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Biomedical subjects

K Amplatz

Publications and source records attributed to K Amplatz.

At least 109 records · Page 6Linked to original sources
PubMed1985

Quantitative assessment of left ventricular function after myocardial infarction using the minnesota Q-QS codes for resting electrocardiograms.

The electrocardiogram as a quantitative predictor of left ventricular systolic function was investigated in subjects with one myocardial infarction. The first 509 consecutive subjects to enter the Program of Surgical Control of Hyperlipidemia were studied by selective left ventriculography. Electrocardiograms taken during a prior hospitalization of the subjects for acute myocardial infarction were classified according to the Minnesota Q-QS codes. This study showed that the lower (ie, the more significant) Q-QS codes were highly correlated with reduced left ventricular function as measured both by a lower ejection fraction and by a greater number of left ventricular segments showing abnormal systolic motion. In addition, the location of segmental wall motion abnormalities correlated with the electrocardiographic site of the Q-QS code.

Adult↗
PubMed1985

Percutaneous management of ureteral calculi facilitated by retrograde flushing with carbon dioxide or diluted radiopaque dye.

Of 356 patients in whom percutaneous nephrostomy was performed at this institution 59 had ureteral stones. In our experience with the first 36 patients antegrade techniques for ureteral stone extraction had many assets but sometimes they were difficult. Recently, we incorporated a retrograde flushing technique, using carbon dioxide and diluted radiopaque dye, into our percutaneous approach to ureteral stones. Based on our experience with this technique in the next 23 consecutive patients, we believe that percutaneous nephrostolithotomy and retrograde flushing should be added to the armamentarium of urologists committed to the percutaneous endourological approach to ureteral stones.

Carbon Dioxide↗
PubMed1985

Percutaneous removal of renal and ureteral calculi: experience with 400 cases.

Percutaneous removal of renal and ureteral calculi was performed in 500 patients since 1979. Experience with our first 100 cases enabled us to accumulate a variety of techniques. We report our experience with the subsequent 400 cases. As judged by plain films of the kidneys, ureters and bladder, and renal tomograms without contrast medium we attained a status free of stones in 99 per cent of the patients with renal and 94.5 per cent with ureteral calculi. Intravenous-assisted local anesthesia was used in 94 per cent of the cases. There was no mortality and the incidence of complications was low. Most patients with renal and ureteral calculi can be managed successfully and safely by percutaneous methods with good patient tolerance and minimal convalescence.

Adolescent↗
PubMed1985

Significance of balloon pressure recording during angioplasty. An experimental study.

During angioplasty of artificial stenoses, atherosclerotic human cadaver arteries, and normal canine arteries, pressure and volume of the dilatation balloons were continuously recorded. We found that a sudden yield of a lesion corresponded to a sudden drop in the pressure curve and an increase of the balloon volume. Volume monitoring was insensitive, but pressure recording was very precise. Continuous pressure recording, using a non-compliant inflation system, correctly demonstrated small breaks and ruptures of atherosclerotic vessels, changes not seen on fluoroscopy.

Angioplasty, Balloon↗
PubMed1985

Percutaneous extraction of urinary calculi: use of the intercostal approach.

The authors achieved successful percutaneous extraction of urinary calculi via an intercostal approach in 24 patients. In one patient, a large hydrothorax developed and thoracentesis was required; 2 patients had moderate and 6 minimal pleural fluid collections which did not require treatment. No patient had pneumothorax. Intercostal puncture provides direct access to the upper and middle poles of the kidney when they lie above the twelfth rib and subcostal angulation is not feasible. Such an approach is advantageous for stones in the ureter, as well as renal stones which are inaccessible from the lower pole. Fluoroscopy should be performed when planning the puncture in order to avoid the lung, and a working sheath is recommended.

Adult↗
PubMed1985

Thrombosed synthetic hemodialysis access fistulas: failure of fibrinolytic therapy.

Seven episodes of acute thrombosis occurring in five patients with polytetrafluoroethylene dialysis fistulas were treated with local infusions of low-dose streptokinase. Bleeding from previous dialysis puncture sites necessitated stopping the infusion in six out of seven patients, although in one of these six, the graft reopened. The seventh patient had never been dialyzed through the graft and thrombolysis was achieved without incident. Surgery was avoided in only one patient. The authors contend that in these patients the risks of fibrinolytic therapy outweigh the benefits. Surgical thrombectomy, coupled with intraoperative angiography and possible angioplasty, is the preferred method of treating these patients. Venography prior to the creation of the fistula helps the surgeon avoid diseased vessels and may avert early failure of the fistula.

Adult↗
PubMed1985

Electrolysis for recanalization of urinary collecting system obstructions: a percutaneous approach.

Nine recent endourologic cases are presented that evidence percutaneous electrolysis and electrocautery as new and safe techniques for incising the urothelium. Electrolysis with balloon dilation was employed to remove stones sequestered behind infundibular and/or diverticular neck stenoses, to correct uretero-pelvic junction (UPJ) stenoses and strictures, and to recanalize a totally obstructed fibrotic UPJ.

Adult↗
PubMed1985

A new pyeloureteral drainage catheter.

We describe a new pyeloureteral drainage catheter that can be used for both genitourinary tract stenting and drainage, as well as tamponade of bleeding from the renal parenchyma or subcutaneous tissue. Primary indications for the use of this catheter and recommendations on insertion techniques are presented. With the exception of one case of minor kinking of the catheter, we have had no complications or failures with this catheter. While insertion through an unprotected tissue track is somewhat difficult, we have had good success introducing the catheter through a 24-F or larger Teflon working sheath. The catheter has excellent patient retention properties. It can be converted from external to internal drainage or vice versa simply and quickly on the ward.

Humans↗
PubMed1985

Detachable steel spring coils for vessel occlusion.

Spring coils for vessel occlusion were modified to include a screw-on attachment for delivery wire, which permitted safe and accurate placement of the coils. We successfully implanted coils in a dog and a lamb. They were easily retrieved from within the delivery catheters and the vessels, which is not possible with conventional coils. Coil design is described.

Blood Vessels↗
PubMed1985

A new universal radiolucent handle.

A new universal radiolucent handle is described that permits needle placement under continuous fluoroscopic observation, while maintaining the operator's hands outside the primary beam. The handle accommodates nearly all needles used for biopsy, anesthesia, nephrostomy, cholangiography, and biliary drainage, which represents a major advantage over previously described radiolucent handles. Reduced operator-hand exposures, improved needle guidance, and quick handle release are also major advantages of the universal handle. It is inexpensive, reliable, and reusable.

Fluoroscopy↗
PubMed1985

Percutaneous catheter balloons: failure to deflate.

Three examples of permanently inflated transluminal catheter balloons are presented. Two of these occurred during attempted percutaneous transluminal angioplasty. Nonsurgical solutions, which were successful in each case, are described. Percutaneous puncture with a needle or a larger diameter coaxial catheter under fluoroscopic guidance may be useful when this complication occurs during attempted balloon angioplasty or embolization with proximal balloon occlusion in large vessels.

Aged↗
PubMed1985

Retrievable vena caval filter percutaneously introduced.

A vena caval filter than can be introduced percutaneously via the femoral vein is described. We placed these filters in five patients without complications. Experimental work in filter removal one to two weeks after insertion in dogs has been performed.

Animals↗
PubMed1985

Percutaneous removal of ureteral calculi: clinical and experimental results.

Between May 1983 and October 1984, 51 patients who had 68 ureteral stones underwent treatment at the University of Minnesota. All 68 stones were removed successfully using percutaneous techniques. The 100% success rate is a great improvement over previous results at our institution. The primary factors appear to be the development of the retrograde-flush technique, familiarity with and access to a wider range of methods, and the increasing use of the retrograde ureterorenoscope to see stones in the lower ureter. The average patient was a 45-year-old man who had no other medical problems. The average hospital stay was 6.8 days. Experimental studies with dogs indicate that injection rates of up to 30 ml/sec of contrast material through a retrograde catheter in the ureter are safe if a vent is present in the upper collecting system.

Adult↗
PubMed1985

Very stiff guide wire with a floppy tip.

Many interventional procedures, particularly dilation of tracts, require stiff guide wires with a floppy tip. Such a guide wire was specially constructed and is commercially available.

Bile Ducts↗
PubMed1985

Coaxial cancer dilator.

In cases in which the ureters or biliary tree is encased by large tumors, it may be difficult to dilate a pathway for a stent with a balloon catheter. In ten consecutive patients in whom balloon dilatation was unsuccessful, a coaxial tapered Teflon cancer dilator successfully crossed the obstruction.

Bile Duct Neoplasms↗