High-resolution manometry studies are frequently imperfect but usually still interpretable

Background & aims: Clinical esophageal manometry can be technically challenging. We investigated the prevalence and causes of technically imperfect, high-resolution esophageal pressure topography (EPT) studies at a tertiary referral hospital.

Methods: We reviewed 2000 consecutive clinical EPT studies that had been performed with consistent technique and protocol. A study was considered technically imperfect if there was a problem with pressure signal acquisition, if the catheter did not pass through the esophagogastric junction (EGJ), or if there were fewer than 7 evaluable swallows (without double-swallowing, and so forth). Data from the technically imperfect studies were interpreted blindly to determine a diagnosis; this diagnosis was compared with the diagnosis based on chart review.

Results: We identified 414 technically imperfect studies (21% of the series). These were attributed to fewer than 7 evaluable swallows (58%), inability to traverse the EGJ (29%), sensor or thermal compensation malfunction (7%), and miscellaneous artifacts (6%). The most frequent causes of failure to traverse the EGJ were a large hiatal hernia (50%) and achalasia (24%). The condition most frequently associated with an incomplete swallow protocol was achalasia (33%). Despite the limitations, the diagnosis of achalasia was achieved correctly by blinded interpretation in 77% of cases and nonblinded interpretation in 94% of cases.

Conclusions: Technically imperfect EPT studies are common in a tertiary care center; large hiatal hernia and achalasia were the most frequent causes. However, despite the technical limitations, the data still could be interpreted, especially in the context of associated endoscopic and radiographic data.