Achalasia Despite Normal Integrated Relaxation Pressure with 5ml Water Swallows

Introduction Resistance to bolus flow across the lower esophageal sphincter (LES) is a hallmark of achalasia. Presently the gold standard of diagnosis is by high-resolution manometry (HRM) demonstration of raised integrated relaxation pressure (IRP) following ten 5 mL water swallows; however, this does not replicate normal swallowing behaviour. It has been demonstrated that the addition of adjunctive tests improves sensitivity of identifying relevant dysmotility. Such tests include multiple water swallows (MWS; 200 mL water drunk freely) and solid swallows. In addition, the timed barium esophagram (TBE) measures esophageal emptying. This study describes a cohort of patients who have been treated as having achalasia based on resistance to flow not exhibited with single water swallows. Method Inclusion criteria were all patients between October 2014–2016 with normal mean and median IRP with 5 mL water swallows but considered to have achalasia due to resistance to flow demonstrated by pan-esophageal pressurisation (PEP) during MWS or solid swallows and/or a persistent column at 5 min during TBE. Outcome post-treatment was based on Eckardt score (ES). Results 14 patients (9 male) fulfilled inclusion criteria. 7 were treatment-naive and 7 treatment-experienced (3 myotomy, 4 dilatation). Mean resting LES pressure was 14.6±7.4 mmHg. In all patients, mean and median IRP values for ten 5 mL water swallows were non-raised (mean 9.1±4.3 and 8.7±4.5 mmHg respectively). Of the 7 treatment-naive patients, 5 demonstrated PEP on MWS, 3 on solid swallows and 6 had a positive TBE at 5 min. In treatment-experienced patients, 5 had PEP on MWS, 1 on solid swallows and all had a positive TBE. Of the 13 who had resistance to flow on TBE, 10 (77%) also had resistance demonstrated during MWS and/or solid swallows. Mean height of the 5 min column of barium at baseline was 16.5±8.9 cm. 8 patients underwent therapy based on these findings; one POEM and 7 pneumatic dilatations. Median baseline ES was 7.5 (IQR 5–8). Median ES at minimum 3 months following treatment was 1 (IQR 0–2.5; p Conclusion A normal IRP for water swallows does not preclude a diagnosis of achalasia. The addition of free drinking/solids during HRM or the TBE can identify pathology that might have been missed with standard 5 mL water swallows alone. Patients treated based on this algorithm exhibit excellent treatment outcomes, validating this approach. Disclosure of Interest None Declared