Percutaneous chemical gallbladder sclerosis after laser-induced cystic duct obliteration: results in an experimental model.

OBJECTIVE. Chemical gallbladder sclerosis has been attempted as a way to defunctionalize the gallbladder in patients who have undergone nonsurgical removal of gallstones and who are unable to undergo surgical/laparoscopic cholecystectomy. The purpose of this investigation was threefold: to study an animal model for chemical sclerosis of the gallbladder with 95% ethanol and 3% sodium tetradecyl sulfate, to attempt chemical sclerosis immediately after percutaneous cystic duct obliteration by laser thermocoagulation, and to assess histopathologic changes in the gallbladder after sclerosis. MATERIALS AND METHODS. Percutaneous cholecystostomy and laser thermocoagulation of the cystic duct was performed in 13 pigs. Eight pigs underwent immediate gallbladder sclerosis with 95% ethanol and 3% sodium tetradecyl sulfate while two pigs received 95% ethanol only. The remaining three pigs served as controls. The cholecystostomy catheter was removed immediately after the procedure. All animals were sacrificed 6 weeks after laser thermocoagulation. Multiple sections through the gallbladder, which included the adjacent liver, the cystic duct, and the common bile duct, were obtained for histologic examination. RESULTS. At autopsy, the gallbladder in all 10 animals who underwent gallbladder sclerosis was reduced in size compared with controls. In all treated animals, the gallbladder mucosa was denuded; however, in nine of 10 cases reepithelialization had occurred. Complete sclerosis without reepithelialization was achieved in one pig who received both ethanol and sodium tetradecyl sulfate. In the two animals who received ethanol only, the depth of wall necrosis around the gallbladder lumen was less than in those pigs who received both ethanol and sodium tetradecyl sulfate. No pigs showed signs of hepatic necrosis or injury to the common bile duct. CONCLUSION. Cystic duct laser thermocoagulation allows immediate gallbladder sclerotherapy without injury to the common bile duct. Sclerosis with ethanol and sodium tetradecyl sulfate results in denudation of the gallbladder mucosa. However, a single therapeutic session with immediate removal of the cholecystostomy catheter was inadequate for gallbladder ablation in this model because of reepithelialization.     

Long-term occlusion of the porcine cystic duct by means of endoluminal radio-frequency electrocoagulation

Recurrent cholelithiasis must be expected after gallstone removal without cholecystectomy. Chemical gallbladder ablation may offer prevention but requires preliminary cystic duct occlusion. Radio-frequency (RF) electrocoagulation of the cystic duct was performed in 15 pigs to induce occlusion by a controlled thermal epithelial injury. A flexible coagulation catheter was placed into the cystic duct lumen under fluoroscopic control by means of either subhepatic cholecystostomy or direct, percutaneous transhepatic gallbladder puncture. Complete cystic duct occlusion was proved in 14 animals. Follow-up ranged from 1 to 17 weeks (mean, 11 weeks). Histologically, the RF technique induced an intense chronic inflammatory and fibroblastic reaction, which eventually obliterated the coagulated cystic duct segments. There was no epithelial regeneration or recanalization of the fibrotic cystic duct segments. The adjacent structures, particularly the cystic artery, were intact in all specimens.     

Gallbladder ablation through radiologic intervention: an experimental alternative to cholecystectomy

Twenty pigs underwent (a) cystic duct occlusion by means of fluoroscopically guided transcatheter endoluminal bipolar radio-frequency (RF) electrocoagulation and (b) gallbladder sclerotherapy with one of two different regimens of ethanol and sodium tetradecyl-sulfate (STS). Serum ethanol levels and hepatic enzyme tests showed no acute toxicity. Postmortem histologic studies showed that the bile ducts beyond the occlusion site remained entirely unaffected in all animals. In three of four animals followed up for 2 weeks, the sclerosants induced necrosis of the gallbladder mucosa, but the adjacent liver, serosa, and blood vessels remained intact. In 13 of 16 animals followed up for 8 weeks, the gallbladder lumen was obliterated by fibrous scar tissue. In the animals treated with 95% ethanol and 3% STS, the gallbladder mucosa was necrotic in all areas after 2 weeks (two of two animals) and eradicated completely after 8 weeks (six of eight animals); the other regimen (70% ethanol plus 1% STS) was somewhat less effective. In this study, the combination of RF-mediated cystic duct occlusion and gallbladder sclerotherapy with ethanol and STS permitted gallbladder ablation in swine without toxic side effects.     

介入性胆囊切除术的实验研究

本文采用输精管粘堵剂闭塞胆囊管,以两种不同浓度的酒精和消痔灵注射液行32只家兔胆囊切除,结果显示仅1例因技术原因胆囊再通,病理检查表明:2周后 A、B 两组动物胆囊粘膜均表现为充血,水肿;4周后,A 组胆囊粘膜完全破坏,而 B 组尚有部分残留;8周后 A 组8只动物有7只胆囊完全被纤维组织代替而 B 组仅2例,同时肝肾未见受损。我们认为:本实验所行胆囊切除是可行、安全的,其中高浓度组效果更为理想。     

A new method for thermocholecystectomy. Initial experience and comparison with other techniques.

RATIONALE AND OBJECTIVES. The authors tested the feasibility of thermocholecystectomy for gallbladder ablation in an animal model. METHODS. Thermal treatment of the cystic duct followed by heating of the saline-filled gallbladder using a separately designed heater/expander was performed in 13 pigs (group I). In four animals, heating of the gallbladder alone was performed (group II). Two animals served as controls (group III). All animals were killed 12 weeks after treatment. RESULTS. There was cystic duct occlusion in 10 (77%) of 13 of group I animals. In 6 (60%) of 10 of these animals with cystic duct occlusion, there was complete ablation of the gallbladder mucosa and complete obliteration of the gallbladder lumen. In group II animals, all cystic ducts were intact with an unchanged gallbladder volume in all four animals (100%), and normal gallbladder mucosa were intact in three (75%) of four animals. The gallbladders and cystic ducts in group III animals were normal. CONCLUSIONS. This study demonstrates many technical difficulties with thermal cholecystectomy. However, under ideal conditions, permanent gallbladder ablation is feasible in our animal model using a specially designed heating system.     

Metallic stent placement in the pancreatic duct: an experimental study in the normal dog pancreas

PURPOSE: To evaluate radiologic and histologic changes in the pancreatic duct and parenchyma after placement of metallic stents in normal dog pancreatic ducts. MATERIALS AND METHODS: Eight dogs underwent duodenotomy and placement of a balloon-expandable metallic stent 1.5 mm in diameter and 1 cm in length in the main pancreatic duct. Two dogs each were killed at 1 day and 1, 3, and 5 months after stent placement. Pancreatic duct injection images were obtained before and immediately after stent placement and just before and after sacrifice. Macroscopic and microscopic examinations were also performed. RESULTS: Pancreatic duct injection images revealed mild dilation of pancreatic ducts related to the procedure immediately and 1 day after stent placement. Microscopically, denudation of the ductal epithelium and small foci of fat necrosis were observed. At 1 month or later, ductal stricture (n = 4) and occlusion (n = 2) were found at the downstream edge of the initially stent-implanted region associated with dilation of the duct upstream. Epithelial hyperplasia was observed at the sites of ductal stricture and occlusion at 1 and 3 months. Stents remained in the region in which they were initially placed until 1 month. However, stents had moved downstream from their initial positions at 3 and 5 months. One stent had migrated into the duodenum at 5 months. Stone formation was found in the ductal lumen and around the stents at 3 and 5 months. Ducts and parenchyma became fibrotic proportional to the period of stent implantation. CONCLUSION: Metallic stent placement in the pancreatic duct causes ductal and parenchymal damage related to the procedure and reaction to the stent in the normal dog pancreas.     

Sclerotherapy of the gallbladder in pigs. Development of a balloon catheter for a single-step procedure

Gallbladder sclerotherapy after permanent cystic duct occlusion, to prevent gallstone recurrence in nonsurgical gallstone therapy, is at least a two-stage procedure. A balloon catheter was developed to perform gallbladder sclerotherapy with only temporary occlusion of the cystic duct, and the efficacy and safety of this method was subsequently investigated. Twenty pigs underwent cholecystostomy for positioning of a 7-Fr triple-lumen balloon catheter with proximal side holes. Sclerotherapy with 96% ethanol and 3% sodium tetradecyl sulfate for 20 minutes was performed. The animals were killed 24 hours, two, six, and 12 weeks after the procedure. The balloon catheter functioned well and seems suitable for procedures in which a temporary occlusion of the cystic duct is required. Although gallbladders after six and 12 weeks were shrunken and fibrotic, a single treatment of gallbladder sclerotherapy with subsequent catheter removal and no permanent cystic duct occlusion, as performed in this experiment, did not produce complete gallbladder ablation. In this study, sclerotherapy proved safe in the short term, but long-term effects remain to be assessed.     

Early biliary complications of laparoscopic cholecystectomy: evaluation on T2-weighted MR cholangiography in conjunction with mangafodipir trisodium-enhanced 3D T1-weighted MR cholangiography

OBJECTIVE: Our aim was to assess preliminary experience with combined conventional T2-weighted and mangafodipir trisodium (MnDPDP)-enhanced T1-weighted MR cholangiography in evaluating early biliary complications of laparoscopic cholecystectomy. SUBJECTS AND METHODS: Conventional heavily T2-weighted MR cholangiography with MnDPDP-enhanced T1-weighted MR cholangiography and ERCP were performed in seven patients with high clinical suspicion of biliary complications after laparoscopic cholecystectomy. The final diagnoses of complications were classified according to the presence and degree of bile duct injury, bile leakage, and retained stones. RESULTS: The diagnoses on MR cholangiography were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 3), partial strictures of the common bile duct with bile leakage (n = 1), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). The final diagnoses at surgery (n = 2) and ERCP (n = 5) were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 2), partial strictures of the common bile duct with bile leakage (n = 2), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). MR cholangiography accurately yielded the same findings as the final diagnoses, except in one case with partial stricture of the bile duct with bile leakage (overdiagnosed as complete occlusion on MR cholangiography). CONCLUSION: Combined conventional T2-weighted and MnDPDP-enhanced T1-weighted MR cholangiography may eliminate the use of other studies for the imaging of biliary complications after cholecystectomy if this preliminary data can be verified in a larger study.     

Experimental gallstone dissolution with methyl-tert-butyl ether (MTBE) and transcutaneous ultrasound energy

The simultaneous application of ultrasound energy greatly accelerated the rate of cholesterol gallstone dissolution by methyl-tert-butyl ether (MTBE). In vitro experiments using this treatment showed that a 498-mg stone burden could be dissolved in 19.5 minutes, approximately 100% faster than what could be achieved with MTBE alone. Pigs (n = 13) with surgically implanted gallstones were treated with MTBE and transcutaneously applied ultrasound from a prototype system built for clinical studies. The average stone reduction of all pigs was 470.46 mg +/- 60.44 mg; 91.39% of an average implanted burden of 515.08 +/- 18.03 mg. Control group pigs (n = 9), receiving only an MTBE infusion, showed an average stone reduction of 51.77%. Enzymes indicative of hepatocellular injury showed no significant abnormalities after 6 weeks. Gallbladder ablation with a fibrous remnant (ie, no mucosa, no lumen, patent cystic duct) occurred in 10 (70%) of the pigs.     

胆石症胆囊管MRCP分析及临床意义

目的:利用MRCP观察胆囊管在肝总管的开口部位及其变异,探讨其临床价值。方法:应用MRCP检查240例拟行腹腔镜胆囊切除术的胆石症病例,重建后观察胆囊管在肝总管的开口部位并对其变异予以分析。结果:MRCP像上胆囊管显示154例(64.2%),胆囊管正常开口于肝总管右侧壁96例(62.3%)、变异开口于肝总管左侧壁、前壁、后壁及低位分别为8例(5.2%)、8例(5.2%)、22例(14.3%)及4例(2.6%),另有16例(10.4%)胆囊管部分显示,其开口部位未显示。结论:MRCP可以观察胆囊管在肝总管的开口部位,对于腹腔镜胆囊切除术前了解胆囊管的变异有一定的临床价值。     

Acute cholecystitis caused by malignant cystic duct obstruction: treatment with metallic stent placement

We report the successful management of acute cholecystitis using cystic duct stent placement in 3 patients with inoperable malignant cystic duct obstruction (2 cholangiocarcinoma and 1 pancreatic carcinoma). All patients underwent stent placement in the bile duct, using an uncovered stent in 2 and a covered stent in 1, to relieve jaundice occurring 8-184 days (mean 120 days) before the development of acute cholecystitis. The occluded cystic duct was traversed by a microcatheter and a stent was implanted 4-17 days (mean 12 days) after cholecystostomy. Acute cholecystitis was improved after the procedure in all patients. Two patients died 3 and 10 months later, while 1 has survived without cholecystitis for 22 months after the procedure to date.     

Using contrast-enhanced MR cholangiography with IV mangafodipir trisodium (Teslascan) to evaluate bile duct leaks after cholecystectomy: a prospective study of 11 patients

OBJECTIVE: The purpose of our study was to determine whether contrast-enhanced MR cholangiography using IV mangafodipir trisodium can accurately detect the presence and location of bile duct leaks in patients who have undergone cholecystectomy. SUBJECTS AND METHODS: Our study group included 11 patients with suspected bile duct leaks after cholecystectomy. Axial single-shot fast spin-echo and gradient-echo images were acquired in all patients before and 1-2 hr after IV administration of mangafodipir trisodium. The contrast-enhanced MR cholangiograms were evaluated for image quality, degree of ductal or small bowel opacification, and the presence and location of bile duct leaks, strictures, and stones. MR cholangiograms were correlated with conventional contrast-enhanced cholangiograms obtained in all patients, including endoscopic retrograde cholangiography (n = 10) and percutaneous transhepatic cholangiography (n = 1). RESULTS: Excretion of mangafodipir trisodium was noted in the intrahepatic and extrahepatic bile ducts in all patients from 1 to 2 hr after IV administration. Bile ducts and fluid collections that contained excreted mangafodipir trisodium showed increased signal intensity on gradient-echo sequences and decreased signal intensity on single-shot fast spin-echo sequences. Conventional contrast-enhanced cholangiography showed the presence of bile duct leaks in six patients and the absence of bile duct leaks in five patients, with false-negative findings in one patient and false-positive findings in one patient for bile duct leak (sensitivity, 86%; specificity, 83%). CONCLUSION: Contrast-enhanced MR cholangiography with IV mangafodipir trisodium can successfully detect the presence and location of bile duct leaks in patients suspected of having such leaks after undergoing cholecystectomy. More research is necessary before acceptance of this examination as routine in the workup of these patients.     

经胆管192Ir内照射对胆管、肝脏放射损伤的实验研究

目的 探讨经胆管192Ir内照射的安全性、可行性以及有效治疗范围,为肝门部胆管癌经胆管192Ir内照射提供理论依据.方法 取雄性健康杂种犬16只,据照射剂量随机分成4组,每组4只.内照射前从犬肝边缘切取1 cm3大小肝组织作对照研究.术中将近距离治疗施源器经胆囊送入胆囊管与肝总管汇合处并用金属夹固定,根据预先设定的剂量进行胆管内照射.10 d后处死动物,取被照射胆管中央部分长约5 mm胆管,及距离胆管壁由近及远按设计距离分别取1 mm3大小肝组织,制备光镜切片,作HE染色;同时用2.5%戊二醛固定后常规制备电镜切片.光镜下观察胆管及周围肝组织的放射损伤并对损伤程度评分.电镜下观察肝组织超微结构损伤变化并计数凋亡肝细胞.结果 经胆管192Ir内照射30 Gy时,胆管损伤达部分肌层;50 Gy时,胆管仅存外膜;60 Gy时,胆管出现全层坏死.胆管周围肝组织放射损伤随剂量增加而加重.在胆管最大安全耐受剂量50 Gy时,距胆管0～15 mm处肝细胞核出现不可逆性改变.结论 正常胆管对192Ir内照射有良好的耐受性.在胆管最大安全耐受剂量50 Gy时,经胆管192Ir内照射有效的治疗范围可达15 mm.     

Minimizing central bile duct injury during radiofrequency ablation: use of intraductal chilled saline perfusion--initial observations from a study in pigs

PURPOSE: To determine whether intraductal perfusion with chilled saline reduces thermal injury to bile ducts during radiofrequency (RF) ablation. MATERIALS AND METHODS: In swine, anesthesia was induced and the common bile duct was surgically cannulated with a pediatric feeding tube. RF thermal lesions were created adjacent to bile ducts by using an expandable-hook 2-cm RF electrode and 90-W generator. In three pigs, chilled saline was perfused through the ducts at 1.5 L/h (26 mL/min), and in another pig, room-temperature saline was perfused at the same rate. In three pigs (control group), RF lesions were created without perfusion. After 48 hours, animals were sacrificed. Periductal sections from all animals were reviewed by a liver pathologist. The degree of injury to biliary epithelium and subepithelial glands was assessed on a scale of 0%-100%. Significance of differences between degrees of injury was assessed with the Mann-Whitney test. RESULTS: In the control group, there was a mean of 100% injury to biliary ductal epithelium and 99.3% to subepithelial ductal glands. In the room-temperature saline group, there was a mean of 100% biliary epithelial injury and 84.4% glandular injury. In the chilled saline group, there was a mean of 52.9% ductal epithelial injury and 12.1% subepithelial glandular injury. In comparison with the control group, there was significantly less (P <.05) thermal injury to biliary epithelium in the chilled saline group and to subepithelial glands in both the room-temperature and chilled saline perfusion groups. CONCLUSION: RF-induced bile duct injury may be decreased significantly with an intraductal infusion of chilled saline.     

Mangafodipir trisodium: effects on T2- and T1-weighted MR cholangiography

The purpose of this study was to determine the effects of mangafodipir trisodium on heavily T2-weighted magnetic resonance cholangiography (MRC) images and on functional T1-weighted MRC. Pre- and post-mangafodipir trisodium heavily T2-weighted MRC and fat-suppressed T1-weighted three-dimensional (3D) gradient-echo MRC images were obtained in a patient with a prior cholecystectomy and a long cystic duct remnant that had apparent biliary stasis. Multiplanar reconstructed images were created. The precontrast T2-weighted MRC showed a long cystic duct remnant and a normal common bile duct (CBD). The postcontrast T2-weighted MRC showed loss of CBD signal, but persistent signal in the cystic duct remnant due to biliary stasis. Post-mangafodipir T1-weighted 3D gradient-echo images showed the main right and left hepatic ducts, but the cystic duct was not depicted. Conventional T2-weighted MRC sequences should not be obtained after administering mangafodipir trisodium because this contrast agent decreases the T2 and therefore the signal intensity of bile within normally functioning bile ducts. Functional MRC images can be acquired by using a post-mangafodipir T1-weighted technique.     

Percutaneous Transcholecystic Biliary Interventions Using Gallbladder Anchors: Feasibility Study in the Swine

The purpose of this study was to report our initial experience with a swine model for biliary interventions by using a percutaneous transcholecystic access after suture anchor of the gallbladder. Telepaque tablets were given to five pigs to opacify the gallbladder. Under fluoroscopy, the opacified gallbladder was punctured percutaneously and three suture anchors were used to fix the anterior wall of the gallbladder to the abdominal wall. Two weeks later, the gallbladder was punctured and access into the distal common bile was obtained through the cystic duct. Balloon expandable stents were deployed into the distal common bile duct. Follow-up cholangiograms were obtained at 1 and 2 weeks. Necropsy was performed after 2 weeks to evaluate the relationship between the gallbladder and abdominal wall. Suture anchor placement was successful in all five pigs. One pig with a deep and highly positioned gallbladder developed fever, anorexia, and vomiting secondary to excessive stretch of the gallbladder. Placement of the guidewire through the extremely tortuous and small cystic ducts proved to be the most challenging step of the procedure. Metallic stents were successfully deployed in all four pigs in which it was attempted. Four animals tolerated the procedures without changes in their clinical conditions and no symptoms. Successful follow-up cholangiograms were performed at 1 and 2 weeks post-stent deployment without complications. All stents remained patent during the follow-up period. Necropsy demonstrated close attachment and adherence of the gallbladders to the antero-lateral abdominal wall in all four animals. Suture anchoring of the gallbladder is feasible in most pigs with superficially located gallbladders. This technique allows a safe and repeat access into the biliary system using a transcholecystic approach.     

Anatomic Variation in Intrahepatic Bile Ducts: an Analysis of Intraoperative Cholangiograms in 300 Consecutive Donors for Living Donor Liver Transplantation

Objective

To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation.

Materials and Methods

The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct.

Results

The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3).

Conclusion

The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%).     

胆囊管解剖变异的MRCP诊断

目的:探讨磁共振胰胆管成像(MRCP)对胆囊管解剖变异的诊断价值及临床意义.方法:搜集2002年8月～2006年8月期间行MRCP检查的900例病例进行分析,对显示不清的胆囊管视为正常.所有病例经胆囊切除术(783例)或逆行胰胆管造影术(117例)证实.结果:MRCP清晰显示胆囊管801例(89%),根据Taoureal胆囊管解剖变异分型标准:胆囊管变异53例,变异率为5.9%,其中胆囊管汇入左右肝管分叉处21例(2.3%),汇入右肝管10例(1.1%),与肝总管并行9例(1.0%),胆囊管低位插入8例(0.9%),旋前插入肝总管7例(0.8%),旋后插入肝总管3例(0.3%),过短1例(0.1%),囊状扩张1例(0.1%),合并胆囊分隔6例(0.7%),先天性胆总管囊肿6例(0.7%).部分患者合并2种或2种以上的变异.其中假阴性2例,显示不清2例.结论:MRCP能显示各种胆囊管解剖变异,术前了解这些变异有助于减少腹腔镜胆囊切除术中的胆道损伤.     

Intraoperative bile duct sonography during laparoscopic cholecystectomy: experience with a 12.5-MHz catheter-based US probe.

During elective laparoscopic cholecystectomy, 20 patients underwent intraoperative evaluation of the biliary tract with a commercial 6.2-F, 12.5-MHz catheter-based ultrasound (US) probe. The study tested the feasibility of this technology for mapping the anatomy of the hepatoduodenal ligament and Calot triangle, assessing bile duct integrity, and detecting choledocholithiasis. The duct was studied with a transmural approach, the catheter being placed parallel to, but remaining outside, the bile duct. The common hepatic duct and common bile duct in the vicinity of the cystic duct were seen in all 20 patients; the junction of the cystic duct with the common hepatic duct was seen in nine patients (45%). After the cystic duct was clamped, no sonographic evidence to suggest bile duct injury was noted in any patient. The transmural imaging approach was tested in four pigs in whose common bile duct a single human calculus had been placed. In all instances the size and location of the calculus were accurately detected. Intraoperative US with a catheter-based system is a safe and effective means for interrogation of the extrahepatic biliary tree during laparoscopic cholecystectomy.     

Treatment of bile duct stones: value of laser lithotripsy delivered via percutaneous endoscopy

Extraction of stones from the bile ducts via standard endoscopic techniques, a percutaneous transhepatic approach, or a T-tube track can be unsuccessful. We report our preliminary experience with a combination of percutaneous cholangioscopy and dye laser lithotripsy. Flash lamp-excited dye laser (504 nm) lithotripsy delivered by percutaneous cholangioscopy (12 F) was evaluated in 13 patients with stones in the bile ducts. Conventional endoscopic treatment had not been attempted in 4 patients after hepaticojejunostomy and had failed in 3 patients after gastric bypass surgery or gastrectomy, and in 6 patients because of technical difficulties, i. e. due mainly to largeness of stones. In 12 patients a percutaneous transhepatic route was used. In 1 patient the T-tube track was used as access to the bile ducts. Laser lithotripsy resulted in successful fragmentation of stones in 12 patients (92%). The bile ducts cleared spontaneously in 2 patients only. Using additional techniques, i. e. sphincterotomy and stent insertion, the overall combined success rate for duct clearance after laser fragmentation was 100%. Four patients had a retrograde endoscopic sphincterotomy after failed attempts for stone removal at endoscopic retrograde cholangioscopy. Two patients had an antegrade fluoroscopically monitored sphincterotomy. Bleeding complications occured in 2 patients. This accounted for a high rate (15%) of severe complications. The intrahepatic bleeding in 1 patient was due to an intrahepatic vessel injury by the 13-F sheath. The periampullary bleeding in the other patient occurred after an antegrade papillotomy. Pulsed dye laser lithotripsy proved to be an effective technique in patients with difficult bile duct stones. The main problem of a percutaneous approach is the complete removal of the fragmented stones, which requires additional procedures in most cases. The percutaneous access is time-consuming and bears a relatively high risk of major bleeding complications. It should therefore be restricted to cases in which conventional endoscopic procedures are impossible or unsuccessful. Correspondence to: H.-J. Brambs