Design: Single-centre retrospective observational study

Setting: Tertiary hospital presentations/admissions with TOA

Patients or Participants: All patients presenting with confirmed TOA on imaging between January 1st, 2010 to December 31st, 2022. 72 patients had TOA: 33 had conservative management; 7 were treated conservatively but required re-admission for further management; 25 underwent surgical management; and 7 underwent IR guided drainage.

Interventions: Conservative management involved at least 18 hours of intravenous antibiotics. Surgical management involved a laparoscopy/laparotomy for abscess drainage +/- surgical removal of para-abscess tissue. IR guided management involved drainage of the abscess under CT or ultrasound guidance.

Measurements and Main Results: Conservative treatment had a 45.8% success rate (33 of 72); surgical management had a 88% success rate (22 of 25); and IR guided management had a 71.43% success rate (5 of 7) in treating TOA. There were no significant differences between mode of intervention (surgical or IR guided) and success, p = 0.286. There was a significant difference in body mass index (BMI) between successful and unsuccessful surgical cases (29.78 vs 43.57 respectively, p = 0.002). There was a significant difference in the largest diameter of the abscess between successful and unsuccessful IR drainage cases (9.48cm vs 5.15cm respectively, p = 0.018). In validating the TOA 7cm diameter cut-off, all successful IR guided cases having a TOA diameter of 7cm or greater, and all unsuccessful IR guided cases having a TOA diameter less than 7cm in diameter, p = 0.008.

Conclusion: Conservative management has success in smaller TOAs. Surgical management can be less successful in patients with a higher BMI. IR guided drainage should be considered in larger TOAs to avoid surgical risks and morbidity.