Biomedical subjects
R C Pfister
Publications and source records attributed to R C Pfister.
Academic uroradiology: the future.
Radiologic education, research, and the practice of radiology will be of the highest quality in the future if academic departments stress organ-system subspecialization while continuing to integrate and interface with technique-based specialists. Planning should begin now to effect an orderly progression to an organ-system-based subspecialty structure for radiology training in general and for uroradiology specifically. Uroradiologists should remain as central consultants to their clinical counterparts, working collaboratively with urologists in clinical endeavors of mutual relevance. More fellowships in uroradiology should be offered that attempt to incorporate all imaging methods and procedures into the curriculum. These issues are addressed in the context of patient care, service, education, and cost containment.
Spontaneous and traumatic rupture of renal cysts: diagnosis and outcome.
Twenty-five patients with spontaneous or traumatic rupture of known renal cysts were encountered over an 18-year period. Blunt abdominal trauma and iatrogenic trauma during retrograde endoscopy accounted for four traumatic ruptures. In 21 patients, spontaneous communication occurred between the cyst and the collecting system or the perinephric space. Hematuria was the most frequent manifestation (21 patients [84%]), followed by flank pain (17 patients [68%]). The diagnosis was made by means of infusion nephrotomography in 22 patients, computed tomography in two, and retrograde pyelography in one. Follow-up information was obtained in 21 patients. The communication of the cyst with the collecting system closed spontaneously in 11 patients and persisted in two. Six patients were operated on because of coexisting stones, persistent hematuria, infection, or the uncertain nature of the cyst, and two underwent cyst evaluation by percutaneous needle aspiration. Renal cyst rupture is an infrequent, usually self-limiting event that may sometimes pose diagnostic dilemmas.
Diagnostic morphologic and urodynamic antegrade pyelography.
Diagnostic antegrade pyelography, with a thin needle, is basically a simple procedure that can be performed relatively rapidly under local anesthesia with few complications of significance. Its role, however, is frequently crucial to subsequent patient management. During morphologic antegrade examination, aspirated urine can be analyzed for tumor cells (cytologic examination), infection (smear, culture), or other biochemical alterations. The use of antegrade pyelography in the demonstration of internal diversion, ureteral fistula, and the site and cause of obstruction is well established. Dynamic antegrade study is crucial in the assessment of many pyeloureteral units in which the issue of current obstruction is equivocal or uncertain. Absolute renal and bladder pressures are obtained simultaneously; these and the calculated differential pressure provide objective data relative to ureteral resistance to urine flow and renal nephron preservation.
Percutaneous occlusion of ureteral leaks and fistulae using nondetachable balloons.
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.
Lower moiety hydronephrosis in duplicated kidneys.
Because of the high incidence of lower pole reflux in complete duplications, decreased, delayed, or absent function in a hydronephrotic lower pole moiety is usually initially attributed to reflux nephropathy. Obstruction occurs commonly in the upper pole moiety due to an ectopic ureteral orifice or ureterocele. However, obstruction is not uncommon in the lower pole segment. Here, the etiologies are more numerous and, on occasion, result in confusing presentations. Eleven cases of obstruction involving the lower pole moiety are discussed. Pathologic entities involved include ureteropelvic junction obstructions in both complete and incomplete duplications, calculi and epithelial tumors obstructing the lower system at various levels, and an ectopic upper pole ureterocele compressing and obstructing the ureteral orifice to the lower pole.
Adrenal pseudotumor: gallbladder simulating a right adrenal mass.
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Percutaneous drainage of postoperative abdominal and pelvic lymphoceles.
Eleven patients with postoperative abdominal and pelvic lymphoceles underwent percutaneous diagnostic and therapeutic intervention with either needle aspiration or catheter drainage. Although initial sonographic or CT examinations accurately identified these collections, definitive diagnosis required fluid sampling and laboratory analysis for confirmation. Seven pelvic and two retroperitoneal lymphoceles demonstrated a gross appearance and composition different from two lymphatic collections in the upper peritoneum. Nine patients underwent catheter drainage; two were managed by needle aspiration alone. Duration of catheter drainage was 4-120 days, substantially longer than is customary for standard fluid collections. Nine of 11 patients were cured by percutaneous aspiration or drainage alone. Bacterial colonization developed in three persistently draining lymphoceles. However, no clinical sepsis or bacteremia occurred. In another patient with persistent high-volume lymphatic output, sclerotherapy with tetracycline instillation was successful in rapidly closing the lymphatic fistula. Percutaneous drainage is a safe, effective procedure for drainage of postoperative lymphoceles.
Percutaneous chemolysis of renal calculi.
Certain types of pyeloureteral calculi can be treated by chemolytic drug irrigation through a percutaneous nephrostomy catheter. Struvite, apatite, and carbonate stones can be dissolved with an acidic solution (hemiacidrin, Suby solution G). An alkaline agent (Tham-E, acetylcysteine) will dissolve cystine calculi. While most uric acid stones are managed by oral alkalinization with sodium bicarbonate or potassium citrate, there are occasions (cardiac, metabolic conditions) where treatment via percutaneous nephrostomy is preferable. Successful nonoperative management of symptomatic calculi has been obtained in 85% of cases with chemolysis of more than 150 stones.
Percutaneous catheter dissolution of cystine calculi.
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.
Primary dissolution therapy of struvite calculi.
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.
Urinary obstruction: pitfalls in the use of delayed contrast material washout for diagnosis.
Delayed washout of contrast material from the renal collecting system has been described as a reliable sign of urinary tract obstruction. However, this finding may appear in the absence of obstruction. Experiments were performed with cylinders containing meglumine iothalamate, which were perfused with water and imaged. The effects of (a) varying flow rate, (b) different volumes of the cylinders, and (c) presence of obstruction on the rate of contrast material washout were observed. In addition, postoperative urography and ureteral perfusion studies in 6 patients who had had ureteropelvic junction obstruction successfully treated by pyeloplasty were reviewed. In the experiments, it was found that changes in flow rate and volume of the reservoir affected contrast material washout; however, the presence of obstruction did not cause a delay in washout. Three of the 6 patients had delayed washout of contrast material on postoperative urographic studies, although ureteral perfusion studies had excluded obstruction. Additional mechanisms that may affect the washout of contrast material are discussed.
Computed tomographic analysis of urinary calculi.
Excised urinary calculi were subjected to computed tomographic (CT) scanning in an attempt to determine whether CT attenuation values would allow accurate analysis of stone composition. The mean, maximum, and modal pixel densities of the calculi were recorded and compared; the resulting values reflected considerable heterogeneity in stone density. Although uric acid and cystine calculi could be identified by their discrete ranges on one or more of these criteria, calcium-containing stones of various compositions, including struvite, could not be distinguished reliably. CT analysis of stone density is not likely to be more accurate than standard radiography in characterizing stone composition in vivo.
Diagnosis and treatment of pyonephrosis.
This article examines current radiologic imaging and interventional techniques used in the diagnosis and initial treatment of pyonephrosis. Included is a review of all pyonephrotic series published in the English literature since 1970. Although the authors found that two thirds of pyonephrotic kidneys are still removed at surgery, there is an increasing emphasis on preservation of renal function. Percutaneous nephrostomy provides an excellent tool for drainage of pus and determination of residual renal function prior to definitive surgery.
Congenital anomalies of the adult bladder and urethra.
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INterventional radiology of the adult bladder and urethra.
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The spectrum of peripelvic cysts.
Nineteen peripelvic cysts with unusual findings are discussed. While usually an incidental radiographic finding, these cysts may obstruct the collecting system and yet not be apparent on nephrotomography. They may also be confused with renal sinus lipomatosis and, ultrasonographically, they may mimic hydronephrosis.
Percutaneous dissolution of renal calculi.
The use of percutaneous nephrostomy catheters has allowed access to intrarenal urinary calculi for dissolution. Renacidin is the successful agent for dissolving struvite stones. THAM-E is the most effective agent for the intrarenal dissolution of cystine stone. Calcium oxalate stones are still resistant to dissolution techniques.