Pathophysiological significance of gallbladder volume changes in gallstone diseases.

Aim: To study the pathophysiological significance of gallbladder volume (GBV) and ejection fraction changes in gallstone patients.

Methods: The fasting GBV of gallstone patients with acute cholecystitis (n = 99), chronic cholecystitis (n = 85) and non-gallstone disease (n = 240) were measured by preoperative computed tomography. Direct saline injection measurements of GBV after cholecystectomy were also performed. The fasting and postprandial GBV of 65 patients with gallstones and chronic cholecystitis and 53 healthy subjects who received health examinations were measured by abdominal ultrasonography. Proper adjustments were made after the correction factors were calculated by comparing the preoperative and postoperative measurements. Pathological correlations between gallbladder changes in patients with acute calculous cholecystitis and the stages defined by the Tokyo International Consensus Meeting in 2007 were made. Unpaired Student's t tests were used. P < 0.05 was deemed statistically significant.

Results: The fasting GBV was larger in late stage than in early/second stage acute cholecystitis gallbladders (84.66 +/- 26.32 cm(3), n = 12, vs 53.19 +/- 33.80 cm(3), n = 87, P = 0.002). The fasting volume/ejection fraction of gallbladders in chronic cholecystitis were larger/lower than those of normal subjects (28.77 +/- 15.00 cm(3) vs 6.77 +/- 15.75 cm(3), P < 0.0001)/(34.6% +/- 10.6%, n = 65, vs 53.3% +/- 24.9%, n = 53, P < 0.0001).

Conclusion: GBV increases as acute cholecystitis progresses to gangrene and/or empyema. Gallstone formation is associated with poorer contractility and larger volume in gallbladders that contain stones.