Does the Management of Anastomotic Leakage After Low Rectal Resection Affect the Long-term Oncological Outcome: A Retrospective Propensity Score Adjusted Cohort Study

Rectal cancer is one of the most common malignancies in the world. Its costs and cancer-related mortality are increasing worldwide. The surgical treatment was revolutionized in recent years by the total mesorectal excision (TME) technique as well as the laparoscopic, robotic, and transanal approach. But anastomotic leakage (AL) remains one of the most feared complications after low rectal resection regarding postoperative morbidity and mortality as well as functional outcome. Several risk factors causing AL like low level of anastomosis, large tumor mass, male gender, smoking, perioperative bleeding, and preoperative radio-chemotherapy are known. Protective ileo- or colostomy formation and transanal tube placement may decrease the risk of AL and reduces the rate of reoperation due to AL. Diverting results of the association between AL and the long-term oncological outcome (local recurrence, systemic recurrence, survival) are described in the current literature.

The International Study Group of Rectal Cancer (ISREC) provides a classification of AL according to its clinical management:

• Grade A results in no change in patient's management
• Grade B requires active therapeutic intervention without re-laparotomy
• Grade C requires re-laparotomy

This classification allows a good stratification regarding postoperative morbidity and mortality. However, the association between the ISREC-classification of AL and the long-term oncological outcome is not yet clear.