Читать книгу The Esophagus - Группа авторов - Страница 194

Achalasia can be classified as primary when it occurs as an idiopathic condition involving the myenteric plexus of the esophagus or as secondary when it is caused by other underlying conditions, most commonly malignant tumor involving the GEJ (especially carcinoma of the gastric cardia and fundus). Primary achalasia is characterized by absent primary peristalsis in the body of the esophagus and incomplete relaxation of the lower esophageal sphincter, manifested on barium studies by tapered, beak‐like narrowing of the distal esophagus directly adjacent to the GEJ [136] (Figure 6.74). In advanced disease, the esophagus can become massively dilated and tortuous distally (also known as a “sigmoid esophagus”). Because of the slow, insidious progression of symptoms, affected individuals typically have longstanding dysphagia when they seek medical attention.

Figure 6.73 Esophageal intramural pseudodiverticulosis. (A) Double‐contrast view shows multiple flask‐shaped outpouchings throughout the esophagus in a patient with diffuse esophageal intramural pseudodiverticulosis. Also note a focal stricture (arrow) in the upper thoracic esophagus. (B) Double‐contrast view in another patient shows a mild peptic stricture in the distal esophagus with multiple pseudodiverticula clustered together in the region of the stricture. When viewed en face, the pseudodiverticula could be mistaken for tiny ulcers. When viewed in profile, however, these structures (arrows) appear to be floating outside the esophagus without communicating with the lumen. This feature is characteristic of pseudodiverticula.

Source: Reproduced from Levine MS. Radiology of the esophagus. Philadelphia: WB Saunders, 1989, with permission.

In contrast, secondary achalasia usually results from tumor at the GEJ that simulates the findings of primary achalasia because of destruction of ganglion cells in the distal esophagus. As a result, secondary achalasia is also characterized by absent peristalsis in the body of the esophagus and beak‐like narrowing near the GEJ. In secondary achalasia, however, the length of the narrowed segment is often considerably greater than that in primary achalasia because of spread of tumor into the distal esophagus [137] (Figure 6.75). The narrowed segment also may be asymmetric, nodular, or ulcerated because of underlying tumor in this region. In some cases, barium studies may reveal other signs of malignancy in the region of the gastric cardia and fundus. The clinical history also is extremely helpful, as patients with primary achalasia almost always have longstanding dysphagia, whereas patients with secondary achalasia are usually older individuals (over 60 years of age) with recent onset of dysphagia (<6 months) and weight loss [137]. As a result, it is often possible to differentiate these conditions on the basis of the clinical and radiographic findings.

Figure 6.74 Primary achalasia. Single‐contrast esophagram shows a markedly dilated esophagus filled with debris. Also note beak‐like narrowing (arrow) of the distal esophagus near the gastroesophageal junction in this patient with longstanding achalasia.