A retroperitoneal abscess caused by Haemophilus parainfluenza after endoscopic retrograde cholangiopancreatography and open cholecystectomy with a common bile duct exploration: a case report.

Introduction: Abscesses after open cholecystectomies have been reported to occur in less than 1% of patients. The majority of these abscesses are colonized by gastrointestinal tract flora. It is clearly known that Haemophilus parainfluenza is a normal inhabitant of the human respiratory tract. However, its origin and route of transmission into the gastrointestinal tract is unknown.

Case Presentation: We present the case of a 68-year-old Caucasian female who developed a retroperitoneal abscess caused by H. parainfluenza after open cholecystectomy and common bile duct exploration. This presented nearly five weeks post-operatively. She underwent a second operation to drain the abscess, and was subsequently placed on appropriate antibiotics.

Conclusion: A retroperitoneal abscess due to H. parainfluenza is extremely rare. It is a normal inhabitant of the human respiratory tract. To the best of our knowledge, there have been only a few reported cases of these abscesses, and they mainly involve the psoas muscle. The retroperitoneal abscess originated from the oropharynx, most likely after the endoscopic retrograde cholangiopancreatography was performed. With the advent of Natural Orifice Translumenal Endoscopic Surgery, oral decontamination will need to be considered to decrease the potential for such infections.