Post-operative Outcomes Following Urgent and Elective Surgery for Ulcerative Colitis: A Systematic Review and Meta-Analysis.

Ulcerative colitis (UC) is a chronic inflammatory condition affecting the large bowel. Surgery remains an important cornerstone in the treatment framework for UC, both in the elective setting for patients refractory to medical management and in the urgent setting for patients with acute severe UC. The aim of this study is to better define the risks associated with urgent surgery for acute severe UC when compared with elective surgery. This would allow clinicians to better outline the risks associated with urgent and elective bowel resections for UC and enable patients to make more informed decisions. A systematic review of the PubMed database was conducted independently by two authors looking at post-operative outcomes following bowel resection for UC within the elective and urgent settings. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion and exclusion criteria were pre-established using the Population, Intervention, Comparison, Outcome and Study (PICOS) framework. The primary outcome was 30-day mortality post-operatively and secondary outcomes were infection and re-operation rates following elective and urgent surgery. Bias was assessed using the Newcastle-Ottawa Score. A random effects meta-analysis was carried out. The absolute risk difference was calculated with 95% confidence intervals and p values for each of the primary and secondary outcomes. The systematic review yielded nine studies which were ultimately included within the meta-analysis. Infection rates following operation were included in two of these studies. Re-operation rates were included in four of these studies. A total of 5797 patients underwent urgent surgery and 12479 patients underwent elective surgery across the nine articles. Eight studies had a low risk of bias and one study had a medium risk of bias when assessed against the Newcastle-Ottawa Score. Overall, there was a 4.8% increased risk of mortality at 30 days post-operatively following urgent surgery when compared to elective surgery (Risk Difference (RD) = 0.048, 95% CI [0.027; 0.069], p < 0.001). This was statistically significant but the data showed significant heterogeneity (Q = 66.6, I2 = 88%). There was a 13% increased risk of post-operative infection with urgent surgery compared to elective surgery; however, this was not statistically significant (RD = 0.13, 95% CI [-0.01; 0.27], p = 0.20). There was a 4.5% increased risk of re-operation with urgent surgery; however, this was not statistically significant (RD = 0.045, 95% CI [-0.018; 0.109], p = 0.48). Patients undergoing urgent bowel resection surgery for UC therefore face a greater risk of mortality at 30 days post-operatively compared to elective surgery. This may be explained by patients in the acute setting being more de-conditioned and co-morbid than their elective counterparts. There was no statistically significant difference in rates of post-operative infection and return to the operating theatre following urgent versus elective surgery for UC. This could be due to better medical treatments allowing for better pre-operative planning and involvement of the multi-disciplinary team in the acute setting. Ultimately, the results from this study provide a reference frame for clinicians when managing patients with UC.