The natural history of achalasia: Evidence of a continuum-"The evolutive pattern theory".

Background: It is currently unclear if the three manometric patterns of esophageal achalasia represent distinct entities or part of a disease continuum. The study's aims were: a) to test the hypothesis that the three patterns represent different stages in the evolution of achalasia; b) to investigate whether manometric patterns change after Laparoscopic-Heller-Dor (LHD).

Methods: We assessed the patients diagnosed with achalasia who underwent LHD as their first treatment from 1992 to 2016. Their symptoms were scored using a detailed questionnaire for dysphagia, food-regurgitation, and chest pain. Barium-swallow, endoscopy, and esophageal-manometry were performed before and 6 months after surgery.

Results: The study population consisted of 511 patients (M:F=283:228). Patients' demographic and clinical data showed that those with pattern III had a shorter history of symptoms, a higher incidence of chest pain, and a less dilated gullet (p<0.001). All patients with a sigmoid-shaped mega-esophagus had pattern I achalasia. One patient with a diagnosis of pattern III achalasia developed pattern II at a follow-up manometry before surgery. At a median follow-up of 30 months (IQR 12-56), the outcome of surgery was positive in 479 patients (91.7%). All patients with pattern I preoperatively had the same pattern after LHD, whereas more than 50% of patients with pattern III before treatment showed pattern I or II after surgery.

Conclusions: This study supports the hypothesis/theory that the different manometric patterns represent different stages in the evolution of the disease-where pattern III is the earliest stage, pattern II an intermediate stage, and pattern I the final stage.