Transcutaneous chemical cholelitholysis with methyl tert-butyl ether (MTBE). lst results in man

Three patients have been treated, with instillation of MTBE through a transcutaneous biliary drainage after transduodenal sphincterotomy. The first had gallbladder stones, the second common bile duct stones and the last intrahepatic stones (V segment). While in the first case there has been only a partial success in the other two we have obtained a total dissolution of the stones, with complete clinical recovery. This treatment has not caused immediate side effects but the absence of long term damage has not yet been proven. We think that the use of MTBE is not indicated in gallbladder stone disease. Its major indication is the dissolution of ductal gallstones when transduodenal sphincterotomy and endoscopic removal of the stones have failed.     

In vitro cholesterol gallstone dissolution: comparison of methyl tert-butyl ether with three new ester solvents

The in vitro effectiveness of three new cholesterol gallstone solvents that have a potential for clinical use--ethyl propionate, isopropyl acetate, and n-propyl acetate--was compared with that of the well-known cholesterol solvent methyl tert-butyl ether (MTBE). Ten sets of matched gallstones were initially weighed, imaged with radiography and computed tomography (CT), and analyzed for content. One stone from each set was incubated in one of the four solvents at 37 degrees C. Solvents were changed at 30-minute intervals. The study was stopped either when the stones were completely dissolved or at the end of 7 hours. Any residual fragments were weighed, reimaged, and reanalyzed for content. There were no statistical differences between dissolution times of the stones in MTBE compared with those in the three new solvents. Ethyl propionate and n-propyl acetate appear to be as efficacious as MTBE in dissolving cholesterol stones and could be attractive alternatives for gallstone chemolysis.     

Choledochoscopic stone removal through a T-tube tract: experience in 75 consecutive patients

Retained biliary stones remain a common clinical problem in patients after surgery. Since 1984, the authors have used choledochoscopy in the treatment of suspected retained biliary stones in 75 patients. These procedures were performed in the radiology department with use of local anesthesia supplemented by an intravenously administered sedative and analgesic. A 15-F flexible fiberoptic choledochoscope was used. Fifty-one of the 75 patients were treated as outpatients. Treatment was successful in 74 of 75 patients; in one patient, intrahepatic stones were not completely removed. Electrohydraulic lithotripsy was used to fragment calculi in 11 patients (15%). Biopsies were performed in four patients (5%). Five minor complications occurred; three required overnight admission. Choledochoscopic-assisted removal of retained biliary calculi is a highly effective and safe procedure. Advantages over standard fluoroscopic stone removal include the ability to directly visualize and fragment adherent or impacted stones and visualize noncalculous filling defects, such as air bubbles, mucus, and biliary tumors.     

Gallbladder and bile duct stones: percutaneous therapy with primary MTBE dissolution and mechanical methods

The authors describe percutaneous treatment of gallbladder or bile duct stones in 18 patients who were poor surgical candidates or in whom conventional therapy failed. Dissolution was performed in most cases with methyl tert-butyl ether (MTBE) because of its potent dissolution properties; other solvents used included monooctanoin or chelating solutions. Gallbladder stones were eliminated in 11 of 13 patients (six of seven with dissolution alone, four of four with dissolution and basket extraction, one with basket removal alone). In five patients with stones in the common bile duct (n = 3), cystic duct remnant (n = 1), and intrahepatic bile ducts (n = 1), stones were eliminated with dissolution alone in two and with dissolution plus basket extraction in one. In two patients percutaneous therapy failed due to complications (vagal hypotension with bile peritonitis and transient respiratory arrest) that occurred during catheter placement. Preliminary results suggest that MTBE is effective for dissolution of many gallbladder stones and some bile duct stones. Noncholesterol solvents and adjuvant mechanical maneuvers are valuable adjuncts to achieve complete stone elimination.     

Iodinated contrast medium as an aid to gallstone dissolution with methyl tert-butyl ether: in vitro study

Methyl tert-butyl ether (MTBE) floats on bile, whereas gallstones sink. Therefore, stones and MTBE are separated by a layer of bile. This study investigates the effect of contrast medium on flotation of gallstones in bile and its role in stone and fragment dissolution with MTBE. Fresh human gallstones, both calcified and noncalcified, from different patients were tested in vitro for flotation in bile, with and without addition of contrast medium. All gallstones or fragments sank in bile before the introduction of contrast medium. Noncalcified stones floated when the contrast medium-bile volume ratio was 1:6 or more, while double this amount of contrast medium was required to float calcified stones. Fragments did dissolve somewhat in MTBE in the presence of bile alone, but when contrast medium was added, almost complete dissolution occurred. This is thought to be due to increased contact between the fragments and MTBE, both floating on the contrast medium-bile mixture. Contrast material may be a useful adjuvant in gallstone dissolution therapy with MTBE in vivo.     

Dissolution of multiple biliary duct stones using methyl tert-butyl ether (MTBE): Experience in two cases

Methyl tert-butyl-ether (MTBE) was sucessfully used for stone dissolution in 2 patients with multiple bile duct cholesterol stones. The presence of a biliary-enteric anastomosis precluded the endoccopic approach. Because of leakage of MTBE into the bowel, dissolution time ranged from 7.5 to 36 h. No significant complications other than mild nausea were encountered. No recurrence of stone formation has been found at a follow-up varying from 9 to 12 months.     

Percutaneous contact dissolution of gallstones: complexity of radiologic care

The clinical and technical considerations for successful gallstone dissolution with methyl tert-butyl ether (MTBE) are often underestimated. Patients are selected for MTBE therapy on the basis of a functioning gallbladder without evidence of acute inflammation or calcified stones at plain radiography. A transhepatic route is favored for percutaneous insertion of the cholecystostomy catheter because of the theoretic reduced frequency of bile leakage. MTBE is delivered manually through the catheter in a closed system, with dissolution times of 4-16 hours. After MTBE dissolution, residual debris in the gallbladder is present at follow-up sonography in up to 75% of patients. The high frequency of residual debris, the potential for stone recurrence, and the labor-intensive nature of MTBE therapy make its future uncertain, especially with the advent of laparoscopic cholecystectomy.     

In vitro dissolution of gallstones with MTBE: correlation with characteristics at CT and MR imaging

The authors undertook a study to determine whether in vitro computed tomography (CT) or magnetic resonance (MR) imaging could enable the prediction of the outcome of gallstone dissolution with methyl tert-butyl ether (MTBE). In vitro CT and MR images were obtained of gallstones removed at surgery from 40 and 30 patients, respectively. The patterns of the gallstones seen on CT scans were categorized as dense, moderately dense, faint, isodense, rimmed, and laminated. Gallstones were categorized by maximal signal intensities seen on T1-weighted MR images. After imaging, gallstones underwent in vitro MTBE dissolution. CT appearances correlated well with dissolution rates. Greatest weight change was noted in gallstones with homogeneously faint and isodense patterns, and least weight change was seen in stones with a homogeneously dense pattern. Rimmed and laminated stones with foci of high attenuation dissolved significantly to 5% or less of the original weight, a finding indicating that such foci do not preclude dissolution. Dissolution rates correlated with attenuation values of homogeneous stones (r = .8) and of the rim portion of rimmed stones (r = .8). No correlation was found between T1-weighted signal intensities on MR images and MTBE dissolution rates.     

Accelerated gallstone dissolution in methyl tert-butyl ether by sonication. An in vitro study.

OBJECTIVES. The authors tested the effect of 195 KHz therapeutic ultrasound energy on gallstone dissolution in concert with methyl tert-butyl ether (MTBE) in vitro. METHODS. Sixteen sets of three gallstones matched for weight and appearance were selected from 16 surgically resected human gallbladders. One stone from each set was analyzed for its density pattern by computed tomography (CT) and biochemically for cholesterol content. Based on CT appearance, the stones were classified into eight noncalcified, four partially calcified, and four heavily calcified sets. The three stones were subjected to dissolution with MTBE: one with simultaneous sonication via an experimental ultrasound unit, one with manual stirring, and one acted as control without added treatment. RESULTS. Sonication reduced the dissolution time of noncalcified stones by 96% (range, 94%-98%; standard deviation [SD], 2%) relative to controls, and it was three to four times more effective than manual stirring. It was similarly effective in helping to dissolve partially calcified stones, but not heavily calcified stones. CONCLUSIONS. This study demonstrates the positive effect of sonication in accelerating gallstone dissolution with MTBE in vitro for stones without heavy calcification.     

Monooctanoin perfusion for in vivo dissolution of biliary stones. A series of 11 patients

Monooctanoin, a cholesterol solvent, was infused into the biliary system of 11 patients. Twenty-eight (74%) of 38 total stones responded to monooctanoin: 16 (42%) decreased in size, and 12 (32%) dissolved completely. Ten stones (26%) did not change in size. We attribute this to inadequate drug-stone contact, which was corrected by placement of the infusion catheter contiguous to the stone(s). The use of a second catheter for biliary drainage avoided the side effect of biliary colic and increased patient compliance. An infusion rate greater than 5 ml per hour invariably produced pain and diarrhea. There were no significant side effects from monooctanoin in any of our patients when a two catheter system and an infusion rate of 5 ml per hour or less were used. A major drawback to use of this still experimental agent is the prolonged hospital stay. This may be ameliorated when at home use of monooctanoin is approved.     

Thin-layer chromatography to monitor cholesterol gallstone dissolution by methyl tert-butyl ether

We describe a simple and inexpensive method of monitoring methyl tert-butyl ether (MTBE) dissolution of cholesterol gallstones with thin-layer chromatography (TLC) in 10 patients. TLC is a routine semiquantitative laboratory method that can be used to measure the cholesterol concentration present in the MTBE and bile mixture aspirated through the cholecystostomy catheter during gallstone dissolution. TLC is practical in the clinical setting because it can be used to determine if gallstone dissolution is occurring and when MTBE lavage is no longer effective. TLC is performed in the laboratory with routine material and is completed in 15 min. Each TLC measurement costs about $1. The procedure provides objective and specific chemical information on effectiveness and progression of gallstone dissolution, apart from the radiologic and sonographic studies. In our study, TLC signaled effective dissolution in the initial phase of gallstone dissolution by detecting large amounts of cholesterol in the MTBE and bile mixture even before a visible change in size or shape of the stone became apparent by transcatheter cholecystography or by sonography (six of 10 patients). Conversely, lack of cholesterol on TLC after 1 hr or more of MTBE infusion indicates that the stones are pigmented or contain substantial calcium. This means that dissolution with MTBE will be ineffective and that solvent infusion should be terminated. In those cases in which dissolution is progressing well, when TLC shows decreasing amounts of cholesterol in the effluent, only residual fragments insoluble to MTBE remain or the stone is sequestered from MTBE; at this point, solvent infusion should be discontinued or the catheter must be repositioned. Monitoring the rate of cholesterol dissolution by TLC provides important complementary information to cholecystography and sonography during gallstone treatment with MTBE.     

Dissolution of gallstones using methyl tertiary-butyl ether in an animal model

Human gallstones were surgically implanted in the gallbladders of six pigs. Through cholecystostomy catheters, methyl tertiary-butyl ether (MTBE) was infused from 3 to 5 days. MTBE successfully dissolved 19 of the 20 cholesterol stones and partially dissolved one mixed cholesterol-bilirubin stone. Gross and microscopic examination of abdominal organs revealed mild superficial ulcerations of the gallbladder and mild to moderate chronic inflammatory changes in the gallbladder of animals treated with MTBE infusion. There were no other significant changes within other abdominal organs except for mild inflammation of the duodenum in one animal and of the common bile duct in another. Because of its efficacy and limited deleterious effects, MTBE may be a good solvent when dissolving pure cholesterol gallstones in the gallbladder.     

Balloon dilation of intrahepatic biliary strictures for percutaneous extraction of residual intrahepatic stones

Intrahepatic ductal strictures in cholangiohepatitis present an obstacle to successful removal of retained ductal stones via T-tube tracts. We studied the effectiveness of stricture dilatation for stone removal. Fifteen patients with intrahepatic gallstones retained behind strictures underwent balloon dilatation of their strictures to allow stone extraction. All had prior surgical T-tube placement allowing percutaneous access. Balloon dilatation was successful in reducing or eliminating strictures in 86.7% (13 of 15 patients), and complete stone extraction after the successful dilatation was possible in 76.9% (10 of 13 patients). The reasons for failure were impacted stones and acute ductal angulation which prevented passage of catheters. It is concluded that balloon dilatation of intrahepatic biliary strictures is an effective adjunct for extraction of intrahepatic biliary calculi associated with recurrent pyogenic cholangiohepatitis.     

Percutaneous nephrostomy in conjunction with ESWL in treatment of nephrolithiasis

The use of percutaneous nephrostomies (PCNs) in 1456 patients (1660 kidneys) treated with extracorporeal shock-wave lithotripsy (ESWL) was evaluated. In this group, 138 PCNs (130 patients) were performed in 133 kidneys. Forty-seven percent of PCNs were placed in patients with staghorn calculi; 24% were for stones in the renal pelvis, and 20% for ureteral stones. The most common indication for PCN was fever and obstruction (57%). In 15%, the indications were failure to decompress an obstructed system from a retrograde direction, clogged double-J ureteral stents, and perforation of the ureter. Prophylactic PCN placement in the treatment of staghorn calculi and large stones in the renal pelvis accounted for 12%. Five percent were placed for miscellaneous other reasons, and for 11% there was no documentation of the indication because they were placed before the patients came to our center. Localization of the collecting system for optimal placement of PCN is unique in ESWL patients because the residual stone fragments provide natural contrast. This eliminates the need for administration of contrast material in 50% of the patients. Twenty-six percent of PCN tracts were subsequently used for other procedures (e.g., percutaneous nephrolithotomy, fragment irrigation, ureteral stone manipulation). Bleeding complications from PCN occurred in 7%. Other minor complications occurred in 12% of cases. PCN is a useful adjuvant to ESWL treatment of kidney stones. Although its major use is to relieve urinary tract obstruction, it is also used as a preliminary step in planning other percutaneous interventional procedures. This is particularly the case in the treatment of large bulky stones in the renal pelvis and staghorn calculi.     

Effectiveness and safety of balloon dilation of the papilla and the use of an occlusion balloon for clearance of bile duct calculi

OBJECTIVE: The purpose of this study was to describe a technique for percutaneous bile duct stone clearance by pushing the stones into the small bowel after balloon dilation of the papilla. SUBJECTS AND METHODS: During a 2-year period, 38 patients were treated percutaneously for stones in the biliary tree. Twenty-one patients were treated through a T tube or transcystic tract. Seventeen patients were treated through a transhepatic tract. Twenty-three patients had one stone each. Eight patients had two stones, and seven patients had three or more calculi. Stone size ranged from 3 to 16 mm in diameter (mean size, 6.7 nm). Balloon diameter based on the transverse diameter of the stones ranged from 7 to 18 mm (mean, 6.7 mm). An 11.5-mm occlusion balloon was used for pushing the stones through a 7- to 9-French vascular introducer. A catheter was left in the common bile duct from 1 to 6 days for external drainage. RESULTS: The technique was successfully used for clearance of stones in 36 (94.7%) of the 38 patients. With 29 patients, the procedure was performed with only one attempt. Two attempts were necessary for five patients, and three attempts were necessary for four patients. Two major complications were cholangitis and biliary pleural effusion. No deaths were related to the procedure. CONCLUSION: Percutaneous bile duct stone clearance by dilation of the papilla and evacuation of the stones in an antegrade fashion with an occlusion balloon is a safe and effective technique. It can be an alternative to basketing stones in selected patients.     

Renal stone disease treated with extracorporeal shock wave lithotripsy: short-term observations in 100 patients

The immediate posttreatment findings are described for 100 patients who underwent extracorporeal shock wave lithotripsy (ESWL) for renal stone disease. Excretory urography was performed both before and 24-72 hours after ESWL. In 21 patients, stones were completely disintegrated, and stone fragments were passed rapidly. Stones were fragmented but not passed entirely within 24-72 hours in 76 patients. There was no appreciable effect on stones in three patients. In nine of 27 patients who had mild to severe ureteral obstruction caused by stone fragments, relief procedures (retrograde ureteral manipulation or percutaneous stone extraction) were necessary. Overall, 70 patients experienced successful stone disintegration without complications. Continued investigation is needed to determine prevalence of residual calculi, reversibility of acute effects of ESWL on the kidney, and possible development of late hypertension.     

嵌顿性胆总管或胆囊管结石的介入性综合治疗

目的 评价多种介入性取石技术综合应用于１组患有嵌顿性胆管结石,且被视为手术高危病人的治疗效果。方法 ９例（男２例,女７例,平均年龄５０．７岁）患者中,６例曾有接受内窥镜下取石失败或手术直视下取石再复发的病史;在发生部位上,计有７例胆总管结石,１例胆囊管结石,１例胆总管合并胆囊管残端结石;多发性结石５例,单发性结石４例;最大结石直径约为３．０ｃｍ。在处理方法上,建立经皮肝胆管和内窥镜下经十二指肠逆向     

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.     

胆道术后并发症的MRI表现分析

目的　明确胆道术后综合征的MRI表现,寻找其真正病因。方法　回顾性分析 41例胆道术后并发症的上腹部MRI检查资料,观察其有无胆管扩张、狭窄、胆管炎、残余结石、残余胆囊等改变。结果　41例胆道术后并发症患者中 38例有胆道异常改变,其中胆管扩张 20例,胆管结石 16例,胆管炎 13例,胆管狭窄 7例,肝门胆管肿瘤 3例。胆管扩张多在术后 3月内出现,胆管炎症和狭窄多在术后半年以后出现。结论　胆道术后并发症主要由胆管扩张、狭窄和残留结石所致,MRI是诊断胆道术后并发症敏感而有效的手段。     

双源双能CT在尿路结石成分分析中的应用

目的:探讨双源CT双能量技术应用于尿路结石成分分析中的临床价值。方法:226例尿路结石患者行双源CT双能量扫描,对其结石成分进行分析,将结果与用红外光谱法分析结石成分的结果作对比,计算双源CT在体分析草酸钙结石、磷酸盐结石、胱氨酸结石及尿酸结石的灵敏度与特异度。结果:双源CT能够准确的区分尿酸结石和非尿酸结石(灵敏度和特异度均为100%),较准确的区分草酸钙结石(灵敏度为89.03%、特异度为85.62%),磷酸盐结石(灵敏度为67.28%、特异度为90.71%)及胱氨酸结石(灵敏度为73.56%、特异度为93.43%)。结论:双源CT双能量技术能在治疗前对尿路结石的成分进行初步分析,对了解结石成因,预防结石形成及指导治疗具有重要的意义。