Showing papers by "Kurt Amplatz published in 1989"

Lubricious antithrombogenic catheters, guidewires and coatings

Abstract: Method for rendering a preformed article lubricious and antithrombogenic and a device being the same. On the surface of the article a thin coating of a biologically compatible, lubricious, hydrophilic polymer including acid groups, is provided. On the coating, ammonium cation, and heparin are applied in the manner that heparin is bound by electrostatic attraction to the ammonium cation of the coating to permit time release of heparin. A buffer solution may be applied in a manner to act to enhance the lubriciousness of the coating.

Experience with the Amplatz retrievable vena cava filter.

Abstract: The Amplatz retrievable inferior vena cava filter was designed to be used as either a permanent indwelling filter or a short-term, percutaneously removable filter. The authors placed 52 filters in 52 patients. No deaths occurred as a result of filter placement or usage. Follow-up in 42 (81%) patients included inferior vena cavography (n = 31), computed tomography (n = 4), duplex ultrasound (n = 4), and autopsy (n = 3). Inferior vena cava thrombosis was found in seven (17.5%) of the 40 previously nonobstructed venae cavae studied. Two patients with caval thrombosis required a second filter to prevent embolization of thrombus that had extended to the lung side of the first filter. No clinically evident pulmonary emboli after filter placement have been noted. Six filters were successfully retrieved or repositioned percutaneously. The relatively high rate of caval thrombosis with extension above the filter may be due to a higher trapping efficiency or to filter geometry. The role of this filter in the treatme...

Mechanical clot dissolution: new concept.

Abstract: The authors present preliminary data on in vitro mechanical clot dissolution by means of a catheter with a tiny high-speed propeller enclosed in a special housing. Preweighed human blood clots were subjected to the catheter in a test tube with saline at various propeller speeds and durations of application. After filtration of the resultant slurry, the clot residue was weighed and examined histologically. Clot dissolution was found to be related to both the duration and speed of propeller rotation. No fibrin residue was seen after dissolution, although potential embolic material, composed of clumps of cellular debris as large as 208 microns in longest dimension, was found. Mechanical clot dissolution could possibly be used in any natural or synthetic blood vessel in which there is acute or subacute thrombosis, with fewer complications and lower cost than obtained with traditional methods.

Combined needle and dilator apparatus

Abstract: The present invention provides a combined needle and dilator comprising a needle having a head with an outer diameter greater than the outer diameter of the body of the needle and a dilating sheath carried about the needle and abutting the rearward needle portion of the needle head. The dilating sheath has a front portion with an outer diameter substantially equal to the outer diameter of the needle head to define, with the head, a generally smooth surface; a body portion with an outer diameter greater than that of the front portion; and a tapered portion disposed between the front and body portions. The tapered portion has an outer surface smoothly merging into the outer surfaces of the front portion and the body portion.

The incidence of myocardial bridges in heart transplants.

Abstract: Coronary angiograms of 64 heart transplant patients were reviewed to determine the incidence of myocardial bridges. In 33% of the patients, myocardial bridges were detected, almost exclusively across the midportion of the left anterior descending coronary artery. The incidence is higher than previously reported in the literature and is thought to be related to increased stiffness and hypertrophy of the myocardium, which facilitates angiographic detection of myocardial bridges in the transplanted heart.

Aorta balloon angioplasty: 9-year follow-up.

Abstract: Nine-year patency and clinical effectiveness of balloon angioplasty of the aorta in a patient with Leriche syndrome are described. The morbidity of surgical intervention for aortoiliac disease is compared with that of percutaneous transluminal angioplasty. These results suggest that aortic balloon angioplasty is a safe and effective procedure with good long-term results.

The importance of separation of prostatic lobes in relief of prostatic obstruction by balloon catheter urethroplasty: studies in dogs and humans

Abstract: We performed balloon urethroplasty in six older normal dogs and 10 patients with benign prostatic hypertrophy to establish the mechanism by which this technique results in relief of bladder outlet obstruction. Thirty-millimeter balloon catheters were used in both the animal and human studies. Autopsy studies showed disruption of the anterior prostatic commissure in four of the six dogs, disruption of both anterior and posterior commissures in one dog, and no disruption in the remaining dog. In all 10 patients, cystoscopy and urethrography showed disruption of the anterior commissure. Separation of the prostatic lobes by disruption of the prostatic commissures may be the most important mechanism by which balloon urethroplasty relieves urethral obstruction.

Percutaneous intravascular biopsy using a Simpson atherectomy catheter: technical note.

Abstract: The design of the Simpson atherectomy catheter makes this device a potentially safe and technically easy tool to obtain adequate pathologic intravascular or intraluminal specimens. The risk of perforation should be low, but this use has to be further studied. We describe the first intravascular biopsy performed with the Simpson catheter.

Aid for safer sclerotherapy of the internal spermatic vein.

Abstract: A device was developed for use during sclerotherapy to treat spermatic varicoceles. It is used to provide external compression of the internal spermatic vein, to prevent distal flow of the sclerosing agent into the scrotal venous network. The device has been successfully used in 27 patients (43 spermatic veins). In no case did sclerosing agent leak past the compressor, and no complications related to the compressor itself have been encountered.