Mirizzi综合征病例讨论2011.11.17•胆囊管或胆囊颈部结石压迫肝总管引起胆道梗阻症状，伴/不伴胆管瘘形成。•在胆囊切除患者中发病率0.7%~1.8%。•男女发病率无明显差异，老年患者多见。•引起胆管梗阻的机制a.机械性梗阻（胆囊管与肝总管位置靠近）b.继发胆管炎症•按是否合并胆管瘘分为两型：TypeI-NofistulapresentIA-PresenceofthecysticductIB-ObliterationofthecysticductTypesII-IV-FistulapresentII-Defectsmallerthan33%oftheCBDdiameterIII-Defect33-66%oftheCBDdiameterIV-Defectlargerthan66%oftheCBDdiameter•推荐治疗方案：TypeI–Partialortotalcholecystectomy,eitherlaparoscopicoropen.CommonbileductexplorationistypicallynotrequiredTypeII–Cholecystectomyplusclosureofthefistula,eitherbysuturerepairwithabsorbablematerial,Ttubeplacement,orcholedochoplastywiththeremnantgallbladder.TypeIII–Choledochoplastyorbilioentericanastomosis(choledochoduodenostomy,cholecystoduodenostomy,orcholedochojejunostomy),isrequired,dependingonthesizeofthefistula.Sutureofthefistulaisnotindicated.TypeIV–Bilioentericanastomosis,typicallycholedochojejunostomy,ispreferredbecausetheentirewallofthecommonbileducthasbeendestroyed.含气胆结石（Gas-ContainingGallstone）胆结石化学成分与CT表现•结论胆结石中胆固醇含量较钙含量对CT表现的影响更大。问题：为什么胆结石中会含有“气体”？“气体”的化学成分是什么？Thanks！
