**5. CAL incidence**

The incidence of CAL in colorectal surgery continues to be under-evaluated and under-reported. It is a much more frequent situation than in the public domain. It is more frequent in more distal anastomoses, and a recent multicenter European work was carried out only with ileocolic anastomoses that confirms this underevaluated frequency. The repercussions it causes are minor and can be interpreted as other causes. On the other hand, there may be caused a certain embarrassment in the surgical environment in admitting its existence and the interpretation of its existence as a technical failure, a wrong surgical indication, or a deficient surgical plan. CAL are frequent and only do not happen to those who do not operate or work in a parallel reality. CAL is typically diagnosed 5–8 days post-surgery, although some case reports have demonstrated that a delayed presentation beyond 30 days is possible [13]. Gessler et al. debated the question of two different types of leakages (earliest and latest), confirming that 20% of patients had their leakage diagnosed after discharge and at readmission [14]. While AL can occur in up to 24% of patients undergoing distal rectal surgery, combined rates for surgery performed

at any level of the intestinal tract are accepted to be 6–7% [15, 16]. One systematic review of preoperative, intraoperative, and postoperative risk factors for colorectal anastomotic leaks shows the prevalence of anastomotic leaks varies from 1 to 19% according to anatomical site. The highest leak rates occur with extraperitoneal anastomoses. The highest rate of AL occurred in coloanal and colorectal anastomoses (5–19%). This rate was significantly greater than that seen in enteroentero (1–2%), ileorectal (3–7%), ileocolic (1–4%), and colocolic (2–3%) anastomoses [17]. Degiuli et al. published a retrospective multicenter study that used data from 24 Italian referral centers of the Colorectal Cancer Network of the Italian Society of Surgical Oncology. The overall incidence of leaks in anterior low resection for rectal cancer was 10.2% and the 30-day leak-related mortality was 2.6% [18]. Goshen-Gottstein et al. analyzed CAL in colorectal procedures that included bowel resection and primary bowel anastomosis performed at Sheba Medical Center in 2012. The overall leak rate was 8.4% [19]. Data were retrieved from the Dutch Surgical Colorectal Audit by Bakker et al. CAL in patients undergoing colonic cancer resection with the creation of an anastomosis occurred in 7.5% of 15,667 patients [20]. Unexpectedly, Frasson et al. reported in a prospective multicentric study of 1102 patients a rate leak in right colectomy of 8.4%, a higher value than most equivalent studies [21].
