Fistulas are abnormal communications between two epithelial-lined surfaces. Gastrointestinal fistulas encompass all such connections that involve the alimentary tract, and they can be congenital or acquired in nature. This review focuses on acquired gastrointestinal fistulas. Development of an acquired gastrointestinal fistula can greatly affect patient outcome, yet the clinical manifestations are often protean in nature and the etiology, elusive. Imaging plays an important role in the detection and management of acquired gastrointestinal fistulas. The more routine use of cross-sectional imaging (especially computed tomography and magnetic resonance imaging) has altered the standard sequence of radiologic evaluation for possible fistulas, but fluoroscopic studies remain a valuable complement, especially for confirming and defining the anomalous communications. In this review, a classification scheme for gastrointestinal fistulas is provided, major causes are discussed, and individual fistula types are elaborated with an emphasis on contemporary imaging approaches.
Gastrointestinal (GI) fistulas represent abnormal ductlike communications between the gut and another epithelial-lined surface, such as another organ system, the skin surface, or elsewhere along the GI tract itself. A GI sinus tract, in comparison, is a similar ductlike passage that communicates with the gut at one end but ends blindly at the other. The development of a GI fistula can markedly increase patient morbidity and mortality, rendering detection of the fistula critical. Imaging often plays a pivotal role in the diagnosis and management of GI fistula, with fluoroscopic contrast agent-enhanced studies serving as the traditional standard bearer. The emergence of cross-sectional imaging techniques, however, has modified the radiologic approach to GI fistulas. Instead of replacing fluoroscopic contrast-enhanced studies, cross-sectional methods complement their conventional counterparts in the evaluation of GI fistulas.
In this review, we will provide an organ-system approach to classifying GI fistulas. A brief discussion of the major causes of acquired GI fistulas will follow. Last, a systematic review of GI fistulas according to our classification scheme will be provided, with an emphasis on contemporary imaging evaluation. The relative contribution and effectiveness of the various imaging modalities will be discussed for individual fistula types, because many unique features and challenges exist. The salient clinical features of specific GI fistulas, including management, will also be covered.