Safety and Feasibility of Combined taTME and Delayed Coloanal Anastomosis in High-Risk Low Rectal Cancer

Overview

This prospective cohort study evaluated the safety and practicality of combining transanal total mesorectal excision (taTME) with delayed coloanal anastomosis (DCAA) in high-risk low rectal cancer patients. The approach aimed to reduce anastomotic leakage and stoma-related morbidity compared to standard immediate coloanal anastomosis with diverting ileostomy (ICAA-taTME).

Background

Laparoscopic total mesorectal excision (TME) for low rectal cancer is challenging in patients with high-risk features such as obesity, narrow pelvis, or post-neoadjuvant therapy changes, often resulting in suboptimal resection margins. Transanal TME (taTME) offers improved visualization and resection quality but is associated with higher anastomotic leakage rates. Immediate coloanal anastomosis with diverting ileostomy reduces leakage severity but carries significant stoma-related complications. Delayed coloanal anastomosis (DCAA), a two-stage technique involving colonic exteriorization followed by delayed anastomosis, may mitigate these risks but lacks contemporary evidence in high-risk patients undergoing taTME.

Data Highlights

Seventy-four consecutive high-risk low rectal cancer patients were prospectively enrolled and assigned to either DCAA-taTME or ICAA-taTME groups based on informed surgical preference. High-risk factors included male sex, ASA class ≥ III, BMI ≥ 25 kg/m2, diabetes, chronic renal insufficiency, alcoholism, smoking, and prior neoadjuvant therapy. Surgical procedures were standardized and outcomes were assessed with serial inflammatory markers and patient-reported functional outcomes.

Key Findings

• taTME facilitates precise distal rectal dissection and improved circumferential resection margin clearance in anatomically complex cases.
• Higher anastomotic leakage rates have been reported with taTME compared to laparoscopic TME (12.9% vs. 8.9%).
• Diverting ileostomy reduces severity of leakage but is associated with a 43% rate of stoma-related complications and >20% morbidity after closure.
• DCAA involves a two-stage approach with colonic exteriorization and delayed anastomosis 10–14 days later, potentially reducing leakage risk by promoting tissue repair and avoiding stomas.
• This study uniquely applies DCAA combined with taTME in a prospectively enrolled high-risk cohort, with rigorous follow-up including inflammatory markers and functional outcomes.

Clinical Implications

Combining DCAA with taTME may offer a safer alternative to immediate anastomosis with diverting ileostomy in high-risk low rectal cancer patients by potentially lowering anastomotic leakage rates and avoiding stoma-related morbidity. Surgeons should consider patient-specific risk factors and discuss the benefits and risks of delayed versus immediate anastomosis approaches. Further adoption requires standardized protocols and careful postoperative monitoring.

Conclusion

The integration of delayed coloanal anastomosis with transanal TME appears to be a feasible and safe strategy in high-risk low rectal cancer patients, potentially reducing anastomotic complications and stoma-related morbidity without compromising oncological or functional outcomes.

References

1. European Society of Coloproctology (ESCP) Multinational Study 2020 -- Anastomotic Leakage Rates after taTME
2. Turnbull and Cutait 1961 -- Delayed Coloanal Anastomosis Technique