Is there any objective benefit from therapeutic dilatation in patients with nutcracker esophagus ?
E.H. Metman, C. Gendreau (Tours)
The « nutcracker esophagus» (NE) has become an easily diagnosed esophageal motility disorder since the development of the accurate low compliance perfusion system in manometry. Esophageal dilatation (bougienage) was considered for treatment of nutcracker esophagus, but the only controlled therapeutic trial  did not show any objective beneficial effect of dilatation in patients with nutcracker esophagus.
However dilatations are effective for some patients , and surgical myotomy for others . This discrepancy appears to be due to variability in definition of the nutcracker esophagus and in the use of manometric criteria.
• Several treatments have been proposed in nutcracker esophagus
Medical management consists of calcium channel blockers, particularly nifedipine orally. Prolonged oral nifedipine therapy results in a significant decrease in lower esophageal pressure (LESP), amplitude and duration of contractions, but
the effect on chest pain is similar to that observed after placebo . The effects of long acting nitrates are controversial, and adverse effects frequently observed.
Esophagomyotomy has been used in nutcracker esophagus. In one report , four patients with severe symptoms despite medical therapy and one patient in another report  underwent an extented esophagomyotomy with favorable outcome. Results showed a decrease in chest pain and in amplitude of peristaltic contractions. However, selection of patients in this series is questionable because 4 out of 5 had high LESP, which is at least « uncommon » in nutcracker esophagus.
Because medical therapy is sometimes unsatisfactory, esophageal dilatation has been tried in nutcracker esophagus. One prospective, randomized, double blind, cross over study, including eight patients with nutcracker esophagus, was performed [18, 19]. A 24 F bougie as a « placebo » and a 54 F as a « therapeutic potential » dilator were used. Results showed : a decrease in score of chest pain before and after « therapeutic » or « placebo » dilatation, and no significant decrease in LESP or in amplitude of contractions after therapeutic dilatation. Finally, these data do not support any objective benefit of these dilatations in patients with nutcracker esophagus.
Psychiatric disorders like depression, anxiety and somatization, often found in nutcracker esophagus, may also explain the variability of the results observed and the general outcome of nutcracker esophagus .
In contrast Ebert, et al., in patients with symptomatic diffuse esophageal spasm (DES) and lower esophageal sphincter dysfunction, obtained a good clinical result with pneumatic dilatation .
• Problems of definition and terminology
Manometric criteria for nutcracker esophagus or symptomatic peristalsis (SP)
First described as mean high amplitude peristaltic contractions in patients with angina-like pain by Brand and co-workers in 1977, the term nutcracker esophagus was proposed by Benjamin, Gerhardt and Castell in 1979 .
First criteria were : 1. Patients with a history of angina-like chest pain. 2. Peristaltic contractions in the esophageal body. 3. High amplitude contractions defined as: mean > 120 mmHg or peak > 170 mmHg.
Later, the same authors limited the criteria to mean amplitude > 150 mmHg in lower esophageal body (2,5 cm up to LES) and mean amplitude > 120 mmHg in medium esophageal body (7,5 cm up to the LES).
Even later, another criterion was required, i.e. > 180 mmHg mean amplitude in distal esophageal body (mean of the two distal registered sites) .
Long duration contractions are often seen but not required for the diagnosis.
Symptomatic peristalsis (SP). Herrington , and then Vantrappen and Hellemans , extended the definition, considering symptomatic peristalsis with either high amplitude, or long duration normal peristalsis; the two patterns were common in patients with chest pain.
Associated manometric abnormalities. Whether some non-peristaltic contractions or frequent simultaneous contractions can occur in nutcracker esophagus or SP is not well defined, and some authors noted non-peristaltic contractions in 50 p. cent of nutcracker esophagus studied for esophageal radionuclide transit time . Whether basal LES pressure is normal or elevated is not taken into account in the definition. This is a crucial point: authors who considered efficacy of dilatation or myotomy had, in fact, more often treated patients with hypertensive lower esophageal sphincter (HLES) [7, 14].
Some authors reported delayed isotopic esophageal transit in nutcracker esophagus , but more recent reports do not confirm this result , and this discrepancy may be due to differences in the selection of patients according to variations in diagnostic criteria . Two abnormalities seemed to be associated with delayed esophageal transit: 1) Frequent non-peristaltic contraction , and 2) HLES .
High amplitude contractions in asymptomatic subjects
The term nutcracker esophagus was applied erroneously in our opinion to asymptomatic patients (alcoholics) in whom high amplitude contractions were seen initially and disappeared at alcohol withdrawal .
• Instrumental treatment
Esophageal dilatation or bougienage is effective in relief of distal obstruction (like in achalasia) in DES or HLES patients. In DES with impaired LES function, results of pneumatic dilatation are good (nine of ten patients from Ebert and Co-workers) . HLES was associated with nutcracker esophagus in one of two cases in the review of 16 patients by Freidin et al. ; they treated 15 patients with nifedipine, four of whom were subsequently treated with mercury bougienage. They obtained good results on dysphagia, whether or not nutcracker esophagus was associated with HLES.
In nutcracker esophagus, esophageal bougienage is not effective, and surgical myotomy is highly questionable .
• So, we must point out the problem of the definition of nutcracker esophagus and its usefulness in managing patients: it seems now that nutcracker esophagus is just an event associated as a marker with angina-like chest pain . The terminology nutcracker esophagus must be limited to high pressure normal peristalsis (minus 10 % non-propagated esophageal contractions), with normal LES basal pressure and relaxation in symptomatic patients.
With more than 30 p. cent simultaneous contractions, the diagnosis of DES must be considered.
When there is associated HLES, the latter must be identified and treated.
When there is impaired LES relaxation, distal obstruction and atypical achalasia (intermediate form) must be considered.
In all other cases, we should use the term of non-specific esophageal motor disorders (NEMD).
In conclusion, nutcracker esophagus per se is not a condition for esophageal dilatation or bougienage as are HLES, or DES with impaired LES function.
6. Ebert EC, Ouyang A, Wright SH, Cohen S, Lipshutz WH (1983) Pneumatic dilatation in patients with symptomatic diffuse esophageal spasm and lower esophageal sphincter dysfunction. Dig Dis Sci 28: 481-485.