An Unusual Complication of Transesophageal Echocardiography

Abstract

To the Editor: Transesophageal echocardiography (TEE) is frequently used by anesthesiologists in the perioperative period [1]. We report an unusual complication of TEE. The case involved a 75-yr-old woman undergoing mitral valve repair. Monitors included a TEE probe and an esophageal stethoscope (Mon-a-therm Registered Trademark; Mallinckrodt Medical Inc., St. Louis, MO) placed in the esophagus after induction of general anesthesia. The esophageal stethoscope was used primarily for monitoring esophageal temperature, and an earpiece was not attached. During surgery, the TEE probe was manipulated several times to evaluate the adequacy of valvular repair. At the conclusion of surgery the TEE probe was removed, and it was noted that the distal end of the esophageal stethoscope had retracted into the mouth and only the thermistor wire was visible. Gentle traction on the wire yielded resistance. On direct laryngoscopy, only the wire was visible entering the esophagus. Gentle traction on the wire under direct visualization was again met with resistance. Finally, rigid esophagoscopy was performed and the stethoscope was retracted with minimal trauma. The stethoscope seemed kinked back upon itself in the esophagus Figure 1. The patient's postoperative hospital stay was complicated by fever and dysphagia. A barium swallow was negative for esophageal perforation but did reveal the presence of a previously undiagnosed Zenker's diverticulum. No further complications developed, and the patient was discharged from the hospital 1 wk after surgery.Figure 1: Shows how traction on the thermistor wire in a previously kinked esophageal stethoscope will result in bending of the distal end at a 90 degrees angle, making it impossible to be pulled out and increasing the potential for esophageal perforation by the hard plastic at the end of the stethoscope.Although esophageal perforation is the most dangerous recognized complication of TEE [2], loss of an esophageal stethoscope due to TEE probe manipulation has not been reported as a cause of perforation so far. Our patient required rigid esophagoscopy, which itself may lead to esophageal perforation. Our patient's undiagnosed Zenker's diverticulum probably exacerbated our difficulties. Many patients undergoing TEE may have similar undiagnosed esophageal abnormalities. The temptation to forcefully pull the stethoscope should be resisted because, as shown in Figure 1, strong traction on the thermistor wire makes the distal, stiff end of the stethoscope bend at 90 degrees, actually wedging the stethoscope into the esophagus, making removal more difficult and trauma by the rigid plastic tip more likely. This case suggests that the anesthesiologist must be aware of this hazard. Easy strategies, such as taping the stethoscope to the endotracheal tube or connecting an earpiece to the distal end, would prevent this complication. This report identifies the often unappreciated potential of the TEE to displace an esophageal stethoscope with potential for esophageal perforation. Similar displacement during a nasogastric tube insertion leading to intestinal obstruction has been described before [3]. Anthony Yasick, MD Satwant K. Samra, MD Department of Anesthesiology, University of Michigan Medical Center, Ann Arbor, MI 48109-0048