Biomedical subjects
Publications and source records attributed to E vanSonnenberg.
Choledocholithiasis was detected by ultrasound in 11 of 87 patients (13%) overall, including 11 of 56 patients (20%) who had dilated ducts. Choledocholithiasis occurred with a normal caliber common bile duct in 31 of 87 patients (36%), and choledocholithiasis occurred without stones in the gallbladder in seven of 66 patients (11%). Biliary ultrasound plays a limited role in the exclusion of choledocholithiasis.
Following the observation of several cases of localized echogenic foci in abdominal parenchymal organs in patients with acute bleeding due to trauma, an experimental study was designed to define the sonographic appearance of fresh, nonhemolyzed blood. Ultrasound scanning performed before and after the injection of blood or air into the parenchyma of cadaveric organs (liver, spleen, and kidney) resulted in consistent ultrasonic patterns. Linear echogenic foci resulted from the injection of 0.5 to 2.0 ml of blood, rounded echogenic foci were seen with air or 3- to 10-ml injections of blood, and the injection of contrast material (into the liver only) caused poorly defined hypoechoic areas. To determine if the ultrasound appearance of the cadaveric organs could have been caused mainly by air, an in vivo experiment was performed in which computed tomograms of the liver of a dog that had been injected with autologous blood were obtained. It is concluded that CT confirmed the ultrasound findings, and that ultrasound is useful for the investigation of hematoma following blunt, and possibly penetrating, trauma.
A prospective study of the ability of ultrasound to accurately determine the site and etiology of biliary obstruction in 62 patients is reported. The site of obstruction was predicted in 27% of the patients, but was indeterminate in 73% because of the inability to visualize the complete biliary tract. The cause of obstruction was correctly predicted in 23% of the patients and was indeterminate in 76%. While sonography is an excellent screening method for distinguishing dilated ducts from nondilated ducts, the authors believe that direct cholangiography, or possibly computed tomography, is necessary if stringent criteria are applied to the determination of the site and cause of biliary obstruction.
Manometric pressure recordings were attempted during percutaneous transhepatic cholangiography (PTC) and after percutaneous biliary drainage (PBD) in 203 cases. Successful readings were achieved at PTC in 85% (104/122) of patients. Pressure measurements were also obtained through 56 biliary drainage catheters, and controlled perfusion challenges were performed in 12 patients (on 18 occasions). Documentation of the occasionally poor correlation between the caliber of ducts and the degree of obstruction (i.e., pressure) was shown, and it was suggested that very high pressures may be predictive of a bile leak after PTC. Adequacy of percutaneous drainage and stricture dilatation were further assessed with these manometric techniques. Pressure and perfusion data aided in detecting and determining the significance of the nondilated obstructed duct, the dilated nonobstructed ductal system, and subtle distal ductal strictures. The knowledge obtained from percutaneous pressure recordings may help to determine appropriate therapy.
A technique for biopsy of small or inaccessible mediastinal, hilar, or pulmonary lesions with computed-tomographic (CT) guidance is described. A modified coaxial system was used in order to make multiple passes possible without multiple punctures. The size of the original puncture needle (23 gauge) provided the inherent safety associated with a fine needle. All repositioning was done using this needle and CT until the lesion was engaged. The hub of the needle was then cut, and a 19-gauge needle was inserted coaxially over the larger needle. After removal of the 23-gauge needle, multiple biopsy specimens were then obtained coaxially with a 22-gauge needle through the 19-gauge needle. One small pneumothorax and no bleeding occurred in 10 instances. Results suggest that the combined use of CT guidance and this modified coaxial system may offer an extra margin of safety for difficult cases.
Localized collections of bile within the peritoneal cavity, "biloma," may occur after surgery or trauma and are readily detected by sonography and computed tomography. Eleven cases in which the diagnosis was confirmed by percutaneous needle aspiration and treatment carried out by radiologic catheter drainage are reported. Specific identification of bile was made by visual inspection, initial rapid dip-stick (Multistix) technique, and formal chemical analysis. Evidence of continued free bile leak included a positive technetium HIDA scintigram and copious amounts of bilious catheter drainage over a prolonged period. Unexpected clinical features of biloma included presentation as a pyogenic subhepatic abscess in four (36%) of 11 cases, localization of the biloma collection in the left upper abdomen despite surgery on the right side in four (36%) cases, and the presence of an active bile fistula in five (45%) cases. Percutaneous radiologic catheter drainage provided adequate therapeutic drainage in all but two patients in whom a continuing active bile leak eventually required surgical correction.
In this study, Fluosol-DA, 20 per cent (composed of perfluorodecalin and perfluorotripropylamine) was tested as a liver-specific ultrasound contrast agent. Twelve normal rabbits were scanned, utilizing the Picker Microview (10 MHz), prior to and two days following the intravenous administration of 24 ml/kg of Fluosol (or 4.8 g/kg of perfluorochemicals) emulsion to ten of the rabbits and 24 ml/kg of Ringer's solution to two rabbits as control. In all ten rabbits given Fluosol, liver echogenicity increased relative to that of the kidney, whereas the liver remained less echogenic than the kidney in the two rabbits given Ringer's solution. Four independent reviewers correctly identified all rabbits that received Fluosol and both rabbits that received Ringer's solution. It is demonstrated that, similar to PFOB, Fluosol serves as an echogenic contrast material for ultrasound and opacifies the normal rabbit liver.
We performed computed body tomography and ultrasound-guided percutaneous catheter drainage in 45 cases of abdominal abscess. Evacuation of the cavity was achieved in 40 cases (89%), eliminating the need for surgery in 34 patients. There were six recurrent abscesses, all due to fistulous communications or recurrent infected tumor. Major complications were a lacerated mesenteric vessel and a small-bowel fistula. Drainage catheters were removed an average of seven days after insertion. In many cases, guided percutaneous radiological drainage is an effective alternative to operative therapy, especially in severely ill patients.
A combination of computed tomography, ultrasonography, and fluoroscopy was utilized to guide percutaneous catheter drainage of 58 abscesses and fluid collections in 51 patients. Cavities were evacuated in 53 cases, with surgery avoided in 44 of these. There were two failures and six recurrences. The mean duration of catheter drainage was seven days. Five complications occurred, including a small bowel fistula and a lacerated mesenteric vessel. Based on this experience, guidelines for drainage are presented, as well as principles for the critical step of access route planning. Double-lumen sump drainage catheters and the irrigation procedure have simplified and improved drainage. Causes and solutions for unsatisfactory results are defined.
This series describes 9 patients in whom a rapid change in bile duct caliber was documented by ultrasonography, intravenous or direct cholangiography, or endoscopic retrograde cholangiopancreatography. Two major observations were made: (a) the capacity of the common duct to distend and collapse over a short period, and (b) discordant measurements of bile duct diameter on successive examinations with different modalities (i.e., ultrasonography followed by cholangiography). It is thought that these discrepant measurements can be explained by the ability of the common duct to distend rapidly in response to pathologic and physiologic fluctuations in biliary pressure.
The sonographic response of the biliary tree to a fatty meal was assessed in 78 individuals by measuring common hepatic duct caliber before and after fat ingestion. In the normal cases, the common hepatic duct remained the same or decreased in caliber. Abnormal responses consisted of a normal-caliber duct that increased in size or a slightly dilated duct that remained the same or increased in size. By employing these criteria, we discovered patients with ampullary stenosis, common duct stones, cholangiocarcinoma, and chronic pancreatitis. It is concluded that biliary sonography after ingestion of a fatty meal can aid in the evaluation of a common hepatic duct that is equivocally or mildly dilated and can indicate the need for further invasive studies.
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Successful function of an indwelling biliary endoprosthesis requires precise initial positioning relative to the stricture site. Delayed failures may occur as a result of migration either proximally or distally. The authors describe a method for retrieval of a distally displaced endoprosthesis using a vascular balloon-dilatation catheter.
Obstruction of the left hepatic duct due to periportal pathologic conditions was identified by fine-needle transhepatic cholangiography in 28 patients. Selective cholangiography of the left duct was performed in 30 instances and subsequent selective left-sided catheter decompression was carried out in 23 cases. Techniques for selective puncture and drainage of the left duct required procedure modifications to accommodate the specific anatomic and pathologic features of the obstructed left duct system. Ultrasonography was indispensable as an aid to delineation of the left duct anatomy for directing needle puncture. Accurate documentation and successful catheter drainage of left duct obstruction are important contributions to the total management of patients with high biliary obstruction.
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Percutaneous needle sampling of suspected malignant tumors was carried out in 150 patients using a technique providing specimens for both cytologic and histologic analyses. Adequate samples for pathologic analysis were obtained in 97% and 89%, respectively. An overall accuracy rate of 85% was achieved with histologic results providing a positive diagnosis in 7% of patients in whom corresponding cytologic information was falsely negative. Both in vivo and in vitro experiments suggest no superiority in the tissue retrieval rate of the different 22 gauge needles used for biopsy. Since the core biopsy technique adds no increase in complication rate and provides a small but definite incremental gain in accuracy, its routine use is suggested.
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Fine-needle transhepatic cholangiography is a diagnostic tool often used for evaluating the biliary tree because of its wide availability and relatively low complication rate. Fine-needle cholangiography is primarily used in patients with obstructive jaundice with dilated ducts, but has been useful in patients with those entities that cause obstruction without dilatation (sclerosing cholangitis, ampullary stenosis, nonobstructing stone). We review our experience with over 700 cases of fine-needle cholangiography. The complication rate (due to bleeding, peritonitis, sepsis, and death) is less than 5%. The central role that fine-needle cholangiography plays in defining the site and cause of biliary obstruction is emphasized.