Retroperitoneal fasciitis

Retroperitoneal fasciitis is a rare potentially life-threatening infection of the retroperitoneum. It is the retroperitoneal equivalent of necrotizing fasciitis or non-necrotizing soft tissue fasciitis, and just like its soft tissue counterpart, can also be either necrotizing or not.

Clinical presentation

Most patients are either known for a systemic illness (diabetes mellitus, neoplasm, etc.), are in a recent postoperative setting or have lower extremity fasciitis, all of which predispose to the development of retroperitoneal fasciitis. Infection is spreading through fascial planes, from retroperitoneal/extraperitoneal spaces.

Main clinical feature include:

  • severe abdominal pain
  • alteration of consciousness
  • shock

Pathology

Etiology

Retroperitoneal fasciitis is usually infectious and polymicrobial in origin. It may occur secondarily to extraperitoneal spread of intra-abdominal infections, including common processes such as acute diverticulitis or acute appendicitis. It may also spread directly or indirectly from lower limb soft tissue fasciitis. Known organisms include:

  • Bacteroides specie
  • Clostridium specie
  • Escherichia coli
  • Klebsiella pneumoniae
  • anerobic streptococci

Radiographic features

CT

CT-scan is the main modality on which retroperitoneal fasciitis is diagnosed. It mainly consists of a variable degree of asymmetrical retroperitoneal fat stranding and fascial enhancement. Other features include:

  • retroperitoneal gas (retropneumoperitoneum)
  • nonfocal retroperitoneal collections - including intrafascial collections
  • vascular thrombosis - in severe cases

Treatment and prognosis

Early recognition is important, as early treatment and debridement may help the poor clinical outcome usually associated with this entity.

Differential diagnosis