Clinical relevance of the nutcracker esophagus: Suggested revision of criteria for diagnosis

Background: Nutcracker esophagus (NE) is a manometric finding defined by peristaltic contractions with a mean distal esophageal amplitude (DEA) > 180 mm Hg. This threshold has been selected as it exceeds the average DEA in healthy volunteers by 2 SDs. Since its introduction the clinical significance of this finding has been challenged, as many patients with NE are asymptomatic. Aim: To evaluate whether defining NE based on a different DEA threshold would be clinically more meaningful. Methods: Retrospective review of prospectively collected manometry data between October 2001 and December 2003. Using previously published normal DEA values (mean and SD) patients with NE were stratified into 3 groups: group A (2 to 3 SD above mean): DEA 180 to 220 mm Hg; group B (3 to 4 SD above mean): DEA 220 to 260 mm Hg; and group C (> 4 SD above mean): DEA > 260 mm Hg. Symptoms, esophageal acid exposure, bolus transit data, and lower esophageal sphincter data were reviewed. Results: The stratification of 56 NE patients into groups A, B, and C were 31, 16, and 9, respectively. The proportion of patients presenting with chest pain increased from 23% in group A to 69% in group B and 100% in group C. Patients in group C had significantly (P < 0.05) higher mean lower esophageal sphincter pressure, shorter bolus transit time, and lower frequency of abnormal reflux. Conclusions: A revised definition of NE to include patients with a DEA > 260 mm Hg, and possibly those with > 220 may have greater clinical relevance.