Postoperative packing of perianal abscess cavities linked to poor outcomes

UK: According to  PPAC2 trial, which has been published in the British Journal of Surgery, postoperative perianal abscess wound cavities treated without internal wound packing produce noticeably less discomfort without markedly raising the risk of perianal fistula and abscess recurrence.

An infection and swelling around the anus brought on by blockage of the anal glands causes perianal abscess, a frequent and unpleasant illness. For more than 50 years, there has been no change in how perianal abscess is treated. Following surgical abscess incision and drainage while under general anesthesia, the community will continue to dress (pack) the resulting wound cavity internally until the wound is healed. There is no evidence to support the surgical orthodoxy that packing decreases the rate of perianal fistula development and abscess recurrence.

The Postoperative Packing of Perianal Abscess Cavities (PPAC2) trial's goal was to ascertain whether leaving perianal abscess cavities unpacked would be less unpleasant overall while reducing the risk of perianal fistula and abscess recurrence.

This research was accomplished with the help of the Postoperative Packing of Perianal Abscess Cavities (PPAC2) trial. A primary perianal abscess in an adult participant who had been hospitalized to an NHS hospital for incision and drainage was the subject of a multicenter, RCT (two-group parallel design). Online randomization was used to assign participants in a 1:1 ratio to either continue postoperative wound packing or not. 433 individuals (mean age 42 years) were randomly distributed across 50 sites between February 2018 and March 2020. Over the course of six months, blinded data were gathered through clinics, the phone, and symptom diaries. Pain was the main result (mean maximum pain score on a 100-point visual analogue scale). Secondary endpoints were pain prior to, during, and following dressing changes; postoperative recurrence of perianal fistula and abscess; bleeding (requiring transfusion or return to theatre); and rate of wound healing (at 4, 8, and 26 weeks).

Conclusive points of the trial:

• 214 subjects assigned to packing experienced more pain than 220 participants assigned to non-packing (38.2 versus 28.2, mean difference 9.9; P <0.0001).
• Fistula-in-ano was uncommon in both groups, with 32/213 (15%) in the packing group and 24/220 (11%) in the non-packing group (OR 0.69, 95% c.i. 0.39 to 1.22; P = 0.20).
• The percentage of patients who experienced an abscess recurrence was also minimal: 13/223 (6%) in the non-packing group and 7/213 (3%) in the packing group (OR 1.85, 95% c.i. 0.72 to 4.73; P = 0.20).
• The no-packing group was favored in terms of pain levels both during and after dressing changes (mean difference 10.2, 95% c.i. 4.1 to 16.3; P 0.001 and 5.8, 95% c.i. 0.1 to 11.5; P = 0.007).
• Fistula was discovered after a follow-up of 6 months in 32/213 (15%) of the packing group and 24/220 (11%) of the non-packing group (OR 0.69, 95% c.i. 0.39 to 1.22; P = 0.204).
• Total healing was documented in 112/163 (69%) in the packing group and 138/175 (79%) in the no-packing group during the course of the 6-month follow-up period (P = 0.046).

The authors came to the conclusion that avoiding abscess cavity packing is less painful without increasing the risk of morbidity. The optimal course of treatment is to avoid packing perianal abscess wounds following drainage surgery, they added.

Reference

Katy Newton, Jo Dumville, Michelle Briggs, Jennifer Law, Julia Martin, Lyndsay Pearce, Cliona Kirwan, Thomas Pinkney, Alexander Needham, Richard Jackson, Simon Winn, Haley McCulloch, James Hill, PPAC2 Collaborators, Postoperative Packing of Perianal Abscess Cavities (PPAC2): randomized clinical trial, British Journal of Surgery, Volume 109, Issue 10, October 2022, Pages 951–957, https://doi.org/10.1093/bjs/znac225