Clinical significance of hiatal hernia

Abstract

The relationship between hiatal hernias and gastroesophageal reflux disease (GERD) has been greatly debated over the past decades, with the importance of hiatal hernias first being overemphasized and then later being nearly neglected. It is now understood that both the anatomical (hiatal hernia) and the physiological (lower esophageal sphincter) features of the gastroesophageal junction play important, but independent, roles in the pathogenesis of GERD, constituting the widely accepted "two-sphincter hypothesis." The gastroesophageal junction is an anatomically complex area with an inherent antireflux barrier function. However, the gastroesophageal junction becomes incompetent and esophageal acid clearance is compromised in patients with hiatal hernia, which facilitates the development of GERD. Of the different types of hiatal hernias (types I, II, III, and IV), type I (sliding) hiatal hernias are closely associated with GERD. Because GERD may lead to reflux esophagitis, Barrett's esophagus and esophageal adenocarcinoma, a better understanding of this association is warranted. Hiatal hernias can be diagnosed radiographically, endoscopically or manometrically, with each modality having its own limitations, especially in the diagnosis of hiatal hernias less than 2 cm in length. In the future, high resolution manometry should be a promising method for accurately assessing the association between hiatal hernias and GERD. The treatment of a hiatal hernia is similar to the management of GERD and should be reserved for those with symptoms attributable to this condition. Surgery should be considered for those patients with refractory symptoms and for those who develop complications, such as recurrent bleeding, ulcerations or strictures.

Keywords: Gastroesophageal reflux disease; Hiatal hernia; Lower esophageal sphincter.

Fig. 1

Endoscopic and radiologic findings of a sliding type hiatal hernia. A hiatal hernia is a portion of proximal stomach between the gastroesophageal junction (B ring; GEJ) and the diaphragmatic indentation (pinchcock action, PCA). If it is large, a hiatal hernia can be easily observed with a forward or retroflexed view during an upper gastrointestinal endoscopy (A, B) or with barium swallows (C).

Fig. 2

Endoscopic diagnosis of short segment hiatal hernias using lower esophageal capillary patterns as guides. Endoscopic identification of the gastroesophageal junction is occasionally difficult, especially in patients with short segment hiatal hernias (HHs). Using the distal margin of longitudinally arrayed subepithelial capillaries (palisade zone, PZ) as a landmark for the gastroesophageal junction, patterns can be classified according to the relationships between the distal end of the PZ with the squamocolumnar junction (SCJ) and the diaphragmatic indentation (pinchcock action, PCA). (A) The PCA is distal to the other two markers that are at the same level. (B) The SCJ is proximal to the distal end of the PZ, which is proximal to the PCA. The HH is the area between the distal margin of the PZ and the PCA, and the columnar-lined esophagus (CLE) is in the area between the SCJ and the distal margin of the PZ.

Fig. 3

Conventional manometric identification of a hiatal hernia. In a pressure tracing over the distal end of the esophagus generated by the station pull-through technique; the high pressure zone is separated into two zones with the proximal zone corresponding to the lower esophageal sphincter and the distal zone corresponding to the diaphragmatic indentation. The respiratory pressure inversion point (PIP) is sometimes observed twice. The numbers on the upper part of the tracing indicate the distance in centimeters from the nostril.

Fig. 4

High resolution manometric identification of a hiatal hernia. A hiatal hernia (HH) can be identified between the two high-pressure zones of the lower esophageal sphincter (LES) and the diaphragmatic indentation (PCA).