Revisiting the Value of Drains After Low Anterior Resection for Rectal Cancer: a Multi-institutional Analysis of 996 Patients

Background Intraoperative pelvic drains are often placed during low anterior resection (LAR) to evacuate postoperative fluid collections and identify/control potential anastomotic leaks. Our aim was to assess the validity of this practice. Methods Patients from the US Rectal Cancer Consortium (2007-2017) who underwent curative-intent LAR for a primary rectal cancer were included. Patients were categorized as receiving a closed suction drain intraoperatively or not. Primary outcomes were superficial surgical site infection (SSI), deep SSI, intraabdominal abscess, anastomotic leak, and need for secondary drain placement. Three subgroup analyses were conducted in patients who received neoadjuvant chemoradiation, had a diverting loop ileostomy (DLI), and had low anastomoses < 6 cm from the anal verge. Results Of 996 patients 67% (n= 551) received a drain. Drain patients were more likely to be male (64 vs 54%), have a smoking history (25 vs 19%), have received neoadjuvant chemoradiation (73 vs 61%), have low tumors (56 vs 36%), and have received a DLI (80 vs 71%) (allp< 0.05). Drains were associated with an increased anastomotic leak rate (14 vs 8%,p= 0.041), although there was no difference in the need for a secondary drainage procedure to control the leak (82 vs 88%,p= 0.924). These findings persisted in all subset analyses. Drains were not associated with increased superficial SSI, deep SSI, or intraabdominal abscess in the entire cohort or each subset analysis. Reoperation (12 vs 10%,p= 0.478) and readmission rates (28 vs 31%,p= 0.511) were similar. Conclusions Although not associated with increased infectious complications, intraoperatively placed pelvic drains after low anterior resection for rectal cancer are associated with an increase in anastomotic leak rate and no reduction in the need for secondary drain placement or reoperation. Routine drainage appears to be unnecessary.