What are the manometric features of a sliding hiatal hernia? How is the best to reduce false negative lower esophageal sphincter manometries in hiatal hernia?
J.H. Schneider, U. Schott, K.E. Grund, H.D. Becker (Tübingen)
A hiatal hernia is established when a part of the stomach slips through the diaphragmatic esophageal hiatus into the thorax; but it is still questionable whether this anatomical finding is strictly an esophageal disease or not.
The importance of hiatal hernia in gastroesophageal reflux disease (GERD) was emphased early by Allison . In the mid of the 70th it became clear that the prevalence of a sliding hernia is age-related and can be seen in the youth to 10% over 50 years to 70%, and in 90 years old individuals to 100% [2, 3]. As a result, the importance of a sliding hernia was downplayed for the pathogenesis of GERD [4, 5]. In recent studies in humans and animals new evidence suggests that the extrinsic force of the diaphragmatic crura generates the gastroesophageal junction competence [6, 7]. If it is like this, the damage of the diaphragmatic crus in sliding hernias has to be reevaluated for the importance of the pathogenesis of GERD.
There are numerous classifications to distinguish sliding hiatal hernias. Rituo determined hernias as congenital or acquired . Richards categorized hernias into true and false hernias, a hernia with a sac is true and without is false . Heitmann classified hypertone, normotone and hypotone lower esophageal sphincter (LES) function . Siewert combined anatomical, manometrical and clinical features to categorize hiatal sliding hernia . Patti used the size of the hernia, the competence of the LES and esophageal acid exposure and mucosal injury . Sloan created a reflux score using a furomanometry technique in patients with sliding hernias .
Depending on manometric or endoscopic studies the percentage of patients with symptoms range between 30 to 60% . When symptoms occur, they normally indicate complications of a sliding hernia . Typical symptoms are: dysphagia, substernal burning, nocturnal reflux and heartburn.
The major problem is caused by gastroesophageal reflux. Severe esophagitis is seen uncommonly without a sliding hernia, but the incompetence of the LES is well documented without any evidence of sliding hiatal hernia. There is clinical evidence that the larger the hernia, the more severe is the incompetence of the LES .
The occurrence of non-iron deficiency anemia in patients with sliding hernia is controversial. Rüsch and Groitl saw chronic bleedings only in mixed and paraesophageal hernias . Cameron and Kerklin found bleedings also in sliding hernias  and its successful surgical repair is well documented . Three locations were found to cause beedings mainly: the esophagus, the gastric pouch and the gastroesophageal junction . Commonly Mallory Weiss lesions are associated with hernias and mucosal intusseption with ortho- or retrograde mucosal prolaps. Concomitant the spontaneous intramural hematoma - a so-called apoplexy of the esophagus - was seen during medical therapy or coagulation deficiency.
Non cardiac chest pain
Sliding hiatal hernias are able to provoke severe chest pain. Similarly to coronary heart disease symptoms may be fugitive and varying in duration, intensity and frequency. The reasons responsible for retrosternal pain attacks are not well understood . Balloon dilation of the distal esophagus produces burning pain, indicating a motor disorder similar to pain sensation after LES dilation in patients with achalasia . The vagal nerve contains efferent and afferent neurons. It might be possible that compression of the vagal nerves or chemical stimulation  causes the chest pain.
Patients and methods
Twenty three symptomatic patients (11 male and 12 females, mean age 53 ± 7.6 years, range 25-73) were referred for evaluation of GERD. Each patient underwent endoscopy, radiographic examination, stationary manometry and 24-hour pH metry. A control group of 32 healthy volunteers (15 male and 17 female, mean age 23 ± 4.8 years, range 19-27) got stationary manometry and 24-hour pH metry.
Each patient was questioned about duration, quality and frequency of dysphagia, substernal burning, nocturnal reflux, heartburn, chest pain and cough (Table I).
The results from barium esophagography were reviewed by an experienced radiologist. The axial length and the diameter of the hiatal hernia was measured at mid swallow in prone position when the esophagus reached the maximum of distention with barium. Special provoking maneuvers like Müller maneuver or leg lifts were not performed.
Endoscopic studies were reviewed and the degree of esophageal injury was graded, according to Savary-Miller classification: grade 1: erythema, grade 2: linear erosions, grade 3: confluent erosions and grade 4: stricture or Barrett's disease.
Each symptomatic patient and healthy volunteer underwent a standard stationary esophageal manometry after an overnight fast as described previously . Using the station pull through method the LES pressures were measured, the LES length, the intra-abdominal length of the esophagus and the duration of LES relaxation. Esophageal body motility was measured assessing 10 wet swallows of 5 ml water. Two independent investigators analyzed the contraction amplitude, duration of amplitude and velocity.
24-hour esophageal pH monitoring
Ambulatory 24-hour pH monitoring was performed in each individual. The pH probe was placed 5 cm above the upper border of the manometrically determined LES. The data were analyzed using the DeMeester score.
Preliminary results showed that the occurrence of symptoms increased significantly
(p = 0.05) in patients with GERD and a hiatal hernia larger than 5 cm vs patients with GERD and a smaller hernia (< 3cm). The comparison between controls with negative acid score and hiatal hernia was highly significant.
Tables II and III summarize the results of esophageal motility. The LES pressure was significantly decreased in larger hernias when compared to healthy individuals. The duration of LES relaxation during swallowing was prolonged in larger hernia.
The proximal esophageal body motility showed no significant difference between healthy volunteers and patients with hiatal hernia and positive acid score. In the distal esophageal body, the contraction amplitude and velocity were significantly decreased
(p = 0.05).
Esophageal acid exposure
Data of 24-hour pH monitoring are summarized in Table IV. Hernias > 5 cm vs 3 cm induced more gastroesophageal acid reflux. The difference was not significant, but compared to the control group, highly significant.
The difficulty to get the right diagnosis in patients with diaphragmatic hiatal esophageal hernia starts with the definifion. In radiographic examinations it is well established that the gastroesophageal junction normally slips during swallowing and respiratory movements through the diaphragmatic hiatus into the thoracic cavity . Due to the tension of the longitudinal muscle layer, the tubular esophagus becomes shorter and the high pressure zone of the gastroesophageal junction becomes, for some seconds, detectable above the diaphragm . To distinguish a physiological from a pathological situation, the persistence of a sliding hiatal hernia should be diagnosed in recumbent position, out of a swallowing event. In some cases, it might be helpful to increase the abdominal pressure by using the Müller maneuver, or to lift the legs. Our data confirm, as in recent studies, that esophageal manometry is only helpful to evaluate motility abnormalities in patients with gastroesophageal reflux, although the majority of diaphragmatic esophageal hernias persist without gastroesophageal reflux and detectable injuries of the esophageal mucosa.
2. Blum AL, Siewert JR. Pathogenese, Diagnostik und konservative Therapie der Refluxkrankheit. In: Siewert JR, Blum AL, Waldeck F, eds. Funktionsstörungen der Speiseöhre. Berlin, Heidelberg, New York: Springer.