Tracheal ring deformation as a cause of recurrent esophageal obstruction in a 13-year-old mare

A 13-year-old mare was presented for recurrent esophageal obstruction since one year. Endoscopy of the esophagus revealed no mucosal lesions but at approximately 70cm from the nostrils, a longitudinal deformation of the lumen was observed in the ventral aspect of the esophagus which did not disappear with esophageal air insufflation. Native radiographs did not show clear abnormalities. A contrast esophagogram showed a dorsal deviation of the esophagus over approximately 5cm at the level of the caudal aspect of the third cervical vertebra. An explorative surgery of the affected region (C3-C4) was performed under esophageal endoscopic guidance. Over a distance of approximately 20cm, the right part of the tracheal cartilage rings showed an elongated ‘processus’, extending dorsal to the tracheal ligament, forming a ridge. Cranially, the esophagus was located to the right of this ridge. At the level of C3-C4 it passed over the ridge towards a more left-lateral position, which explained the deviation on the esophagogram and the recurrent obstructions. The esophageal wall itself did not show any abnormalities. Over a distance of 7cm, resection of the elongated right part of the tracheal rings was performed which eliminated the external pressure on the esophagus. After excision, the longitudinal fold in esophagus had disappeared on endoscopy. A repeat contrast esophagogram after five days showed a normal esophageal trajectory. Food was gradually introduced, and the horse no longer showed signs of esophageal obstruction. The horse was discharged after one week. ConclusionTo our knowledge, this is the first report of a longitudinal fold caused by abnormal tracheal ring formation resulting in recurrent esophageal obstructions.A 13-year-old mare was presented for recurrent esophageal obstruction since one year. Endoscopy of the esophagus revealed no mucosal lesions but at approximately 70cm from the nostrils, a longitudinal deformation of the lumen was observed in the ventral aspect of the esophagus which did not disappear with esophageal air insufflation. Native radiographs did not show clear abnormalities. A contrast esophagogram showed a dorsal deviation of the esophagus over approximately 5cm at the level of the caudal aspect of the third cervical vertebra. An explorative surgery of the affected region (C3-C4) was performed under esophageal endoscopic guidance. Over a distance of approximately 20cm, the right part of the tracheal cartilage rings showed an elongated ‘processus’, extending dorsal to the tracheal ligament, forming a ridge. Cranially, the esophagus was located to the right of this ridge. At the level of C3-C4 it passed over the ridge towards a more left-lateral position, which explained the deviation on the esophagogram and the recurrent obstructions. The esophageal wall itself did not show any abnormalities. Over a distance of 7cm, resection of the elongated right part of the tracheal rings was performed which eliminated the external pressure on the esophagus. After excision, the longitudinal fold in esophagus had disappeared on endoscopy. A repeat contrast esophagogram after five days showed a normal esophageal trajectory. Food was gradually introduced, and the horse no longer showed signs of esophageal obstruction. The horse was discharged after one week. ConclusionTo our knowledge, this is the first report of a longitudinal fold caused by abnormal tracheal ring formation resulting in recurrent esophageal obstructions.C