Esophageal disease states

Achalasia

Definition

Achalasia is a primary esophageal motor disorder of unknown cause, which is characterized by insufficient lower esophageal sphincter (LES) relaxation and aperistalsis.

Etiology

The cause of achalasia remains unknown. Available data suggest degenerative, autoimmune, infectious and hereditary factors as possible causes (1).

4.1 Esophageal motor innervation. The striated muscle of the proximal esophagus is innervated directly by the somatic efferent cholinergic fibers of the vagus nerve originating from the nucleus ambiguus. Smooth muscle of the distal esophagus is innervated by the preganglionic vagus nerve fibers from the dorsal motor nucleus. The neurotransmitter released, acetylcholine, affects two types of post-ganglionic neurons in the myenteric plexus: excitatory cholinergic neurons and inhibitory nitrinergic neurons.

Esophageal motor innervation and normal physiology

The proximal one-third of the esophagus (striated muscle) is innervated directly by the somatic efferent cholinergic fibers of the vagus nerve originating from the nucleus ambiguus (4.1). The distal two-thirds of the esophagus (smooth muscle) are controlled by the myenteric plexus, which is innervated by the pre-ganglionic cholinergic vagus nerve fibers from the dorsal motor nucleus. The myenteric
plexus has two types of post-ganglionic neurons: (i) excitatory cholinergic neurons; and (ii) inhibitory nitrinergic (nitric oxide, NO) neurons and vasoactive intestinal polypeptide- (VIP) containing neurons.

At baseline, the esophagus is in a contractile state mediated by excitatory cholinergic neurons. Deglutition induces inhibitory NO and VIP neuron excitation, resulting in esophageal and LES relaxation. Peristalsis results from coordinated relaxation and contraction mediated by the inhibitory and excitatory myenteric plexus neurons along the path of the esophagus.

Pathophysiology

The hallmark of achalasia is the loss of inhibitory NO and VIP neurons in esophageal myenteric plexus. In early achalasia, there is inflammation of the myenteric plexus (Tcell lymphocytic infiltration) without the loss of ganglion cells (4.2). In later stages, loss of myenteric ganglion cells and neural fibrosis ensues. In a selective manner, postganglionic inhibitory myenteric neurons containing NO and VIP are lost, whereas post-ganglionic excitatory cholinergic neurons are spared. The net result is unopposed cholinergic stimulation. This results in high basal LES pressure and failure of LES relaxation. In addition, loss of latency gradient along the esophageal body, which is mediated by nitric oxide, results in aperistalsis.

4.2 Histology of achalasia. There is inflammation of the myenteric plexus with T-cell lymphocytes.

Epidemiology

The incidence is 1-2 per 200,000 (2). Both sexes are affected equally, with onset usually in the third to fifth decades, but can occur at any age.

Clinical presentation

Dysphagia to solids is present in nearly all achalasia patients. Dysphagia to liquids present in two-thirds of achalasia patients. Regurgitation is found in 60-90% of achalasia patients. It usually occurs shortly after a meal, or while recumbent. Undigested food is regurgitated.

Chest pain is found in one-third of achalasia patients. It is located retrosternally and is typical of non-cardiac chest pain. Pain is precipitated by eating, which thus causes decreased intake and weight loss.

Other symptoms include weight loss (associated with advanced disease), pulmonary symptoms, and coughing spells secondary to aspiration.

Diagnosis

Diagnosis of achalasia requires radiographic, manometric, and endoscopic evaluation.

Radiographic studies

Barium esophagram (4.3, 4.4)

This is the primary screening test for evaluation of achalasia, and has a 95% accuracy in diagnosing achalasia. Essential features are:

‘Bird’s beak’ narrowing of the LES with incomplete opening.
Loss of primary peristalsis.
Delayed esophageal emptying.

Supportive features include a dilated or sigmoid-shaped esophagus, and epiphrenic diverticula.

Timed barium swallow (4.5)

This provides objective evaluation of esophageal function. It is performed as a primary evaluation of achalasia or assessment of response to pneumatic dilation (3, 4).

4.3 Characteristic barium esophagram of achalasia. There is poor emptying of the barium from the esophagus which is dilated. There is a characteristic ‘bird’s beak’ narrowing of the distal esophagus due to a non-relaxing LES.

Three-on-one spot films are taken 1, 2, and 5 minutes after ingestion of 100-250 ml low-density barium. The volume ingested is based on patient tolerance. The degree of emptying is estimated qualitatively by comparing 1- and 5-minute films, or quantitatively estimated by measuring the height and width for both films. On subsequent follow-up studies, the same volume of barium is used for accurate serial assessment (3). In normal individuals, the esophagus is devoid of barium within 1 minute. The goal of therapy in achalasia is to normalize emptying by 5 minutes (3).

This technique has been shown to be a simple and reproducible method for objective assessment of esophageal function before and after treatment of achalasia (3). Additionally, it has been shown to be a reliable predictor of response to pneumatic dilation therapy and is an important tool in post-pneumatic dilation evaluation (4, 5).

4.4 End-stage achalasia (sigmoid esophagus). The esophagus is markedly dilated and tortuous, forming a sigmoid shape.

4.5 Timed barium swallow (TBS) in two patients (A and B) with significant delay in esophageal emptying. TBS provides objective evidence of esophageal function and is most useful in diagnosing achalasia and assessing the response to therapies such as pneumatic dilation, or surgical myotomy. It is performed with 250 ml of barium. After the barium is ingested, an X-ray is taken in upright position at time 1, 2, and 5 minutes. The barium height and width at 1, 2, and 5 minutes are measured. In normal population, the barium completely empties in 1 minute.

Esophageal manometry

This is needed to confirm or establish the diagnosis of achalasia, especially when an esophagram is inconclusive. Essential features are:

Aperistalsis in the distal two-thirds of the esophagus (4.6).
Simultaneous onset.
Isobaric (identical pressure tracings in all leads).
Abnormal LES relaxation with swallows.

Supportive features include hypertensive LES pressure (LES pressure >45 mmHg), and low amplitude esophageal contractions (contraction amplitude <30 mmHg).

Endoscopy

Endoscopy is necessary to rule out pseudoachalasia secondary to malignancies at the esophagogastric junction.

A typical esophagus on endoscopy in an achalasia patient is dilated and tortuous. It is not uncommon to find retained food debris and secretions in the esophagus. The LES remains closed with air insufflation and appears puckered (4.7). The gastroesophageal junction (GEJ) and gastric cardia (4.8) are carefully examined for evidence of tumors.

4.6 Manometric findings in achalasia. Achalasia is defined manometrically by aperistalsis and failure of LES relaxation. The pressure tracing shows low amplitude simultaneous contractions. Pressure tracings in all leads are identical or isobaric. Isobaric contractions are due to the esophagus being a closed chamber (dilated esophagus closed by sphincters on both ends), where pressure changes are detected by all manometric sites. In addition, LES does not relax with wet swallow.

4.7 Upper endoscopy of an achalasia patient reveals a characteristic puckered GEJ. Retained secretions and food in the esophagus are also frequently seen.

4.8 Retroflexed view of the gastric cardia shows very tight LES around the endoscope. There is no evidence of malignancy causing pseudoachalasia.

Differential diagnosis

Various disorders with similar manometric and radiologic features as achalasia (pseudoachalasia) should be considered in making a diagnosis of achalasia (Table 4.1).

The most important cause of pseudoachalasia is malignant neoplasm. Tumors cause pseudoachalasia by encircling or compressing the distal esophagus or infiltrating the esophageal myenteric plexus and impairing inhibitory LES innervation. Clinical features that suggest malignancy are:

Duration of symptoms <6 months.
Onset after age 60 years.
Excessive weight loss.
Difficulty with endoscope passage through GEJ during esophagogastroduodenoscopy (EGD).
Computed tomography (CT) scan showing marked (>1 cm) and/or asymmetric esophageal wall thickening.

4.9 Achalasia treatment algorithm. (PD: pneumatic dilation.)

4.1 Disorders with manometric and radiologic features similar to achalasia

Malignancy		Chronic intestinal pseudo-obstruction
•	Gastric adenocarcinoma	Amyloidosis
•	Esophageal squamous cell carcinoma	Sarcoidosis
•	Lymphoma	Chagas’ disease
•	Lung carcinoma	Post-vagotomy
•	Pancreatic carcinoma	Pancreatic pseudocyst
•	Prostatic carcinoma	Von Recklinghausen’s neurofibromatosis
•	Anaplastic carcinoma	Anderson-Fabry’s disease
•	Colon carcinoma	Familial glucocorticoid deficiency syndrome
•	Esophageal lymphangioma	MEN type llb
•	Pleural mesothelioma
MEN: multiple endocrine neoplasia

Treatment

There is no cure for achalasia. Treatment options include:

Pneumatic dilation.
Surgical myotomy (Heller).
Botulinum toxin injection.
Medical therapy (calcium channel blockers, nitrates) (see Table 4.2, 4.9).

4.10 A: Rigiflex pneumatic dilator. B: The dilator comes in three balloon sizes: 3.0, 3.5, and 4.0 cm. Pneumatic dilation uses air pressure to disrupt traumatically the circular muscle layer of the LES. A 3.0 cm balloon is usually used for initial dilation. With symptom recurrence, repeat dilations are performed in a stepwise graded fashion using larger sized balloons.

4.2 Comparison of treatments for idiopathic achalasia

	Pneumatic dilation	Laparascopic myotomy	Botulinum toxin	Nifedipine/nitrates
Response	60-90% at 1 year; 60% at 5 years	90% at 1 year; 85% at 5 years	90% at 1 month; 60% at 1 year	50-70% initially; <50% at 1 year
Complications	2—5% perforation	10% symptomatic reflux	20% rash, transient chest pain	30% headache, hypotension
Advantages	Good response rates	Minimally invasive surgery	Low morbidity	Rapidly initiated
Disadvantages	Risk of perforation	Risks associated with general anesthesia; may need conversion to open procedure	Need frequent repeat injections within 1 year; causes fibroinflammatory reaction at LES	Poor effect on esophageal emptying; tachyphylaxis
LES: lower esophageal sphincter. (Adapted from Feldman M, Friedman LS, Sleisenger MH (2002). Sleisenger & Fordtran’s Gastrointestinal and Liver Disease, 7th edn. Saunders, Philadelphia.)

Pneumatic dilation

All patients considered for pneumatic dilation should be good surgical candidates because of the 2-5% risk of esophageal perforation. Pneumatic dilation uses air pressure to disrupt traumatically the circular muscle layer of the LES. Rigiflex balloon dilators are most commonly used and are available in three diameters (3.0, 3.5, and 4.0 cm) (4.10). A 3.0 cm balloon is usually used for initial dilation. With
symptom recurrence, repeat dilations are performed in a stepwise graded fashion using larger sized balloons. The balloon is positioned over a guidewire using either endoscopic or fluoroscopic control across the LES. The balloon is then inflated until the balloon waist (formed by the LES) is obliterated. The pressure applied is usually 10-14 psi (4.11, 4.12). After dilation therapy, all patients undergo gastrograffin esophagram followed by barium esophagram to rule out perforation (4.13).

Studies have shown a 50-93% response rate with pneumatic dilation (6). A higher clinical response rate is seen with each successive dilation, with increasing balloon size. A recent evidence showed that males <40 years old will likely fail when a 3.0 cm balloon is used and that they may beneift from the use of a 3.5 cm balloon as initial therapy.

Surgical therapy: Heller myotomy (4.14)

The goal of myotomy is to reduce LES resting pressure without causing gastroesophageal reflux. Heller myotomy consists of anterior myotomy across the LES, which is performed either laparoscopically (abdominal approach) or open (transthoracic approach). The circular muscle fibers are divided down to the level of the mucosa and the myotomy extends to several centimeters above the LES and <1 cm onto the stomach. Anti-reflux surgery (Dor fundoplication) is usually performed concomitantly. Good response rates are observed, from 80-90% (7).

4.11 The balloon is positioned over a guidewire using either endoscopic or fluoroscopic control across the LES. Then, the balloon is inflated until the balloon waist detected on fluoroscopy (formed by the LES) is obliterated. The pressure applied is usually 10-14 psi.

Botulinum toxin injection (4.15)

This can be performed on patients who are high risk for pneumatic dilation or surgical myotomy, such as the elderly or those with other co-morbidities. Botulinum toxin inhibits acetylcholine release from nerve terminals, thereby blocking excitatory effects of the cholinergic neurons. It is initially effective in about 85% of patients. However, the response only lasts about 6 months, with >50% symptom recurrence in 6 months.

4.12 Pneumatic dilation is usually performed using fluoroscopic control. When the balloon is inflated, a waist is formed secondary to a poorly relaxing LES. The balloon is slowly inflated further until the waist is obliterated.

4.13 Esophageal perforation a patient with post-pneumatic dilation.

4.14 Open Heller myotomy. Heller myotomy consists of anterior myotomy across the LES. The circular muscle fibers are divided down to the level of mucosa. The myotomy extends to several centimeters above LES and <1 cm onto the stomach. Anti-reflux surgery (Dor fundoplication) is usually performed concomitantly.

4.15 A: Botulinum toxin injection is performed on patients who are high risk for pneumatic dilation or surgical myotomy, such as the elderly or those with other co-morbidities. Botulinum toxin inhibits acetylcholine release from nerve terminals, thereby blocking the excitatory effects of the cholinergic neurons. B: It is injected at about 1 cm above the gastroesophageal junction (large arrow). The LES is highlighted by the smaller arrows at the puckered GEJ. Botulinum toxin is initially effective in about 85% of patients. However, the response only lasts about 6 months with >50% symptom recurrence in 6 months.

Other pharmacologic options

Calcium-channel blockers and long-acting nitrates reduce LES pressure. The clinical response is not complete and is short lasting, with decreased efficacy over time. Therefore, medical therapy is recommended for those who are not candidates for pneumatic dilation or surgical myotomy and who fail to respond to botulinum toxin injection.

Complications

Complications are related to retention and stasis in the esophagus. They include esophagitis secondary to irritation of the mucosal lining, aspiration of esophageal contents (nocturnal coughing spells or aspiration pneumonia), and esophageal squamous cell carcinoma (SCC).

References

1 Park W, Vaezi MF (2005). Etiology and pathogenesis of achalasia: the current understanding. Am J Gastroenterol 100(6):1404-1414.

2 Howard PJ, Maher L, Pryde A, et al. (1992). Five year prospective study of incidence , clinical features, and diagnosis of achalasia in Edinburgh. Gut 33:1011.

3 de Oliveira JM, Birgisson S, Doinoff C et al. (1997). Timed barium swallow: a simple technique for evaluating esophageal emptying in patients with achalasia. AJR 169:473-479.

4 Vaezi MF (2001). Quantitative methods to determine efficacy of treatment in achalasia. Gastrointestinal Endoscopy Clinics of America 11(2):409-424.

5 Vaezi MF, Baker ME, Achkar E et al. (2002). Timed barium oesophagram: Better predictor of long term success after pneumatic dilation in achalasia than symptom assessment. Gut 40:765-770.

6 Vaezi MF, Richter JE (1998). Current therapies for achalasia: comparison and efficacy. J Clin Gastroenterol 27:21-35.

7 Vantrappen G, Hellemans J (1980). Treatment of achalasia and related motor disorders. Gastroenterol 79:144.

Further reading

Vaezi MF, Richter JE (1999). Diagnosis and management of achalasia. Am J Gastroenterol 94:3406-3412.

Summary

Definition: primary esophageal motor disorder. Etiology: unknown.

Pathophysiology: loss of inhibitory neurons in myenteric plexus required for LES relaxation. Aperistalsis also occurs.

Symptoms: dysphagia, regurgitation, chest pain, weight loss, pulmonary symptoms and coughing.

Diagnosis: contrast radiography (barium esophagram), esophageal manometry and endoscopy. DDx: pseudoachalasia due to neoplasia. Treatment: pneumatic dilation, surgical myotomy, botulinum injection, medical therapy (calcium channel blockers, nitrates).

Complications: esophagitis, aspiration of esophageal contents, SCC.

Non-achalasia motility disorders

Introduction

Esophageal motility disorders are associated with abnormal manometric motility patterns primarily in patients with noncardiac chest pain and non-obstructive dysphagia (Table 4.3). Their clinical significance is unclear (1), and they are associated with poor correlation between manometric findings and symptoms. In some cases, treatment may reduce symptoms but manometric findings are unchanged. In one study of 1,161 adult patients with chest pain or dysphagia, motility abnormality was found in 33% (2). Motility abnormality was more common in patients with symptoms of dysphagia than chest pain (53% and 28% respectively)(2).

Clinical presentation

Esophageal motility disorder should be considered in patients presenting with dysphagia, chest pain, or odynophagia. For symptoms of dysphagia, structural lesions must first be ruled out with barium esophagram or upper endoscopy. Cardiac chest pain cannot be distinguished from esophageal chest pain. Therefore, heart disease must be excluded before non-cardiac chest pain is entertained. Odynophagia is rare in primary esophageal motility disorder. It is usually due to infectious, pill-induced, or reflux esophagitis and work-up should be performed to rule out such causes.

Diagnosis

Barium esophagram is sensitive and specific in detecting motility disorder when carefully performed with videofluoroscopy.
EGD has little role in the evaluation of esophageal dysmotility. It is used in conjunction with barium studies to rule out structural lesions or esophagitis.
Manometry is necessary in order to characterize and define esophageal motility disorder.

4.3 Manometric diagnosis of motility disorders

Functional defect	Diagnosis	Manometric criteria
Aperistalsis	Achalasia	Isobaric simultaneous contractions; poorly relaxing LES
	Scleroderma	Low amplitude or absent contraction in distal esophagus, with or without low LES pressure
Incoordinated motility	DES	≥20% simultaneous esophageal contractions
Hypercontractile	NE	Normal peristalsis with DEA >180 mmHg
	Hypertensive LES	LES resting pressure >45 mmHg
Hypocontractile	IEM	≥30% of swallows with amplitude <30 mmHg in either of the two distal sites at 5 and 10 cm above LES
	Hypotensive LES	LES resting pressure <10 mmHg
DEA: distal esophageal amplitude: DES: diffuse esophageal spasm; IEMD: ineffective esophageal motility;
LES: lower esophageal sphincter; NE: nutcracker esophagus

Diffuse esophageal spasm (DES)

Etiology and pathophysiology

The etiology of DES is unknown. Suggested mechanisms of disease include a hypersensitivity response to cholinergic and hormonal stimulation, mediated by defects in neural inhibition.

Clinical presentation

Recurrent chest pain is indistinguishable from cardiac chest pain and is relieved with nitroglycerin. It is associated with meals but rarely exertionally induced. Dysphagia is intermittent and non-progressive.

Diagnosis

Manometry is the only way to diagnose DES accurately. The diagnostic criteria are the presence of normal peristalsis intermixed with simultaneous contractions in ≥20% of wet swallows (4.16)(3).

4.16 Manometric finding in DES. There are repetitive simultaneous contractions in the esophageal body, but some normal peristalsis is maintained. LES relaxation is normal and complete.

Finding from barium swallows are variable and are usually normal. Therefore, normal radiographic study does not rule out the diagnoses. Tertiary activity produces esophageal coiling appearance (‘corkscrew’) (4.17). The LES region is usually normal.

Natural history

Patients with DES have an excellent prognosis in general. Transition to achalasia occurs in approximately 3-5% (4).

Treatment

Treatment consists of medications that relax the esophagus, including nitrates and calcium channel blockers. They are usually not effective.

4.17 Barium esophagram in DES. The barium swallow study shows characteristic ‘corkscrew’ appearance.

Nutcracker esophagus

Etiology

The cause of nutcracker esophagus (NE) is unknown. However, findings of infrequent transition to achalasia suggests it may be an early part of a spectrum of disease that results in achalasia (5). Some believe it may be a functional disorder similar to irritable bowel syndrome and associated with increased visceral pain perception (6).

Clinical presentation

Chest pain is the most common (90%) symptom. Dysphagia is less frequent. These patients usually present to gastroenterologists after cardiac chest pain is ruled out by their internist and cardiologist.

4.18 Manometric finding in NE. NE is diagnosed manometrically as high amplitude (≥180 mmHg) peristaltic contractions with wet swallows.

Diagnosis

Manometry is required to diagnose NE. Diagnostic criteria require that all contractions are peristaltic and that the contraction amplitude is ≥180 mmHg (4.18). Patients with NE may present later as normal or with different manometric tracing, such as DES (7).

Radiographic findings are usually normal, since all patients have normal peristalsis by definition.

Hypertensive lower esophageal sphincter

Hypertensive LES is defined by a resting LES pressure >45 mmHg. As part of a peristaltic sequence, LES relaxation occurs with normal residual pressure (4.19). Of unknown etiology, it is typically seen in patients with symptoms of chest pain. Dysphagia can also be seen. Barium swallow is usually normal with normal esophageal function.

4.19 Manometric finding in hypertensive LES. The resting pressure of the LES is >45 mmHg. As part of the peristaltic sequence, LES relaxation occurs with normal residual pressure.

4.20 Manometry tracing of a patient with ineffective esophageal motility showing normal weak amplitude peristaltic contractions (A) and nontransmitted (NT) esophageal contraction in distal esophagus (B). (Adapted from Dig Dis Sci [1997] 42: 9.)

Ineffective esophageal motility (4.20)

The manometric abnormality is characterized by a hypocontractile esophagus, which is defined as distal esophageal contraction amplitude <30 mmHg in ≥30% of wet swallows. It is commonly associated with gastroesophageal reflux disease (GERD).

Treatment (Table 4.4)

GERD should be treated if present. Sublingual nitrates are given as needed if symptoms are mild and intermittent. For unexplained chest pain in patients with depressive or anxiety component, trazodone 50-100 mg three times daily or imipramine 50 mg at bed time is recommended. Calciumchannel blockers are prescribed in those who are refractory to the above treatment: diltiazem 60-90 mg three times daily, or nifedipine 10- 20 mg three times daily. For severely refractory patients with LES dysfunction, botulinum toxin, pneumatic dilation, or myotomy should be considered.

Table 4.4 Therapeutic options for esophageal motility disorders

Nitrates	Nitroglycerin 0.4 mg sublingually before meals or as needed
	Isosorbide 10-30 mg orally 30 minutes before meals
Viceral analgesic	Imipramine 50 mg orally at bedtime
Sedatives/antidepressants	Alprazolam 2-5 mg orally four times daily
	Trazadone 50 mg orally three or four times daily
Calcium-channel blockers	Nifedipine 10-30 mg orally four times daily
	Diltiazem 60-90 mg orally four times daily
Smooth muscle relaxant	Hydralazine 25-50 mg orally three times daily
	Botulinum toxin 80 U (injected into LES using endoscopy)
Dilation	50-60 French bougie
	Pneumatic dilation
LES: lower esophageal sphincter

References

1 Richter JE (2001). Oesophageal motility disorders. Lancet 358:823-828.

2 Katz PO, Dalton CB, Richter JE, et al. (1987). Esophageal testing of patients with noncardiac chest pain and/or dysphagia. Results of a three year experience with 1161 patients. Ann Intern Med 106:593.

3 Richter JE, Castell DO (1984). Diffuse esophageal spasm: Reappraisal. Ann Intern Med 100:242.

4 Rhoton AJ, et al. (1992). The natural history of diffuse esophageal spasm (DES): a long term follow-up study. Am J Gastroenterol 87:A1256.

5 Anggiansah A, Bright NF, McCullagh M, et al. (1990). Transition from nutcracker esophagus to achalasia. Dig Dis Sci 35:1162.

6 Richter JE, Obrecht WF, Bradley LA, et al. (1986). Psychological comparison of patients with nutcracker esophagus and irritable bowel syndrome. Dig Dis Sci 31:131.

7 Narducci F, et al. (1985). Transition from nutcracker esophagus to diffuse esophageal spasm. Am J Gastroenterol 80:242.

Webs and rings

Table 4.5 shows the similarities and differences between esophageal webs and the two types of esophageal rings (A and B). Although the terms ‘web’ and ‘ring’ are often used interchangeably, there do exist several important differences, and an accurate distinction should be made in describing these lesions.

Proximal web

Definition

A proximal web is a thin, transverse membrane of squamous mucosal epithelium occurring anywhere in the esophagus, though most often in the proximal esophagus.

Epidemiology

The prevalence of webs is not well described, although an estimate is 1-8% of the population. Webs have been found in 5-15% of patients with benign causes of dysphagia who undergo endoscopic evaluation. They can be located anywhere in the esophagus, but typically occur in the postcricoid area of the upper esophagus, located on the anterior cervical wall. The prevalence of webs increases with age, and symptomatic rings are more common in women.

Table 4.5 Webs and rings

Characteristic	Esophageal web	Mucosal (B ring)	Muscular (A ring)
Location	Posterior cricoid region along anterior wall	Schatzki’s ring, squamocolumnar junction – associated with hiatal hernia	1.5 cm proximal to squamocolumnar junction – at upper LES
Histology	Mucosa and submucosa covered by epithelium	Mucosa and submucosa covered by squamous and columnar epithelium	Hypertrophied muscle covered by squamous epithelium
Symptoms	Intermittent solid food dysphagia	Intermittent solid food dysphagia – size dependent	Usually asymptomatic – solid food dysphagia if symptomatic
Imaging	Thin projection off anterior surface of post-cricoid esophagus	Thin, transverse, circumferential ridge	Smooth, symmetrical narrowing
Treatment	Bougie or balloon dilation	Maloney dilation – 50-60 French	Maloney dilation – 50-60 French
LES: lower esophageal sphincter

Pathophysiology

The cause of webs is unclear, and most are classified as being idiopathic. GERD has been suggested as a possible cause. Several other conditions have been associated with webs, but the cause and effect relationship is uncertain. These conditions include thyroid disease, duplication cyst, Zenker’s diverticula, chronic graft-versus-host disease (GVHD), blistering skin diseases (pemphigoid and epidermolysis bullosa), psoriasis, Stevens-Johnson syndrome, and laryngeal carcinoma.

Clinical presentation

The majority of all rings and webs are asymptomatic. The most common complaints of patients with esophageal webs who do experience symptoms are solid food or pill-induced dysphagia. The proximal location of the web leads to a sensation of choking while eating.

Diagnosis

The diagnosis of webs is difficult, and they are often missed during endoscopic evaluation as well as on radiographic examination. The most sensitive test for diagnosis is a barium esophagram, and the radiologist must focus on the proximal esophagus to detect the webs (4.21). Webs will appear as a thin membranous filling defect just below the upper esophageal sphincter (UES), and they are best visualized on lateral images. Webs are 2-3 mm thick, and lie at the lower border of the cricoid cartilage. They may be unilateral or circumferential. Endoscopy is less reliable, but webs may be seen as a thin, eccentric lesion with normal appearing mucosa (4.22) compromising the esophageal lumen. The webs may impinge on the passage of the scope depending on their size. The passage of the scope may also disrupt the webs without the endoscopist being aware.

4.21 Barium esophagram showing a proximal esophageal web (arrow). This is the most sensitive test to detect this lesion. The most common location for this lesion is the posterior cricoid area of the upper esophagus.

Treatment

The most common treatment is Savary dilation over a guidewire, with most physicians using dilators 15 mm or greater in diameter. Webs may persist even following symptom relieving therapy. Other methods of treatment include endoscopic biopsy, balloon dilation, laser ablation, and surgery.

4.22 Endoscopic appearance of a proximal esophageal web. The web appears to be a thin, eccentric lesion. The mucosa is normal in appearance. If located proximally, it is possible to fracture the web during passage through the UES without being aware of its presence.

Plummer-Vinson or Patterson-Kelly syndrome

This syndrome is a triad of esophageal web, iron-deficiency anemia, and dysphagia.

The webs are typically hypopharyngeal or in the upper esophagus, may be single or multiple, and may be associated with stricture formation. It is more common in the middleaged, and in white women.

Ringed esophagus

This is a rare condition that most often occurs in young males, with most patients being younger than 30 years. Clinical presentation is often a complaint of long-standing solid food dysphagia, usually going back to early childhood. Patients may present with an acute food impaction, after spending years accommodating their chronic dysphagia.

Proposed etiologies include GERD, congenital abnormalities, and possible allergic conditions (eosinophilic esophagitis) (4.23, 4.24). Endoscopy shows multiple esophageal rings, often associated with an area of esophageal narrowing. The esophageal mucosa appears normal throughout.

4.23 Endoscopy depicting a ringed esophagus. This rare condition is most prevalent in young men, and presents with dysphagia. There are multiple esophageal rings seen on endoscopy, and treatment includes dilation and possible addition of an acid suppressive agent. Complications, such as deep mucosal tears, are more common with treatment of this condition.

Treatment is with mechanical bougienage and a consideration of acid suppressive therapy. It is not uncommon to require multiple dilations, and these patients are at increased risk of painful, deep mucosal tears.

Schatzki’s rings

A prevalence of 0.2-14% in the general population has been reported, with an increase in incidence with increasing age (most occur after the age of 40 years). The rings are located at the GEJ, at the distal margin of the LES, and are composed of annular membranes of mucosa and submucosa. Due to their location, the proximal aspect is usually squamous mucosa, with gastric columnar mucosa distally (4.25). By definition, there is a hiatal hernia present with all Schatzki’s rings. Schatzki’s rings are the most
common cause of intermittent solid food dysphagia, which may be slowly progressive over years. Other clinical presentations include food impaction and, rarely, perforation.

4.24 Histology from an esophageal biopsy in a patient with eosinophilic esophagitis. This condition is most common in young males, and patients present with chronic solid food dysphagia. Associated conditions are often present, and include allergies, asthma, and atopy. Endoscopy will show multiple mucosal rings, and a narrow, slender esophagus. The demonstration of eosinophils on biopsy is necessary in order to make the diagnosis.

4.25 Schematic figure to show the difference in appearance of esophageal ‘A’ rings (A) and ‘B’ rings (Schatzki’s ring) (B). The ‘A’ ring is located proximal to the SCJ, and is an annular ring composed of hypertrophied muscle. The ‘B’ ring, or Schatzki ring, is located at the SCJ, and is always located in association with a hiatal hernia. This ring is composed of normal esophageal epithelium, but may have a columnar mucosa on the gastric side.

The presence of symptoms depend on luminal diameter: if <13 mm the patient will have symptoms; if >20 mm the patient will almost never have symptoms. Symptoms are variable at diameters between 13 and 20 mm. Pathogenesis is controversial, and proposed etiologies include congenital abnormalities and GERD.

For diagnosis the most sensitive test is the barium esophagram (4.26), and yield may be enhanced by using a barium bolus (tablet, marsh mallow). Most rings can also be seen on endoscopy (4.27) using patience, air insufflation, or the Valsalva maneuver.

Treatment is only necessary if the patient is symptomatic. In these cases, mechanical bougienage is the treatment of choice, usually using a single pass with a large bore (48 F) dilator. It is not uncommon to have recurrent symptoms requiring repeat dilation. Acid suppressive therapy may be used considering the possible association with GERD.

4.26 Esophagram showing a Schatzki’s ring after barium swallow (arrow). Notice the presence of the hiatal hernia. Presence of dysphagia is dependent on the diameter of the ring, with nearly all patients having symptoms if <13 mm.

4.27 An endoscopic view of a Schatzki’s ring, depicting a significant narrowing of the esophageal lumen (A: esophageal view (arrows); B: retroflex gastric view). Endoscopists may use air insufflation to identify these rings better during the examination.

‘A’ ring

An ‘A’ ring is a muscular ring located in the lower esophagus at the proximal margin of the LES, approximately 2 cm proximal to the squamocolumnar margin (SCM) (4.25). This ring is composed of hypertrophic bands of circular muscle, covered with normal squamous epithelium. The incidence increases with age, with most symptomatic patients being older than 40 years of age. These rings are rarely symptomatic, but can lead to intermittent solid food dysphagia.

Diagnosis is made by barium swallow, which shows a smooth, symmetrical narrowing of the distal esophagus (4.28). This may also be seen on endoscopy. As with other rings, treatment is with large-bore dilation (>50 F), and should only be considered if the patient is symptomatic.