Impaired fasting pyloric compliance in gastroparesis and the therapeutic response to pyloric dilatation

BackgroundPyloric pressure and compliance have never been investigated in health nor gastroparesis. AimWe hypothesised that pyloric pressure and/or compliance may be altered in gastroparesis. MethodsFasting pyloric pressure and compliance were investigated in 21 healthy volunteers (HV), 27 gastroparetic patients (GP) and 5 patients who had undergone oesophagectomy without pyloroplasty as positive controls. Under videofluoroscopic control, pyloric compliance and pressure were measured by the EndoFLIP technique. Gastric emptying half time (T-1/2) using C-13-octanoic acid breath test, as well as symptoms and quality of life (GIQLI score) were also monitored. ResultsMean fasting pyloric compliance was measured at 25.22.4mm(2)/mmHg in HV, and was lower both in GP (16.9 +/- 2.1mm(2)/mmHg; P<0.05) and patients with oesophagectomy (10.9 +/- 2.9mm(2)/mmHg; P<0.05). By contrast, fasting pyloric pressure was not different among groups. Fasting pyloric compliance and pressure correlated with T-1/2 in GP (R=-0.43; P=0.04). Fasting pyloric compliance, but not pressure, correlated with symptoms and GIQLI score. Pyloric dilation in 10 GP with low fasting pyloric compliance (<10mm(2)/mmHg) increased compliance from 7.4 +/- 0.4 to 20.1 +/- 4.9mm(2)/mmHg (P<0.01) and improved the GIQLI score from 72.5 +/- 5.5 to 89.3 +/- 6.1 (P=0.04). ConclusionThis prospective study assessed pyloric compliance for the first time, and showed that fasting pyloric compliance is decreased in gastroparetic patients and is associated with T-1/2, symptoms and quality of life. This suggests that pyloric compliance may be a new relevant metric in gastroparetic patients, and may be useful to target patients for pyloric dilation or botulinum toxin injection.