Gallbladder contractility in patients with spinal cord injuries: a sonographic investigation

Approximately 30% of all patients who have spinal cord injuries have gastrointestinal symptoms. One cause is gallstone disease; indeed the literature suggests that gallstones are more common in patients with spinal cord injuries because these patients have impaired contractility of the gallbladder with a reduced ejection fraction. To test this hypothesis, we obtained gallbladder sonograms in 30 patients with spinal cord injuries (16 quadriplegics and 14 paraplegics) and in 32 uninjured age-matched control subjects. Four patients and four asymptomatic control subjects had gallstones and were excluded. The remaining 26 patients and 28 control subjects fasted for 12 hr. Longitudinal and transverse sonograms of the gallbladder were made immediately before the ingestion of 25 g of fat, and at 10, 20, 30, 45, and 60 min thereafter. Gallbladder volumes were measured by using the ellipsoid method. Resting and residual volumes and the emptying times were determined and the ejection fractions were calculated. The ejection fractions were significantly lower (p = .003) in the patients than in the control subjects because the resting volumes were lower than in the control subjects (p = .013). However, the emptying times and residual volumes were the same in the two groups. We conclude that gallbladder contractility is normal in patients with spinal cord injuries and that the lower ejection fraction found in such patients is due to a smaller resting volume.