Contribution of standard oesophageal manometry in sliding hiatal hernia: from the gastro-oesophageal pressure gradient to the diagnosis.

OBJECTIVE: We tested whether gastro-oesophageal pressure gradient is augmented in sliding hiatal hernia and the yield of oesophageal manometry in diagnosing sliding hiatal hernia.
METHODS: Patients with equivalent body mass index were categorised according to manometry and endoscopy in groups: (1) no sliding hiatal hernia (n=147); (2) sliding hiatal hernia solely at endoscopy (n=46); and (3) sliding hiatal hernia at manometry (n=22). The yield of manometry was assessed taking endoscopy as referential.
RESULTS: Gastro-oesophageal pressure gradient was similar between groups both at inspiration (13.3+/-5.7 mm Hg vs. 13.6+/-5.4 mm Hg vs. 12.6+/-4.4 mm Hg; P=0.874) or expiration (5.1+/-3.8 mm Hg vs. 5.2+/-3.6 mm Hg vs. 5.1+/-3.7 mm Hg; P=0.767). Group 3 patients were older than those of groups 1 and 2 (59+/-10 vs. 42+/-15 vs. 45+/-13 years; P<0.001). Sliding hiatal hernia was larger when characterised by manometry than at endoscopy [4 cm (2.25-4.75) vs. 2 cm (2-3); P<0.001]. Manometry showed sensitivity of 28% (95%CI 19-40%), specificity of 97% (95%CI 93-99%) and positive predictive value of 82% (95%CI 63-92%) in diagnosing sliding hiatal hernia.
CONCLUSIONS: By using manometry in patients with equivalent body mass index, sliding hiatal hernia presence and size are related with age rather than gastro-oesophageal pressure gradient. This technique may be clinically useful when positive for sliding hiatal hernia.