What is the relationship between diffuse esophageal spasm with LES abnormalities and vigorous achalasia?
J. Salducci (Marseilles)
Diffuse esophageal spasm (DES) is clinically characterized by retrosternal pain or dysphagia. In some cases these two symptoms occur simultaneously. Radiologically, the two-thirds of the esophageal body composed of smooth muscle fibers shows a succession of dilatations and spasms giving the classical « corkscrew » shape of esophagus.
The manometric pattern in DES is not uniform. In most cases, the peristalsis wave disappears and is replaced by simultaneous repetitive and prolonged large contractions ; these alterations of esophageal body motility are associated with normal relaxation of the lower esophageal sphincter (LES). In some other cases, different manometric patterns were observed , consisting of:
1) A normal peristalsis wave recorded in the proximal part of the esophagus followed by simultaneous contractions in the mid-esophagus and a return of the peristaltic wave in the lower part of the esophageal body, called «interrupted peristalsis » by Kaye. .
2) An abnormally slow distal propagation of the peristaltic wave.
3) Incomplete LES relaxation after wet swallows.
The classical manometric pattern of vigorous achalasia (VA) consists of simultaneous, repetitive, large nonperistaltic waves recorded mostly in the lower two-thirds of the esophageal body. These abnormalities of esophageal motility are induced by wet swallows. Incomplete and/or short duration LES relaxations are more frequently observed than in typical cases of achalasia.
In most cases, the manometric pattern allow differentiation between DES and VA, but sometimes the distinction is not very clear. Moreover, in some patients, a follow up for several years clearly demonstrates a manometric pattern evolving from DES to VA. The question is whether the manometric study of primary esophageal motility disorders is capable of identifying them. The occurrence of interrupted peristalsis in certain manometric tracings from patients with DES is not susceptible to physiologic explanations. Our knowledge of the nervous vagal control of esophageal motility does not explain why a normal peristaltic wave initiated in the upper part of the esophagus is followed first by an «interrupted peristalsis » in the mid-esophagus and finally by a sequential contraction below it. A more realistic explanation is proposed by Kaye .
In these cases of « interrupted peristalsis »the mid-esophagus is in fact aperistaltic. Thus, the high nonperistaltic waves recorded in this area are conducted pressures initiated by the contraction of the upper and lower esophagus and recorded at a distance. This phenomenon may also explain why the sequential contraction recorded below this « interrupted peristalsis » area may be delayed in appearance.
This hypothesis could explain the relationship between DES and VA. It may be imagined that these two types of esophageal motor abnormalities share the same pathophysiology. The initial abnormality of both types of disorders may be a functional obstruction of the LES, with consequential motor abnormalities of the esophageal body. If we accept this hypothesis, we may postulate the following sequence: so long as the capacity for luminal obliteration during esophageal contraction is maintained, normal forceful peristaltic contractions will be observed in the body of the esophagus, suggesting the manometric pattern of a nutcracker esophagus.
As the smooth esophageal muscle become hypertrophic in response to LES obstruction, the capacity for luminal obliteration is lost in the lower esophagus and the manometric patterns will suggest DES with « interrupted peristalsis » or « slow distal propagation ». As the capacity for esophageal obliteration extends upwards, the manometric pattern will evolve to the picture of VA.
The role played by LES tone on subjacent esophageal motility seems to be confirmed by clinical observations: while the association DES hiatus hernia is frequent, the association VA hiatus hernia is very rare. The occurrence of hiatus hernia in a patient with DES reduces the degree the functional LES obstruction and helps to prevent the evolution of the manometric pattern from DES to VA.
In conclusion, DES and VA seems to be two evolutive stages of the same dyskinetic esophageal disorder, where the role played by the lower esophageal sphincter is preponderant. This hypothesis could explain, on the one hand, the «typical» manometric patterns of DES and VA and, on the other, intermediate manometric patterns such as DES with LES abnormalities, this stage representing a manometric evolutive pattern in the spectrum between DES and VA.