[Aberrant course of the left pulmonary artery--a contribution to a rare disease picture].

An anomalous left pulmonary artery obstructs the right main bronchus and/or the trachea. Depending on the severity of the obstruction, symptoms range from a more or less disturbing stridor over attacks of shortness of breath to a life-threatening or even lethal apnoea. An 18-month-old girl suffering from a mild form of this anomaly is presented. The diagnostic and therapeutic possibilities are discussed. After exact clarification of the characteristics of the pulmonary sling, exclusion of associated aberrations, and considering good experience with a former case a conservative approach is recommended if the patient is not substantially impaired.