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Biomedical subjects

K Amplatz

Publications and source records attributed to K Amplatz.

At least 289 records · Page 16Linked to original sources
PubMed1978

Silent unilateral pulmonary venous obstruction. Occurrence after surgical correction of transposition of the great arteries.

An 11-year-old girl was found to have completely obstructed left pulmonary veins eight years following corrective surgery for transposition of the great arteries. The patient was acyanotic and asymptomatic. Retrograde flow of arterial blood from the affected left lung accounted for an angiographic appearance that mimicked occlusion of the left pulmonary artery and resulted from a failure of systemic venous development. Pulmonary venous anatomy could only be demonstrated by pulmonary arterial wedge angiographic studies. This experience emphasizes that complete unilateral pulmonary venous obstruction may occur in an asymptomatic patient and underlines the importance of investigating pulmonary venous anatomy in any patient with gross inequality of the distribution of pulmonary blood flow.

Blood Pressure↗
PubMed1978

Improved safety of splenoportography by plugging of the needle tract.

Splenoportography, a useful preoperative diagnostic procedure in patients with portal hypertension, has been largely discontinued because of the risk of hemorrhage. We have used both Ivalon and Gelfoam in particle and plug form to plug the needle tract after splenoportography. Initial studies were conducted on six dogs. Plugging of the needle tract by injection of suspensions of small Gelfoam or Ivalon particles resulted in intravasation of these particles into the splenic vein. This was demonstrated by radioactive tagging of particles and the direct collection of splenic blood during the intrasplenic injection. Plugging of the splenic needle tract with compressed Gelfoam caused immediate, complete cessation of bleeding in fully heparinized animals. Because of these experimental results, five humans with decreased platelet counts and severe portal hypertension underwent successful splenoportography without significant hemorrhage. At surgery, successful plugging of the needle tract by Gelfoam was confirmed.

Adult↗
PubMed1978

Bleeding from cecal ulcers in renal transplant patients.

Cecal ulcerations represent a high percentage of causes of gastrointestinal bleeding in renal transplant patients. A close association of these lesions with cytomegalovirus (CMV) infection has been found, even though a cause-effect relationship has not been established. All of these patients are usually critically ill, and a progressive deterioration leading to death is the rule. Our experience suggests that the decrease of immunosuppressive drug therapy, followed by the nephrectomy of the transplanted kidney if signs of rejection are present, and right hemicolectomy are the best therapy. Angiographic procedures are of importance to determine the site of bleeding, stabilize the bleeding with the use of vasoconstrictor drug therapy, and to plan the surgical treatment.

Adult↗
PubMed1978

Renal blood flow changes following mannitol infusion.

The effect of mannitol infusion on the renal physiology, was evaluated in experimental animals and in man. In animals plasma flow and glomerular filtration rate were determined by the PAH extraction and by the innulin clearance technique. In patients renal blood flow measurements were carried out using the Xenon133 washout technique. Baseline studies were obtained and repeated following the intravenous infusion of 20% mannitol. A significant increase in total renal blood flow could be demonstrated in experimental animals, but only a minimal increase of total flow was demonstrated in man following the infusion of mannitol. This observation suggests that the diuretic effect of mannitol is very likely due to the osmotic effect in the tubule causing increased interstitial renal pressure rather than by an increase of actual renal blood flow. This observation is supported by the clinical experience that mannitol remains a powerful diuretic in even hypotensive patients with low renal blood flow.

Animals↗
PubMed1977

Redistribution of renal blood flow caused by contrast media.

Rerouting of blood from the renal cortex to the renal medulla (Trueta shunting), observed in 5 cases, may occur in normal kidneys during renal angiography. The temporary nature of this artifact may be proved by performing an abdominal aortogram with the catheter tip inserted farther away from the renal arteries. The exact mechanism of this phenomenon is unknown; it may also occur with various renovascular disorders.

Adult↗
PubMed1977

Angiography of the liver in lymphoma.

Three cases of lymphocytic lymphoma are reported. The diagnosis of liver involvement is critical since it may be a determining factor in the selection of chemo- or radiotherapy. Angiographic diagnosis of liver lymphoma is frequently unsuccessful. Though liver lymphomas usually display a hypovascular pattern, the hypervascular pattern should be considered in the differential diagnosis of hepatic lesions.

Aged↗
PubMed1977

Coronary artery fistula seen as a mediastinal mass.

The authors describe a case of coronary artery fistula seen as a mediastinal mass on a chest radiograph. Such a diagnosis should be considered when a bulge is seen along the left cardiac border on the plain film.

Adult↗
PubMed1977

Approximation of the left ventricle by a cone of revolution using biplane measurements.

A new method based only on area measurements was developed for calculating left ventricular volume from biplane (RAO and LAO) left ventriculograms; the ventricle was approximated by a cone of revolution. Twenty-three patients with normal and 23 patients with abnormal left ventricles were studied. The Dodge method provided reference values. There was no significant difference between values for EDV calculated by either method; values for ESV calculated by the cone method were consistently higher, but the error is acceptable. The cone method provides results similar to those obtained by the corrected Dodge method, eliminating the problem of choosing and measuring the long axis.

Cineangiography↗
PubMed1977

Comparison of the left ventricular volume using the Ahlkerg and Dodge methods.

Single plane cine left ventriculography was performed in 24 patients, 12 with normal and 12 with abnormal ventricular shapes. End diastolic and systolic volume and ejection fractions were calculated by two methods (Ahlberg and Dodge). The volumes and ejection fraction from either method were not significantly different. If calculated manually, the Ahlberg method took ten times longer than the Dodge method. At present some steps are difficult but a computer can perform the measurements and calculations, and print the results for ventricular areas.

Angiocardiography↗
PubMed1977

A new simple power injector.

A new simple pneumatic-hydraulic injection device has been constructed, tested, and used in clinical angiography. Is is the only injector which produces a square wave velocity curve with immediate rise time. Disposable plastic syringes are used which convert the velocity profile of the plunger into a smooth buildup time of the injectate, reducing recoil. The unit can be operated by both local or remote triggering. It has numerous advantages over commercially available devices, such as small size, simplicity of design, and safety features which eliminate shock hazards and reduce human error.

Angiography↗
PubMed1977

Nonsurgical splenectomy.

Surgical removal of the spleen is a well established procedure which is indicated for various hematologic disorders. Patients who are poor surgical risks may be considered for nonsurgical "splenectomy* using an embolization technique. This new technique should only be performed in patients who represent high surgical risk. The possible effectiveness of this procedure should be previously tested with the use of intraarterial vasopressin infusion. The following conditions should be fulfilled: (1) small emboli should be used to eliminate collateral flow; (2) the procedure should be carried out in two or three stages to minimize flank pain and the risk of massive splenic necrosis; and (3) most important, the spleen should be surgically removed as soon as the hematologic condition has improved in order to prevent splenic abscess formation. Splenic embolization was carried out in three patients with hypersplenism. One survived but was not helped by the procedure. Two died, one definitely and the other possibly as a result of the embolization. These discouraging results were reproduced in the animal laboratory where 11 of 14 animals developed severe complications, six of which were acutely fatal. The high incidence of late complications precludes non-surgical splenectomy as a routine procedure, but it can be carried out provided the spleen can be removed surgically.

Aged↗
PubMed1977

Lymphography as a guide during laparotomy in Hodgkin's and non-Hodgkin's lymphomas.

Lymphography of 123 newly diagnosed patients with lymphoma was followed by staging laparotomy without intra-operative abdominal roentgenography. These patients were retrospectively evaluated for residual abnormal nodes with postoperative abdominal roentgenography. Sixteen patients with pathologically normal nodes at laparotomy had residual lymphographically abnormal nodes at postoperative roentgenography. Nine patients received less extensive irradiation than they would have if the remaining abnormal nodes had been biopsied and found to contain tumor. Two had shortened survivals as an apparent consequence.

Adolescent↗
PubMed1977

Three year experience with percutaneous introduction of inferior vena cava filter.

Fifteen patients with recurrent pulmonary embolism were treated with a Mobin-Uddin umbrella filter (UF) introduced percutaneously via femoral vein. There were not technical difficulties, bleeding, or migration of the UF. The incidence of lower extremity edema or phlebitis was not higher than in patients with transjugular application of the UF or in patients with surgical inferior vena cava clipping. Two patients had fatal recurrent pulmonary embolism: in one of them the UF was positioned correctly in the vicinityof the renal veins; in the second the UF was placed too low and a large clot may have formed proximal to the UF. The transfemoral approach of the UF insetion represents a significant simplication of the inferior vena caval interruption, but it can only be used if thrombi are excluded by venography in the iliac vein and inferior vena cava. The UF should be placed as close as possible to the orifices of the renal veins to prevent a thrombus formation proximal to the filter.

Adolescent↗
PubMed1976

Nonsurgical closure of large arteriovenous fistulas.

We report a nonsurgical closure of large postnephrectomy arteriovenous fistulas in two patients. To out knowledge, this method has not previously been attempted because of the large size of the communication and the risk of pulmonary embolization. However, the development of new embolization techniques makes a nonsurgical approach feasible and safe.

Adolescent↗
PubMed1976

Peripheral angiograph enhancement by long leg pneumatic boots.

In patients with arterial occlusive disease it is virtually impossible to predict the speed of blood flow due to the presence of stenoses, occlusions, and collaterals. Repeated exposures and injections can be avoided by the use of pneumatic boots which increase peripheral blood flow by reactive hyperemia, are well tolerated by patients, and decreases the pain associated with injection of contrast material.

Angiography↗
PubMed1976

A new, simple test for thrombogenicity.

A simple technique is described to test thrombogenicity in dogs. Materials to be tested are introduced percutaneously into the femoral arteries of dogs in the form of a No. 5 catheter which is advanced to the aortic bifurcation. Another catheter can be introduced into the contralateral femoral artery in order to test two different materials in the same animal at the same time. After the catheter has been exposed to arterial blood for one hour, it is removed with a large-bore retrieval system, and all fibrin deposits are collected in a plastic basket. Significant thrombus formation was almost uniformly present in over 100 control studies. The technique has the advantage of being relatively noninvasive, allowing the testing of several materials in the same animal and yielding consistent results.

Animals↗