Diagnostic value of real-time dynamic gastric contrast ultrasound for hiatal hernia

Gastric contrast ultrasound (GCUS) is a real-time, dynamic, noninvasive and radiation-free imaging technique. The diagnostic performance of GCUS in evaluating hiatal hernia (HH) was assessed relative to that of conventional modalities. This retrospective study enrolled 177 patients with suspected HH. GCUS was performed at rest and during the Valsalva manoeuvre. The diagnostic performance of GCUS was compared with that of upper gastrointestinal series (UGIS), oesophagogastroduodenoscopy (EGD), contrast-enhanced computed tomography (CECT), and high-resolution manometry (HRM), using surgical or comprehensive clinical diagnosis as the reference standard. GCUS demonstrated a significantly greater diagnostic area under the curve (AUC) for HH than did UGIS, EGD, CECT and HRM (0.974 vs. 0.871, 0.803, 0.822, and 0.672, respectively; all P < 0.05). The sensitivity of GCUS was significantly greater than that of EGD, CECT, and HRM (93.9% vs. 68.6%, 67.8%, and 40.0%, respectively; all P < 0.001). Notably, 52.9% (73/138) of the hernias identified by GCUS were detectable only during the Valsalva manoeuvre. Compared with hernias detectable at rest, these Valsalva-only HHs exhibited smaller hernial sacs (44 vs. 30 mm) and hiatal diameters (26 vs. 20 mm) (both P < 0.001), with significantly greater miss rates for all conventional methods (all P < 0.05). Real-time dynamic GCUS is a highly accurate, safe and efficient diagnostic tool for detecting HH and is particularly valuable for detecting Valsalva-only HHs, which can be easily missed by conventional methods.