Pneumomediastinum after endoscopic sphincterotomy.

Pneumomediastinum is a rare complication of endoscopy that usually indicates free peritoneal or retroperitoneal perforation. We report an unusual case of self-limiting pneumomediastinum after endoscopic sphincterotomy in which there was no radiological evidence of gut wall perforation. We postulate that this was due to interstitial tracking of air from the duodenal wall, and we discuss the possible pathophysiology. This complication should be recognized as distinct from pneumomediastinum associated with perforation, particularly as it appears to be benign and therefore does not require surgical or radiological intervention.