Peritonitis due to intraperitoneal perforation of infected urachal cysts.

Acute bacterial peritonitis due to intraperitoneal perforation of an infected urachal cyst represents a potentially lethal complication of the rare anomalies of the fetal urachus. We report four cases of this disease, including what we believe is the first to have been correctly diagnosed prior to operation. All four patients underwent emergency laparotomy and curative excision of the urachal remnant. Review of our four cases plus seven previously reported cases disclosed the perforated urachal cyst to be predominantly a disease of young males who initially have acute peritonitis but often without specific indication of a urachal anomaly. Bacteriologic examination has identified a wide variety of infecting organisms. Umbilical sinography or abdominal ultrasonography may allow accurate preoperative diagnosis. Broad-spectrum antibiotic coverage and laparotomy are indicated and excision of the entire urachal remnant is consistently curative.