Five retrospective case series (306 patients, of whom 86 underwent SIAA and 220 IPAA) were included in the review.
Quality scores ranged from 1 to 5.
There were statistically significant differences between the groups for reconstruction failure (OR 3.21, 95% CI: 1.24, 8.34), abdominal salvage (OR 9.50, 95% CI: 3.14, 28.77) and perianal sepsis (OR 2.36, 95% CI: 1.01, 5.53), all of which favoured the IPAA group (based on three or four studies). Anastomotic stricture, inflammation of neorectum/ileal pouch, enterovaginal fistula, anastomotic leak and small bowel obstruction did not differ significantly between the groups. Statistically significant heterogeneity was not found for any outcome, although I2 was greater than 50% for anastomotic stricture and inflammation of the neorectum/ileal pouch. Functional outcomes favoured IPAA (based on one or two studies). Statistical significance was not found for abdominal salvage or perianal sepsis in subgroup analyses of studies with a mean age below 18 years and of studies scoring 3 or more for quality. Funnel plots (presented for one outcome) did not show evidence of publication bias.