P1132Transanal Transection Single-Stapled (TTSS) versus Double-Stapled (DS) Ileal Pouch-Anal Anastomosis (IPAA) in Ulcerative Colitis: first comparative study advancing functional precision

Abstract Background Restorative proctocolectomy with Ileal Pouch-Anal Anastomosis (IPAA) is the reference option for Ulcerative Colitis (UC) requiring surgery. The traditional Double-Stapled (DS) technique has intrinsic limitations related to the stapled-line intersections and the suboptimal control of rectal cuff length, predisposing to dehiscence and cuffitis. The Transanal Transection and Single-Stapled anastomosis (TTSS), introduced in 2019 and initially applied to rectal cancer, was conceived to improve pouch physiology through more precise rectal cuff management. This study evaluates TTSS as a practical embodiment of functional-precision surgery and provides the first direct comparison with DS in restorative IPAA. Methods A prospective single-centre comparative study was conducted on 41 UC patients undergoing IPAA (9 TTSS and 32 DS), all operated by one senior colorectal surgeon, ensuring technical uniformity. Consecutive patient enrolment minimized selection bias. Functional performance, assessed at 3 and 6 months after stoma closure through the validated Pouch Functional Score (PFS) - a composite index of continence, urgency and medication use - was the primary endpoint. Operative safety and feasibility were secondary endpoints. Data were analysed with Wilcoxon-Mann-Whitney and Fisher tests; results are reported as medians with IQR and p-values. Results Baseline characteristics (age, sex, BMI, smoking, comorbidities) were well balanced between groups, confirming the suitability for direct comparison. Median PFS was similar between TTSS and DS at 3 months (5 IQR 2-9 vs 7 IQR 4-10; p = 0.4) and 6 months after stoma closure (7 IQR 0-13 vs 4 IQR 3-9; p = 0.6). No significant differences emerged in postoperative complications (4% vs 33%; p = 0.8), leakage (0% vs 3%; p 0.9), hospital stay (10 IQR 7-11 vs 7.5 IQR 6-9 days; p = 0.2) or interval to stoma closure (4 IQR 3-6 vs 4.5 IQR 3-6; p = 0.8). Operative time was longer for TTSS (335 IQR 293-353 vs 198 IQR 150-255 minutes; p = 0.001). Conclusion As the first comparative evaluation of TTSS versus DS in restorative IPAA, this study identifies TTSS as a feasible, reliable and function-oriented alternative, advancing the concept of functional-precision surgery in benign colorectal disease. Notably, it offers a true head-to-head comparison, explicitly evaluating TTSS as a distinct technique rather than grouping it within the category of transanal approaches. The longer operative time of TTSS reflects the learning curve of a recently introduced technique. By enriching the growing literature on TTSS, this study encourages its broader adoption and supports the development of multicentre datasets, paving the way for more robust conclusions and helping refine the role of TTSS in UC surgery. References: Magro, F., Gionchetti, P., Eliakim, R., Ardizzone, S., Armuzzi, A., Barreiro-de Acosta, M., Burisch, J., Gecse, K. B., Hart, A. L., Hindryckx, P., Langner, C., Limdi, J. K., Pellino, G., Zagórowicz, E., Raine, T., Harbord, M., & Rieder, F. (2017). Third European evidence-based consensus on diagnosis and management of ulcerative colitis. Part 1: Definitions, diagnosis, extra-intestinal manifestations, pregnancy, cancer surveillance, surgery, and ileo-anal pouch disorders. Journal of Crohn’s and Colitis, 11(6), 649–670. https://doi.org/10.1093/ecco-jcc/jjx008 Spinelli, A., Foppa, C., Carvello, M., Sacchi, M., de Lucia, F., Clerico, G., Carrano, F. M., Maroli, A., Montorsi, M., & Heald, R. J. (2021). Transanal Transection and Single-Stapled Anastomosis (TTSS): A comparison of anastomotic leak rates with the double-stapled technique and with transanal total mesorectal excision (TaTME) for rectal cancer. European Journal of Surgical Oncology, 47(12), 3123–3129. https://doi.org/10.1016/j.ejso.2021.08.002 Spinelli, A., Foppa, C., Maroli, A., Sacchi, M., Armuzzi, A., Danese, S., Bemelman, W., & Carvello, M. (2023). Transanal transection and single-stapling techniques are associated with shorter rectal cuff and lower urgency rate after pouch surgery compared with the double-stapled approach. Surgery (United States), 174(4), 808–812. https://doi.org/10.1016/j.surg.2023.06.027 Lovegrove, R. E., Fazio, V. W., Remzi, F. H., Tilney, H. S., Nicholls, R. J., & Tekkis, P. P. (2010). Development of a pouch functional score following restorative proctocolectomy. British Journal of Surgery, 97(6), 945–951. https://doi.org/10.1002/bjs.7021 Conflict of interest: Colombo, Francesco: No conflict of interest Micheloni, Laura: None Gatti, Francesca: No conflict of interest Pennacchi, Luca: No conflict of interest Gridavilla, Daniele: No conflict of interest Maconi, Giovanni: Personal Fees: Abbvie, Arena Pharmaceuticals, Alfa-Wasserman, Fresenius-Kabi, Gilead, Janssen Cilag, Roche Non-financial Support: Takeda, Abbvie, Alfa-Wasserman Danelli, Piergiorgio: No conflict of interest