[Function research of esophageal lower sphincter in infant with hiatal hernia]

To investigate the relationship between gastroesophageal dynamics of infantile hiatal hernia (HH) and gastroesophageal reflux (GER) and to assess the curative effects of antireflux surgery.

Ambulatory 24-hr esophageal pH-metry and esophageal manometry were studied in 26 patients with HH before and after surgery.

By radiology, patients were divided into group of sliding HH (n = 16, group I) and group of para-esophageal or combined HH (n = 10, group II). All patients showed GER. The duration of the longest episode, and the percentage of the time at pH < 4 were significantly greater in lying position than those in upright position (P < 0.05). All parameters were significantly decreased after operation (P < 0.01). Lower esophageal sphincter length (LESL) increased significantly postoperatively. In group I, lower esophageal sphincter pressure (LESP) and barrier pressure (BP) was increased after surgery, but no significant difference was seen in LESP and BP in group II. Intragastric pressure (GP) significantly reduced after operation. GP in group II before operation was higher than that in group I (P < 0.05). A second high pressure zone in the esophagus was found in 67% of patients in group I and 14% patients in group II.

Most patients with infantile HH and GER decreased LESL, LESP and increased GP. Differential gastroesophageal dynamics is associated with types of hiatal hernia. It is very important to remain enough LESL in mechanism of Dor antireflux surgery. To prevent respiratory infection is an important measure to prevent patients from relapse after surgery.