Is the distinction between DES and achalasia not sometimes arbitrary ?
H.J. Stein, T.R. DeMeester (Omaha)
Achalasia and diffuse esophageal spasm are the classic primary esophageal motor disorders causing dysphagia and/or esophageal chest pain[l]. The diagnosis and differentiation of both disorders is usually based on standard esophageal manometry. Recent studies, however, indicate that there might be a greater similarity between the two disorders than has previously been appreciated .
The classic manometric findings of achalasia include complete absence of peristalsis in the esophageal body, hypertension of the lower esophageal sphincter with a failure to relax completely on swallowing, and an increased intraluminal esophageal pressure. In deference to this classic description, recent studies have reported normal pressure and/or complete relaxation of the lower esophageal sphincter in patients with otherwise typical features of achalasia . Also, peristaltic activity of the esophageal body has been observed to return in patients with classic achalasia following a Heller myotomy or balloon dilatation [1, 4, 5]. In addition, a subgroup of patients with typical features of classic achalasia have simultaneous repetitive contractions of high amplitude in the esophageal body resembling the manometric findings of diffuse esophageal spasm. This manometric pattern has been termed « vigorous achalasia » and chest pain is more common in these patients than in those with classic achalasia.
On the other hand, the diagnosis of diffuse esophageal spasm is based on the manometric demonstration of an increased frequency of simultaneous contractions with intermittent normal peristaltic activity. The lower esophageal sphincter in these patients usually shows normal resting pressure and relaxation on deglutition. As in achalasia, there have been a number of reports which take exception to this classic presentation. For example, a hypertensive sphincter and incomplete relaxation on swallowing have been documented in patients with otherwise typical features of diffuse esophageal spasm . There have also been several reports that show the manometric progression of diffuse esophageal spasm to classic achalasia in patients followed over a long period.
Twenty-four hour ambulatory monitoring of esophageal motility indicates that there may be an even greater similarity between the two disorders than on standard
manometric evaluation . Patients who meet the classic criteria for achalasia on standard manometry have occasional peristaltic contractions when monitored over a complete circadian cycle, and patients with diffuse esophageal spasm can show episodes of complete aperistalsis with an increase in intraesophageal pressure baseline as found in classic achalasia [2, 7, 8].
These observations support the concept that diffuse esophageal spasm and achalasia may represent different expressions of a common underlying esophageal motor abnormality. There appears to be a broad range of overlap between the two disorders with a frequent occurrence of intermediate forms displaying typical characteristics of both disorders. The possibility of transition of the manometric pattern from one extreme to the other and vice versa suggests that a rigorous distinction between the two disorders may be arbitrary.
5. Csendes A, Braghetto I, Mascano J, Henriquez A (1988) Late subjective and objective evaluation of the results of esophagomyotomy in 100 patients with achalasia of the esophagus. Surgery 104 : 469-475.