Radioisotopic evaluation of renal function in cyclosporine-treated pediatric and adult renal transplant recipients and their living donors. A study of 152 donor-recipient pairs.

Renal function was studied in 2 groups of renal transplant recipients and their donors by technetium-99m diethylenetriamine pentaacetic acid and a gamma camera. The pediatric group (group A) comprised 40 children and their adult kidney donors. The adult group (group B) consisted of 112 consecutive adult renal transplant recipients and their adult donors. All patients received kidneys from living donors and were given the same immunosuppression protocol (PRED plus CSA). Donor glomerular filtration rate (GFR) was determined before nephrectomy and at a mean period of 30 (range 10-50) months after nephrectomy. The graft GFR was measured at 1, 3, 6, and 12 months and at the most recent follow-up visit. Moreover, the functional reserve of the graft was assessed by infusion of dopamine and an amino acid. The postnephrectomy GFR of donors in groups A and B were 74 +/- 18 and 72 +/- 20 ml/min/1.73 m2, respectively. The GFR of pediatric recipients was significantly lower than that of adult recipients at corresponding time points along the course of follow-up. The mean values of graft GFR were 47.6 +/- 20 and 63.8 +/- 29.6 ml/min/1.73 m2 for pediatric and adult recipients, respectively (P < 0.001). Moreover, the graft functional reserve was significantly lower in pediatric recipients. These data demonstrate that adult kidneys transplanted into pediatric recipients have lower GFR than those transplanted into adults, despite corrections for body surface area. Although the reason for this phenomenon is unknown, the observation may have important implications for management of pediatric recipients.

The modified rectal bladder (the augmented and valved rectum) for urine diversion in children.

OBJECTIVES: Urinary diversion is usually the procedure of choice for children having complicated primary closure for bladder exstrophy. We introduce the modified rectal bladder as a low pressure and functionally isolated rectal reservoir as a bladder substitute for these cases. METHODS: Modified rectal bladder urinary diversion was done on 15 children as a low pressure and functionally isolated rectal reservoir via the adoption of sigmoid intussuscepted valve and the rectal patching with detubularized sheet of ileum. Fourteen of these children are currently evaluable, with follow-up ranging from 16 to 72 months (median 55 months). All of them are subjected to thorough history-taking, clinical examination, laboratory and radiologic investigations, and urodynamic study. RESULTS: A high rate of urinary continence was achieved and so far the upper urinary tract and the metabolic status were preserved. Reflux to the colon and kidneys was prevented. Urine samples from the renal pelvis through percutaneous needle aspiration revealed sterile cultures in 82% of the renal units (23 of 28). CONCLUSIONS: Our results demonstrate the distinct advantages of the modified rectal bladder over the conventional methods of urinary diversion to the rectum or the abdominal reservoirs coupled to the skin via continent catheterizable stomas.

Endourologic management of ureteric complications after live-donor kidney transplantation.

Among 620 consecutive live-donor kidney transplants, 40 patients (6.5%) developed ureteric complications in the form of fistula (N = 16) or obstruction (N = 24). Patients with these complications were stratified into two consecutive groups according to the use of graft percutaneous nephrostomy (PCN) in their initial management. Group A was comprised of 17 patients (8 fistulas and 9 obstructions) treated by conventional open surgery without graft PCN. In Group B, 23 patients (8 fistulas and 15 obstructions) were initially treated by graft PCN until resolution of azotemia and control of infection, then treated definitively by endourologic procedures or open surgery. Patients of Group B demonstrated significantly better graft function 2 weeks after treatment, better 1-year graft survival, a shorter hospital stay, and a lower incidence of secondary post-treatment complications. Moreover, in this group of patients, endourologic procedures provided definitive management in 3 of 8 patients with ureteric fistula and in 9 of 15 patients with ureteric obstruction. These data supplement the growing evidence that endourologic techniques are good adjuncts to or substitutes for open surgery in renal allograft recipients with ureteric complications.

Percutaneous treatment of lymphocele in renal transplant recipients.

Of 700 consecutive live-donor kidney transplants, 37 patients (5%) developed a symptomatic lymphocele. Two of ten patients were treated successfully by a single percutaneous needle aspiration. Percutaneous catheters were inserted in 30 patients, either primarily of after failure of other treatments. Of these 30 patients, tetracycline sclerotherapy was used in 21. The overall success rate of percutaneous catheter drainage was 93% (28/30). Surgical marsupialization was successful in 7 of 8 patients (88%). We conclude that percutaneous needle aspiration is ineffective in the treatment of symptomatic lymphocele, while percutaneous catheter drainage with tetracycline sclerotherapy is safe and effective. Should catheter drainage fail, surgical marsupialization will usually be effective.

Ethanol sclerotherapy for symptomatic simple renal cysts.

Twenty-eight patients with 30 symptomatic simple renal cysts were treated by percutaneous aspiration of the cyst and injection of 95% ethanol. All patients were available for follow-up during mean period of 19 (range 14-40) months. In all patients, successful resolution of the cyst with disappearance of the symptoms was observed within 1 month after treatment. During the whole period of follow-up, no patient experienced recurrence of symptoms or required repeat therapy. Of all renal cysts treated, resolution was complete in 25 (83%) and partial (recurrence of < 50% of original cyst volume with no symptoms) in 5 (17%). The degree of response to sclerotherapy (whether complete or partial) correlated significantly with cyst size (P > 0.0008). Major complications were not encountered, while microscopic hematuria was seen in two patients, and low-grade fever was observed in another two. Ethanol sclerotherapy is simple, noninvasive, and highly cost-effective and should be recommended for the treatment of symptomatic simple renal cysts.

Can we increase hepatic oxygen availability? The role of intentional hypercarbia.

Our hypothesis is that hypercarbia produces sympathetic stimulant effect and local vasodilatation. We studied the effect of intentional hypercarbia (IHC) on hepatic venous oxygen saturation. The hepatic vein (HV) was cannulated in 15 patients through either the right internal jugular vein or the femoral vein to measure HV oxygen saturation and calculate oxygen content. The inferior vena cava (IVC) was cannulated in 6 patients above and below drainage of the hepatic veins for oxygen saturation and content difference along the IVC. IHC was achieved in awake patients by breathing oxygen enriched air at a flow rate of 2L/min for 10 min, and during anesthesia by increasing anesthetic dead space and reducing tidal volume. IHC increased HV blood oxygen saturation, decreased the arterio-hepatic vein oxygen content difference and decreased oxygen saturation difference and oxygen content difference along IVC.

Role of diffusion-weighted MRI in diagnosis of acute renal allograft dysfunction: a prospective preliminary study.

OBJECTIVE: The aim was to evaluate the effects of diagnostic performance of diffusion-weighted (DW) MRI in the assessment of acute impairment of transplanted kidneys. METHODS: From January 2009 to January 2010, 49 patients with stable renal allograft function (Group 1) and 21 patients with acute graft impairment (Group 2) were included in the study. All patients were evaluated with coronal T(2) weighted (T(2)W) and DW MRI of the kidney. Patients in Group 2 underwent graft biopsy to determine the underlying histopathological aetiology. Apparent diffusion coefficient (ADC) was calculated and the kidneys were studied for any areas of diffusion restriction. Two radiologists, who were blinded to the results of histopathology, independently interpreted the T(2)W and DW images. RESULTS: The histopathological diagnosis of Group 2 (21 patients) was acute cellular rejection (ACR) in 10, acute tubular necrosis (ATN) in 7 and immunosuppressive toxicity in 4 patients. ADC values in Group 1 were significantly higher compared with Group 2 (p<0.001), patients with ACR (p<0.001), patients with ATN (p<0.001) and patients with drug toxicity (p<0.001). Using 2 × 10(-3) mm(2) s(-1) as a cut-off, there was no overlap between the ADC values of patients with normal graft function and those with ATN. Both ACR and ATN had a low ADC value, but on the ADC map the kidney in cases of ATN appears heterogeneous with a characteristic mosaic pattern resembling the Tiger skin. There was no significant T(2)W morphological difference between the two groups. CONCLUSION: These results show how DW MRI is a promising new technique for the diagnosis of acute renal transplant dysfunction.

MRI in patients with chronic obstructive uropathy and compromised renal function: a sole method for morphological and functional assessment.

The aim of this study was to assess the role of MRI as a single modality for anatomical and functional evaluation of obstructed kidneys in patients with compromised renal function. The study included 96 adults with unilateral or bilateral chronic obstructive hydronephrosis and compromised renal function (serum creatinine >or=1.8 mg dl(-1)). Patients were subjected to gadolinium-enhanced MRI (Gd-MRI), which determined the anatomy of both renoureteral units, as well as their function, through selective calculation of the glomerular filtration rate (GFR) of each kidney. All patients underwent a technetium-99m diethylenetriamine-pentaacetic acid renal scan. Moreover, a correlation was made between the GFR determined by Gd-MRI and the isotope GFR. The study comprised 59 males and 37 females. A comprehensive MRI study detected the cause of obstruction in all kidneys with non-calcular obstruction (sensitivity of 100%) and in 21 kidneys with calcular obstruction (sensitivity of 70%). The overall sensitivity of MRI combined with plain X-ray of the abdomen and ultrasound in the detection of various causes of obstruction was 97%. A comparison between the isotope GFR of the obstructed kidneys and the corresponding magnetic resonance urography (MRU) GFR showed perfect correlation. In conclusion, combined static and dynamic MRU is a promising technique that allows anatomical and functional evaluation of obstructed kidneys in patients with impaired renal function but, owing to the possible risk of nephrogenic systemic fibrosis in patients with a GFR <30 ml min(-1), the lowest possible dose of the most stable Gd-macrocyclic chelates should be used if a functional MRI study is required.

Urethral controlled bladder substitution: a comparison between the intussuscepted nipple valve and the technique of Le Duc as antireflux procedures.

A urethral controlled bladder substitute was constructed from a detubularized, double folded ileal segment in 40 male patients following cystoprostatectomy for bladder cancer. For reflux prevention patients were prospectively randomized to receive either an intussuscepted nipple valve or the ureters were implanted by the Le Duc mucosal trough technique. All patients had normal upper tracts preoperatively. Mean patient age, performance status and stage of cancer were comparable in both groups. Patients were evaluated 6 to 18 months postoperatively. In addition to history taking, assessment included excretory urography, ascending cystography and voiding cystourethrography. During the observation period all patients with nipple valves had normal radiographic appearance of the upper tracts without evidence of reflux. On the other hand, following the Le Duc procedure 12 of 38 renal units (31%) showed evidence of radiographic dilatation. Of the 12 units 11 had stenotic ureters and 1 had reflux. We conclude that nipple valves are more effective in reflux prevention and protection of the upper urinary tract in patients for whom an ileal neobladder is indicated.

The nutcracker syndrome: new methods of diagnosis and treatment.

OBJECTIVE: To study the pathophysiology of the nutcracker syndrome and to describe a new method of treatment. SUBJECTS AND METHODS: Computerized tomography (CT) was used to compare the anatomical relations of the left renal vein with the aorta and the superior mesenteric artery in three patients with the nutcracker syndrome and in a control group of 12 healthy kidney donors. RESULTS: Abnormal branching of the superior mesenteric artery from the aorta was identified as the cause of the nutcracker syndrome. Two patients were treated by autotransplantation of the left kidney, while the third refused surgery. In the treated patients haematuria ceased 4 and 6 weeks after surgery. Postoperative excretory urography and repeated isotopic studies revealed perfect configuration and function of the autotransplanted kidneys. The patients remain asymptomatic 6 and 12 months after surgery. CONCLUSION: In patients with haematuria from the left kidney, angiographic CT must be considered before phlebography and pressure measurement of the left renal vein. If the diagnosis of the nutcracker syndrome is established, autotransplantation of the left kidney is a treatment alternative.

Salvage of difficult transplant urinary fistulae by ileal substitution of the ureter.

We report our experience with 4 cases of ileal substitution of the ureter after live-donor kidney transplantation and review the literature. The indications were recurrent ureteric fistula and obstruction in 3 cases and extensive necrosis of the ureter and renal pelvis in one case. Nephrostomy tube drainage was a useful adjunct to diagnosis and treatment of the 4 cases. No mortalities or graft losses were encountered and satisfactory graft function was maintained 2-14 years after ileal substitution of the ureter. Moreover, no electrolyte or acid-base disturbances were observed. One patient developed recurrent vesical stones 2 and 4 years after ileoureteral replacement secondary to bladder neck obstruction. Ileal substitution of the ureter seems a feasible operation to salvage difficult and recurrent transplant urinary fistulae in exceptional situations when it is impossible to restore urinary continuity using urinary tract tissues.

Bladder stone: a complication of intravesical migration of Lippes loop.

We report on a woman in whom an intrauterine contraceptive device (Lippes loop) migrated from the uterus to the bladder with formation of a calculus. Eight years elapsed between intrauterine insertion of the device and its retrieval with the calculus from the bladder.

Percutaneous nephrolithotripsy for renal stones in over 1000 patients.

Over a period of 5 consecutive years, 1039 renal units were treated by percutaneous nephrolithotripsy for stone disease of the kidney. The success rate was 93.7%. Residual stones remained in 4.2% of patients and in 2.1% we failed to remove the stones. The complication rate was 17.8%. Complications were treated conservatively in most cases but nephrectomy was required on one occasion to control severe bleeding. The average hospital stay was 6.9 days. Follow-up of 339 renal units (333 patients), for a minimum of 60 months, revealed minor late sequelae such as pelviureteric junction obstruction in 1 patient (0.3%) and post-catheterisation strictures of the anterior urethra in 4 (1.2%). Stone recurrence was observed in 9.1% of patients. Percutaneous nephrolithotripsy is an effective, safe treatment for renal stones with minimal late sequelae and is still required even in the era of extracorporeal shock wave lithotripsy.

Renal effect of dopexamine hydrochloride in patients with chronic renal dysfunction.

Dopexamine hydrochloride, a dopamine analogue, has been reported, both experimentally and clinically, to increase renal blood flow (RBF) and improve renal function in normal kidneys. The availability of computer-enhanced radionuclide scintigraphy, which provides accurate non-invasive measurement of changes in RBF, enabled us to study the renographic effects of dopexamine hydrochloride in patients with chronic renal dysfunction (CRD). Ten patients suffering from CRD and ten normal kidney donors were the study population. Renography was performed, heart rate (HR) and blood pressure (BP) measured, and hematological and biochemical tests carried out before and after intravenous infusion of dopexamine 2 micrograms kg-1 min-1 for 60 min. The patient population displayed significant increases in total cortical and medullary RBF and renographic clearance rate (CR), while in kidney donors the RBF was increased in all kidney regions with no change in CR. HR increased in both groups, while BP showed no significant changes. The hematological and biochemical changes were transient and returned to preinfusion levels after 24 h. It is concluded that dopexamine hydrochloride 2 micrograms kg-1 min-1 increases RBF and CR in patients with CRD.

Multiple but different urothelial tumours in one side of a urinary tract.

We present a combination of transitional cell carcinoma and a well differentiated squamous cell carcinoma in the right side of the urinary tract of a bilharzial patient. The right renal pelvis and the right ureter demonstrated transitional cell carcinoma, while the right lateral wall of the bladder showed squamous cell carcinoma.

Urological complications following live donor kidney transplantation: effect of urinary schistosomiasis.

Urological complications were studied in 310 live donor kidney transplants. All recipients and donors were investigated for urinary schistosomiasis by examining tissue obtained intra-operatively from the donor's ureter or the patient's bladder. Schistosomiasis was histologically documented in 76 cases (patient's bladder (46), donor's ureter (9), both (21)). The incidence of urological complications was 11/76 (15%) in the schistosomal group and 14/234 (6%) in the non-schistosomal group; this was statistically significant. Among the schistosomal patients, the site of infestation had no statistically significant effect on the incidence of urological complications. No deaths or graft losses were directly attributable either to these complications or to their surgical correction.

Digital subtraction angiography in potential live-kidney donors: a study of 1000 cases.

Intravenous digital subtraction angiography (IV-DSA) combined with excretory urography (IVU) were utilized to study the renal anatomy of 1000 potential live-kidney donors. In the entire series, 712 donors (71.2%) had bilateral single renal arteries, whereas 255 (25.5%) had unilateral multiple, 26 (2.6%) had bilateral multiple, and 7 (0.7%) had unilateral hypoplastic or absent renal arteries determined by IV-DSA. Major renal abnormalities that might be potentially significant for safe renal donation were detected in 76 donors (7.6%) by combined IV-DSA and IVU studies. In 10% of the potential donors, intraarterial digital subtraction angiography (IA-DSA) was required because of the equivocal results of IV-DSA. Of the 1000 potential donors, 700 underwent nephrectomy and the number of renal arteries at nephrectomy was compared with both IV-DSA and IA-DSA reports. Analysis of data revealed a sensitivity of 96% vs 95%, a specificity of 57% vs 75% and an overall accuracy 93% vs 90% for IV-DSA and IA-DSA, respectively, both IV-DSA and IA-DSA were accurate enough in identification of single renal arteries. However, the accuracy of IA-DSA was better than that of IV-DSA in visualization of double (84% vs 64%) and triple (66% vs 33%) renal arteries. It is concluded that IV-DSA combined with IVU is an effective technique for the evaluation of potential kidney donors. In cases where IV-DSA is equivocal, we recommend confirming IA-DSA.