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Biomedical subjects

K H Barth

Publications and source records attributed to K H Barth.

116 records · Page 7Linked to original sources
PubMedDate not supplied

Transcatheter embolization with microfibrillar collagen in swine.

Transcatheter embolization of the gastrosplenic and renal arteries was performed in 7 domestic swine with suspensions of microfibrillar collagen (MFC), a recently developed topical hemostatic agent. Embolized vessels remained occluded 2 days following embolization. Recanalization occurred by 14 days, although some occlusion in distal vessel persisted at 3 months. Pathologically a marked granulomatous arteritis was noted at 14 days which resolved by 3 months. Gastric ulcers or infarcts were present in two animals. The severe vasculitis and gastric pathology observed with MFC in this study would seem to preclude its use as a general embolic agent. It may be useful, however, in the preoperative embolization of neoplasms, especially in pediatric patients since its physical characteristics allow it to be easily injected through small diameter catheters.

Animals↗
PubMedDate not supplied

Metrizamide, the ideal radiopaque filling material for detachable silicone balloon embolization.

Porcine visceral and extremity arteries were embolized with detachable silastic balloons; 10 balloons were filled with isoosmolar metrizamide, five were filled with 30% meglumine-sodium diatrizoate and five were filled with 3:1 mixtures of blood and 76% meglumine-sodium diatrizoate. Follow-up radiographs were obtained weekly for 2 weeks, at 4 weeks and at 5 months. At 3 months, arteriography was performed. All balloons occluded the vessel completely upon detachment. Balloons filled with metrizamide did not change their volume or radiopacity during the entire observation period and all remained inflated. The balloons filled with diatrizoate salts enlarged by osmotic growth during the first two weeks and there was a decrease in opacity. Thereafter, one balloon filled with 30% diatrizoate salt solution and one filled with blood-76% diatrizoate deflated. In the former, the embolized artery remained occluded, while in the latter, the vessel reopened and the balloon was found incorporated into the vessel wall at the site of detachment. It is concluded that isoosmolar metrizamide is an ideal filler for detachable silastic balloons since it does not lead to changes in volume or radiopacity and also guarantees long-term vascular occlusion.

Angiography↗
PubMedDate not supplied

Therapeutic embolization with detachable silicone balloons: long-term effects in swine.

Twenty-one embolizations were performed in 12 swine using a detachable silicone balloon-catheter system. In 11 embolizations, balloons were filled with 60% meglumine sodium diatrizoate (R-60); 30% meglumine sodium diatrizoate (R-30) was used in 10 embolizations. Serial radiographs were obtained to determine the duration of balloon inflation. Repeat angiography and autopsy examinations were performed three to six months following embolization. Eighty percent of balloons filled with R-30 were still inflated after 10 days, as opposed to 27% of the balloons filled with R-60. Balloons which remained inflated for more than 10 days caused permanent occlusion of the embolized arteries. The vessels were occluded precisely at the point at which the balloons were initially attached. Pathologically, the occluded vessels exhibited organized thrombi with minimal inflammation. Detachable balloons appear to be an effective, safe method of performing selective vascular occlusion in many circulatory systems. Careful control of the volume and osmolarity of the contrast medium used to inflate the balloons produces permanent arterial occlusion.

Angiography↗
PubMedDate not supplied

Organ ablation by fluid emboli. An experimental study comparing two solidifying liquids.

Embolization for ablation of organs and tumor infarction requires uniform permanent occlusion of the distal vasculature. This is best accomplished through the use of solidifying liquids. The study on 15 dogs reported here compares the degree of peripheral vascular embolization and its relation to tissue infarction both acutely and chronically following embolization of the renal arteries with two solidifying liquids, a low viscosity silicone and the occlusion gel Ethibloc. Silicone produced quite uniform distal distribution including 50 to 80% (mean 66%) of renal glomeruli, whereas Ethibloc occluded more proximally and reached only 10 to 50% (mean 22%) of all glomeruli. After three months complete cortical infarction of all nine kidneys embolized with silicone was found, whereas two of the three kidneys embolized with Ethibloc retained nests of viable glomeruli. Balloon occlusion of the entire renal artery inflow during embolization prevented distal venous emboli whereas partial inflow occlusion allowed systemic venous embolization. It is concluded that due to its more uniform distal penetration low viscosity silicone is a more suitable embolization agent than Ethibloc for organ ablation. Total arterial inflow occlusion during embolization effectively prevents systemic venous embolization.

Animals↗
PubMedDate not supplied

A double-blind comparative study of Hexabrix and Renografin-76 in aortography and visceral arteriography.

A diatrizoate compound (Renografin-76) and low osmolality Hexabrix were compared in a double-blind study of 50 adults undergoing arteriographic examination. Subjective and objective assessment of pain reaction for each contrast injection rated lower overall for Hexabrix. Discomfort associated with Renografin was greatest for injections into extremity arteries. Hexabrix showed the least change in serum osmolality. No impairment of renal function was evidenced with either contrast media. No difference in the angiographic quality of the control agents was noted.

Adult↗
PubMedDate not supplied

Gadolinium enhanced MR imaging of vascular stents.

The feasibility of obtaining in-plane magnetic resonance (MR) vascular images in the presence of a vascular stent and the value of infusing an MR contrast agent during imaging was assessed. Coronal and sagittal MR imaging at 1.5 T was performed on six dogs with tantalum aortic stents using single-section gradient echo (GRE) imaging and MR angiography techniques before and during intravenous infusion of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In-plane gradient echo (GRE) imaging and MR angiography clearly showed flow within the stented vessel as increased signal, with a minimum amount of stent-related artifact. Infusion of Gd-DTPA significantly increased the signal of flowing blood and allowed for better delineation of the stented aortic lumina. Our results demonstrate that in-plane GRE imaging and MR angiography can potentially be used as noninvasive methods for evaluating vascular patency in the presence of MR-compatible endovascular devices. In addition, Gd-DTPA infusion during MR vascular imaging clearly enhances the definition of flowing blood in the lumina of stented vessels.

Animals↗
PubMedDate not supplied

Ultrasound guided percutaneous cholecystocholangiography for early differentiation of cholestatic liver disease in infants.

Direct visualization of the extrahepatic biliary tree is difficult in infants and young children without resorting to an intraoperative cholangiogram. Small size and lack of dilated intrahepatic ducts especially in infants with cholestatic jaundice often preclude using the techniques of percutaneous transhepatic cholangiography or endoscopic retrograde cholangiopancreatography. We studied the feasibility of ultrasound-guided percutaneous cholecystocholangiography (US-guided PCC) in differentiating extrahepatic from intrahepatic causes of cholestatic jaundice in four infants. Clinical, laboratory, radiographic, and histologic criteria had not conclusively excluded extrahepatic obstruction prior to the use of this technique. Four infants, between 4 and 10 weeks of age, were studied without complications. In one patient, biliary atresia was diagnosed at 4 weeks of age; in another, aspirated bile was cultured leading to a specific diagnosis of bacterial cholangitis; and, in two others, intrahepatic cholestasis was confirmed by the demonstrated patency of the extrahepatic biliary tree. In infants and young children in whom a gallbladder lumen can be seen, US-guided PCC offers a potential rapid, nonoperative means of differentiating intrahepatic and extrahepatic causes of cholestatic jaundice, defining the anatomy of the extrahepatic biliary tree, and directly sampling gallbladder bile.

Biliary Atresia↗