Clinical Research Of Sub-total Excision Of Cystic Duct During Laparoscopic Cholecystectomy Based On Routine Preoperative MRCP

BACKGROUND AND OBJECTIVESCholelithiasis is a common surgical disease. Symptomatic cholecystolithiasis needsto seek positive treatment. Surgical treatment is the dominant mode with symptomaticcholecystolithiasis. Laparoscopic cholecystectomy(LC) became the gold standard fortreatment of gallstones, which basically replace the traditional open cholecystectomy(OC), with the advantage of slight surgical trauma, less bleeding, low cost, quickrecovery, exact efficacy and less complications. Bile duct injury is the most seriouscomplication. The incidence of bile duct injury(BDL) was up to0.5％in LC, comparedto0.1％-0.2％in OC. How to reduce the occurrence of complications such as bile ductinjury has been a hot issue in Biliary Surgery.The occurrence of bile duct injury involves many reasons. Besides early learningcurve,the inflammation of gallbladder and hemorrhage, etl, anatomical abnormalities ofbile ducts in Calot’s Triangle and lack of knowledge of the variation of structures aremain risk factors. Extra-hepatic bile duct variation is common, with the occurrence rateof approximately20％reported in literature. These common but subtle variationscannot be clearly demonstrated with commonly used checking tools, like ultrasound andcomputed tomography(CT). MRCP is a rapidly developed and widely used method inchecking hepatobiliary and pancreatic dieases, with non-invasion, no radiation, no contrast agent in recent years.Three key steps were in cholecystectomy: sepration and ligation of cystic artery,ligation and cut off the cystic duct and completely dissection of gallbladder. Peopleagreed to ligate the cystic duct,3-5mm from the root of cystc duct at the present time.Too long cystic duct remnant (≥10mm) is prone to cause Cystic duct stumpinflammation, cystic duct remnant stone or even a carcinoma. But too closure to the rootmight led to bile duct injury, and moreover, acessory hepatic duct(AHD) injury is alsoa common type.Preoperative MRCP here is for adequate assessment of the normal anatomy andvariation of the extrahepatic bile duct system. Combined with preoperative MRCP,carefully dissection to the root of the cystic duct were operated to explore the safety andeffectiveness in LC.METHODS(1)108consecutive patients (male: n=45, female: n=63) with benign gallbladderdisease were examined with preoperative routine MRCP.(2) Two observers (A, B) observed the configuration of the extrahepatic bile duct,measured the length and the inner diameter of the cystic duct, common hepatic duct andcommon bile duct.(3) Use completely randomized design two overall mean t-test to compare the results ofthe length and inner diameter of cystic duct, common hepatic duct and common bileduct measured by observer A,B. Use kappa test to compare the consistency of cysticduct between two observers.(4) Read the MRCP pictures carefully preoperatively, Use appropriate method toseparate the cystic duct to the confluence of cystic duct and the common hepatic duct, based on the anatomy form and running mode of the cystic duct. Clamp the cystic ductwith absorbable clip and cut off the cystic duct subtotally.(5) Make follow-up and review regularly.RESULTS(1) Cystic ducts were clearly showed in92cases(81.5％),Hepatic bile ducts andcommon bile ducts were clearly showed in all108cases. Cystic duct stones(CDS)and common bile duct stones (CBDS) were found separately in4cases.(2) Average length of cystic duct:(32.46±8.20) mm; average inner diameter of cysticduct:(2.36±0.46) mm; average length of the hepatic duct:(19.66±8.71) mm,average inner diameter of the hepatic duct (6.17±1.93) mm; average length ofcommon bile duct (62.51±16.55) mm, average inner diameter of the common bileduct (5.70±1.52) mm.(3) A number of24Variations of cystic duct were found, including confluence of cysticduct into the bifurcation of left and right hepatic duct (2cases). Confluence intoright hepatic duct(2cases). Parallel with common hepatic duct (a parallel courselonger than20mm)(6cases). Low confluence (a confluence to distal one third part ofcommon hepatic duct)(5cases). Medial anterior confluence (2cases). Medialposterior confluence (3cases). Short cystic duct (shorter than5mm)(1case).Accessory right hepatic duct(3cases).(4) The choledocholithotomies were underwent in4cases with CBDS. LC weresuccessfully underwent in the other104cases. The cystic duct was totally dissectedto the root in97cases(93.3％)，with sub-total excision.3-5mm long of cystic ductremnants were left in the last7cases for reasons.(5) Drainage tube was placed in13cases, and removed in2-3days. Postoperative low fever emerged with4cases, and returned to normal in2-3days.(6) Outpatient follow-up was made in5-6months, No clinical abdominal pain, jaundice,abnormal liver function, significant expansion of the common bile duct or residualcommon bile duct stone emerged.CONCLUSIONS(1) MRCP is a pretty good non-invasive imaging method in displaying extra-hepaticbile duct system in recent years.(2) MRCP can make an visualized display about the position, configuration anddirection that cystic duct afflux into the common hepatic duct.(3) Routine preoperative MRCP might confirm anatomical variation structures of cysticduct, cystic duct stones, common bile duct stones and other diseases.(4) Guided with preoperative MRCP, the complete separation of the cystic duct to theroot is safe intra-operatively.(5) It is feasible to make a sub-total resection of the cystic duct, in favor of avoidingresidual cystic duct stones and eliminating part of PCS caused by cystic ductremnants.