Impact of Transanal Drainage Tube Placement on Anastomosis Leakage Incidence After Rectal Cancer Surgery

Background: Anastomotic leakage (AL) following rectal cancer surgery is a significant cause of mortality and morbidity. Although transanal drainage tubes are expected to reduce the rate of AL, their preventive effect remains controversial. Aim: To evaluate whether transanal drainage tube (TAD) provides protection against AL in patients without other protective methods after low anterior resection (LAR). Methods: A retrospective cohort study was performed in patients undergoing LAR for rectal cancer between 2018 and 2023. Based on postoperative management, patients were divided into four distinct groups as follows: in TAD group, after colorectal anastomosis, a 32F silicone tube was inserted through the anus by more than 5 cm above the anastomosis. The tube was secured around the anus with a skin suture and a drainage bag was attached. The tube was removed after 3-5 days after surgery. In the non-TAD group, no transanal drainage tube and no diverting stomas, respectively, were used after the anastomosis. In the ileostomy and colostomy group a stoma was often performed as a primary measure in preventing anastomotic leakage. Clinical characteristics and postoperative complications were compared among the groups. Complications were categorized as general (eventration, seroma) or septic (fistula, abscess) and further classified as early (<7 days after surgery) or tardive (between 7 and 30 days after surgery). Statistical significance was defined as a p-value < 0.05. Results: A total of 171 patients were included: 47 (27.5%) in the TAD group, 54 (32.2%) in the non-TAD group, 25 (14.6%) in colostomy group, and 45 (26.3%) in ileostomy group. Overall, eight patients (4.7%) developed anastomotic leakage (AL). In the non-TAD group, 3 patients experienced AL (all early); in the ileostomy group, 2 patients (1 early, 1 tardive); and in the colostomy group, 2 patients (both tardive). The TAD group had one patient with AL as a tardive complication. The incidence of early general complications was significant lower in TAD group compared with the non-TAD group (OR 0.23, 95% CI [0.06-0.85]; p = 0.004), while there was no significant difference in early septic complications between TAD and ileostomy group (p = 0.71). The incidence of tardive general complications was significantly more frequent in the ileostomy group (OR 0.10, 95% CI [0.02-0.44]; p = 0.0008) compared with TAD group. Overall, total complications were significantly lower in TAD group compared to non-TAD (OR 0.15, 95% CI [0.05-0.44]; p < 0.001), ileostomy (OR 0.20, 95% CI [0.07-0.56]; p = 0.003), and colostomy ((OR 0.46 CI [0.21-0.99]; p = 0.049) groups. Furthermore, the TAD group showed a reduction rate of AL compared to the ileostomy, colostomy, and non-TAD groups (2.12% vs. 4.4%, 8%, and 5.5%) but the incidence of AL was almost similar (p = 0.65). Conclusions: The elective use of TAD is a simple and effective protective method for the prevention of overall postoperative complications, also helping to reduce the rate of AL in patients. Nevertheless, there is limited information in the literature regarding the optimal size and material of TAD, despite these factors playing an important role in the viability and effectiveness of the method.