New endoscopic indicator of esophageal achalasia: "pinstripe pattern"

Abstract

Background and study aims: Endoscopic diagnosis of esophageal achalasia lacking typical endoscopic features can be extremely difficult. The aim of this study was to identify simple and reliable early indicator of esophageal achalasia.

Patients and methods: This single-center retrospective study included 56 cases of esophageal achalasia without previous treatment. As a control, 60 non-achalasia subjects including reflux esophagitis and superficial esophageal cancer were also included in this study. Endoscopic findings were evaluated according to Descriptive Rules for Achalasia of the Esophagus as follows: (1) esophageal dilatation, (2) abnormal retention of liquid and/or food, (3) whitish change of the mucosal surface, (4) functional stenosis of the esophago-gastric junction, and (5) abnormal contraction. Additionally, the presence of the longitudinal superficial wrinkles of esophageal mucosa, "pinstripe pattern (PSP)" was evaluated endoscopically. Then, inter-observer diagnostic agreement was assessed for each finding.

Results: The prevalence rates of the above-mentioned findings (1-5) were 41.1%, 41.1%, 16.1%, 94.6%, and 43.9%, respectively. PSP was observed in 60.7% of achalasia, while none of the control showed positivity for PSP. PSP was observed in 26 (62.5%) of 35 cases with shorter history < 10 years, which usually lacks typical findings such as severe esophageal dilation and tortuosity. Inter-observer agreement level was substantial for food/liquid remnant (k = 0.6861) and PSP (k = 0.6098), and was fair for abnormal contraction and white change. The accuracy, sensitivity, and specificity for achalasia were 83.8%, 64.7%, and 100%, respectively.

Conclusion: "Pinstripe pattern" could be a reliable indicator for early discrimination of primary esophageal achalasia.

Fig 1. Typical findings of primary esophageal achalasia.

(a) Dilation of the esophagus. Dilated esophagus drooped to both sides of the spine. (b) Food remnant in the esophagus. (c) Whitish coating of the mucosa caused by adhesion of the remained food inside of the esophagus and thickening of the mucosa. (d) Functional stenosis of the esophago-gastric junction. Endoscope passes through the tight segment with some resistance. (e) Abnormal contraction of the esophagus. Simultaneous contraction is clearly observed.

Fig 2. Pinstripe pattern (PSP).

(a) Minute superficial wrinkle was observed on the mucosal surface. (b) Indigocarmine spraying made the superficial structure clearer. (c) Magnifying observation after indigocarmine spraying. Slight gap was observed between each longitudinal line. (d) NBI Image with magnification. The gap observed by magnifying chromoendoscopy was also identified via NBI magnification. Each superficial microvessel was substantially transparent at the gaps between stripes.

Fig 3. Comparison between achalasia (left) and non-achalasia (right) patients using indigocarmine and NBI.

Fig 4. PSP change before and 3 months after POEM.

(a) Conventional white light observation before POEM. Minute whitish stripe is observed on the surface of mucosa. (b) White light with indigocarmine dye. Indigocarmine emphasizes the mucosal pattern. (c) Conventional white light observation 3 months after POEM. Minute stripe was nearly disappeared. (d) Chromoendoscopy image 3 months after POEM. Minute stripe was decreased.