Barrier pressure at the gastroesophageal junction in anesthetized dogs.

OBJECTIVE: To evaluate the effect of body position on barrier pressure at the gastroesophageal junction in anesthetized Greyhounds and to assess alterations in barrier pressure following gastropexy. ANIMALS: 8 adult Greyhounds. PROCEDURE: Barrier pressure at the gastroesophageal junction was measured by fast (1 cm/s) and slow (1 cm/10 s) withdrawal of a subminiature strain gauge transducer through the gastroesophageal junction in 8 anesthetized dogs. The effect of body position was measured. Each dog then was placed in right-lateral recumbency, and gastropexy was performed in the left flank. Additional measurements were obtained 1, 5, 10, 20, and 30 minutes after gastropexy. RESULTS: Barrier pressure for dogs positioned in sternal recumbency (mean +/- SEM, 1.1 +/- 0.53 mm Hg) was significantly less than for dogs positioned in right lateral or left lateral recumbency. Following gastropexy, there was a steady increase in barrier pressure. Thirty minutes after gastropexy, barrier pressure was significantly higher (13.36 +/- 3.46 mm Hg), compared with the value before surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Barrier pressure in anesthetized dogs is highly variable and influenced by body position. This is most likely the result of anatomic interrelationships between the diaphragm, stomach, and terminal portion of the esophagus. Gastropexy also increases barrier pressure in the immediate postoperative period, which may be clinically relevant in terms of understanding how resolution of gastroesophageal reflux disease associated with hiatal hernia may be affected by gastropexy combined with hernia reduction.