Background: The contribution of the crural diaphragm to the gastroesophageal high pressure zone (HPZ) may be important in prevention of gastroesophageal reflux. The purpose of this study was to investigate the manometric characteristics of the thoracoabdominal junction in patients after surgical removal of the lower esophageal sphincter.
Methods: Ten patients with prior esophagogastrectomy were studied manometrically.
Results: Esophageal manometry showed a HPZ and pressure inversion point distal to the anastomosis in 9 of 10 patients. Midrespiratory and end expiratory pressures were 14 +/- 7 and 6 +/- 4 mm Hg above intra-abdominal pressure, respectively. Breath holding caused inhibition of the phasic pressure component. This HPZ relaxed partially in response to deglutition (60% +/- 22%) and contracted in response to increased intra-abdominal pressure induced by either leg lifts or abdominal compression (delta HPZ/delta intra-abdominal pressure = 1.87 +/- 0.64 and 1.96 +/- 0.40, respectively).
Conclusions: This study shows an HPZ at the thoracoabdominal junction after surgical removal of the lower esophageal sphincter. We suggest that this sphincterlike HPZ is due to the crural diaphragm.