Weak Areas of the Pharyngoesophageal Narrowing (Pharyngoesophageal Union): Anatomic Description and Implication on the Development of Pharyngoesophageal Diverticulum

In the pharyngoesophageal narrowing ("pharyngoesophageal junction") there is a difference between the smooth and striated pharynx and esophagus, identifying points of weakness where pharyngoesophageal diverticula originate. In 1874 Albert von Zenker along with Ziemssen presented the first scientific publication on these diverticula. The aim of this work is to perform a surgical anatomical description and demonstration of the weak areas of the pharyngoesophageal narrowing ("pharyngo-esophageal junction") and its implication in the "Zenker diverticulum." We dissected Caucasian adult cadavers, in 5% formaldehyde and researched the pharyngoesophageal region with a review of the literature. In one case a markedly weak area was located presenting a true hernial sac. From the anatomo-surgical study of pharyngoesophageal narrowing ("pharyngeal esophageal junction") we observed the "weak pharyngoesophageal areas" in the pharynx, represented by a pharyngooesophageal diamond. It is crossed transversely by cricopharyngeal portion of the inferior constrictor muscle of the pharynx, and divides into two triangles, an upper, the "Killian Triangle" and a lower, "or Lannier Laimer Triangle Hackermann". Zenker's diverticulum originates from the "Killian Triangle" area of major weakness of the pharyngoesophageal narrowing ("pharyngoesophageal junction"). For its part, the lower triangle, "Laimer Triangle or Lannier Hackermann" where diverticula is rarely formed, because the space is occupied by a layer of circular fibers. The "Zenker diverticulum" represents 60-65% of all esophageal diverticula, and treatment is exclusively surgical. In order to understand and adequately treat this disease, specific knowledge of the anatomy of the area is necessary.