S35 Transanal Ileal Pouch-anal Anastomosis for Inflammatory Bowel Disease (ta-IPAA): A Systematic Review and Meta-analysis
Bibliographic record
Abstract
Background: Restorative proctocolectomy with transabdominal ileal pouch-anal anastomosis (abd-IPAA) has become the standard surgical treatment for medically-refractory ulcerative colitis (UC). However, this approach requires a technically difficult distal rectal dissection and anastomosis due to the bony confines of the deep pelvis. To address these challenges, the transanal IPAA approach (ta-IPAA) was developed. This novel approach may offer increased visibility and range of motion compared to abd-IPAA, although its postoperative benefits remain unclear. We performed a systematic review and meta-analysis to compare postoperative outcomes between ta-IPAA and abd-IPAA for patients with UC and to inform the frequency of postoperative outcomes in patients who underwent ta-IPAA. Methods: Ovid MEDLINE(R), EMBASE, Cochrane and Cochrane Central Register of Controlled Trials, and Scopus databases were searched from inception until May 2022 for comparative and non-comparative studies reporting postoperative outcomes of patients undergoing ta-IPAA. Reviewers, working independently and in duplicate, evaluated studies for inclusion, extracted data, and graded risk of bias. Odds ratios (OR), mean differences (MD), and prevalence ratio (PR) and their corresponding 95% confidence intervals (CI) were calculated using random-effects models. Sensitivity analysis was performed. Risk of bias was assessed based on the 9-star Newcastle Ottawa Scale for cohort-studies and for case series with a modified tool proposed by Murad et. al. Results: Ten studies comprising 283 patients with ta-IPAA were included. The cuff length was 1 to 2 cm from the transition zone in almost all studies. Total mesorectal excision was performed in 61.8% of cases and close rectal dissection in 27.9%. There was no difference in the odds of Clavien-Dindo I-II complications (OR: 0.96, 95%CI 0.27, 3.40; I2: 83%; n = 137) between ta-IPAA and abd-IPAA. The ta-IPAA pooled Clavien-Diendo I-II complications rate was 18% (95%CI 5%, 35%; I2: 83%; n = 83). ta-IPAA had no difference in the risk of Clavien Dindo III-IV complications (OR: 1.18, 95%CI 0.65, 2.16; I2: 0%; n = 57) when compared to abd-IPAA. The ta-IPAA pooled Clavien-Diendo III-IV complications rate was 10% for ta-IPAA (95%CI 5%, 17%; I2: 41%; n = 42). There was no difference in the risk of anastomotic leak between ta-IPAA and abd-IPAA (OR: 1.37, 95%CI 0.58, 3.23; I2: 0%). The pooled anastomotic leak rate was 6% for ta-IPAA (95%CI 2%, 10%; I2: 0%; n = 15). There were no deaths reported for ta-IPAA. There was no difference in mean operative time (MD: -5.34, 95%CI -24.01, 13.32; I2 = 49%; n = 329) or mean length of hospital stay (MD: −0.45, 95%CI −2.93, 2.03; I2 = 95%; n = 329) between ta-IPAA and abd-IPAA. Overall, the risk of bias was low in 3 studies, moderate in 4 studies, and high in 3 studies. Conclusion(s): This meta-analysis compared the novel ta-IPAA to the traditional abd-IPAA and found no difference in postoperative complications. Though, the frequency of postoperative complications was high in ta-IPAA. While the need for randomized controlled trails and comparison of functional outcomes between both approaches remains, this evidence should assist colorectal surgeons in deciding if the ta-IPAA is a viable alternative.
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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 | 0.013 | 0.034 |
| Meta-epidemiology (narrow) | 0.003 | 0.001 |
| Meta-epidemiology (broad) | 0.021 | 0.038 |
| Bibliometrics | 0.010 | 0.010 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.003 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.003 | 0.002 |
| 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".