Normal Values of High-resolution Manometry Parameters With Provocative Maneuvers

Background/Aims Incorporation of complementary and provocative test swallows to the high-resolution manometry (HRM) protocol offers potential to address limitations posed by HRM protocols that involve only a single swallow type. The aim of this study is to describe normal findings of a comprehensive HRM testing protocol performed on healthy asymptomatic volunteers. Methods Thirty healthy asymptomatic volunteers completed HRM with 5-mL liquid swallows in the supine position. They also completed 5-mL liquid swallows in the upright position, viscous swallows, solid test swallows, multiple rapid swallows, and a rapid drink challenge. HRM studies were analyzed via Chicago classification version 3.0. Results The median (5th-95th percentiles) for integrated relaxation pressure (IRP) on supine swallows was 11 (4-16) mmHg; IRP was lower than supine on upright liquid 9 (0-17) mmHg, viscous 6 (0-15) mmHg, solid 9 (1-19) mmHg, multiple rapid swallows 3 (0-12) mmHg, and rapid drink challenge 5 (-3-12) mmHg; P < 0.005. While an "elevated" IRP value was observed on 1 to 2 test maneuvers in 8/30 (27%) subjects, all 30 subjects had an IRP value < 12 mmHg on at least one of the test maneuvers. Conclusions Normal values and findings from a comprehensive HRM testing protocol are reported based on evaluation of 30 healthy asymptomatic volunteers. Isolated "abnormalities" of IRP and contractile parameters were observed in the majority (80%) of these asymptomatic subjects, while all subjects also had normal features observed. Thus, the definition of "normal" should be recalibrated to focus on the entirety of the study and not individual metrics.