What is the role of mechanical bowel preparation in patients with pilonidal sinus undergoing surgery? Prospective, randomized, surgeon-blinded trial.

The aim of this study was to determine the effect of a mechanical bowel preparation on postoperative surgical wound infections in patients treated with identical antimicrobial prophylaxis undergoing wide excision and primary closure for chronic pilonidal sinus disease. Patients more than 18 years old were included in the study. All patients had intravenous antimicrobial prophylaxis at the time of anesthesia induction. In a prospective, randomized setting, patients were allocated to either the bowel preparation group or the no-bowel-preparation group. Mechanical bowel preparation was performed using an oral sodium phosphate solution. On the morning of the procedure a rectal enema was performed with the phosphate solution. The primary outcome measure was the rate of wound infection, but all postoperative complications and recurrences were recorded. All patients were actively observed for 1 year after discharge. The overall infection rate for the entire study population was 12.8% (13/101) including 14.3% (7/49) of those who had had the bowel preparation and 11.5% (6/52) of those with no bowel preparation. There was no statistically significant difference between groups (P = 0.680). The mean rate of recurrence for all 101 patients was 4.9% (5/101) at 19.2 months (range 12-32 months) of follow-up. The recurrence rate was 6.1% (3/49) in the bowel preparation group and 3.8% (2/52) in the no-bowel-preparation group (P = 1.000). Although the number of patients is small in this study, our results showed that the mechanical bowel preparation does not cause a decrease in the rate of surgical wound infections after excision and primary closure in patients with chronic pilonidal sinus disease.