OBJECTIVETo explore the effect of continuous negative pressure drainage with intermittent irrigation on surgical site infection (SSI) after laparoscopic extralevator abdominoperineal excison (ELAPE).

METHODSClinical data of 28 rectal cancer patients who underwent continuous negative pressure drainage with intermittent irrigation following laparoscopic ELAPE (negative irrigation group) at our department from March 2016 to August 2017 were analyzed retrospectively. At the same time, 32 rectal cancer patients who underwent laparoscopic ELAPE and simple presacral drainage from January 2014 to February 2016 were included as controls (simple drainage group). Self-made double cannula: one silicon rubber drainage tube was used; 3 side holes were cut at the front end with 1-2 cm interval; tube was ranked intermittently and oppositely; a small hole was cut in the middle of rear; the infusion tube was placed through the small hole to the front side of the drainage tube (to rinse when the drainage was turbid). The placement and use of self-made double cannula: it was placed in the presacral space and was drawn from the medial to the sciatic tubercle, then was connected to drainage bag for 24 hours; when no blood was observed, the drainage tube was connected to negative pressure drainage ball, keeping negative pressure status. The development of SSI within 30 days postoperatively and other perioperative parameters were compared between the two groups.

RESULTSThere were no statistically significant differences in baseline data between two groups (all P>0.05). Incidence of SSI in negative irrigation group was significantly lower than that in simple drainage group [14.3% (4/28) vs. 43.8% (14/32), χ=6.173, P=0.013]. Additionally, a shorter postoperative hospital stay was observed in negative irrigation group [(9.8±1.5) days vs. (11.4±2.6) days, t=2.918, P=0.005]. Besides, other perioperative parameters, including operative time, intraoperative blood loss, time to removal of drainage tube, etc were not significantly different between two groups (all P>0.05). After adjusting to confounders, multivariate analysis showed that negative pressure drainage was an independent protective factor for SSI following laparoscopic ELAPE (OR=0.214, 95%CI:0.060-0.762, P=0.002).

CONCLUSIONContinuous negative pressure drainage with intermittent irrigation can effectively decrease the incidence of SSI following laparoscopic ELAPE, and is safe and simple.