Phlebography. Survey and present state.

Milestones in the history of phlebography are shortly reviewed. The present state of phlebography with emphasis upon the role of new nonionic contrast media is presented.

Safety of nonionic agents in visceral angiography.

RATIONALE AND OBJECTIVES: To compare the safety of ionic and nonionic contrast agents in visceral angiography. METHODS: Beginning in 1989, a prospective, open trial was begun, and 1,890 patients who have undergone contrast injection were enrolled. Patients considered to be high risk were graded according to Palmer and received nonionic contrast media, while all other patients received ionic contrast media. RESULTS: Because of the small number of visceral angiography procedures performed (38), no definitive conclusions could be drawn as to the differences between ionic and nonionic agents regarding grade-2 and grade-3 adverse events. However, a difference in grade-1 events was apparent in favor of nonionic agents. CONCLUSIONS: More than 10 years ago, the Department of Radiology staff at Aker Hospital began using iohexol, first in infants, then in children, pregnant women, patients undergoing leg phlebography, and patients with serious, previously documented reactions from contrast media. Currently, the department staff administers nonionic agents exclusively for coronary angiography and other cardiac procedures in approximately 300 patients per year. Today, use of nonionic contrast media is the standard for almost all procedures requiring intra-arterial or intravenous application.

Iohexol in phlebography of the leg. A comparative investigation with meglumine metrizoate.

Comparing iohexol 240 mg I/ml, iohexol 300 mg I/ml and meglumine-Ca metrizoate 200 mg I/ml in phlebography of the leg in patients on or without anticoagulants, no sign of postphlebographic thrombosis was found using the 125I-fibrinogen uptake test and repeat phlebography. More adverse reactions occurred with metrizoate than with iohexol. Metrizoate provided significantly poorer demonstration than the two iohexol concentrations with higher iodine content.

Adjustable temporary venous spring filter: in vitro assessment.

RATIONALE AND OBJECTIVES: The authors performed an in vitro study to evaluate a temporary venous spring filter that can extend vessels of a wide range of diameters to a slit-shaped canal. MATERIALS AND METHODS: Filters were placed in thin polyethylene tubes or in porcine inferior vena cava specimens (diameter, 10.0-16.0 mm). Physiologic saline was substituted for blood flow, and blood clots of three sizes (6 x 10, 6 x 20, and 9 x 20 mm) were funneled to the filter. Clot-trapping ability was assessed by the degree of luminal extension. RESULTS: When the luminal extension was increased from 2.6r to 2.8r (where r is the original radius of the vein models), clot-trapping ability increased significantly (61.1%-87.5% in polyethylene tubes and 15.8%-77.5% in venous specimens, P < .001). When the luminal extension was increased to 3.0r, more than 90% of the clots were trapped in all tubes. After trapping the small, medium, and large clots, mean intraluminal pressure elevation was 1.0, 1.0, and 17.0 cm of saline, respectively. CONCLUSION: Despite its simple design, the spring filter proved to be an efficient filtering device.

In vitro function of an adjustable temporary venous spring filter: comparison with the temporary RF02 filter and the permanent Greenfield vena cava filter.

RATIONALE AND OBJECTIVES: The authors compared in vitro function of a temporary venous spring filter with that of a temporary RF02 filter and a permanent Greenfield filter. MATERIALS AND METHODS: All three types of filters were placed in thin polyethylene tubes (diameters, 10.0-18.0 mm). Physiologic saline was substituted for flowing blood, and blood clots of three sizes (6 x 10 mm, 6 x 20 mm, 9 x 20 mm) were funneled to the filters. Clot-trapping ability of each filter and elevation of intraluminal pressure after clot trapping were assessed for each tube size. RESULTS: No statistically significant elevation in intraluminal pressure was detected immediately after placement of any filter. The clot-trapping ability of the spring filter and of Greenfield filter were slightly lower than that of the RF02 filter, but the differences were not statistically significant. After filters had trapped large clots, a high pressure gradient was detected in the 10.0-mm tube for all filters. The spring filter was associated with a higher pressure than the other filters in the 12.0-mm tube (P < .05). CONCLUSION: In vitro function of the spring filter was satisfactory in comparison with that of the RF02 filter and the Greenfield filter. For efficient filtering in the inferior vena cava, development of a larger version of the filter may be necessary.

In vivo evaluation of the adjustable temporary venous spring filter and the RF02 temporary filter: comparative study.

RATIONALE AND OBJECTIVES: The authors performed this study to compare the in vivo efficacies of the temporary venous spring filter and the RF02 filter in an animal model. MATERIALS AND METHODS: Either the spring filter or the RF02 filter was placed in the inferior vena cava of 10 pigs each, and two clots (5 x 20 mm) were funneled into the filters at 1-hour intervals. The second clots were funneled without removing the first clots captured by the filters. Clot-trapping ability, caval occlusion associated with the clot-trapping procedure, arterial blood gas concentrations, and changes in arterial and iliac venous pressures were evaluated. RESULTS: Placement of the RF02 filter caused elevation of iliac venous pressure with a maximum of 2.2 mm Hg (median) (n = 13, P = .003). Placement of the spring filter parallel to venous flow enabled capture of 90% (nine of 10) and 100% (six of six) of the first and second clots, respectively. The RF02 filter captured clots consistently. The difference between filters was not statistically significant. Both filters equally contributed to elevation of iliac venous pressure (median, 9.3 and 7.2 mm Hg [n = 9] with the spring filter and RF02 filter, respectively). Caval occlusion occurred in 17% (one of six) and 67% (six of nine) of animals after two clots were trapped in the spring filter and RF02 filter, respectively (P = .06). Other parameters were not influenced by the clot-trapping procedure. CONCLUSION: Although a larger version should be developed and better stability of the filter is needed, the spring filter proved to be an efficient filtering device and had a lower rate of caval occlusion compared with the RF02 filter.

Left coronary artery contrast transit time.

With our method for selective left coronary arteriography it is possible to determine the time interval between the start of the contrast injection into the artery and the appearance of the contrast in the coronary sinus. This time-interval, coronary contrast transit time (CCTT), has been determined in patients with or without obstructing coronary artery disease. The average CCTT was about four seconds with some individual variations. The CCTT tended to decrease with advancing age. There was no significant difference between the CCTT in patients with normal angiograms compared to the CCTT in patients with coronary stenoses or occlusions. In the latter patients, there was no correlation between the degree of narrowing on the angiograms and the time-measurements. Alternative explanations for these findings are discussed.

Phlebography. Survey and present state.

Milestones in the history of phlebography are shortly reviewed. The present state of phlebography with emphasis upon the role of the new non-ionic contrast media is presented.

Management of retained biliary calculi via a postoperative T-tube tract.

Of 12 patients admitted for percutaneous retrieval of retained biliary stones through a postsurgery T-tube tract, 10 patients were successfully treated. The method using catheter technique and Dormier basket is reviewed.

Angina pectoris in aortic valvular disease and its relation to coronary pathology.

Angina pectoris is a common symptom in aortic valvular disease. In our study of 100 consecutive patients it was found more commonly in patients with aortic stenosis than in those with aortic insufficiency. Only 21 of 80 patients with angina pectoris had significant narrowing (more that 75%) of one or several coronary arteries. Angina pectoris in aortic valvular disease thus seems to be most often functional due to disproportion between myocardial oxygen supply and demand. On the other hand, 5 of 20 patients without angina pectoris had significant coronary artery stenosis. As coronary artery involvement may jeopardize the results of aortic valve replacement in these patients, coronary angiography should always be carried out in patients evaluated for surgery of aortic vavlular disease. Coronary bypass surgery should be carried out during the same operation if the stenosis is severe and bypass is technically feasible.

The behavior of collateral circulation after coronary artery bypass surgery.

The changes in coronary collateral circulation after bypass surgery were analyzed in 50 patients with coronary disease. The demonstration of collateral circulation was found to be dependent upon the severity of the coronary heart disease and the patency of the bypass. When the graft was patent, it was usually not possible to visualize the collateral circulation demonstrated preoperatively. When the bypass was occluded, the same collateral circulation as before surgery was frequently found.

Left coronary artery transit time in latent coronary heart disease.

In a group of 104 cases with possible silent coronary heart disease, 36 had normal angiographic findings and 68 significant coronary artery disease. The transit time of the contrast medium in the left coronary artery was significantly shorter in cases with abnormalities of the artery than in non-afflicted cases. The extent of arterial disease seemed to influence the transit time inversely, whereas the location of the abnormalities did not influence the transit time.

Portography of normal and regenerating dog liver.

The angiographic appearance of the portal vein in the dog before and after major hepatic resection is described. An increased diameter and length of the lobar vein and their ramifications were found following resection. The appearance both in the portal and sinusoidal phase indicated a diffuse growth of the liver remnant. One week after resection a portal hypertension was recorded, which had usually receded after six weeks. Major hepatic resection seems to imply a higher risk for fatal toxic effects from the contrast medium.

Hepatic venography of normal and regenerating dog liver.

Total and selective hepatic vein angiographies were performed preoperatively and 6 weeks after 70 per cent liver resection in 6 dogs. The alterations in the hepatic vein system, increased diameter and elongation of the remaining lobar veins and their major tributaries plus increased angle between the radicles, are consistent with the findings earlier described by angiography of the hepatic arterial and portal venous system after major hepatic resection in dogs.

The synthesis and excretion of non-erythroid bilirubin in the dog.

Between 10 and 20% of the bilirubin excreted in the bile is not derived from the breakdown of hemoglobin. When delta-aminolevulinic acid is given as a bilirubin precursor, 99% of the bilirubin formed is of this non-erythroid variety. The non-erythroid bilirubin has been supposed to be synthetized exclusively in the liver. Sequential samples of arterial, portal and liver vein blood, as well as of bile and thoracic duct lymph, were analyzed for bilirubin and non-bilirubin radioactivity following the injection of labeled delta-aminolevulinic acid in dogs. Radioactive bilirubin appeared in blood before it could be demonstrated in bile or lymph. The concentration differences between aortic, portal and liver vein blood displayed a considerable extrahepatic non-erythroid bilirubin synthesis. Most non-erythroid bilirubin synthetized in the liver is excreted directly into the biliary canaliculi.