Location of GEJ
Above diaphragmatic hiatus
Asymptomatic or GERD
Normal anatomic position
Asymptomatic but may become strangulated or incarcerated
Reflux and possible incarceration
Above diaphragmatic hiatus
Risk of volvulus, obstruction and/or bleeding
The definitions of the four types of hiatal hernias
Any symptomatic hiatal hernia should be considered for surgical repair, including Type I hernias that are associated with GERD . The symptomatic hernia should be repaired especially if there are obstructive symptoms or volvulus . Anemia can occur in up to 20% of patients with paraesophageal hernias, especially in the presence of Cameron’s lesions, and should also be an indication for repair . There is debate whether an asymptomatic hiatal hernia or those causing only minimal symptoms should be repaired; considerations for surgical repair in these patients should include overall clinical presentation, patient’s co-morbidities, and age.
1.4 Endoscopy in the Evaluation of Hiatal Hernia and GERD
The use of endoscopy in evaluation of the upper gastrointestinal tract has become commonplace. Its use in the diagnosis of hiatal hernia is not necessarily mandatory, as contrast radiographic images can be used to evaluate patients with suspected hiatal hernias. However, given the increased utilization of endoscopy, hiatal hernias are frequently found when endoscopy is done for other symptoms and/or conditions. Hiatal hernias are associated with GERD and this can lead to other esophageal pathology for which endoscopy can determine the presence and extent. Endoscopy can determine the size of the hiatal hernia, extent of esophagitis, presence of neoplasia and suggest the existence of delayed gastric emptying. Specifically, understanding these clinical components and using endoscopy as a tool for diagnosis and management will better help the physicians devise a management plan of their patients.
1.5 Endoscopic Assessment of Hiatal Hernia
Despite increased use of endoscopy as an adjunct in evaluating patients with a hiatal hernia, the diagnostic criteria remain unclear. The most commonly accepted definition in the literature is identification of proximal dislocation of the gastroesophageal junction (GEJ) >2 cm above the diaphragmatic indentation. This definition seems to provide a systematic method of diagnosing and reporting size of a hiatal hernia, but the confusion lies in the reference mark for the GEJ.
There are three anatomic possibilities used to assess the position of the GEJ: the squamocolumnar junction (SCJ) , the upper margin of the gastric folds, and the distal margin of the palisade zone. Clarification of the endoscopic reference for the GEJ needs to be undertaken for several reasons. The SCJ, also known as the transition zone or “Z-line” is not consistent across all patients . The contour and length varies, especially in those with Barrett esophagus because the junction extends cranially and is, thus, unreliable in these patients. This is important given many patients with hiatal hernias may have Barrett esophagus and may affect the estimation of the axially dimension of the hernia. Identification of the upper gastric folds is another marker that has been used as a reference of the GEJ, but may be difficult to clearly define if the stomach is not fully insufflated and anatomy is not clearly delineated endoscopically. Studies have demonstrated operator variability with regards to this measurement for hiatal hernias even in healthy individuals .
Another proposed system for assessing the GEJ is the Hill classification . This approach evaluates the GEJ and hiatal integrity based on a “flap-valve” mechanism which is also used to predict reflux . In this classification scheme, grade I flap-valve is consider the “normal” configuration. It demonstrates close adherence of the SCJ to the shaft of the endoscope with a “ridge” of tissue corresponding to the angle of His. There is no hiatal hernia (Fig. 1.2a). In grade II, the adherence of the GEJ to the endoscope is less well-defined and there is effacement of the angle of His ridge (Fig. 1.2b). Hill grade III flap valve demonstrates incomplete closure of the GEJ around the endoscope, with esophageal mucosa frequently visible and complete effacement of the angle of His ridge (Fig. 1.2c). These are frequently associated with sliding hiatal hernias. Lastly, Hill grade IV is always associated with a hiatal hernia with the diaphragmatic hiatus seen making and extrinsic compression on the gastric mucosa. There no GEJ adherence to the shaft of the endoscope and the squamous epithelium of the distal esophagus can be readily seen (Fig. 1.2d). A population-based study evaluating the concordance with hiatal hernia size and Hill classification included 334 subjects and demonstrated the Hill classification was slightly better at measuring a hiatal hernia but was not necessarily a stronger predictor . The reproducibility of these results in an objective, accurate manner have yet to be elucidated.
The Hill classification of the gastroesophageal junction flap valve. Black arrow in (a) shows a normal angle of His ridge of a competent valve. Black line in (d) shows the transverse diameter of the hiatal hernia
Once it is determined that a hiatal hernia is present, there are two dimensions that determine its size. One is the axially dimension as measured from the GEJ to the “pinch” of the diaphragmatic hiatus around the stomach (Fig. 1.3). The other is the transverse dimension, as measured from the impression of the left crura against the herniated stomach to the impression of the right crura against the herniated stomach. These are measurements that are frequently not made during routine endoscopy. In patients with paraesophageal hernias, a twisting of the stomach within the hernia may be seen suggesting volvulus (Fig. 1.4).
The determination of the axial length of a sliding (type I) hiatal hernia from the Z-line (gastroesophageal junction, black arrow) to the “pinch” of the diaphragmatic hiatus around the stomach (white arrow). In conjunction with the transverse diameter (Fig. 1.2d), the size of the hiatal hernia can be determined
Twisting of the stomach within a paraesophageal hernia suggesting gastric volvulus
1.6 Endoscopic Evaluation of the Esophageal Mucosa
When evaluating patients for hiatal hernia it is also important to note the esophageal mucosa and any abnormalities. Specifically, the presence of erosive or non-erosive esophagitis needs to be determined. The severity of erosive esophagitis is graded based on the Los Angeles Classification (LA Classes) . Grade A is the presence of one or more mucosal breaks that are ≤5 mm in length; Grade B is the presence of one or more mucosal breaks that are >5 mm; Grade C includes one or more mucosal breaks that interconnect between the apices of two or more mucosal folds, but encompass <75% of the esophageal circumference. Grade D is the most extensive and includes continuous breaks within the mucosa that exceeds 75% of the esophageal circumference (Fig. 1.5). Biopsies of the area of esophagitis, in the absence of suspicion for neoplasia, appear not to have any additional value to endoscopic examination .
An example of Los Angeles grade D esophagitis . Description of grades A, B and C in text
Conversely, non-erosive esophagitis is more difficult to diagnose via endoscopy and primarily diagnosed via biopsy. The presences of eosinophils, lymphocytes, balloon cells, and polymorphonuclear leukocytes have been seen on microscopy but have poor sensitivity and specificity if only one of these histologic abnormalities is identified. Specificity is increased if there are three or more of these abnormalities on microscopy but, consequently, sensitivity is decreased . Nonetheless, the routine use of endoscopic biopsies in the setting of otherwise normal appearing esophageal mucosa is not recommended.
1.6.2 Barrett Esophagus
Barrett esophagus is defined as a change in the normal mucosa of the esophagus from squamous epithelium to metaplasia columnar epithelium. Barrett esophagus is a result of damage to the esophageal mucosa from persistent reflux disease. Under endoscopic visualization, it appears as salmon colored mucosa projecting proximally into the distal esophagus from the normal SCJ (Fig. 1.6a). With narrow-band imaging there is enhanced visualization of the GE junction in addition to mucosal abnormalities such as Barrett metaplasia (Fig. 1.6b). Suspicious areas seen on endoscopy and/or narrow-band imaging must be biopsied to confirm or rule out mucosal abnormalities; specifically, biopsies need to determine the presence of intestinal metaplasia and goblet cells. In the presence of esophagitis, patients need to be treated with proton pump inhibitors to enhance histologic evaluation of the Barrett metaplasia.
Barrett esophagus as seen by white light (a) and narrow band imaging (b). Narrow band imaging enhances the difference between the area of normal squamous epithelium and metaplastic epithelium
Obtaining endoscopic biopsies of the esophagus that are concerning for Barrett esophagus typically follow the Seattle protocol; this is defined as four quadrant biopsies taken every 1 cm over the length of the Barrett esophagus . The extent or severity of Barrett’s is then further classified based on the Prague classification . This incorporates then length of circumference (Denoted as “C”) of Barrett and the total length of the esophagus that includes Barrett’s (Denoted as “M”) . For example, if a 2 cm circumferential portion of esophagus was involved and included 5 cm non-circumferential Barrett, this would be documented as C2M5.
The length and circumference is an important classification system for Barrett, but the presence of the type of metaplasia and/or dysplasia is also clinically important. Non-nodular Barrett or flat dysplasia is typically biopsied; depending on size and grade of dysplasia this is commonly managed with endoscopic eradication. This applies in the case of nodular metaplasia as well. Ulceration of the columnar epithelium and/or Barrett segment can be found in up to 60% of patients . These are typically found incidentally, but may be complicated by bleeding or even perforation. There have been rare reports of fistula formation due to ulceration of Barrett esophagus . Development of these findings is concerning for underlying malignancies and if seen endoscopically should be managed as such.
1.6.3 Esophageal Neoplasia
Endoscopy certainly plays a curative role in treating select patients with esophageal carcinoma. Primarily, endoscopic therapy is used for mucosal cancers. Endoscopic approaches can be divided into ablative and resection techniques. In the latter, endoscopic mucosal resection (EMR) offers the advantage of obtaining more tissue for appropriate cancer staging and even adequate treatment (Fig. 1.7a, b). EMR is primarily used in nodular Barrett’s esophagus , T1a esophageal adenocarcinoma lesions, and in some instances, flat Barrett’s esophagus with high-grade dysplasia . Curative rates for EMR have reported ranges between 60% and 100%; one of the largest studies included 349 patients with high grade neoplasia or mucosal adenocarcinoma; with a follow-up of 5 years reported long-term eradication was 95% . Although there has been no comparison to surgical resection, EMR offers a promising alternative to minimally invasive resection of these lesions. Complications of this intervention includes bleeding, perforation, and stricture formation.
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