Characterization and correction of pressure drift in the ManoScan(™) high-resolution manometry system: In vitro and in vivo.

BACKGROUND: A substantial pressure drift in high-resolution manometry (HRM) has been reported; however, fundamental questions remain regarding the origin and management of this drift. The aim of this study was to provide critical in-depth analyses of ManoScan(™) HRM drift in vitro and in vivo.

METHODS: A total of sixteen 15-min studies and twelve 5-h studies were performed in a water bath at 37 °C at 4.0 cm depth (2.9 mmHg) with ESO and ESO Z catheters. Six 5-h in vitro studies were performed similarly at a depth of 9.0 cm (6.6 mmHg). Eight 15-min studies and nine 8-h in vivo studies were performed with healthy participants. Two correction methods - thermal compensation (TC) and interpolated thermal compensation (ITC) - were tested.

KEY RESULTS: Overall pressure drift varied both between studies (p < 0.01) and within sensors (p < 0.01). Drift resulted from thermal shock, an initial pressure change at intubation, and baseline drift, a linear drift over time (R(2)  > 0.96). Contrary to previous reports, there was no correlation between drift and average (r = -0.02) or maximum pressure exposure (r = -0.05). Following data correction, ITC had the lowest median error but persisted with a maximum error of 2.5 mmHg (IQR = 3.0).

CONCLUSIONS & INFERENCES: The substantial drift in the ManoScan(™) HRM system is highly variable and not corrected via the standard operating instructions. ITC has superior performance but requires communication with the manufacturer to enable this option. This has a substantial impact on clinical diagnosis, utility of existing normative data, and future research of HRM.