Biomedical subjects
Publications and source records attributed to K Amplatz.
The previously unreported occurrence of concomitant pulmonary and cerebral arteriovenous fistulae was found in an individual with severe neurologic complications. Both polycythemia and paradoxical embolization were implicated in the genesis of the cerebral symptoms while the cerebral fistulae were asymptomatic. An improved method of therapeutic embolization was used to treat the pulmonary lesions, avoiding surgical resection.
Canine carotid, iliac, and femoral arteries underwent transluminal angioplasty with increasing balloon pressure from 4.5 to 12.5 atm. Balloons were selected according to vessel diameter: equal to (zero), 50% larger, and 100% larger than the vessel. The aim of this study was to assess possible disruption of the artery by a bursting balloon. With zero or 50% overdilation, arterial rupture did not occur despite balloon rupture. With 100% overdilation, arterial rupture always preceded balloon rupture. Rupture of all layers of the vessel was caused by severe overdistension, followed by secondary rupture of the balloon because it had lost its external support.
Twenty-five renal staghorn stones measuring at least 5 cm in diameter were removed percutaneously from 24 patients. Twelve patients required multiple access tracts for complete stone removal. Estimated blood loss more than 1000 ml occurred in 16 patients and temperature greater than 38.5 degrees C in 19 patients. All stones were successfully removed, with only two patients having definite residual fragments. Percutaneous nephrostolithotomy may be successfully applied to large staghorn stones. The relative roles of percutaneous therapy and extracorporeal lithotripsy remain to be determined.
Explore the source record for details and available documents.
Obliteration of the gallbladder without formal cholecystectomy was attempted in 36 rabbits, using an open technique for cannulation of the gallbladder during laparotomy. The gallbladder was cannulated, the proximal cystic duct was occluded with cyanoacrylate-nitrocellulose 2% wt/wt, and the gallbladder mucosa was exposed to various sclerosing agents to induce fibrosis. Heated 60% diatrizoate meglumine and absolute alcohol induced a controllable chronic cholecystitis with transmural fibrosis within two weeks, a result not seen with morrhuate sodium or in the control groups. All animals survived without complications, and no instances of common bile duct damage or occlusion was noted. The results reported are promising and indicate the need for further studies of this technique for its efficacy and safety.
Peliosis in a 13-month-old infant is described. This patient appears to be the youngest reported case. The radiologic diagnosis of peliosis is difficult. The condition may be confused with other more common liver diseases. Peliosis is best assessed angiographically.
An angiographic appearance of "pseudo" intramural injection is commonly produced following intraluminal balloon dilatation resulting from the dehiscence of the atheromatous intima that is an unavoidable consequence, and not a complication of angioplasty. These angioplasty-induced changes differ from true intramural dissections in that they are confined to the dilatation site and do not extend beyond this area.
Coil embolization of an incompetent spermatic vein of a patient resulted in a complication from the use of a sidehole catheter. Alternative procedures are suggested to avoid the problem.
Significant immediate and delayed vascular complications occurred in 4 of 140 patients (3 per cent) undergoing percutaneous removal of renal and ureteral calculi. An understanding of renovascular anatomy, use of a safety guide wire and intraoperative availability of an angiographic balloon catheter may help to prevent and to treat bleeding problems.
Percutaneous removal of renal stones is becoming an established procedure, especially for stones lying free in the renal pelvis. However, some renal stones, particularly caliceal stones, are less accessible and require special techniques for removal. We discuss these techniques, which include 1) retrograde pyelography to facilitate a thorough understanding of caliceal anatomy and stone position in 3 dimensions, 2) approaches for accurate placement of a nephrostomy tract for straight-line access to the stone(s), 3) judicious use of percutaneous punctures above the 12th rib and secondary percutaneous tracts, and 4) skilled choice and use of a large variety of cutting, extracting and disintegrating instruments with endoscopic and/or fluoroscopic control. The flexible nephroscope is valuable especially to reach inaccessible areas, although its skilled use requires experience. Flexible endoscopy often is aided by pressure irrigation, an assistant and simultaneous fluoroscopic control.
Percutaneous removal of renal stones (percutaneous nephrolithotomy) is becoming an established procedure, especially for stones lying free in the renal pelvis. However, some renal stones, particularly caliceal stones, are less accessible and, therefore, more difficult by the percutaneous route. We removed percutaneously 95 caliceal or otherwise poorly accessible renal stones from 53 patients with a variety of techniques, including percutaneous puncture above the 12th rib, double or Y percutaneous nephrostomy tracts, rigid and flexible endoscopy, and intrarenal cutting with diathermy. Intravenously assisted local anesthesia was used exclusively in 89 per cent of the patients. Status free of stones was achieved in all but 1 patient who retained 2 small fragments. The average number of sessions was 1.89 and the average hospital stay was 7.9 days. Complications were minor except for 1 patient who required tertiary renal artery embolization for bleeding. Illustrative cases are presented. Virtually all renal stones can be removed percutaneously.
A 16F nephroscope with a 5F cutting element was used for percutaneous removal of kidney stones in 10 patients in whom an open operation otherwise would have been necessary. Stone removal was accomplished via percutaneous incision of narrowed infundibula, caliceal diverticula and the ureteropelvic junction. A thorough knowledge of renal vasculature, meticulous care and fluoroscopic control are necessary for successful percutaneous intrarenal electrosurgery.
A percutaneous nephrostomy tract was used as a conduit to the kidney and ureter for extraction of 149 calculi in 100 patients. A variety of grasping and fragmentation techniques under fluoroscopic and endoscopic control were used to extract calculi in 88 per cent of the patients. With experience, operator efficiency and rate of stone extraction increased from 76 per cent early in the series to 91 per cent in the most recent patients, and the incidence of complications decreased from 17 to 5 per cent. Percutaneous removal of upper tract urinary calculi appears to be an appropriate alternative to an open operation in most patients with symptomatic urolithiasis.
A new device provides an automatic photographic record of left ventricular contraction and expansion. A radially slotted disk is interposed between the moving cine left ventriculogram and a disk of photographic film. By rotating either the slotted disk or the film, a kymographic record of regional wall motion is obtained. Unlike more complex computer programs, the speed as well as the magnitude of contraction can be determined.
A new technique for percutaneous arterial grafting was developed using a unique metal alloy (nitinol) with a heat dependent memory. Ten tightly wound nitinol coils (5-15 mm in diameter and 2-5 cm in length) were straightened in ice water and passed via catheter into the iliac artery or abdominal aorta of nine animals. Long term patency (15 weeks) was demonstrated in all but one graft. In one animal, an experimentally created abdominal aortic aneurysm was successfully treated by interposition of a nitinol graft. This new technique may be a valuable adjunct to conventional treatment of both obstructive and aneurysmal arterial disease in man.
A simple, lightweight plastic device is described for the inflation of balloons in order to perform transluminal angioplasty.
The successful performance of a percutaneous nephrostomy requires contrast material in the renal collecting system. For an exact delineation of all renal calices in a patient allergic to iodine, carbon dioxide was injected into the renal pelvis. The stone was removed successfully.
Two cases of spasm of the coronary artery bypass graft are reported, and the angiographic and clinical findings are discussed. Few previous reports of this entity were found in a search of the literature. The therapeutic implications are also presented.