Internal carotid artery as source of tonsillectomy and adenoidectomy hemorrhage.

There is a 1% incidence of congenital internal carotid tortuosity, which places this vessel into apposition with the superior pharyngeal constrictor instead of its usual location 2 to 3 cm lateral to it. Two angiographically documented cases are reported and the embryologic cause of this anomaly is discussed. Palpation of the pharyngeal wall prior to tonsillectomy or adenoidectomy is recommended.