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Biomedical subjects

R C Pfister

Publications and source records attributed to R C Pfister.

At least 73 records · Page 4Linked to original sources

Therapy for renal calculi via percutaneous nephrostomy: dissolution and extraction.

Nephrostomy catheters offer nonsurgical modes of therapy for some renal stones. Continuous lavage of the stones using hemiacidrin (Renacidin) for struvite stones, THAM-E or acetylcysteine for cystine stones, and bicarbonate solution for uric acid stones may dissolve either entire stones or stone fragments remaining after surgery. Although irrigation is not without potential complications, recent developments in technique have minimized these. Nephrostomy tubes can also be used to transmit stone baskets through steerable catheters to snare stones from the upper collecting system or from the ureter; any stone that can be engaged and withdrawn through the tube tract can be removed; stones larger than those which can be safely extracted through the ureterovesical junction can be so treated. Neither of these procedures requires general anesthesia, the rate of serious morbidity is low, and the required hospital stay is often less than that for surgery; these modes of therapy are therefore valuable for certain patients.

Acetylcysteine↗

Radiology of urinary undiversion.

Many patients with urinary diversions are now considered candidates for "undiversion". Radiographic evaluation prior to undiversion of the urinary tract includes cystography to determine bladder capacity and sensation, urinary continence, and the presence of reflux. Urography, loopography, and/or ureterography (antegrade and/or retrograde) are necessary to completely visualize the remaining urinary structures. Surgical techniques involved in the reconstruction are briefly discussed to facilitate an understanding of the often unusual radiographic appearance of the undiverted urinary tract. Stentograms and cystography are recommended for early postoperative evaluation to exclude urinary leakage or significant obstruction. Percutaneous ureteral perfusion studies are often useful in the long-term follow-up of these patients.

Adolescent↗

Angiodilator technique for hysterosalpingography in cervical os stenosis.

Obstruction of the endocervical canal of the uterus, frequently encountered after cauterization or cone biopsy, may result from a variety of benign and malignant diseases. Severe stenosis of the cervical os has made hysterosalpingography difficult. In ten patients, progressive dilatation with small vascular dilators was successful.

Adult↗

Whitaker test after pyeloplasty: establishment of normal ureteral perfusion pressures.

Twenty-seven patients underwent percutaneous ureteral perfusion after successful surgical repair of ureteropelvic junction obstruction in order to determine the perfusion pressures in ureters without obstruction. In each patient, the postoperative ureteropelvic junction appeared widely patent and the rest of the ureter appeared entirely normal. Ureteral perfusion was performed via percutaneous puncture of the collecting system; the pressure in the pelvis was measured through this needle and bladder pressure was monitored through a urethral catheter. "Absolute" (renal pelvic) and "differential" (renal pelvic minus bladder) pressures were measured at 10, 15, and 20 ml/min perfusion rates. Absolute and differential pressures rose as the perfusion rates increased; absolute pressure rose but differential pressure fell as the bladder was filled. The upper limit of normal differential pressure encountered with the bladder empty was 13 cm of water during perfusion at 10 ml/min.

Adolescent↗

Filling defects in small bowel urinary conduits.

Radiographic evaluation of patients with urinary diversion by small bowel conduit includes excretory urography, loopography, and, if necessary, percutaneous pyelography. Five patients with discrete filling defects in their conduits are discussed. These defects represented stones (two cases), antirefluxing ureteral nipples, metastatic bladder carcinoma, and a "turn-in" loop construction defect. While the nature of loop filling defects can often be discerned by radiographic studies and a knowledge of the conduit construction technique, endoscopic biopsy may occasionally be necessary for definitive diagnosis.

Adult↗

Primary leiomyosarcoma of ureter.

The tenth case of primary leiomyosarcoma of the ureter is reported, and previous cases are summarized. It is the first example studied by percutaneous pyelography and ultrasonography. The former was more informative than retrograde ureterography. The ultrasonic study suggested a cystic lesion rather than the solid tumor encountered. Nephroureterectomy, selective para-aortic node dissection, and radiotherapy were used, but distant metastasis and death ensured fifteen months later.

Aged↗

Renal-stone dissolution via percutaneous nephrostomy.

Recurrent renal stones associated with urinary infection were treated in eight kidneys in six patients by percutaneous nephrostomy and irrigation with hemiacidrin, a commercially available solution of organic acids and magnesium. The stones, presumably composed of triple phosphates (magnesium, ammonium and calcium phosphate), were completely dissolved in six kidneys; in two they were partially dissolved and subsequently recovered by other methods. No serious complications were encountered. The technic requires special precautions against perinephric and intravascular dissemination of infection, but it offers potentially effective therapy for certain kidney stones without the use of general anesthesia or operation.

Adult↗

Giant hydronephrosis in children.

Twenty pediatric patients with giant hydronephrosis were reviewed. This was defined as a kidney that occupied a hemiabdomen, met or crossed the midline, and was at least 5 vertebrae in length. The majority (16) were cases with ureteropelvic junction obstruction. In 2 cases, the primary pathology was obstructive megaureter. In 2 cases, the infants had severe urethral valves with massive upper tract dilatation. In 6 patients with a normal contralateral kidney, nephrectomy was performed. In one patient with bilateral pathology, one nonfunctioning kidney was removed later. A reconstructive operation was undertaken in 14 of the 20 patients. There was one late death from septicemia in an infant male with urethral valves and bilateral dysplastic kidneys.

Child↗

Expanded high iodine dose in computed cranial tomography: a preliminary report.

Fifty patients undergoing cranial CT had expanded-high-iodine-dose (EHID) scans. The EHID was given either as an additional bolus dose (37--40 g iodine) after a routine infusion contrast scan (42.3 g), or as a continuous infusion (total 74--80 g). Diseases presented include primary and metastatic neoplasm, pituitary neoplasm, and demyelinating disease. The results suggest that the primary usefulness of the EHID is in (a) detecting multiple rather than solitary brain lesions, (b) the definitive demonstration of an equivocal area of abnormal enhancement, and (c) differentiating solid histologically microcystic from frankly macrocystic neoplasms.

Adult↗

The nephrogram.

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Acute Kidney Injury↗

Polycystic kidneys without radiologic enlargement.

Polycystic kidneys in adults usually appear in the middle years and are described as large kidneys with most of their parenchyma displaced by a large number of cysts. Often the diagnosis is excluded if the intravenous pyelogram reveals kidneys of normal size. This report describes a patient with normal sized polycystic kidneys discovered at an advanced age.

Aged↗