A pilot randomised controlled trial evaluating postoperative packing of the perianal abscess

Traditional management of a perianal abscess involves incision and drainage followed by packing of the cavity until healing by secondary intention is complete. The evidence supporting this is lacking however, and regular postoperative packing is time-consuming, painful and costly. This pilot study aimed to assess whether healing could be achieved safely without packing and to obtain preliminary results to enable sample size calculation in order to facilitate the implementation of a large multicentre randomised controlled trial. ClinicalTrials.gov Identifier: NCT01853267.

Fourteen patients with perianal abscesses were randomised to packing or non-packing of the abscess cavity postoperatively. Outcome measures were time to healing, abscess recurrence, fistula formation and postoperative pain.

Healing in the non-packing group was faster compared to the packing group: mean 26.8 days (95 % confidence interval 22.7 to 30.7) vs 19.5 days (13.6 to 25.4); P = 0.047. There were no differences in recurrence rates between the groups (37.5 % packing group vs 33.3 % non-packing group; P = 0.580) at a median follow-up of 90.0 weeks (interquartile range (IQR) 26.0). In patients presenting with recurrence, one fistula was found in the packing group with no fistulas in the non-packing group. The non-packing group reported less pain 2 weeks postoperatively: median (IQR) 2.00 (3.00) vs 0.00 (1.00); (P = 0.030).

Within the limitations of a small sample population, the results of this pilot study suggest that not packing the perianal abscess cavity after incision and drainage is safe. Our results show not packing confers less pain with a faster healing time compared with the conventional packing method, and this is a novel finding. These results need to be corroborated in the setting of a larger multicentre randomised controlled trial.