Clinico-radiological indications for drainage of isolated amebic liver abscess using a rule of 5's: results of a 10 year retrospective review

Abstract

Introduction: Liver abscesses from amebiasis are primarily managed using medical therapy. Although guidelines exist for drainage of hepatic abscess, these indications are usually individualized. A simplified approach to determine the need for surgical intervention may be desirable. Methods: A 10 year retrospective study was carried out at the University of Ilorin Teaching Hospital, Nigeria between October 2007 and September 2017. A structured pro forma was used to study patients with suspected amebic liver abscess. Patient demographics, clinical and laboratory features as well as radiological findings were noted. The types of treatment and outcomes of management were also determined. The SPSS v20 software was used. Appropriate statistical analysis including chi square, Fischer's exact, Independent T test and Mann U Whitney test were utilized. A p- value of < 0.05 was considered significant. Results: A total of 89 patients were treated for amebic liver abscess during this period. Thirteen (13) patients required drainage. Variables associated with drainage included the following: Symptom duration >5 weeks, Abscess cavity >5cm, estimated fluid volume >500mls on imaging, abscess cavity wall thickness >5mm, liver segment involved < segment 5(i.e. segments 1-4 or the left hemi-liver) and parenteral antibiotic therapy lasting more than 5 days. Open drainage via a mini-laparotomy was the preferred method of intervention for technical reasons. Conclusion: A simplified rule of 5's may be used to determine the need for drainage of liver abscesses. These findings need to be validated by appropriately powered prospective studies.