Clinical topographical anatomy of the gastro-oesophageal junction in the cat

Abstract

Objectives The purpose of the present study was to describe histologically the gastro-oesophageal junction in the cat and interrelationships of this region. Our hypothesis was that cats are devoid of abdominal oesophagus. Methods Three centimetres of the terminal oesophagus, the phreno-oesophageal membrane with 1-2 cm margins of the diaphragmatic crural muscle and the proximal 3 cm of the gastric cardia were obtained from nine domestic shorthair cats and one domestic longhair cat that were euthanased for reasons other than digestive tract pathology. Longitudinal samples were examined histologically. Evaluated parameters included the location of the phreno-oesophageal membrane with reference to the transition between the oesophageal and gastric mucosa, the thickness of the circumferential smooth muscle of the muscular layer of the distal oesophagus at points 3 mm and 6 mm cranial to the mucosa transition, and the thickness of the circumferential smooth muscle layer at the mucosa transition level. Median differences in the thickness of the smooth muscle layer were compared by performing non-parametric statistical analysis using the Mann-Whitney U-test. Results The transition of the oesophageal to gastric mucosa was abrupt and corresponded to the point of insertion of the phreno-oesophageal membrane at the diaphragm level in all cats. The mean thickness of the circumferential smooth muscle layer at the point of oesophageal to gastric mucosa transition was significantly greater than the mean thickness of the oesophageal circumferential smooth muscle layer at 3 mm and 6 mm cranial to the mucosa transition ( P ⩽0.05). The increased muscle thickness at the gastro-oesophageal junction correlates with the accepted location of the high-pressure zone, reflecting the caudal oesophageal sphincter. It seems that the whole oesophagus was situated within the thoracic rather than the abdominal cavity. Conclusions and relevance No distinct abdominal oesophagus was observed in nine domestic shorthair cats and one domestic longhair cat. These findings might have implications for the pathophysiology of hiatal hernia in cats.

Extraluminal oesophageal stricture following traumatic diaphragmatic hernia repair in a cat

“…The whole oesophagus, inclusive of the caudal oesophageal sphincter, is situated within the thoracic cavity rather than the abdominal cavity. This may suggest that in this report, the stricture is located extraluminal to the cardia of the stomach as opposed to an extraluminal caudal oesophageal stricture 15…”

“…This may suggest that in this report, the stricture is located extraluminal to the cardia of the stomach as opposed to an extraluminal caudal oesophageal stricture. 15 Several studies have described the closure of diaphragmatic hernias with the emphasis being on: (i) closure in a dorsal to ventral direction allowing the surgeon greatest exposure and (ii) avoidance of an excessively tight closure, lowering the likelihood of necrosis of the repaired tissue and/or overt tension leading to breakdown. 7 Both non-absorbable and absorbable suture materials have been used and there is little evidence to support the use of one over the other.…”

Surgical Anatomy of the Gastrointestinal Tract in Cats

“…The phrenoesophageal membrane, with its ascending and descending limb, is the ligament that connects the esophagus to the diaphragm, with the descending limb being connected to the stomach just below the gastroesophageal junction [ 29 ]. However, Voutsinou et al reported the absence of abdominal esophagus in nine domestic shorthaired cats and one domestic longhaired cat, with the zone of mucosa transition being detected between the bifurcation of the diaphragm and the phrenoesophageal membrane [ 30 ]. The gastroesophageal junction is also surgically important during the localization of the gastro azygos shunt, which usually runs adjacent to it [ 31 ].…”

“…The cardia, which is the cranial part of the stomach that is connected to the esophagus, lies on the left side of the midline [25] (Figure 7). The esophagogastric junction is an bifurcation of the diaphragm and the phrenoesophageal membrane [30]. The gastroesoph-ageal junction is also surgically important during the localization of the gastro azygos shunt, which usually runs adjacent to it [31].…”