Objective:To summarize and analyze the clinical and histopathological features of chronic acalculous cholecystitis （CAC） and to investigate the diagnosis and surgical treatment of chronic acalculous cholecystit.Methods:The study subjects were 39 patients with chronic biliary symptoms but no evidence of stones in the gallbladder by B ultrasonography and magnetic resonance cholopancreatography （MRCP） （CAC group）.The CCC group consisted of 66 patients taken randomly from concurrent all patients of chronic calculous cholecystitis （CCC）.All patients accepted fibergastroscopy

B ultrasonography

MRCP

laboratory examination preoperatively.We retrospectively analyzed the clinical features

B ultrasonography and MRCP findings

histopathological results and clinical outcomes between the two groups.Results:All the 39 patients were diagnosed by clinical symptoms

B ultrasonography

fatty meal gallbladder contractability studies under ultrasound

fibergastroscopy and magnetic resonance cholangiopancreatography （MRCP）

what’s more

they were pathologically verified postoperatively.In all patients

there was a complete absence of gallbladder wall contractability.Mucosa epithelial defect was found in 21 patients in CAC group （53.8%） and 16 patients in CCC group （24.2%） respectively （P<0.005）.Thickened arteriole wall was found in 29 patients in CAC group （74.4%） and none patient in CCC group （P<0.0001）.Thickened gallbladder wall （4 mm or more in thickness） was found in 33 patients in CAC group （84.6%） and 28 patients in CCC group （42.4%） respectively （P<0.005）.Bile stasis was found in 23 patients in CAC group （59.0%） and 14 patients in CCC group （21.2%） respectively by ultrasonography preoperatively and confirmed in operation （P<0.005）.The outcomes of cholecystectomy

expressed as total or near total relief

was similar in the two groups.No statistically significant differences were observed between patients with CAC （90%） and CCC （80%）

the P-value >0.05.Conclusion:Chronic acalculous cholecystitis could be diagnosed by symptoms

ultrasound

fatty meal gallbladder contractability studies under untrasoundand MRCP.The optimal treatment of chronic acalculous cholecystitis characterized by thickened arteriole wall and mucosa epithelial defect is cholecystectomy.