Assessing the diagnostic yield of achalasia using provocative testing in high-resolution esophageal manometry: Serial diagnostic study.

BACKGROUND: Chicago Classification v4.0 recommends that if achalasia is demonstrated with single water swallows (SWS); provocative testing is not required. We determine whether provocative testing in patients with suspected achalasia can change manometric findings and reproduce symptoms.

METHODS: Between 2016 and 2022, 127 consecutive manometry studies of patients with achalasia were retrospectively analyzed. All patients underwent SWS, a solid meal (SM) and/or a rapid drink challenge (RDC). Demographic data, fluoroscopy, gastroscopy, and pre-and post-treatment Eckardt scores were collated.

KEY RESULTS: Of 127 achalasia patients (50.6 ± 16.6 years and 54.6% male), all completed a SM and 116 (91.3%) completed RDC; overall 83 were naïve (65.4%) to previous therapy. 15.4% patients with normal integrated relaxation pressure (IRP) on SWS demonstrated obstruction with RDC. SM gave a different achalasia phenotype in 44.9% of patients (p ⟨ 0.001). Twelve patients with normal IRP during SWS had persistent/recurrent obstruction during provocative testing; 83.3% had previous achalasia therapy. None of 13 patients with Type III (TIII) achalasia with SWS exhibited a change in manometric findings with provocative testing. Impedance bolus heights were lower in patients with TIII achalasia and those with normal IRP with SWS. During the SM, symptoms were reproduced in 56.7% of patients. Forty-six of 103 patients (44.7%) underwent therapy based upon the final achalasia subtype which was defined by the provocative test result of the high-resolution manometry (HRM) study. All treatments were effective, regardless of the achalasia subtype.

CONCLUSIONS AND INFERENCES: Manometric findings remain unchanged when TIII achalasia is diagnosed with SWS. In patients with normal IRP, Type I, or Type II achalasia during SWS, provocative testing can alter achalasia phenotype or uncover achalasia where diagnosis is unclear. Further, it can reproduce symptoms. Such findings can personalize and guide effective therapeutic decisions.