Effect of incomplete obstruction on feline esophageal function with a clinical correlation

Abstract

This study was performed because of the observation of unexplained esophageal dysfunction in patients with incomplete esophageal obstruction. A Gore-Tex band, measuring 110% of resting esophageal circumference, was placed about the esophagus at the gastroesophageal junction of 17 cats to produce incomplete obstruction by limiting the normal distention that occurs with swallowing. Esophageal manometry was performed before surgery and at 1 and 4 weeks after surgery. Lower esophageal high-pressure zone pressure was not influenced, but sphincter relaxation was impaired. Evaluation of esophageal body contractions showed that simultaneous contractions increased from 0% before surgery to 68% at 1 week and 85% at 4 weeks after surgery (p less than 0.001 versus preoperative for both comparisons). The incidence of repetitive contractions increased from 3.1% before surgery to 10.5% at 1 week and 10.9% at 4 weeks after surgery (p = NS). The average contraction pressure decreased from 22.5 mm Hg before surgery to 13.9 mm Hg at 4 weeks after surgery (p less than 0.05). Barium swallows showed esophageal dilatation, that was confirmed on gross examination. Histologic examination was remarkable only for retention esophagitis. Sham surgery in three cats with identical mobilization of the gastroesophageal junction did not affect motility. Motility returned to normal after the band was removed in three cats. Manometric evaluation of 15 patients with distal esophageal peptic strictures and 17 patients with excessively tight antireflux repairs showed a significantly increased (p less than 0.001) frequency of simultaneous contractions, 35% and 34%, compared with the 2.1% of 25 normal subjects. The following conclusions can be drawn: Partial obstruction alters feline esophageal body function and these achalasia-like changes are reversible on relief of the obstruction and similar motility aberrations occur in patients because of mechanical or functional distal obstruction; this suggests that dysmotility can synergistically contribute to dysphagia.