[Retroperitoneal leiomyosarcoma. A rare differential diagnosis of an adrenal tumor]

A pararenal mass is a clinical finding that cannot be explored preoperatively regarding its parent organ even nowadays. We report in the following about a patient who was admitted with dull pain located in the flank and upper abdomen. Ultrasound investigation at admission showed a solid homogeneous mass close to the upper pole of the left kidney. Urinalysis and catecholamine levels were normal. Intraoperatively, a sarcoma infiltrating the renal capsule and renal vein was observed. In the case of a mass located in the area of the adrenal gland, an extra-adrenal tumor must be considered especially if there are normal findings for urinalysis and catecholamine levels even if modern imaging techniques had been applied.

Pitfalls of repeat subureteral bovine collagen injections for the endoscopic treatment of vesicoureteral reflux

PURPOSE

Collagen has been used for the endoscopic subureteral treatment of vesicoureteral reflux since the late 1980s. We evaluated the long-term efficacy of repeat subureteral glutaraldehyde bovine cross-linked collagen injections for the endoscopic management of vesicoureteral reflux.

MATERIALS AND METHODS

We prospectively evaluated 14 girls and 2 boys (21 ureteral units) 6 months to 16 years old (median age 6 years). In all patients initial treatment failed or reflux recurred after a single subureteral collagen injection and injection was repeated. Patients were followed with voiding cystography. Reflux-free periods after each injection and reflux grade were documented.

RESULTS

All patients were treated twice with subureteral bovine collagen injection. Mean injected collagen volume of injections 1 and 2 was 1. 5 ml. (range 0.7 to 3.0) and 1.6 ml. (range 1.0 to 2.3), respectively, at a concentration of 35 mg./ml. In all but 4 cases reflux disappeared after injection 2. Mean followup was 11 months (range 1 to 41) after treatment 2. However in 10 patients (13 ureteral units) treatment failed or reflux recurred a mean of 10 months after injection 2. The reflux-free period after injection 2 was prolonged compared to that after injection 1 (p <0.05).

CONCLUSIONS

Our results suggest that repeat endoscopic subureteral bovine collagen injections prolong the reflux-free period but remain ineffective at long-term followup for correcting vesicoureteral reflux.

Failure of subureteral bovine collagen injection for the endoscopic treatment of primary vesicoureteral reflux in long-term follow-up

OBJECTIVES

To evaluate the long-term efficacy of subureteral glutaraldehyde cross-linked collagen injection (GAX 35) for endoscopic treatment of primary vesicoureteral reflux (VUR).

METHODS

We prospectively studied 36 patients (58 ureteral renal units), 30 girls and 6 boys with a median age of 6 years (range 2 months to 18 years). All patients had primary VUR and were treated with a single subureteral collagen injection (GAX 35). The patients were followed up by voiding cystography.

RESULTS

According to the International Reflux Study Classification, we found the following reflux grades preoperatively: grade I, 2 ureteral units; grade II, 21 units; grade III, 28 units; grade IV, 4 units, and grade V, 3 units. All patients were treated with subureteral bovine collagen injection (GAX 35, mean volume 1.7 mL, range 0.7 to 3.5). All but 3 cases of reflux resolved initially. The mean follow-up was 13 months (range 1 to 108). After 37 months of follow-up, only 5 (9%) of 57 treated units remained reflux free. One unit was followed up for 17 months and also remained reflux free.

CONCLUSIONS

These data suggest that a single endoscopic subureteral collagen injection is not effective in the long-term follow-up of patients with primary VUR. In the future, it will be important to determine whether the new, currently used, and soon be approved bulking agents show better long-term clinical results to prevent VUR recurrence than bovine collagen does.

Long-term efficacy of subureteral collagen injection for endoscopic treatment of vesicoureteral reflux in neurogenic bladder cases

PURPOSE

We evaluated the long-term efficacy of subureteral glutaraldehyde cross-linked collagen injection (GAX 35) for endoscopic treatment of vesicoureteral reflux in patients with neurogenic bladder dysfunction due to meningomyelocele.

MATERIALS AND METHODS

We prospectively studied 12 women and 8 men (26 ureteral renal units) with a median age of 8 years (range 1 to 51) who had neurogenic bladder due to meningomyelocele. Reflux into single collecting systems was treated with subureteral collagen injection (GAX 35). Followup with video urodynamics included voiding cystography.

RESULTS

All patients performed intermittent catheterization to control the bladder. During the study all bladders were areflexic with normal compliance. Preoperative reflux according to the International Reflux Study Classification was grade I in 1, II in 9, III in 10, IV in 4 and V in 2 ureteral renal units. All patients were treated with subureteral collagen injection (mean volume 1.9 ml., range 0.7 to 3.5). Reflux resolved initially in all but 2 cases. Mean followup was 16 months (range 1 to 71). Reflux was still absent in only 15% of treated units after 24 months.

CONCLUSIONS

Our data suggest that endoscopic subureteral collagen injection in neurogenic bladder cases is not effective with long-term followup. New biocompatible and biodegradable materials should be tested to control vesicoureteral reflux.

Ureteral complications in renal transplantation with more than one donor ureter

BACKGROUND

The purpose of this study was to evaluate the ureteral complications of renal transplant recipients with more than one donor ureter

METHODS

Between 1967 and 1997, 19 patients (median age 34 years, range 6-62 years) received renal transplants from donors with more than one ureter. There were 18 donor organs with two ureters, and one patient underwent en bloc renal transplantation with four donor ureters. In nine patients, the ureters were implanted separately at the bladder dome according to the extravesical technique of Witzel, Sampson, Lich and Röhl. In 10 patients, we performed a modification of this extravesical technique according to Nghiem with a side-to-side anastomosis of the ureters before completing the ureteroneocystostomy.

RESULTS

After a median follow-up of 55 months (range 2-218 months), no graft loss due to ureteral complications was noted. One patient died due to myocardial infarction, seven patients returned to dialysis without ureteral complications. There were two patients (one patient after side-to-side ureteral anastomosis, one patient with separate implantation of the two ureters) with ureteral obstruction of one donor ureter. Both patients underwent open surgical revision with temporarily placement of internal ureteral stents.

CONCLUSIONS

The presence of multiple ureters from donor kidneys is associated with a higher complication rate in our patient population compared with donor kidneys with one ureter. There was no difference in the long-term outcome between the two implantation techniques used.

Progression to end-stage renal disease in children with posterior urethral valves

Diagnostic and therapeutic strategies in boys with congenital posterior urethral valves (PUV) have much improved in past decades, but the impact of these changes on the progression to end-stage renal disease (ESRD) has rarely been investigated. We followed renal function in 20 boys with PUV from diagnosis to ESRD. From the first observation period (1969-1978) to the second period (1979-1992) we found a marked drop in age at diagnosis, at valve resection, at first increase of serum creatinine (SCr), and at onset of ESRD. The progression was analyzed by calculating the slope of 1/SCr and the probability of renal survival. In all patients combined, renal survival at the age of 10 years was 35%. In children undergoing valve resection in the 1st year of life, renal survival was worse than in those undergoing later surgery (15% vs. 65% after 10 years, P=0.006). Patients with a SCr>1.2 mg/dl before the age of 12 months progressed more rapidly to ESRD than those attaining this level later. The lower the minimum level of SCr observed after initial surgery, the older the patient at the onset of ESRD. The presence of renal dysplasia or hypoplasia, but not of vesicoureteric reflux, was associated with a more rapid progression. Mean body height at ESRD was -2.3+/-1.3 standard deviation score compared with controls, and was lower if PUV was diagnosed before the age of 6 months.

[Diagnosis of vesicoureteral reflux with echo-enhanced micturition urosonography]

AIM

To ascertain the diagnostic efficacy of reflux sonography with the application of the echo-enhancing agent Levovist in comparison with X-ray voiding cystourethrography (VCUG).

PATIENTS AND METHODS

Echo-enhanced voiding urosonography (VUS) and VCUG were performed successively in one examination session in 114 children referred for the investigation of possible vesicoureteral reflux (VUR). After sonography of the urinary tract the bladder was filled with normal saline and Levovist was administered. Reflux was diagnosed when hyperechogenic, floating microbubbles appeared in the ureters or renal pelvises.

RESULTS

A total of 226 kidney-ureter units were available for analysis. Reflux was diagnosed in 80 units. All grades of reflux were represented. In 15 kidney-ureter units VUR was diagnosed with echo-enhanced VUS but was not seen at VCUG. The contrary was true in 3 units. High sensitivity and specificity in comparison to the VCUG could be attributed to the echo-enhanced VUS. The long imaging window attainable with Levovist makes the documentation of convincing images possible, contributing to the high diagnostic efficacy.

CONCLUSION

Echo-enhanced VUS is comparable to VCUG in the diagnosis of reflux.

[Spontaneous kidney ruptures--a complication of panarteritis nodosa]

Besides renal cell carcinomas and angiomyolipomas panarteritis nodosa (PAN) is a common underlying disorder for spontaneous perirenal hematomas (SPH). Herein we report on 3 cases with PAN associated kidney ruptures where diagnosis of PAN was not known before in 2 instances. The hematoma was identified by computerized tomography (CT) in all patients, nevertheless CT failed to reveal the underlying disorder in any case. In this situation angiography was extremely valuable visualizing multiple renal microaneurysms that are typical for PAN. Operative exploration and drainage of the hematoma was necessary in two patients because of hemodynamic instability. In one patient bleeding could be controlled after an immediate immunosuppressive therapy with prednisone and cyclophosphamide. Due to the high incidence of PAN associated spontaneous perirenal hematomas angiography should be performed in all cases with unclear SPH after CT evaluation. In our opinion an immediate surgical intervention is only indicated in cases with hemodynamic instability. Otherwise a conservative approach including immediate immunosuppression seems justified. Nephrectomy should be avoided whenever possible.

Transurethral incision of the prostate following renal transplantation

Urinary retention in male patients after renal transplantation may cause serious complications in terms of graft function and even patient survival. Only few data concerning the management and outcome of these patients are reported in the literature. Therefore, we retrospectively analyzed the outcome of patients who underwent transurethral incision of the prostate immediately after renal transplantation. Between 1990 and 1993, we performed 259 renal transplantations and 15 patients had symptoms of urinary retention postoperatively. These patients underwent a midline transurethral incision of the prostate from the bladder neck to the verumontanum. Median peak flow preoperatively was 7 ml. per second (range 0 to 11.4) and median residual urine volume was 100 ml. (range 30 to 500). Median prostate volume was 28 ml. (range 12 to 45). After transurethral incision of the prostate a significant improvement (p < 0.001) in peak flow rates (19.6 ml. per second, range 8 to 49) as well as a significant decrease in residual urine volumes (40 ml., range 20 to 80) could be achieved. After a median followup of 19 months the effect was still present.

Monitoring of renal allograft recipients by quantitation of human cytomegalovirus genomes in peripheral blood leukocytes

The ratio of human cytomegalovirus (HCMV) genomes per cellular genomes in serial peripheral blood leukocyte (PBL) extracts of renal allograft recipients was quantitated by competitive nested polymerase chain reaction (PCR). Patients were also monitored for the development of acute HCMV infection by detection of HCMV pp65 antigenemia, HCMV IgM antibodies, and viruria. Compared to qualitative nested HCMV PCR, the frequency of positive PCR results in renal allograft recipients without further evidence of acute HCMV infection was significantly reduced by quantitative HCMV PCR. HCMV DNA levels > or = 1,000 copies HCMV/10(6) copies beta-globin were found to be highly indicative for the development of a clinically symptomatic HCMV infection following renal allograft transplantation. In patients treated with ganciclovir, quantitation of HCMV target sequences allowed the assessment of the efficacy of antiviral therapy.

[Kidney transplantation in children]

Renal transplantation has become an established form of therapy for children with endstage renal disease. Evaluation and elimination of potential risk factors, standardization of operative technique and better immunosuppressive regimens improved the outcome in paediatric patients. A shortage or organs means that transplantations cannot always be offered to children for whom it would be the treatment of choice. Kidney donation by living relatives opens up the potential for optimal rehabilitation of patients in the paediatric age group.

Quantitative determination of human cytomegalovirus target sequences in peripheral blood leukocytes by nested polymerase chain reaction and temperature gradient gel electrophoresis

A competitive nested PCR-temperature gradient gel electrophoresis protocol (nPCR/TGGE) has been established for the quantification of human cytomegalovirus (HCMV) target sequences. The measurement was achieved by co-amplification of a defined copy number of an internal standard (st) and separation of st and wild-type (wt) amplimers by temperature gradient gel electrophoresis (TGGE). The number of HCMV target sequences could be precisely determined within wt/st ratios of 0.1 to 10. With 50 copies of the st sequence the detection limit of nPCR/TGGE was found to be five to 10 copies of the target sequence. Effects of sample preparation on quantitative HCMV PCR were minimized by the additional quantification of beta-globin target sequences and calculation of the ratio of HCMV copies/beta-globin copies. Serial peripheral blood leukocyte specimens of 17 renal allograft recipients positive in a qualitative nested HCMV PCR were tested using nPCR/TGGE. Thirty healthy blood donors served as negative controls. Positive results were obtained by nPCR/TGGE in nine renal allograft recipients but in none of the healthy blood donors. Five of five patients with an HCMV pp65 antigenaemia and positive for HCMV IgM were positive in nPCR/TGGE. The highest HCMV/beta-globin ratios (10,000 to 8000 copies HCMV/10(6) copies beta-globin) were found in transplant recipients experiencing acute clinically symptomatic HCMV infection. HCMV DNA levels in asymptomatic patients ranged from 900 to 200 copies HCMV/10(6) beta-globin.

[Is organ saving kidney operation in extensive traumatic parenchyma lesions justified?]

The management of renal trauma is facilitated by using modern imaging techniques such as ultrasound and CT-Scan. Regarding the sequelae of conservative treatment we recommend an early operation within three days after the trauma. The complication rate after an organ preserving technique is low, and good functional results reaffirm our concept of early operation. Even in cases of severe parenchymal disruption organ preservation should be achieved. In polytraumatized patients the decision of organ preservation versus nephrectomy should be made depending on the blood loss and the cardiocirculatory stability of the patient.

Changing pattern of chronic renal failure and renal replacement therapy in children and adolescents: a 20-year single centre study

We analysed the demographic data, clinical course and survival on different forms of renal replacement therapy (RRT) of 374 children and adolescents with chronic renal failure observed between 1969 and 1988 and compared the findings for the four subsequent 5-year periods. The proportion of children below 5 years of age rose from 21% to 47%. With time the incidence of glomerulonephritis increased and that of pyelonephritis decreased. As RRT became more common, more very young children and more adolescents were admitted to the study. In the last 5 years continuous ambulatory peritoneal dialysis (CAPD) and haemodialysis (HD) were performed to the same extent as the initial form of RRT. The time a subject had to wait for a first transplant decreased from 36 to 21 months. Between 1969 and 1988 overall survival on any form of RRT increased to 77% after 10 years of therapy. In the last observation period 2-year patient survival was 100% both on HD and CAPD. First cadaver graft survival after 4 years improved from 25% in 1969-1973 to 69% in 1984-1988.

Renal histology in polycystic kidney disease with incipient and advanced renal failure

Renal specimens were obtained at surgery or postmortem from patients with autosomal dominant polycystic kidney disease (ADPKD). Patients had either serum creatinine (SCr) below 350 mumol/liter (N = 12) or terminal renal failure (N = 50). Specimens were examined by two independent observers using a carefully validated score system. Mean glomerular diameters were similar in ADPKD patients with early renal failure (176 +/- 38 microns) and in victims of traffic accidents (177 +/- 23 microns), while they were significantly greater in diabetics with comparable renal function (205 +/- 16 microns). Glomerular diameters in ADPKD patients with terminal renal failure (191 +/- 45 microns) and with early renal failure were not significantly different. On average, 29% of glomeruli (17 to 62) were globally sclerosed in early renal failure, and 49% (19 to 93) in terminal renal failure. The proportion of glomeruli with segmental sclerosis was less than 4% in both groups. Marked vascular sclerosis, interstitial fibrosis, and tubular atrophy were present in early renal failure, and even more so in terminal renal failure. Interstitial infiltrates were scarce and consisted mainly of CD4 positive lymphocytes and CD68 positive macrophages. Immunestaining with monoclonal renin antibodies showed an increased juxtaglomerular index and expression of renin by arterioles adjacent to cysts, as well as by cyst wall epithelia. The data show more severe vascular and interstitial, but not glomerular, changes in ADPKD with advanced as compared to early renal failure.

[Screening study for early detection of intestinal tumors after urinary diversion]

The increased risk of colon carcinoma following urinary diversions via colon makes knowledge about preneoplastic changes necessary. In 30 ureterosigmoidostomy patients with a mean observation period of 16 years flexible sigmoidoscopy with biopsies and nitrosamine analysis of the feces/urine mixture have been performed. In the biopsies we found an increased sialomucin concentration at the ureterocolonic anastomosis in 29.2%--sialomucin is supposed to be a preneoplastic change--with no significant difference to the mucosa periureteral and in the rectum. In 58.3% we found chronic inflammation at the anastomosis, in 29.2% periureteral and 4.2% in the rectum. 2/30 patients developed adenocarcinoma, 1 patient an atypia and 1 patient a juvenile polyp. The nitrosamine excretion of the ureterosigmoidostomy patients were significantly increased compared to 20 healthy controls with no correlation to the histology at the anastomosis or the observation time. Because of the multilocular presence--colon carcinomas develop only at the anastomosis--sialomucin and chronic inflammation seem to be no preneoplastic changes in urinary diversions. The nitrosamine analysis is not suitable for routine follow-up as well.

[Magnetic resonance, a means for anatomically reliable imaging and noninvasive metabolic studies of kidney transplants]

As an adjunct to the monitoring of intracellular high-energy phosphorus metabolites by 31P NMR1 for assessment of renal viability, a study of vasculature of preserved kidneys was performed by Image-Guided Volume Selective 19F MR Spectroscopy. 1H and 19F of the same preserved rat and porcine kidneys were obtained. The technique enabled the analysis of the vessel and tissue properties and opens new possibilities for pretransplant assessment of renal vasculature.

[Preventive use of pedicled omentum majus within the scope of kidney transplantation]

The interposition of the greater omentum was used for treatment of lymphoceles in combination with peritoneal fenestration and for prevention of urinary fistulas in cases of lower pole renal artery lesions and feared ureteral necrosis as well as for protection of pyeloureterostomics and pyelovesicostomics, secondary to ureteral necrosis postrenal transplantation. Especially the combination of peritoneum fenestration with interposition of the greater omentum proved to be the procedure of choice for treatment of posttransplant lymphoceles. The incidence of lymphoceles following renal transplantation is in the range of 5-15%. Even by meticulous surgical technique--ligature of donor and recipient lymph vessels--they cannot be prevented totally since perioperative anticoagulation plays a significant role. Following unsuccessful repeated punctures for decompression, external drainage, local application of tetracycline or fibrinogen glue, internal marsupialisation to the peritoneal cavity is the established ultimate treatment. Inherent risks and difficulties of this procedure can be reduced, if peritoneal fenestration of the lymphoceles is combined with the interposition of the greater omentum. This technique described in details gave totally satisfactory results in 14 cases.

[Risk oriented urologic preparation of children for kidney transplantation]

Among 1050 consecutive renal transplants (Rtx) performed in Heidelberg since 1967 we have gained experience with 163 children and adolescents under the age of 16, receiving a Rtx since 1969. 30% of these were terminally renal insufficient due to congenital obstructive uropathy, mainly infravesical obstruction and/or reflux nephropathy. A special diagnostic work-up (flow chart) for evaluating and eliminating potential pre- and posttransplant risk factors consisted of noninvasive screening methods (ultrasonography and uroflow) followed step by step by more invasive imaging procedures (MR, MCU) and finally invasive methods of evaluating upper urinary tract and voiding disorders (complete urodynamic work-up). We emphasize the preservation or rehabilitation of urinary bladder function, eradication of significant UTI and pre-Rtx surgical treatment of otherwise hard to handle nephrogenic hypertension. Unnecessary psychologically and somatically traumatizing pretransplant diagnostic and therapeutic procedures can be avoided in pediatric non-obstructive nephropathy patients.

Tumor induction in a rat model for ureterosigmoidostomy without evidence of nitrosamine formation

Twenty rats were randomized into a vesicosigmoidostomy and an unoperated control group. In both groups the 24 hour excretion of secondary amines, nitrate, nitrite and nitrosamines was measured before and after gavage of proline and nitrate, piperazine and nitrate, N-nitrosoproline, mono-N-nitrosopiperazine. The urinary nitrosamine concentrations were not significantly different between both groups neither before nor after application of the several substances. Thirty rats were randomized into two vesicosigmoidostomy groups with and without antibiotic coverage and an unoperated control group. After ligation of distal rectum and mesosigmoid the rectosigmoids were removed. No significant concentrations of volatile nitrosamines could be measured in the rectosigmoid contents of the three groups. One hundred and twenty rats randomized into three groups following vesicosigmoidostomy received the potential nitrosamine antidotes sodium-2-mercaptoethane sulfonate or sodiumpentosan-polysulfate or acted as controls. 12/118 (10.2%) developed adenomas and 25/118 (21.2%) adenocarcinomas at the vesico-colonic anastomosis with no significant differences between the three groups concerning tumor incidence or mortality. The results show that colon carcinomas occur in a rat model for ureterosigmoidostomy without evidence for thus induced nitrosamine formation. This and the missing effect of nitrosamine antidotes suggest that other factors than nitrosation must be responsible for colon carcinogenesis following urinary diversion via intestine.

Do antibody-coated bacteria prove bacterial prostatitis?

Using the immunofluorescence technique in 187 patients with bacteriologically proven prostatitis according to the Meares-Stamey test demonstrated a significant amount of antibody-coated bacteria (ACB) in their ejaculates. The ACB test was useful to discriminate between chronic bacterial prostatitis and prostatodynia with a sensitivity of 65% and a specifity of 92%; likewise the ACB test is superior to complement and coeruloplasmin estimation in the ejaculate by radial immunodiffusion usually recommended for the differential diagnosis of inflammatory and psychosomatic diseases of the prostate.

[Intravesical prevention of recurrence of superficial urinary bladder cancer with BCG and KLH. A prospective randomized study]

In a prospective randomized trial intravesical prophylaxis for recurrence of superficial bladder cancer with BCG versus KLH was performed in 42 patients, 38 of whom were then evaluable. After a mean observation period of 20 +/- 7 months (8-32 months) 41.2% (7/17) of the patients in the KLH and 14.3% (3/21) of the patients in the BCG group developed recurrent bladder tumours. The recurrence rate according to EORTC was 1.95 in the KLH group versus 0.76 in the BCG group. Among the BCG treated patients, 60% (15/25) had cystitis and 28% (7/25) fever, whereas only 1 of 19 (5.3%) patients treated with KLH had cystitis. BCG is a highly effective prophylactic against recurrence of superficial bladder cancer. Intravesical instillation therapy with KLH has only a slight prophylactic effect if treatment is started 6 weeks postoperatively.

Effect of vitamin C on endogenous formation of N-nitrosamines in ureterosigmoidostomy patients

The bacterially catalyzed formation of nitrosamines in the rectosigmoid is a favorite theroy for the increased risk of colon carcinomas following ureterosigmoidostomy. The urine/feces mixtures of 20 ureterosigmoidostomy patients were analyzed for nitrate, nitrite, volatile and nonvolatile nitrosamines prior to, and after, oral administration of vitamin C, a known nitrosation inhibitor. Following a 4-week period of daily ingestion of 2 g vitamin C (1 g in children) there was a slight, but not significant, decrease of volatile and nonvolatile nitrosamines and nitrite, as well as a nonsignificant increase in nitrate in the urine/feces of these patients. No correlation between the vitamin C concentration in serum or urine/feces mixture and the nitrosamine excretion was observed. These results suggest that the administration of vitamin C is not a suitable method for prophylaxis of endogenous nitrosation in ureterosigmoidostomy patients. Clinical and experimental findings implicate that factors other than nitrosamines play an important role in colon carcinogenesis of patients with ureterosigmoidostomies or other forms of urinary diversions using the small or large bowel.

Ureterosigmoidostomy: long-term results, risk of carcinoma and etiological factors for carcinogenesis

We followed postoperatively 75 patients who underwent ureterosigmoidostomy between 1942 and 1987. Of the patients 30 were asked to undergo routine examination, including fiberoptic sigmoidoscopy with biopsy and analysis of a urine-feces slurry for nitrate, nitrite and nitrosamines in comparison to 20 control volunteers. After a mean observation of 14 years 7 months (1 to 46 years) 64.5% of the patients had bilaterally normal kidneys without any previous complications, 77.5% of the renal units being normal. Sigmoidoscopic biopsy revealed 3 carcinomas at the ureterocolonic junction resulting in an 8.5 to 10.5-fold increased risk of colon carcinoma compared to the general population. The excretion of nitrite and N-nitrosamines was increased, and nitrate excretion was decreased compared to healthy control volunteers, suggesting endogenous formation of nitrosamines by bacterially reduced nitrate and endogenous amines. The urological long-term results of ureterosigmoidostomy are similar to those of conduits. However, the increased incidence of colon carcinoma is not yet proved to be higher than in conduits.

[Diagnostic tumor resection in kidney tumors of unclear quality]

From 1985 to June 1989 diagnostic tumour resections have been performed on 37 kidney tumours with unknown dignity following the preoperative imaging techniques. The kidney tumours were completely excised with about 1 cm of adjacent parenchyma outside the pseudocapsule during temporary ischemia. The tumours and biopsies from the resection margins were sent to quick frozen section. In case of benign histology or low grade clear cell carcinomas with exophytic growth and a size of less than 5 cm in diameter the operation was finished without removing of the kidney. In 21 patients with benign and 11/16 with malignant disease the kidneys could be preserved. In 5/16 patients the kidneys were removed after tumour resection and result of the quick frozen section. In our opinion the diagnostic kidney tumour resection in cases of kidney tumours with unknown dignity should be preferred to fine needle biopsies combining diagnostic and therapeutic proceeding in selected cases. On the other hand tumour resections without nephrectomy in patients with renal cell carcinoma and normal contralateral kidney should be done only in low grade tumours of small size.

The role of nitrate, nitrite and N-nitrosamines in carcinogenesis of colon tumours following ureterosigmoidostomy

Urinary diversion in both a rat model for ureterosigmoidostomy and in ureterosigmoidostomy patients result in an increased incidence of colon tumours. Bacterial and chemical investigations on feces-urine mixtures from both the rat model and ureterosigmoidostomy patients showed the presence of a complex nitrate-reducing bacterial flora in both rats and humans. This bacterial flora actively reduced urinary nitrate to nitrite in humans and increased the endogenous formation of N-nitroso compounds. No evidence of urinary nitrate reduction and increased nitrosamine formation in the rectosigmoid of rats was found. The results support the N-nitrosamine theory of carcinogenesis of the colon following ureterosigmoidostomy in humans, but not in rats. As the rat model induces colon carcinomas, factors other than the increased endogenous formation of N-nitroso compounds in the rectosigmoid may contribute to the initiation of colon carcinomas following ureterosigmoidostomy.

Low-dose cyclosporin A therapy in cadaver renal transplantation in children

Fifty-one pediatric patients undergoing a first cadaveric kidney transplantation were followed for at least 2 years after grafting. They were divided into two groups: those treated with methylprednisolone plus azathioprine (AZA) and those treated with methylprednisolone plus low-dose cyclosporin A (CyA; median dose 109 mg/m2 per day = 3.4 mg/kg per day after 1 year). The steroid dosage given was significantly lower in the second group. The 4-year graft survival rate was 68% for the AZA group and 78% for the CyA group. Renal function did not differ significantly in the two groups; after 1, 2, and 3 years, the median 24-h creatinine clearance was 79, 69, and 51 ml/min/1.73 m2, respectively, for the AZA group and 78, 63, and 68 ml/min/1.73 m2, respectively, for the CyA group. Linear growth was similar in the two groups. We conclude that in pediatric patients the results of low-dose CyA immunosuppression do not differ significantly from those obtained with AZA in terms of graft survival, renal function, or growth.

[Neurofibromatosis of the bladder in infancy. 10 years' follow-up]

Urinary tract involvement in neurofibromatosis is rare. We found 51 cases documented in the literature, the majority of these (n = 31) were children. More than half of these (n = 18) developed upper urinary tract obstruction. A report is given of a 10-month-old boy with neurofibromatosis of the bladder. Treatment consisted in radical surgery with cystoprostatectomy and uretero-transureterocutaneostomy. Follow-up of 10 years presents a good result. The different modalities of treatment are reviewed in the literature.

Generalized amyloidosis secondary to xanthogranulomatous pyelonephritis

Unilateral nephrectomy in an 8-year-old male with chronic renal failure and urosepsis revealed a combined histologic lesion of xanthogranulomatous pyelonephritis and amyloidosis. Amyloid deposits were found also in the rectum and liver. On clinical grounds xanthogranulomatous pyelonephritis was also suspected in the remaining kidney. Common causes of systemic amyloidosis were excluded. After operation the signs of amyloidosis diminished, probably due to removal of the infected kidney, but renal function deteriorated rapidly.