Retroperitoneal abscess resulting from perforated acute appendicitis: analysis of its management and outcome

Abstract

Background: Acute appendicitis may become life threatening if it is complicated by retroperitoneal abscess. To the best of our knowledge, only case reports have been documented; thus, we analyzed the published experiences and reviewed this issue.

Materials and methods: In addition to two patients treated at our institution, a PubMed search identified 22 cases of acute appendicitis, complicated by retroperitoneal abscess, reported by 18 authors between 1955 and 2005. The patients' characteristics, onset of symptoms, timing and methods of diagnosis and management, and outcome are reviewed and analyzed.

Results: Most of the patients were adults (21/24, 87.5%), of whom seven were older than 65 years. None of the patients presented with the classical symptoms of acute appendicitis at the onset of the disease, and less than half (9/24) reported abdominal pain. The average interval between the onset of symptoms and diagnosis was 16 days, and the most effective diagnostic tool was computed tomography. Pathogens were usually polymicrobial, and appendectomy followed by adequate drainage of the abscess was the best treatment. The mortality rate was 16.7% (4/24), and all deaths were caused by profound sepsis. According to the available data, the average hospital stay was 27.3 days for the survivors.

Conclusion: The formation of complicated retroperitoneal abscesses involving thigh, psoas muscle, perinephric space, or even the lateral abdominal wall is a serious complication of perforated acute appendicitis. An intra-abdominal pathological abnormality cannot be excluded in a patient presenting without abdominal symptoms. The mortality rate can only be reduced by a high index of suspicion, accurate diagnosis, and appropriate treatment.