureteral Catheters
Bibliographic record
Abstract
BACKGROUND AND PURPOSE: Flexible 5F, open-ended ureteral catheters are currently available only with an end hole, which can lead to difficulties during retrograde pyelography and when aspirating urine for culture or cytology, as the hole frequently sucks up urothelium or debris and becomes occluded. We compared the traditional end-hole ureteral catheter with a catheter having a sidehole as well. PATIENTS AND METHODS: Twenty-two patients requiring aspiration of urine from the renal pelvis for cytology study or culture or to empty the collecting system during retrograde pyelography or prior to percutaneous nephrolithotomy were enrolled. Both end-hole-only and end-hole + sidehole catheters were employed in each patient, but the order of use was randomized, and the endourologist was blinded to the catheter type. Catheters were placed in the renal pelvis under fluoroscopy, and the renal collecting system was filled with 5 mL of contrast medium. The catheters were compared on volume aspirated initially, volume aspirated after repositioning, and ease of use judged on a three-item adjectival scale. RESULTS: The end-hole + sidehole catheters were able to aspirate more fluid initially (5.1 mL v 2.6 mL; P < 0.001) and after repositioning (6.0 mL v 3.4 mL; P < 0.001). In addition, blinded urologists rated these catheters easier to use (12.0 v 3.0; maximum score 15; P < 0.001). CONCLUSIONS: The addition of a sidehole to ureteral catheters offers significant advantages to the endourologist seeking to aspirate urine from the upper collecting system for culture or cytology or during retrograde pyelography and in preparation for stone removal. The sidehole prevents occlusion of the catheter when it sucks up the urothelium and provides more efficient drainage of the upper tract.
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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 | 0.005 | 0.009 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.007 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.004 | 0.003 |
| Insufficient payload (model declined to judge) | 0.009 | 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".