Background and purpose: Stapled anterior resection (AR) and low anterior resection (LAR) are standard procedures for colorectal cancer, with colorectal anastomosis performed using a circular stapling device, resulting in two circular stapler donuts. This study evaluated the association between anastomotic donut morphology and the risk of anastomotic leakage (AL).
Materials and methods: In this prospective single-centre study, 75 patients with colorectal cancer who underwent AR or LAR with stapled colorectal anastomosis between December 2017 and November 2019 were included. During surgery, the maximum and minimum heights and widths of both colonic and rectal donuts were measured and assessed in relation to AL and postoperative complications.
Results: Among the 75 patients, 33 (44%) had rectal cancer, 53% had stage III disease, and 16 (21%) underwent ultra-low anterior resection. The mean operative time was 135.68 minutes, and the median tumour distance from the anal verge was 9.5 cm. All retrieved donuts were complete, and all intraoperative air leak tests were negative. Anastomotic leakage occurred in 3 patients (4%). A smaller minimum colonic donut width was significantly associated with an increased risk of AL (P = 0.011), while a smaller minimum colonic donut height was significantly associated with postoperative surgical complications (P = 0.011). Although all cases of AL occurred in patients with a colonic donut height of ≤4 mm, this finding was not statistically significant (P = 0.073). No significant associations were found between rectal donut morphology and AL or postoperative complications.
Conclusion: A smaller minimum colonic donut width was associated with an increased risk of AL, whereas a smaller minimum colonic donut height was associated with postoperative complications. These simple intraoperative measurements may complement established risk factors and help identify patients who may benefit from a diverting stoma or immediate revision of the anastomosis