The anatomic similarities between the human and feline esophagus include the fact that the feline distal esophagus is composed of smooth muscle, the abdominal esophagus is well defined, and the gastric sling fibers are very similar to theose of
the
human. But differences also exist. The lower esophagus of the cat has less smooth muscle than that of human. The feline phrenoesophageal membrane differs from that of human. Its descending limb attaches below the esophagogastric angle. We
performed
this
study to evaluate the functional similarities and differences of the feline esophagus to human esophagus by manometric study and to examine the validity of the feline esophagus as an appropriate model for investigation of human esophageal
function
and
motility disorders. Fifteen healthy mongrel cats were manometrically evaluated under ketamine anesthesia, given intramuscularly, to quantitate the of upper esophageal sphincter, esophageal body, and lower esophageal sphincter. The manometric
values
were
recorded and analyzed with the same computer program that is used for human esophageal manometry to obtain more accurate and objective data.
@ES The results of esophageal manometry were as follows;
@EN The average relaxation of upper esophageal sphincter associated with deglutition was 92.3±3%, and the response to swallowins when relaxation coincides with pharyngeal contraction (normal in 14 of 15 cats) were very similar to those of
humans.
But
the resting pressure(25.5±1.6 mmHg) and post deglutitive pressure(35.7±3.1mmHg) were lower than those of humans, presumably due to the influence of ketamine anesthesia. Contraction of the esophageal body had similar amplitude and duration as
that
seen
in the human esophagus, and the patterns of peristaltic contraction and wave progression were similar to those of humans. The abdominal length of the distal esophageal sphincter was well definded manometrically and the distal esophageal high
pressure
zone was clearly identifiable in all cats.(94.6±1.5%), the same as the human lower esophageal sphincter. The resting pressure(31.3±1.3mmHg) was somewhat higher than that of humans, presumably because cats. with a horizontal axis. require a more
competent sphincter to prevent gastroesophageal reflux.
In conclusion, the characteristics of feline upper and lower esophageal sphincter, and esophageal body were found to be essentially the same as the human esophagus and this study shows that the feline esophagus is an appropriate model for
investigations
of human esophageal physiology and pathophysiology.
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