Bibliographic record
Abstract
Introduction: Sacral neuromodulation (SNM) is an approved therapy for OAB, urinary retention without obstruction, and bowel disorders.During surgical implantation, fluoroscopy is used to target an electrical lead to the sacral nerve and images are stored in the electronic medical record (EMR); however, these images are not routinely used for quantitative measurements of SNM lead location.We, therefore, conducted a retrospective study to capture and quantify lead depth and implant angle from these fluoroscopic images to test their utility.To examine the functional relevance of these measurements, we compared them to motor thresholds obtained during surgery.Methods: EMRs were reviewed from 16 patients with implanted Axonics SNM leads (model 1201).Lead angles and contact depths were measured from lateral fluoroscopic images.Contact depths were measured relative to the posterior sacral plane.Without image magnification, we calculated depths as the percent-age of each patient's sacral thickness (%ST).Lead angle was measured in degrees between the ventral aspect of the sacrum and the lead.As a measure of therapy relevance, we compared lead and contact locations to available bellows motor or sensory thresholds (bipolar stim) which are related to SNM efficacy.Student's t-test (Bonferroni adjustment for multiple comparisons) was used for statistical significance (p<0.05).Results: Mean contact depths ranged from 81% ST±15 (SD) for the shallowest contact (#3) to 184% ST±27 for the deepest (#0).Mean implant depths across the contacts (0-3) were all significantly different (t-test, Bonferonni adjustment).The mean lead angle was 80±11°.Bellows threshold was significantly smaller for cathodic stimulation at contact 3 vs.contact 0 (0.9±0.1, SEM vs 1.2±0.1 mA, p<0.05).Results also revealed a potential optimal lead angle for angles between 75-85°.Within this range, mean bellows thresholds across the lead were significantly lower and had a smaller range relative to implant angles outside this range (Figure 1).Conclusions: SNM contact depths and implant angles can be measured from fluoroscopic images captured during implantation.There are significant relationships between these measurements and bellows motor thresholds.Together, these results suggest quantitative fluoroscopic measurements of lead angles and contact depths are therapeutically relevant.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.373 | 0.212 |
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".