Renal Calculi

Renal Calculi

462 RENAL CALCULI potential (PEP) was abnormal, and eight of these also had abnormal bulbocavernous reflex (BCR). Three patients had abnormal PEP an...

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RENAL CALCULI

potential (PEP) was abnormal, and eight of these also had abnormal bulbocavernous reflex (BCR). Three patients had abnormal PEP and normal BCR, and of these, two had normal and one had abnormal nocturnal erectile activity. The validity of PEP/BCR testing was supported by normal findings in six patients with MS and without erectile problems. Nocturnal erectile activity was normal in 11 patients, of whom nine had abnormal PEP and/or BCR. A high disability score corresponded poorly with both reduced sexual function, insufficient nocturnal erectile activity, and abnormal PEP and/or BCR. Intracavernous injection of papaverine gave erection in 27 patients, the dose needed to create an erection being inversely related to the level of disablement. PEP and BCR testing may be more sensitive in defining neurogenic erectile dysfunction (ED) than nocturnal erectile activity. We considered 26 of the cases to have a neurogenic cause of ED and three to have mainly a psychogenic cause.

Editorial Comment: Of 29 impotent patients with multiple sclerosis 26 had abnormal pudenda! evoked potential and 8 of these also had an abnormal bulbocavernosus reflex. Nocturnal penile tumescence and rigidity were normal in 11 patients, of whom 9 had abnormal pudenda! evoked potentials and/or bulbocavernosus reflex. Intracavernous injection of papaverine produced erection in 27 patients. The authors conclude that 26 of these patients have neurogenic and 3 have psychogenic impotence. This study exposes some of the deficiencies in the diagnosis of impotence. Although sensory neuropathy currently can be detected by evoked potential testing, we still have no direct, reliable way to assess autonomic neuropathy. Of interest is the presence of normal (9 patients) and abnormal (14) nocturnal tumescence and rigidity in the 26 patients with abnormal pudenda! evoked potentials. Is the abnormal nocturnal penile tumescence and rigidity due to autonomic neuropathy? If this can be proved, we may finally have a good test. Tom F. Lue, M.D.

RENAL CALCULI Comparative Evaluation of General, Epidural and Spinal Anaesthesia for Extracorporeal Shockwave Lithotripsy

J. K. RICKFORD, J. A. TYTLER, H. M. SPEEDY St. Thomas's Hospital, London, England

AND

M. LIM,

Ann. Roy. Coll. Surg. Engl., 70: 69-73, 1988 The results of a prospective randomised evaluation of general anaesthesia (GA), epidural anaesthesia (EA) and spinal anaesthesia (SA) for extracorporeal shockwave lithotripsy are presented. GA provided speed and reliability but resulted in a high incidence of postoperative nausea, vomiting and sore throat. Both regional techniques conferred the advantages of an awake, cooperative patient, but EA required a longer preparation time than SA and more supplementary treatment with fentanyl or midazolam. A major drawback associated with the use of SA was a 42% incidence of postspinal headache. All three techniques were associated with hypotension on placement in the hoist; bath immersion resulted in significant rises in blood

pressure in the EA and SA groups and a more variable (overall non-significant) response in the GA group.

Editorial Comment: The authors confirm the suspicion of every urologist that turnaround time is much greater when regional anesthesia is used than with general anesthesia. This is apparent particularly to those who work at teaching hospitals. In the United Kingdom epidural anesthesia required an average preparation time of 43.4 minutes, spinal anesthesia 27.8 minutes and general anesthesia 19. 7 minutes. Preparation time can be minimized greatly by having a second anesthesiologist administer epidural anesthesia, while the first monitors the patients in the tub. The time required for the anesthetic preparation becomes significantly less important with the advent of second generation lithotriptors that do not require anesthesia. Mani Menon, M.D. Percutaneous Renal Biopsy Specimens in Stone Formers

D. J. HARRISON, J. A. INGLIS AND D. A. TOLLEY, Department of Pathology, University of Edinburgh Medical School, and Department of Urology, Royal Infirmary of Edinburgh, Edinburgh, Scotland

J. Clin. Path., 41: 971-974, 1988 A series of renal biopsy specimens taken at the time of percutaneous nephrolithotomy were investigated for the presence and location of foci of microcalcification. Calcium was found in 18 of 25 (72%) of biopsy specimens from stone formers and in only seven of 30 (23%) of control biopsy specimens. This may indicate defective intrarenal handling of calcium as plasma calcium concentration was normal and 40% had a raised 24 hour urinary calcium excretion.

Editorial Comment: Percutaneous renal biopsy was performed in 25 patients undergoing percutaneous nephrolithotomy and the presence of calcium in these biopsy specimens was evaluated with von Kossa's stain, which detects calcium phosphate, and alizarin red, which detects calcium directly. The extent and location of the microscopic deposits were noted and compared to those present in 30 control renal biopsy specimens obtained from patients without stone disease. Small deposits of calcium were identified in 7 4 per cent of the stone patients and 23 per cent of the controls. Most calcium deposits were amorphous bodies in the tubular lumen, cells and occasionally, the interstitium. Electron microscopy showed small dense bodies on the tubular basement membrane and within the mitochondria. However, whether these were calcium deposits was not established. Other than a mild degree of focal chronic interstitial nephritis, the renal biposies appeared to be normal in the patients with renal stones. This report corroborates the earlier study of Boyce and associates who showed that calcium deposits were present in the tubular cells of all 52 patients with calcium oxalate stones who underwent renal biopsy. In that and the present study roughly a quarter of the patients without renal calculi had tubular calcium deposits. These observations raise the intriguing possibility that the renal cell may have a role in the initiation of calcium oxalate stone formation. The problem with this and with similar studies is that it never has been shown that the

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i:ntracelhdar crystals noted in stone patients are composed of calcium oxalate. Cellular injury of any type is associated with in.creased calcium uptake by the cells, usually in the form of calcium phosphate. Thus, the intracellular calcium deposits §een in patients with renal stone§ may be calcium phosphate crystals formed as the result of renal injury and not a specific initiating lesion for calcium oxalate stone formation. Mani Menon, M.D.

does not discriminate between these 2 types of patients, Finally, stone patients may excrete more calcium and less citrate, and, thus, they may have a greater :risk fo1" stone fo:rmatio:n at any given quantity of protein than normal subjects. For these rea§ons I am not wiHing to change my dietary recommendation (decrease ,neat intake and increase fiber intake) to the patient with recurrent calcium oxalate stones, Mani Menon, M.D,

Diet and Renal Stones in 72 Areas in England and Wales

Dietary Factors in the Pathogenesis and Prophylaxis of Calcium N ephrolithiasis

D. J. P. BARKER, J. A. MORRIS AND B. M. MARGETTS, MRC Environmental Epidemiology Unit, Southampton General Hospital, Southampton, England Brit. J. Urol., 62: 315-318, 1988 Geographical differences in emergency admission rates for renal stones and colic in England and Wales have been shown to correlate with the incidence of renal stones determined from case registers. The rates of 72 areas were related to per capita consumption of different foods, measured from household food purchases. There was an inverse relation with consumption of dietary fibre and all cereal foods. Differences in adult diet are not, however, the major determinants of the geographical variations in renal stone incidence within Britain. Editorial Comment: The authors present an epidemiological study of the relationship between diet and stone disease in selected areas in England and Wales. The average per capita consumption of food in these areas was calculated from data provided from the Ministry of Agriculture, which :recorded food purchases during l week in 150 households in each of the geographic areas studied (somewhat like determining television viewing practices using the Nielsen ratings system). Renal stone incident rates were calculated from the emergency hospitalization rates for patients with ureteral colic. The authors showed a negative correlation between stone incidence and fat or meat consumption. In othe:r wo:rds, stone formation was lower in populations that consumed mo:re fat and protein. A weaker negative co:r:relation was found between dietary fiber ingestion and stone formation. There appeared to be no correlation between calcium, oxalate or ascorbic acid ingestion and stone formation, At fi:n,t glance this study, conducted a dh;tinguished epidemiologist, seems to be g:reat news for the stone patient-he need not abstain from eating all of the fat and animal protein he wants. However, I wonder whether such an extrapolation can be made from the results of this study, The dietary intake measured was that of the average subject in the area studied, The food intake of the individual patient with stone disease may be different from that of the average in the area. Also, although there appears to be a broad correlation between over-all stone incident rates and the emergency room visit rates for ureteral colic, the actual numbers may be different enough that the results of the statistical analysis may have been altered if over-all stone incidence rates, rather than emergency room visit rates, were used for the calculations. Dietary excesses may be more important in the patients with recurrent than in those with occasional stones and the design of this study

S.

GOLDFARB, Hospital of the University of Pennsylvania and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania

Kidney Int., 34: 544-555, 1988

No Abstract Editorial Comment: In this review of the putative role of dietary factors in the pathogenesis of calcium oxalate :renal stone disease, the author states th.at for a dietary factor to have a role in stone formation 3 points must be established: 1) intake of the factm· should be increased in stone patients compared to controls, 2) restriction of the factor should decrease Hie rate of stone formation and 3) the mechanisms for the lithogenic activity should be identified. While definitive proof acco:rding to these criteria does not exist, substantial indirect evidence is present that dietary factors have a significant role in :recurrent nephrolithiasis. Dietary protein. Epidemiological studies from a Ii.Umber of cmmtries have shown that the incidence of renal stones is higher in populations in which protein intake is greater. This effect may be partly because protein intake is greater i.n affluent people and stm1e formation for some reason seems to be higher in the economically advantaged, When population§ a.re matched for economic status the intake of protein and other' dieta:ry constituents does not seem to differ in :recu:rrel1l.t stone patients and controls. Even in subjects thus matched, however, stone patients secrete greater quantities of calcium in the urine than C(HJ.trols for a given intake of protein. Thus, stone may be more sensitive to dietary protein increment@ than normal """'J"'''-""'o P1°0tein loading increa§es urinary calcium oxalate and uric acid excretion, and the derived p:r'Oil,attnl,ty of stone formation even in normal subjects. Why does protein in.take lead to hypernalciuria? Thi§ fa at least partly because p:rotehi ingestion i:ncirea§es endogenous acid production and secretion. In expe:rimental animals acidosi§ inhibits calcium reabsorption in the distal nephron and, thus, augments u:rinary calcium excretion, Metabolism of methionine :results in sulfate formation, which may cause the formation of calciumsulfate ion complexes in the tubular lumen, thereby producing hypercalciuria. The acidosis induced by a high protein intake also may decrease citrate excretion. Citrate is a chelator of calcium and induces calcium oxalate complex formation. In addition, citrate directly inhibits calcium oxalate crystal growth, The author cites an unpublished study in which dietary protein restriction increased urinary citrate excretion, the effect being

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more marked in hypercalciuric patients. Protein intake increases and restriction reduces urinary uric acid excretion; hyperuricosuria is a common finding in recurrent stone patients. Dietary sodium. N atriuresis causes hypercalciuria. Sodium and calcium are reabsorbed at common sites along the renal tubule-the proximal nephron, thick ascending limb of the loop of Henle and distal nephron. There is a good correlation between urinary sodium excretion and calcium excretion, and dietary sodium restriction reduces sodium and calcium excretion. While controlled studies have shown that patients with recurrent nephrolithiasis do not ingest greater amounts than controls, these patients excrete more calcium at a given level of sodium intake than controls. Thus, patients with recurrent nephrolithiasis may be more sensitive to a sodium load than normal subjects. Dietary oxalate. Small increments in urinary oxalate excretion increase calcium oxalate crystallization much more than equal increments in calcium excretion. Most of the oxalate in urine comes from amino acid degradation and from the metabolism of ascorbic acid. In normal individuals less than 5 per cent of the ingested oxalate is absorbed through the gastrointestinal tract. Thus, dietary oxalate forms a trivial contribution to urinary oxalate. The situation is different in patients with malabsorption. These patients often absorb greater than 10 per cent of the ingested oxalate and can have marked hyperoxaluria. Two factors are responsible for the increased oxalate absorption: 1) steatorrhoea results in excessive calcium losses in the feces, which lowers intraluminal calcium and leaves oxalate in an absorbable form, and 2) colonic permeability is altered, allowing for increased absorption of oxalate. Thus, dietary restriction of oxalate results in decreased oxalate excretion in these patients. However, such a maneuver has not been uniformly successful in lowering oxalate excretion in patients without malabsorption. Dietary calcium. Increased gastrointestinal calcium absorption occurs in many patients with renal stones. This may be a primary event or a response to excessive renal losses of calcium. In some but not all patients an increase in 1,25-dihydroxyvitamin Dis seen. Only 6 per cent of an oral calcium load is excreted in the urine by normal individuals and, thus, the high urinary calcium levels found in at least some patients with hypercalciuria may be related to increased protein intake. Severe dietary calcium restriction can lead to hyperoxaluria, through the mechanism discussed previously. For these reasons it may be unwise to restrict calcium severely in patients with recurrent renal stones. What is a suggested diet for patients with recurrent renal stones? The author suggests a diet containing not more than 100 mmol./kg. sodium, 1;500 mg. calcium, 1 gm./kg. protein and at least 2,000 mg. fluid per day. I ask patients to measure their 24-hour urine volume once a week for 4 weeks and adjust fluid intake to achieve a urine output of 2,000 ml. per day. This may be surprisingly difficult for patients to do, because the average urine output in stone patients is around 1,000 to 1,200 ml. per day. However, if they are able to do this for about a month the habit becomes automatic. While any form of fluid can be consumed, at least half of the fluid increment must be from water. Pharmacological ther-

apy should be given only to patients who have a new stone or who have documented stone growth while on this treatment; passage of a previously formed stone does not warrant drug treatment. Mani Menon, M.D. Reverse Lithotomy: Modified Prone Position for Simultaneous Nephroscopic and Ureteroscopic Procedures in Women

T.

LEHMAN AND D. H. BAGLEY, Department of Urology, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania

Urology, 32: 529-531, 1988 Occasionally there is need for nephroscopic and ureteroscopic access during the same surgical procedure. Patient positioning is problematic and usually the patient must be turned from supine to prone position or vice versa. Simultaneous access is possible by placing the patient in a prone position with the thighs and knees cradled laterally in a "boot" type stirrup. Thus access is afforded to a percutaneous nephrostomy tract and to the urethra for nephroscopic and ureteroscopic procedures, and at the same time adequate operator comfort is maintained. This approach has been used four times in 3 patients and has been a valuable factor in the endoscopic removal of massive renal and ureteral calculi.

Editorial Comment: The authors describe the use of a modified prone position that allows for simultaneous cystoureteroscopy and percutaneous nephroscopy. They used this technique 4 times in patients who required simultaneous access to both ends of the urinary tract. The patient is placed in the prone position with the thighs and knees in a molded cradle. The legs are abducted at the hips and the foot end of the table is lowered. Prone cystoureteroscopy and percutaneous manipulation of the kidney then can be done as a 1-step maneuver without repositioning the patient. The procedure has particular appeal in patients who are undergoing retrograde percutaneous nephrolithotomy. At my institution access to the kidney usually is obtained with this approach. I have found it cumbersome and frustrating to place the patient in the lithotomy position initially to perform the retrograde puncture, and then to turn the patient over, reposition and redrape to dilate the needle tract and perform the lithotomy. The modified prone position described should make retrograde percutaneous nephrolithotomy easier. Mani Menon, M.D. Comparison of Interpleural and Epidural Anesthesia for Extracorporeal Shock Wave Lithotripsy K. E. 8TR0MSKAG AND P. A. STEEN, Department of Anesthesiology, Ulleval Hosital, Oslo, Norway Anesth. Analg., 67: 1181-1183, 1988 Several types of anesthesia have been used for extracorporeal shock wave lithotripsy (ESWL). General or epidural anesthesia are more frequently used, but recently the combined use of intercostal blocks and local infiltration of the skin has been advocated. A new method for postoperative pain control after cholecystectomy, renal surgery, and breast operations has recently been described, involving the interpleural administration

RENAL CALCULX

of local anesthetics through a catheter. The present study compares the interpleural technique with our standard epidural block technique with regards to pain relief, side effects, and circulatory stability during ESWL. Editorial Comment: The authors describe a :relatively new anesthetic technique, interpleural anesthesia, and compare it to epidural anesthe,;ia in 20 patients undergoing ESWL.* b1trapleu.ral anesthesia was induced by placing an epidural catheter in the pleural space and injecting 400 mg. lidocaine interpleurally. While the exact mechanism by which this method relieves pain is unknown, it is th.ought to be the result of the anesthetic solution diffusing from the pleural space into the intercostal nerves. Thus, the effect is that of multiple i.ntercostal nerve blocks. I was intrigued by this technique because it would be uniquely useful for ESWL, and perhaps also for flank procedures, by following Sutton's law-delivering anesthesia "where the money is". However, I was worried about the possibility of pneumotho:rax. I was wrong on both counts. Interpleural anesthesia did not deliver as satisfactory pain :relief as epidural anesthesia but it also did not cause clinically detectable pneumotho:rax. Mani Menon, M.D, Crystal Adsorption and Growth Slowing by Neph:rocalcin, All:mmin, and Tamm-Horsfall Protein

E. M. WORCESTER, Y. NAKAGAWA, C. L. WABNER, 8. KUMAR AND F. L. COE, Renal Program, Pritzker School of Medicine, University of Chicago, Chicago, Illinois Amer. J. PhysioL, 255: Fll97-Fl205, 1988 Urine inhibition of calcium oxalate monohydrate (COM) crystal growth (CG) seems due to a glycoprotein that contains -y-carboxyglutamic acid and has been named nephrocalcin (NC); however, Tamm-Horsfall protein (THP) and albumin resemble NC and make its measurement and role uncertain. NC in urine is aggregated to molecular mass 64 kDa and higher, similar to albumin (64 kDa) and THP (87 kDa). Albumin and THP are calcium binding, albumin adsorbs to COM crystals, and THP has been described as an inhibitor of COM Antisera to NC have cross-reacted with THP even though the NC was isolated from cultured renal cells. Here we have com-pared highly purified NC, THP, and albumin ,.,,,_,..,,,,..n,nn with COM crystals and CG inhibition; also we compared their patterns of cross-reactivities with a new antiserum against NC and a monoclonal antibody to THP. NC adsorbs to COM crystals, THP does not. Albumin and THP do not inhibit CG. Cross-reactivity of albumin and THP to the antiserum is slight by direct enzyme-linked immunosorbent assay and nonexistent by competitive ELISA; reaction of NC to the anti-THP monoclonal antibody is absent. Editorial Comment: The authors present part of a larger study on the calcium oxalate monohydrate inhibitor nephrocalcin. N ephrocalcin is a naturally occurring glycoprotein that is believed to be the principal peptide inhibitor of calcium oxalate monohydrate crystal growth in urine. However, 2 other urinary proteins, albumin and Tamm-Horsfall protein, are kn.own to bind calcium and Tamm-Horsfall protein has been shown to inhibit crystal growth" Because it has been difficult to *Dornier Medical Systems, Inc., Marietta, Georgia.

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pu.:rify and separate these 3 proteins, it has been difficult to identify which of the 3 is the principal crystal growth inhibitor of mrine. The authors describe techniques to pm·ify nephrocalcin and Tamm-Horsfall protein. An anti1>er11.m was prepared against nephrocalcin and a monoclonal antibody was raised to Tamm-Horsfall protehL With these tools the authors demonstrate that the proteins do not cross-react with each other and, therefore, they are pure. In a seeded crystal growth assay purified nephrocalcin inhibited calcium oxalate monohydrate crystal growth, whereas albumin and TammHo:rsfall protein did not. These observations strengthen the contention that neph:rocalcin is the xn·incipal urinary peptide inhibitor of calcium oxalate monohydrate crystal growth. Mani Menon, M.D. Acute Pyelonephritis Associated With Bacteriuria Dtuing Long-Term Catheterization: A Prospective Clinicopathological Study J. W. WARREN, H. L. MUNCIE, JR. AND M. HALL-CRAGGS, Departments of Medicine (Division of Infectious Diseases), Family Medicine and Pathology, University of Maryland School of Medicine, Baltimore, Maryland J. Infect, Dis., 158: 1341-1346, 1988 Bacteriuria is virtually universal in long-term catheterized patients. This blinded autopsy study of 75 aged nursing home patients demonstrated that acute inflammation of the renal parenchyma was present in 38% of patients with a urinary catheter in place at death versus 5 % of noncatheterized patients (P = .004). Of a number of clinical and demographic variables studied, catheterization was significantly related to acute renal inflammation. Acute cystitis was uncommon, but each case was associated with inflammation of at least one kidney. The majority of kidneys showing acute inflammation (21 [68%] of 31) were not accompanied by acute pyelitis. Acute renal inflammation with or without pelvic inflammation is a common finding in nursing home patients dying with urethral catheters in place. This finding provides additional support for the development of alternatives to the indwelling urethral catheter. Editm·l.al Comment: To estahli§h the relationship between indwelling nri:rmry cathete:rs and n,nal inflammation in the elderly, the authors examined the urinary tracts of 75 consecutively autopsied subject§ from a large Baltimore nursing home . .AH patients •,vere mo:re th.an 65 years old and 55 had indwelling u1tina1·y catheters. Demographic and clinical information was obtained from the patients and their families with particular emphasis being placed on urinary tract infection and. obstruction, Autopsies we:re peE"fo:rmed by a pathologist who was not aware of the clinical history or catheter use. Of the patients who died with indwelling catheters 38 per cent had acute renal inflammation, compared to only 5 per cent of those who did not have a catheter, a statistically significant difference. Roughly a third of the patients with renal inflammation had acute pyelitis, diagnosed by the presence of polymorphonuclear leukocytes in the mucosa or su.bmucosa of the :renal pelvis. All patients with acute pyelitis were febrile at death. There was no conelation between the duration of cath-

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eterization and prevalence of renal inflammation. Of all the clinical and demographic variables examined, catheterization was the only one that was associated statistically with the presence of acute renal inflammation. However, I am not sure that they used the best statistical methods for the analysis. There were 1.5 million nursing home patients in the United States in 1988. If 9 per cent of these patients had indwelling catheters (data from demographic studies in Maryland nursing homes) and 38 per cent of these patients had renal inflammation, one can calculate that the prevalence of catheter-associated re:nal inflammation in the nursing home population is 51,300. This study shows clearly that indwelling urinary catheters can cause considerable morbidity in the elderly and that every attempt should be made to avoid indwelling catheters, even in the elderly, debilitated nursing home population in whom leaving an indwelling catheter may seem to make sense. Mani Menon, M.D. Renal Calculi After Shock Wave Lithotripsy: US Evaluation With an In Vitro Phantom P. L. CHOYKE, J. H. PAHIRA, W. J. DAVROS, E. NILGES, A. J. DWYER AND S. K. MUN, Departments of Radiology and Urology, Georgetown University Medical Center, Washington, D. C. and Diagnostic Radiology Department, The Clinical Center, National Institutes of Health, Bethesda, Maryland Radiology, 170: 39-44, 1989 Fragments of renal calculi from patients who had undergone extracorporeal shock wave lithotripsy (ESWL) were embedded in an in vitro tissue-equivalent ultrasound (US) phantom to assess (a) the accuracy with which such fragments could be measured; (b) the influence of stone composition, stone depth, and transducer frequency; and (c) the effect of fragment "clumping" on size determinations and acoustic shadowing. Fragments as small as 0.8 mm in diameter could be detected at 7.5 MHz, although a practical limitation of 1-2 mm for lower transducer frequencies (3.5 and 5.0 MHz) was observed. Fragment diameter tended to be overestimated with US by a mean of 1 mm. Transducers of 5 and 7.5 MHz were more accurate in determination of size than 3.5-MHz transducers. Struvite fragments were less echogenic and were therefore measured more accurately, but smaller struvite fragments were less detectable than other fragment types. Fragment "clumping" led to significant overestimation of residual stone size even when small fragments were separated by as much as the distance equal to the diameter of one fragment. This study demonstrates that even under the best circumstances the disadvantage of US in assessing residual stone disease are significant.

Editorial Comment: The limits of ultrasonography in the detection of stone fragments after ESWL were studied by embedding fragments of renal calculi in an in vitro tissue phantom and examining them with ultrasound transducers of 3.5, 5.0 and 7.5 MHz. frequency. All fragments greater than 2 mm. were detected. The smallest fragment that was detected was 0.8 mm. and it was visualized with the 7 MHz. transducer. The minimal detectable size of fragments was 1.0 to 2.0 mm. with the 5.0 and 3.5 MHz. transducers. In a clinical study the average distance from the skin to the renal hilus was

6.4 to 7.7 cm. At this distance only the 3.5 MHz. transducer permitted reliable stone visualization. The minimal detectable sizes of stones at this depth were 1.5 mm. for calcium oxalate, 1.5 mm. for urate, 2.0 mm. for struvite and 1.0 mm. for cystine. Fragment diameter was overestimated by ultrasound by an average of 1 mm. Calcium oxalate fragments had more distinct acoustic shadows than the other types of stone: struvite stones showed the poorest shadowing. Stone fragments packed side by side at 1 mm. distances give the ultrasonic appearance of an unfragmented calculus. These measurements represent the best possible results achievable because they were made in an in vitro phantom and with state of the art ultrasound technology. The result can be expected to be considerably poorer in vivo because of artifacts, motion and echogenic renal sinus fat. This has to be an important consideration when performing ultrasound-guided ESWL or piezoelectric lithotripsy. I have found it difficult, personally, to be totally convinced about the adequacy of gallstone fragmentation when using ultrasound detection, whereas my radiology colleagues appear to have no such problems. I had attributed this to my inexperience and lack of visual discrimination but now realize that fragmentation, like beauty, is in the eyes of the beholder. Mani Menon, M.D. Anastomosed Ureters: Fluoroscopically Guided Transconduit Retrograde Catheterization M. P. BANNER, M.A. AMENDOLA AND H. M. POLLACK, Department of Radiology, University of Pennsylvania School of Medicine and Hospital, Philadelphia, Pennsylvania Radiology, 170: 45-49, 1989 Fluoroscopically guided, transconduit retrograde catheterization of ureters that have been diverted to a bowel conduit is often feasible in patients with patent ureteroenteral anastomoses who might otherwise require a percutaneous nephrostomy (PCN) for reasons other than high-grade anastomotic obstruction. This procedure was attempted on 14 occasions and successfully accomplished on 12. In 11 of these cases, retrograde catheterization obviated PCN to provide renal drainage for a partially obstructing ureteral stricture or obstructing renal calculi, to remove ureteral calculi, or to insert a new ureteral stent after an unsuccessful attempt to exchange an existing occluded retrograde ureteral stent. The procedure also obviated Whitaker testing. On one occasion the retrograde procedure greatly facilitated subsequent PCN in an obese pateint with faintly opaque calyceal calculi. These procedures were accomplished with standard angiographic equipment and, in many instances, Teflon sheaths in the bowel conduit to stabilize catheters and guide wires. No complications were encountered. The two patients whose ureters could not be catheterized in retrograde fashion subsequently required PCN.

Editorial Comment: The authors describe their experience with fluoroscopically guided retrograde catheterization of ureterointestinal anastomoses. The procedure was done on 14 occasions and was successful in all. In no case was endoscopy used. The most common indication was drainage of a partially obstructed kidney, avoiding percutaneous nephrostomy. AU patients had refluxing ureterointestinal anastomoses that could be

RENAL TUMORS, RETROPERITONKOM, URETER, AND URINARY DIVERSION AND RECONSTRUCTION

visualized fluoroscopically: the procedure cannot be used in patients with nonirefluxing ureters. The authrnrs give several important pointers that will make retrograde catheterization easier. I can only marvel at the technical skills of the authors but wonder why endoscopy of the conduit was not used in these patients. I believe that retrograde catheterization should be attempted initially under endoscopic guidance. The message that I obtain from this study is that catheterization of ureterointestinal anastomoses is possible even when the anastomoses are not visualized endoscopically (provided one has the talents and experience of th.is group of radiologists). Mani Menon, M.D.

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nation of .radiation. On the other band, in an incompletely resected Wilms tumo:r with anaplastic histological findings additional aggressive chemotherapy might be considered, inchu:l.ing the use of ifosfamide and cisplatinum-etoposide combinations. Fray F. Marshall, M.D.

Tumor Grade and Stage as Prognostic Variables in Upper Tract Urothelial Tumors RP, HUBEN, A, M, MOUNZERAND G, P, MVRPHY,Department

of Urologic Oncology, Roswell Park Memorial Institute and Department of Urology, State University of New York, Buffalo, New York Cancer, 62: 2016-2020, 1988

RENAL TUMORS, RETROPERITONEUM, URETER, AND URINARY DIVERSION AND RECONSTRUCTION Reduced Therapy for Wilms' Tumor: Analysis of Treatment Results From a Single Institution J, A, WILIMAS, K C, DOUGLASS, 8, LEWIS, D, FAIRCLOUGH, G, FULLEN, D, PARHAM, A, P, M, KUMAR, ff 0, HUSTU

L FLEMING, Departments of Hematology-Oncology, Pathology and Laboratory Medicine, Radiation Oncology and Surgery, and the Biostatistics Section, St. Jude Children's Research Hospital; and Division of Hematology-Oncology, Department of Pediatrics, College of Medicine, The University of Tennessee, Memphis, Tennessee AND

J, Clin, OncoL, 6: 1630-1635, 1988

From 1968 to 1986, 192 patients from O to 17 years of age were enrolled in three consecutive protocol-controlled studies of Wilms' tumor at St Jude Children's Research HospitaL Tumors were completely excised at the time of diagnosis whenever possible, and patients were subsequently treated with chemotherapy and radiotherapy according to the initial extent of disease. All patients received dactinomycin and vincristine, with doxorubicin added to the regimens in studies 2 and 3, Chemotherapy was extended to 18 months in 2 (n = 53), but was limited to 12 months for most patients in study 3 (n = 107), In the third radiation was eliminated altogether for patients with stage I or II tumors and was reduced to 12 for those with more advanced disease. Intensification of chemo-therapy in study 2 improved the 5-year relapse-free survival rate over that in study 1 (82% v 52%), but the accompanying increase in toxicity was considered unacceptable, Comparison of 2-year relapse-free survival rates in studies 2 and 3 indicated that the reduction of therapy in the latter trial did not jeopardize disease control: 88% v 86% for patients with stage II or III disease, favorable histology; 75% v 57% for the same stages, unfavorable histology; and 57% v 61 % for stage IV patients, At least 80% of all patients enrolled in study 3 will be long-term survivors, We conclude that rescheduling of effective antitumor drugs and eliminating or reducing radiotherapy are feasible alternatives in the treatment of Wilms' tumor with favorable histologic features, Editorial Comment: As studied in the recent past, patients with lower stage Wilms tumor, particularly those with favorable histological findings, may do just as well with less therapy, particularly with reduction or elimi-

Clinical and pathologic data of 54 patients with clinically localized transitional cell tumors of the upper urinary tract were reviewed to determine the significance of tumor grade and stage on patient survivaL There were 43 tumors of the renal pelvis (one bilateral) and 11 tumors of the ureter. The primary tumor was staged by the new TNM classification into low stage (Ta: limited to mucosa; T,: lamina propria invasion) and high stage (T 2: muscularis invasion: T 3 ; invasion beyond the muscularis), Tumors were low stage (Ta/T 1 ) in 28 cases (5L8%) and advanced (T2/Ts) in 26 cases (48,2%), Twenty-five of 54 (46,3%) of the patients had low grade (Grades 1 and 2) and 29 of 54 (53,7%) had high grade (Grades 3 and 4) tumors, Median survival for all patients from date of diagnosis was 31 months, with a 5-year survival rate of 45,8%, Grade (low/high) matched stage (low/high) in 45 of 54 patients (83%), Median survival for patients with low grade tumors was 66,8 months compared to 14,l months in patients with high grade tumors, Median survival for low stage tumors was 9Ll months and for high stage tumors was 12,9 months, These differences in survival related to both tumor stage (P = 0,001) and grade (P = 0,004) were statistically significant by log-rank test, Fourteen of the 54 patients (25,9%) developed local recurrence and 29 (53,7%) developed distant metastases, The lung was the most common site of metastasis, Eighteen patients (33,3%) had or developed transitional cell carcinoma of the bladder, which preceded the diagnosis of transitional cell carcinoma of the upper tract in seven cases and developed subsequently in 11 cases, Primary tumor stage the new TNM classification is a better predictor of prognosis than tumor grade, although both variables are strongly predictive of patient course and survivaL The advantages of the new TNM classification are discussed. Editorial Comment: The authors do nl[)t describe any major new findings but they do summarize the International Union Against Cancer classification of upper tract urothelial tumors. As indicated, the primary tumor stage by new tumor, nodes and metastasis classification was a better predictor than tumor grade although both variables were strongly predictive. Chemotherapy may change the dismal prognosis of the patient with a metastatic upper tract transitional cell carcinoma. We have had favorable responses of metastatic upper tract urothelial tumors to the standard methotrexate, vinblastine, doxorubicin and cisplatin regimen. Several patients have had marked resolution of back pain as well as objective resolution of masses. Fray F. Marshall, M.D.