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Biomedical subjects

C D Becker

Publications and source records attributed to C D Becker.

At least 37 records · Page 2Linked to original sources
PubMed1990

Ablation of the cystic duct and the gallbladder. Experimental basis and initial clinical observations.

Bipolar radiofrequency electrocoagulation of the cystic duct by catheter can be performed safely and reproducibly using fluoroscopic control and induces endoluminal scar formation. The scar within the cystic duct forms a reliable barrier between the gallbladder and the biliary system and avoids recanalization of the cystic duct at a later date. Sclerotherapy of the isolated gallbladder with 95% ethanol and 3% STS can be performed without toxic or otherwise adverse effects and is suitable to ablate the porcine gallbladder. Initial clinical trials with this new technique on a small number of patients are promising and have demonstrated that the protocol can be applied safely to humans. The electrocoagulation technique by catheter appears suitable to ablate the human cystic duct. Follow-up evaluation of our first patients is under way and must determine whether our regimen is appropriate to ablate the human gallbladder on a long-term basis. Further development of this new approach may eventually enable definitive nonoperative treatment of cholecystolithiasis in selected patients.

Animals↗
PubMed1989

The use of intravenous cholangiography in teaching hospitals: a survey.

Thirty academic radiology departments active in biliary imaging were surveyed to document how frequently intravenous cholangiography (IVC) was being performed. Over a 10-year period the number of examinations has decreased precipitously from approximately 1728 in 1976 to 8 in 1986. This coincides with the increased availability of alternative procedures. The availability of new contrast agents with improved diagnostic yield and decreased toxicity suggests that its use may have been prematurely abandoned.

Cholangiography↗
PubMed1989

Biological effects of biliary shock wave lithotripsy in swine.

Extracorporeal shock waves generated with an electromagnetic lithotriptor of the second generation were administered to the gallbladder or bile ducts of 24 domestic piglets. In six animals, fresh human cholesterol gallstones were implanted into the gallbladder two weeks before shock wave administration. Treatment with 3,000 shock waves resulted in fragmentation of the majority of the gallstones in all six animals. In the other animals, 3,000 shock waves (n = 12) or 6,000 shock waves (n = 6) were directed at the gallbladder or the bile ducts without previous stone implantation. Twelve of all 24 animals were killed immediately after shock wave treatment, the other 12 after one week. Autopsy in all 24 animals revealed no gross traumatic changes; the peritoneal fluid was clear in all 24 animals. Microscopically, acute hemorrhage was found in the gallbladder wall (3/12 animals) or in the portal fissure and right lung base (1/12 animals) in those animals who were killed immediately. After one week, resolving hemorrhage with scar formation was found in the right or left lung base in 2/12 animals.

Animals↗
PubMed1989

Catheter for endoluminal bipolar electrocoagulation.

An interventional catheter was designed that can induce controlled endoluminal tissue lesions by means of bipolar radio-frequency (RF) electrocoagulation under fluoroscopic guidance. The technique was used to obtain safe and reproducible percutaneous occlusion of the porcine cystic duct by reactive endoluminal scar formation. The new triple-lumen, 7-F, polyethylene catheter contains two insulated active wires and accommodates a 0.038-inch steerable guide wire, which facilitates insertion and placement of the active catheter tip under fluoroscopic control. The coagulation technique is relatively simple and requires only a small, portable bipolar RF generator and ammeter.

Animals↗
PubMed1989

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.

Animals↗
PubMed1989

Biliary lithotripsy: early observations in 106 patients. Work in progress.

One hundred six patients underwent extracorporeal shock wave lithotripsy for cholelithiasis. Of these, 28 patients underwent cholangiographically guided lithotripsy for bile duct stones to assist nonoperative stone removal by endoscopic or radiologic intervention. Fragmentation occurred in 20 of 28 cases (71%) with an average of two lithotripsy sessions. Hemobilia was observed in four patients (14%) for a 24-hour period. Seventy-eight of the 106 were outpatients with symptomatic cholecystolithiasis with one to five calculi who underwent cholecystographic or ultrasound-(US) guided shock wave lithotripsy as definitive therapy. US examination showed stone fragmentation in 86% of cases. With an average of 1.6 treatment sessions and 4,750 shocks, fragments were 4 mm or smaller in 46% of patients. Nine percent of patients had no fragments after an average of 10 weeks, but long-term follow-up is not yet available. Two patients developed acute pancreatitis attributable to fragment passage and one patient acute cholecystitis, likely due to cystic duct obstruction by a fragment.

Adult↗
PubMed1989

Soft-tissue effects of biliary extracorporeal shockwave lithotripsy in swine.

This study investigates the soft-tissue effects of biliary extracorporeal shockwave lithotripsy (BESWL) using a recently developed lithotripter, which consists of an electromagnetic shockwave generator and an integrated ultrasonic targeting system. Sixteen swine, evenly divided into four groups, underwent BESWL. One group had one BESWL session targeted on the gallbladder and another group had two BESWL sessions targeted on the gallbladder. The third group had one BESWL session targeted on implanted gallbladder stones and the fourth group had one BESWL session targeted on the region of the common bile duct (CBD). Half of each group were sacrificed on the day of lithotripsy and half 1 week later. Post-mortem examinations were performed. Each implanted gallstone had fragmented. There were no findings attributable to BESWL in 11 animals. Three animals had pulmonary haemorrhagic spots (the largest was 10 mm in diameter) and one had a submucosal CBD petechia; these findings were attributable to BESWL. In two animals, microscopic haemorrhage associated with bronchopneumonia (usually present in our pig population) was more prominent than usual. This was possibly attributable to BESWL. The swine's deep posterior costophrenic sulcus makes it difficult to avoid the lung base during BESWL in swine. We conclude that this BESWL device can fragment gallstones without causing clinically significant soft-tissue damage.

Animals↗
PubMed1989

Is routine chest radiography required with biliary lithotripsy?

Routine pre- and postlithotripsy chest radiographs are usually obtained on patients undergoing biliary extracorporeal shock-wave lithotripsy. To evaluate the need for this procedure, we reviewed posteroanterior and lateral chest radiographs obtained before and after 107 lithotripsy sessions in 75 patients. In each case, posteroanterior and lateral chest radiographs were obtained as a routine baseline (not to detect incidental abnormalities) before the patient was scheduled for lithotripsy. Posteroanterior and lateral chest radiographs were obtained routinely after each lithotripsy session. Seventy-five patients had 107 lithotripsy sessions on a second-generation lithotripter. Sixty had gallbladder stones, five had cystic duct stones, and 10 had common duct stones. All chest radiographs were reviewed by a chest radiologist. No pulmonary or pleural changes occurred after lithotripsy. We conclude that routine pre- and postlithotripsy chest radiographs are not warranted in patients undergoing biliary lithotripsy.

Cholelithiasis↗
PubMed1989

Accuracy of sonography for determining the number and size of gallbladder stones before and after lithotripsy.

Accurate knowledge of gallstone number and size is required both for selection of patients for treatment by lithotripsy and for the evaluation of therapeutic results. We measured the accuracy of sonography for use in counting and measuring gallstones and gallstone fragments in a three-part study. First, specimen gallstones of known size were examined in a water bath with four different sonographic units. Second, seven pigs with surgically implanted gallstones had sonography before and after lithotripsy. Finally, we compared the measurements made on the preoperative sonogram with postoperative surgical specimen measurements in 27 patients who underwent cholecystectomy. In vitro gallstone measurement errors were 1.0 mm or less with each of the four sonographic units. In the animal experiments, all prelithotripsy measurements were highly accurate (+/- 1.1 mm). The animal postlithotripsy measurements were similarly accurate in five of seven cases, but substantial errors were made in the remaining two cases. In precholecystectomy patients, the sonographic stone counts and measurements were accurate in all 16 patients who had fewer than six stones. In all 11 patients with six or more stones, we correctly determined with sonography that at least six stones were present, but in only four of 11 cases was the largest stone measured accurately (+/- 2.0 mm). We conclude that sonography can be used accurately to count and measure gallstones when fewer than six stones are present, can reliably determine when six or more stones are present, and, in many cases, can determine the size of the largest fragments remaining after lithotripsy.

Animals↗
PubMed1988

Human amnion as a bioprosthesis for bile duct reconstruction in the pig.

Despite technical advances in management, the complication of late stricture formation and biliary sepsis still occur in bile duct reconstruction. In an attempt to avoid bilioenteric anastomosis, which bypasses the biliary sphincter mechanism, various biologic and artificial materials have been employed clinically and experimentally to replace the damaged bile duct. No satisfactory biliary replacement material has yet been found. In the experimental model of bile duct stricture that has been presented, human amnion bile duct injuries mimicking those seen in clinical practice were repaired using human amnion as a free graft. Noncircumferential duct loss appeared to be satisfactorily repaired using amnion, and the amnion repair was found to be as good as or superior to plastic repair; however, circumferential duct loss was not adequately repaired with the amnion graft.

Alkaline Phosphatase↗
PubMed1988

An animal model for radiologic biliary interventional procedures.

Procedural development, in vivo evaluation, and professional training in interventional biliary radiology require an animal model that provides easy and safe access to the gallbladder and bile ducts. A porcine model was used successfully for catheterization of the biliary system under fluoroscopic control. Permanent access to the gallbladder of ten pigs was achieved with a large-bore cholecystostomy catheter. Catheterization of the common bile duct through the cystic duct was feasible in all animals. Repeated interventional radiologic procedures were performed with intramuscular sedation of the animals, which made this model particularly useful for studies requiring multiple procedures or serial follow-up over several weeks. This article describes the technical aspects of the animal model and the radiographic anatomy of the extrahepatic biliary system in 27 domestic pigs.

Animals↗
PubMed1988

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.

Animals↗
PubMed1988

Sonography of the hepatic vascular system.

The possibility of blood-flow analysis with Doppler techniques is a valuable addition to B-mode real-time scanning and enhances the role of sonography as the primary noninvasive imaging method for the liver and its vessels. Duplex sonography has already proved useful for qualitative assessment of hepatic blood flow in clinical practice. Preliminary experience with color Doppler flow imaging suggests that this technique may make assessment of the presence and direction of blood flow in intra- and perihepatic vessels easier and less time-consuming.

Hepatic Artery↗
PubMed1988

Biliary lithotripsy by extracorporeal shock waves: integral part of nonsurgical intervention.

Nine patients with cholelithiasis were selected for adjuvant therapy with extracorporeal shock-wave lithotripsy when radiologic or endoscopic intervention alone had been unsuccessful for stone removal. This preliminary experience with shock-wave lithotripsy includes four patients with one or more common duct stones, one patient with a large solitary gallbladder stone, and four patients with impacted cystic duct stones. Lithotripsy failed in two patients with cystic duct stones. The seven patients with successful lithotripsy underwent subsequent fragment extraction by intervention via T-tube tract, minicholecystostomy, or endoscopic sphincterotomy. Our approach to cholelithotripsy varied from previous reports in that we included patients with cystic duct stones, relied on interventional fragment removal without adjuvant chemolitholysis, and treated four patients with acute symptoms or multiple risk factors. Our initial experience with biliary lithotripsy in selected patients indicates that it can play an integral part in nonsurgical intervention for cholelithiasis.

Adult↗