Evolution of the Remaining Rectum after Colectomy in Patients with Ulcerative Colitis in the Era of Biologic Therapy

Background: The treatment of ulcerative colitis (UC) has evolved significantly with the introduction of biotherapies and advanced endoscopic techniques, reducing the need for surgical intervention. However, surgery remains essential in cases of severe acute colitis, refractory disease, or complications such as toxic megacolon, perforation, or colorectal cancer. Methods: We conducted a retrospective analysis of 81 patients who underwent ileorectal anastomosis (IRA) for ulcerative colitis between 2010 and 2023, evaluating surgical outcomes and the long-term evolution of the remaining rectum. Data were collected on disease activity in the rectum, the incidence of rectal cancer, and the need for secondary proctectomy. Results: The study included 81 patients who underwent surgery for ulcerative colitis. The median follow-up duration was 6 years. The average age of the patients was 39 years, with a slight male predominance. Among the 81 patients, 57 (70.37%) had a prior diagnosis of ulcerative colitis, while in 24 patients (29.63%) the disease was revealed by a complication that immediately required colectomy. Regarding the extent of the disease, pancolitis was the most common form, found in 47 patients (58.02%). Concerning maintenance treatments administered before surgery in diagnosed patients, 22 patients (38.57%) were on azathioprine, 19 (33.33%) were receiving infliximab, and 16 (28.07%) were treated with mesalazine. The average duration of disease before surgery was 5 years. The surgical indications were mainly dominated by severe acute colitis, representing 61 cases (75.3%). Regarding surgical procedures, 68 patients (83.9%) initially underwent subtotal colectomy with ileostomy and sigmoidostomy, followed by restoration of continuity through ileorectal anastomosis. The average time to restoration of continuity was 16 months. Additionally, 13 patients (16.04%) directly underwent total colectomy with ileorectal anastomosis. Postoperatively, all patients received local enemas. Subsequently, 49 patients (60.49%) were treated with anti-TNF therapy, 27 (33.33%) with azathioprine, and 5 (6.17%) remained on enemas alone. Endoscopic evaluation of the remaining rectum, performed after surgery and initiation of maintenance therapy, revealed a Mayo score of 0 - 1 in 22 patients (27.16%), a Mayo score of 2 in 13 patients (16.04%), and a Mayo score of 3 in 46 patients (56.79%). Overall assessment of the remaining rectum’s evolution showed clinical and endoscopic remission in only 22 patients (27.16%). In contrast, 58 patients (71.60%) developed refractory proctitis, and one case of high-grade dysplasia was diagnosed. Finally, 31 patients (38.27%) required secondary proctectomy. Conclusion: The long-term outcomes of the remaining rectum are not always favorable. While some patients achieve clinical and endoscopic remission, a significant proportion develop refractory proctitis, necessitating additional interventions such as secondary proctectomy.