Incidental diagnosis of tracheal trifurcation detected during general anesthesia from Nepal: a case report.

Introduction and importance: Tracheal trifurcation is an uncommon condition characterized by a three-branched bronchial structure that can be directed either to the right or the left, most commonly on the right. It is associated with tracheobronchial anomalies, cardiovascular defects, and esophageal malformations. The intraoperative diagnosis of tracheal trifurcation is important when lung isolation is needed. Presentation of case: A three-branched structure at the carina was incidentally found in a 55-year-old female via a bronchoscope after the induction of general anesthesia when the lungs could not get isolated for a tricuspid valve replacement procedure, which was planned via right-sided thoracotomy. Initially, the patient complained of shortness of breath on exertion with concomitant multiple episodes of sore throat and fever. The patient was undergoing tricuspid valve replacement for rheumatic heart disease. There was no postoperative complication encountered. Discussion: Tracheal trifurcation or tracheal bronchus is an aberrant bronchus arising most commonly from the right side in the right upper bronchus between the carina and the cricoid cartilage. It is a very uncommon condition with most cases being asymptomatic. The condition has anesthetic implications, especially with the placement of endotracheal tube. These include lung field hypoxemia, shunting, and atelectasis. Conclusion: Through our case report, we aim to highlight the importance of viewing the bronchial morphology if the lung cannot be isolated after double-lumen endotracheal tube insertion. Hence, a careful assessment of both anatomical and physiological parameters of the bronchial tree and the lungs is to be done for such cases.