A40 FACTORS AFFECTING MEGAPOLYPECTOMY SUCCESS
Bibliographic record
Abstract
Endoscopic management of large colon polyps is increasingly favoured over surgical resection. However, complete resection of polyps 3 cm or larger, called megapolyps, is challenging with associated risks of bleeding, perforation, and unsuccessful resection. There are numerous factors that may impact success in megapolypectomy. Evaluate the success rate of attempted megapolypectomy performed at The Ottawa Hospital, and identify factors which may impact success. Additionally, we reviewed complications associated with megapolypectomy. All endoscopic procedures at TOH are flagged based upon indication and all those from 2008 onward were captured. In addition, patients were identified retrospectively using a specific billing code for endoscopic removal of polyps 3cm or larger. Chart review was performed for data collection. 356 patients with a mean age of 67 y/o and a ratio of 1:1.4 female to male patients were identified for the study. 244 megapolypectomies were successful as defined by the absence of adenoma in 4 to 6 months follow-up. In 17 cases, where the endoscopist opined a complete resection, recurrence was found on 6 to 24 months follow up. 28 patients were referred to surgery, and 67 had no follow-up information available. The 28 polyps referred to surgery were on average 4.0cm of size, and the pathologist identified in samples no disease(28.7%), high-grade dysplasia(14.2%), and malignancy(57.1%). The endoscopist was not able to complete the resection during the first intervention of 12 cases due to non-lift sign (50%) or difficult resections (50%). The remaining 16 cases had a series of endoscopic interventions to remove residual adenoma leading to the decision of referring the patient for surgical resection due to the inability of completing the resection. Of the successful megapolypectomies, the average number of interventions required for completion was 1.3 for 3-4cm polyps, and 1.6 for 4.1–5 cm polyps (P=0.0047). On average the therapeutic endoscopists removed 3.7cm polyps successfully compared to gastroenterologists removed 3.3cm polyps successfully (P=0.043). We observed a rate of 22.6 % (N=235) incorrect impression for the first intervention. The complication rate of megapolypectomies was found to be 7.6%. 25 were bleeds (93%) and 2 were perforations (7%). The overall success rate of megapolypectomy at The Ottawa Hospital is 93%. Failed resections are associated with increased polyp size, polyp location, high-grade and greater dysplasia, and increased interventions. Although endoscopists appeared confident in having performed a complete resection, in 22.6% of the failed resections, the endoscopist’s impression was incorrect. None
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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 | 0.010 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.008 | 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".