Richard C. Pfister
Harvard University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Richard C. Pfister.
Urology | 1982
Edward S. Amis; John J. Cronan; Richard C. Pfister; Isabel C. Yoder
Renal ultrasound is an excellent screening examination for suspected urinary tract obstruction. Its usefulness is based on the ability to detect hydronephrosis. However, it must be recognized that a significant number of conditions exist which can mimic or produce dilatation of the collecting system without urinary tract obstruction. Similarly, obstruction without hydronephrosis, although infrequent, exists. Situations causing either false positive or false negative renal sonograms are discussed. Renal sonography suggesting hydronephrosis should be followed with additional diagnostic studies to confirm or exclude obstruction. Similar persistence should be used when obstruction is strongly suggested clinically, and ultrasound fails to demonstrate hydronephrosis.
The New England Journal of Medicine | 1979
Stephen P. Dretler; Richard C. Pfister; Jeffrey H. Newhouse
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.
Journal of Pediatric Surgery | 1979
K.K. Crooks; W. Hardy Hendren; Richard C. Pfister
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.
The Journal of Urology | 1984
Stephen P. Dretler; Richard C. Pfister
Percutaneous nephrostomy and hemiacidrin were used as primary treatment of magnesium ammonium phosphate calculi in 32 surgical candidates. Of 28 patients who actually received hemiacidrin 24 (85 per cent) had successful treatment (no surgery necessary), including 19 (68 per cent) who had total stone dissolution. There were no significant complications. Patients have been followed for 3 months to 7 years. Percutaneous nephrostomy with hemiacidrin infusion is another possible treatment in the growing alternatives available for patients with urinary struvite calculi.
The Journal of Urology | 1984
Stephen P. Dretler; Richard C. Pfister; Jeffrey H. Newhouse; Edwin L. Prien
In 11 kidneys with presumed cystine stones that were symptomatic and obstructing, percutaneous nephrostomy and stone lavage with either acetylcysteine-bicarbonate solution or tromethamine-E were performed. There were 7 complete stone dissolutions: 2 of 6 attempts with acetylcysteine-bicarbonate alone, 3 of 5 with tromethamine-E, 1 partial with acetylcysteine-bicarbonate, which was completed with tromethamine-E, and 1 proved mixed stone (cystine and calcium phosphate) that required acetylcysteine-bicarbonate and hemiacidrin. In 1 case tromethamine-E irrigation was 97 per cent complete but a few tiny caliceal fragments remained. There were 3 failures of chemolysis: 2 pure cystine stones (1 each acetylcysteine-bicarbonate and tromethamine-E) and 1 mixed calculus with a surface shell of calcium oxalate. Irrigation time was 6 to 42 days for the 7 unoperated kidneys. Tromethamine-E appears to be a more effective agent for cystine stone dissolution. Percutaneous nephrostomy and dissolution are an alternative to an operation in patients with cystine calculous disease.
Urologic Radiology | 1985
Nicholas Papanicolaou; Richard C. Pfister; Isabel C. Yoder
High-output ureteral fistulae were managed percutaneously in 3 patients with pelvic malignancies. Urine flow was diverted by combining percutaneous nephrostomy catheter drainage with transrenal balloon occlusion of the affected ureter proximal to the site of extravasation. This technique can be used either alone as the definitive method of treatment or as the initial procedure to preserve renal function and reverse the inflammatory reaction prior to subsequent surgical repair; its primary application is in patients in whom antegrade or retrograde ureteral stenting is not feasible or possible.
Radiology | 1979
James M. Davis; Kenneth R. Davis; Jeffrey H. Newhouse; Richard C. Pfister
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.
Urology | 1976
W. Hardy Hendren; Patricia K. Donahoe; Richard C. Pfister
Nine children were treated with crossed fused renal ectopia, and in 8 there were serious other urinary tract malformations which were surgically correctable. The finding of crossed fused renal ectopia warrants complete urologic investigation including cystogram and cystoscopy to rule out surgically correctable pathology in the urinary tract.
The Journal of Urology | 1977
Michael E. Mitchell; Isabel C. Yoder; Richard C. Pfister; James J. Daly; Alex F. Althausen
Stenosis of the ileal conduit was a late complication in 12 patients (10 adults) who underwent urinary diversion by this means at our hospital. The duration of the ileal loop at diagnosis ranged from 4 to 14 years, averaging 9 years. Loop stenosis was generally without symptoms and was suggested only by routine excretory urography, while loopography confirmed the diagnosis. The etiology of the condition is not clear. A variety of possible factors is considered, including microvascular ischemia, urine-borne toxic material, infectious and allergic stimuli and an immunologic defect. The pathogenesis of the condition appears to be based upon a chronic inflammatory reaction, with progressive fibrosis in the mucosa and submucosa of the ileal segment.
Radiology | 1975
Richard C. Pfister; Alfred Weber; Edward H. Smith; Robert H. Wilkinson; Detliff A. May
Coexistent abdominal disease was found in 9 cases of congenital asymmetry. These patients appear to be at risk of malignant neoplasms of the adrenal gland, kidney, and liver. Five of the 6 neoplasms in this group of patients were malignant. Approximately 25% of the reported cases of hemihypertrophy have been associated with hamartomas or congenital defects, especially genitourinary anomalies. Benign disorders encountered in this group included medullary sponge kidney, renal ectopia, renal cyst, nephromegaly, adrenomegaly, and hypospadius.