RETROPERITONEAL COLLECTIONS - ETIOLOGY AND RADIOLOGICAL IMPLICATIONS

Purpose: Retroperitoneal collections related to the psoas, in the abse nce of pancreatitis, are uncommon. This study reviews the imaging, pat hogenesis and management of retroperitoneal collections with particula r emphasis an distinguishing imaging features and the role of percutan eous drainage. Materials and Methods: Twenty-three retroperitoneal col lections in 22 patients were reviewed in a 2-year period. Twenty-one p atients underwent computed tomography (CT), with ultrasound (US) condu cted in 14 acid magnetic resonance imaging (MRI) in four. The clinical history and associated aetiological factors were noted. Methods of dr ainage were compared, pathological/microbiological results were record ed and the clinical outcome noted. Results: The mean age of presentati on was 46.9 Sears (range 18-85 years). There was a male to female prep onderance (17 to 6). Eighteen collections proved to be abscesses with five haematomas confirmed. Of the abscesses, three were primary and 25 were secondary to spinal, gastrointestinal or renal disease. Escheric hia coli was the commonest isolated organism followed by Mycobacterium tuberculosis. No haematomas were drained. Twelve abscesses were drain ed successfully by percutaneous methods; three were managed with antib iotics alone; three were managed surgically. Conclusion: Secondary abs cesses predominate and investigation should be directed at excluding a gastrointestinal or renal source. Tuberculous disease remains a signi ficant problem. Percutaneous drainage allows effective management, eve n in the presence of a secondary abscess.