Rings and Webs

The esophagus may be narrowed by a band of tissue composed of mucosa and submucosa. By tradition, this type of lesion is called a ring when located at the esophagogastric junction and a web when located elsewhere in the esophagus or hypopharynx.

Although classically described in patients with iron-deficiency anemia (sideropenic dysphagia), the majority of esophageal webs are not associated with iron deficiency. Webs of the pharyngoesophageal segment or cervical esophagus are frequently asymmetric, most often impinging on the esophageal lumen from the anterior wall (Figure 7-1, A). A suspected web at the cervical level also can be seen in Video 7-1 on the Evolve site accompanying this text.

Schatzki’s rings are the most common bandlike constriction of the esophagus. This lesion is typically symmetric and located at the esophagogastric junction (Figure 7-1, B). Asymptomatic Schatzki’s rings are detected in approximately 10% of the population.⁴ The ring is always noted in the presence of a hiatal hernia. However, most hiatal hernias are not associated with Schatzki’s rings. The etiology of a Schatzki’s ring is unknown. Because they are rarely seen in childhood and generally are first noticed in middle age, it is unlikely that a Schatzki’s ring represents a congenital abnormality. A video image of a Schatzki’s ring can be seen in Video 7-2 as a narrowing of the esophageal lumen in the distal esophagus during swallowing of a thicker bolus.

Webs and rings typically produce dysphagia for solids only. Patients often report that symptoms are intermittent and less likely if they select their food wisely and chew carefully (see the section on differential diagnosis). Conversely, symptoms are more likely if the patient eats away from home or carries on a conversation while eating; in these situations the choice of food is more restricted and proper preparation of food before swallowing is more difficult. The patient often must end the episode by inducing regurgitation. Once the food is dislodged, the patient often can return to the meal without further difficulty.

The extent to which attention to the mechanics of cutting and chewing controls symptoms is limited. When the lumen is severely compromised, the patient may find it impossible to maintain the level of attention required to remain symptom free without avoiding solids entirely. The patient may describe symptoms without any apparent progression in frequency or severity that date back for many years. Progression, when it does occur, usually is slow.

Radiographically, rings and webs appear as thin (2 to 4 mm) bands that form shelflike constrictions anywhere along the esophagus. Although radiologists occasionally refer to thicker lesions as webs or rings, these are probably short strictures or abnormal muscular contractions.

Treatment of webs or rings involves dilatation or rupture of the ring by any one of a variety of esophageal dilator systems. The ring is thin, nonfibrotic, and easy to dilate. Complete, or nearly complete, symptomatic relief can be anticipated. Failure to respond is unusual. Dilatation may provide permanent relief, although a large proportion of patients need periodic redilatation at variable intervals.⁵

Benign Stricture

Strictures are rarely seen in children, although congenital strictures do occur. The majority of benign esophageal strictures are acquired in adulthood as a consequence of esophagitis. In a circular structure such as the esophagus, edema resulting from ongoing inflammation and fibrosis as part of the healing process occurs at the expense of luminal diameter.

As with webs and rings, dysphagia is generally for solids only. However, dysphagia is progressive, with episodes becoming more frequent and severe over a period of months or years. As luminal narrowing increases, the patient reports trouble swallowing food that previously caused no difficulty. Stenosis occasionally can become so severe that even thick liquids cause dysphagia. Even then, however, dysphagia is virtually always greater for solids than liquids.

Benign strictures are usually secondary to reflux-induced esophagitis, although most patients with gastroesophageal reflux disease (GERD) do not have esophagitis. Esophagitis refers to inflammation of the lining of the esophagus. Esophagitis may vary in severity from microscopic inflammation to mucosal edema to erosion, ulcerations, and stricture. Patients usually describe a history of heartburn or chest pain and may report the frequent use of antacids or other ulcer medications. In some patients the esophagus appears to be relatively insensitive to acid exposure. These individuals never experience significant reflux symptoms despite severe esophagitis and progression to stricture formation. Although most benign esophageal strictures are a result of reflux esophagitis, any source of esophagitis can cause stricture formation (Box 7-1).

Drug-induced or pill esophagitis can be seen in young or elderly patients. Typically, commonly administered medications that are larger in size (tetracycline, potassium, quinidine) become lodged at the level of the aortic arch and dissolve, causing inflammation and stricture. Symptoms of chest pain, odynophagia, heartburn, and dysphagia may be present, usually more acutely in younger patients.⁶

Radiographically, a benign stricture is seen as a narrowed segment of esophageal lumen that may range from 1 cm to many centimeters long (Figure 7-2). The stricture usually is smooth and gradually tapering, with a symmetric lumen that follows the anticipated path of the normal esophagus. Ongoing inflammation may produce an eroded appearance along its course. A lateral and anteroposterior (AP) video image of a midesophageal stricture caused by GERD can be seen in Video 7-3 on the Evolve site. In the AP view barium flow is interrupted, with barium building up above the stricture. The lateral view shows a long, tapered appearance of a stricture in the esophagus.

Proper management requires both treatment of the underlying inflammation and dilation of the stricture. Treatment of the cause of esophagitis requires accurate diagnosis. Although reflux is the most common cause of esophagitis, other possibilities must be considered, especially in patients with atypical histories, an unusual distribution of inflammation, or failure to respond to reflux treatment.

Dilatation often can be performed by using the same techniques available for a Schatzki’s ring. However, the stricture may be relatively unyielding and require stiffer dilator systems. Effective dilatation usually improves symptoms, although edema from inflammation may result in less-complete symptomatic relief than with a Schatzki’s ring and in relatively rapid restenosis. Frequent dilatations are more often required in benign strictures than with Schatzki’s rings. Even when ongoing inflammation completely ceases, periodic dilatation may be necessary, especially during the first year after initial treatment, when maturation of the fibrotic reaction continues at the expense of luminal diameter.

Malignant Stricture

Although benign tumors may arise from the esophagus, the majority of clinically significant tumors of the esophagus are malignant. In the past, most esophageal malignancies were squamous cell carcinomas, although recent studies suggest a dramatic increase in adenocarcinoma of the distal esophagus. Most esophageal adenocarcinomas appear to arise from Barrett’s esophagus, a premalignant condition in which columnar cells replace the usual squamous epithelium covering the lower end of the esophagus as a result of severe GER.

As with other types of stenotic lesions, dysphagia initially occurs for solids only. However, it usually progresses rapidly, with dysphagia for soft foods and even liquids developing within a few months of the onset of symptoms.

Radiographically, esophageal malignancies appear as strictures of variable length. By the time of presentation, the cancerous tumor or area is usually many centimeters long and involves the entire circumference of the esophageal lumen, producing a stricture. The typical malignant stricture is characterized by its shelflike proximal margins and irregular channel, which may diverge substantially from the anticipated course of the esophageal lumen (Figure 7-3). However, not all esophageal cancers are obviously malignant on barium radiography, and occasional malignant-looking strictures may be benign.⁶ For this reason, endoscopy with tissue sampling by biopsy with or without cytologic brushing is essential to differentiate benign and malignant strictures.

Curative treatment is primarily surgical, although apparent cures by radiotherapy have been reported. Unfortunately, by the time symptoms develop, the cancer is usually very advanced and incurable. The overall 5-year survival rate for esophageal cancer is only approximately 5%.¹ Even among those in whom resection for apparent cure is possible, the 5-year survival rate is only approximately 15%.⁷ Recent studies suggested that the 5-year survival rate could be doubled with a combination of preoperative radiotherapy and chemotherapy.⁸ Surprisingly, almost 25% of patients had no evidence of cancer by gross or histologic examination. Among these patients, survival was improved fourfold over rates reported for surgery alone and twofold over those with evidence of residual tumor at surgical resection.

For patients in whom curative resection is not possible, palliative resection often is still feasible and provides good symptomatic relief. In the past, a high perioperative mortality rate of approximately 29% combined with the infrequency of cure made surgery unattractive.⁹ However, with better nutrition provided by preoperative and perioperative hyperalimentation the risk of palliative surgery has declined.¹⁰

Alternative approaches include dilatation, tumor ablation (thermal treatment to destroy tumor obstructing the esophagus) by laser or bipolar electrocautery, and stent placement. Each of these approaches is directed at opening the esophageal lumen to permit eating, in recognition that the major cause of early death in patients with esophageal cancer is malnutrition and aspiration pneumonia.

Dilatation generally provides limited and short-lived relief but is useful in preparing for other forms of therapy. The choice between other modalities depends on specific features of the tumor and local technical expertise and resources. Endoscopic laser therapy and bipolar electrocautery can be used to destroy tumor tissue that blocks the esophageal lumen; this may provide a number of months of relief, allowing continuing oral intake. Treatment can be repeated if obstruction recurs.

An esophageal stent is a tube with a large channel that can be placed through the strictured segment to maintain luminal patency. The stent permits ingestion of a modified diet, concentrating on soft, easily chewed foods and purees. The use of stents for palliation has decreased dramatically since the development of thermal methods of treatment. However, stents continue to be useful in certain situations, especially in the presence of a tracheoesophageal fistula that often complicates the natural history or treatment of esophageal cancer. In this situation, a properly placed stent can maintain the esophageal lumen while covering the opening to the airway. The recent introduction of expandable metal stents has made insertion easier and provides a larger internal luminal diameter, allowing patients to eat a less-restrictive diet.

Although endoscopic treatment with laser, bipolar electrocautery, or stent placement may be highly successful in reestablishing luminal patency, a substantial proportion of patients with esophageal cancer have poor appetites and are unable to gain weight. The early use of endoscopically placed or fluoroscopically guided gastrostomies should be considered in patients who do not eat once the lumen is reestablished or who are scheduled to undergo chemotherapy or radiotherapy, treatments that may produce or exacerbate anorexia. (See Chapter 8 for a discussion of transhiatal esophagectomy.)

Diffuse Esophageal Spasm

Esophageal spasm is a graphic term with an imprecise meaning. The diagnosis of esophageal spasm is used quite freely among physicians, including gastroenterologists. All too often esophageal spasm is diagnosed on the basis of minor degrees of dysmotility seen radiographically (Figure 7-4) or manometrically (Figure 7-5), or even on the basis of consistent symptoms in the absence of radiographic or manometric confirmation. Esophageal spasm constitutes the end of a spectrum of nonspecific esophageal dysmotility. At one end of the range are the abnormal contractions seen occasionally in normal individuals. At the other are repeated high-amplitude, prolonged, simultaneous, or multiphasic contractions or some combination of these in the absence of any normal peristaltic activity (Figures 7-5 and 7-6). Although few would argue against calling the latter spasm, little agreement exists on where less-severe abnormalities of esophageal peristalsis end and spasm begins.