Two-Stage Turnbull-Cutait Pull-Through Coloanal Anastomosis for Low Rectal Cancers

To the Editor: Biondo et al¹ evaluated the efficacy of 2-stage Turnbull-Cutait pull-through hand-sewn coloanal anastomosis (TC) vs standard hand-sewn coloanal anastomosis (SHS).¹ The primary end point was 30-day postoperative morbidity. A total of 92 patients were randomized in a 1:1 ratio, presumably to detect a potential difference of 30.5% in morbidity rate between the 2 arms. The observed rates were 34.8% and 45.7% for TC and SHS. The difference (TC minus SHS) was −10.9%, which was much lower than the difference assumed at the design stage. The study was underpowered, resulting in a very large 95% CI that suggested the true difference between the 2 groups ranged from −29.5% to 8.9%.