Shozo Hosokawa

Clinical characteristics of primary vesicoureteral reflux in infants: multicenter retrospective study in Japan.

PURPOSE We evaluate clinical characteristics of primary vesicoureteral reflux in infants in a multicenter study in Japan with special reference to the relation of renal parenchymal damage to urinary tract infection and gender. MATERIALS AND METHODS Infants younger than 1 year old with primary vesicoureteral reflux were recruited from 14 hospitals during the 3-year registration period beginning in January 1996 and ending in December 1998. Various clinical parameters as well as renal parenchymal lesion on dimercaptosuccinic acid scintigraphy were evaluated. RESULTS Of 356 infants enrolled 296 (83%) were male and 60 (17%) were female. In 85% of infants presenting symptom was febrile urinary tract infection. There were 204 bilateral (57%) and 152 unilateral (43%) cases. Reflux was bilateral in 56% of males versus 65% of females, and high grade (grades IV and V) in 58% of males versus 55% of females. Diffuse parenchymal lesion was similarly noted in infants with or without prior urinary tract infection (38% and 46%, respectively) and was more often noted in male than in female infants (42% versus 25%). CONCLUSIONS Despite the current use of screening prenatal ultrasound, many infants are still diagnosed as having vesicoureteral reflux only after the occurrence of urinary tract infection. The greater severity of renal parenchymal lesion in male infants combined with similar incidence of diffuse parenchymal lesion in those with or without prior infection suggests preexisting congenital abnormalities in the male refluxing kidney.

FOLLOW-UP OF CHILDREN AFTER FETAL TREATMENT FOR OBSTRUCTIVE UROPATHY

Background: Improvement in the ability to evaluate fetuses with obstructive uropathy, combined with technologic advances, has allowed successful fetal treatment of these conditions in Japan. We analyzed the prenatal and postnatal clinical courses of patients who underwent shunt placement in utero.

Ultrasonographically demonstrated nutcracker phenomenon: alternative to angiography.

We report on a child with nutcracker phenomenon, which is a possible cause of intermittent gross haematuria of unknown origin. Early serial ultrasound examinations can demonstraste the lesions.The merits and demerits of conventional angiographic imaging are also discussed.

Standard method for diagnosing dilatation of the renal pelvis and ureter discovered in the fetus, neonate or infant

With the increased use of ultrasonography in prenatal diagnosis in the field of obstetrics, and with more neonates and young children receiving abdominal ultrasonographic examinations, the discovery of various congenital anomalies has also increased. Many congenital anomalies of the kidneys and urinary tract are easily discovered by ultrasonographic examination because fluid is retained in the dilated urinary tract. These account for about 50% of the congenital anomalies discovered in this period. The number of reports of the dilatation of the renal pelvis and ureter (hydronephrosis and hydronephroureterosis, respectively, referred together as HN hereafter) in particular are increasing, and there is growing concern regarding their management. Ultrasonography and diuretic renography are the most commonly used procedures for the diagnosis of dilatation of the upper urinary tract, but methods of diagnosis and evaluation have not been standardized. The Japanese Society of Pediatric Urology (JSPU), which handles the management of HN, has realized that it is necessary to standardize the methods of description in ultrasonography and the methodology of performing diuretic renography so that the natural course, therapeutic strategy and therapeutic results can be discussed on common terms. In response, JSPU, mainly its Academic Committee, have prepared the following protocol. Since HN is a continuous entity from fetal to neonatal and infant stages, it is important to call upon not only JSPU but also the related societies to join in sharing this standardized methodology. The protocol proposed by JSPU aims to provide a standard method to: (i) describe and evaluate HN; (ii) be used widely in institutions with pediatric urology cases; (iii) eliminate as much of the variability among institutions or doctors performing the examination as is possible; and (iv) to be used universally. It is not for recommending the therapeutic regimen or method to be selected. In regard to the terminology used to describe the various degrees of dilatation of the renal pelvis and ureter, the terms hydronephrosis and hydronephroureterosis refer to these entities, generalizing their morphological characteristics and are sometimes used synonymously. In some opinions, they are used only if the dilatation of the urinary tract is judged to be pathological; and shows variability with the discipline. As a result of this situation, in the guidelines we present, we use the term dilatation of the renal pelvis and ureter.

Urinary Concentrations of Alpha-1-Microglobulin and Albumin in Patients with Reflux Nephropathy before and after Puberty

We determined urinary concentrations of α1-microglobulin and albumin in 155 patients with reflux nephropathy including 72 prepubertal (48 males and 24 females) and 83 postpubertal patients (43 males and 40 females) to elucidate the effect of age and gender in the progression of renal damage. Vesicoureteral reflux was resolved in all patients at least two years before enrollment into this study. Renal scarring was diagnosed with 99mtechnetium dimercaptosuccinic acid renal scan. More severe renal scarring was found predominantly in male compared to female patients. Urinary α1-microglobulin levels were significantly lower in postpubertal female patients (mean ± SD: 1.59 ± 1.02 mg/g creatinine) than in prepubertal males and females (3.32 ± 3.53 and 4.06 ± 4, respectively; p < 0.007 and p < 0.002, respectively), and in postpubertal males (3.69 ± 2.6; p < 0.002) regardless of severity of renal scarring. In the patients with severe unilateral renal scarring, urinary albumin levels were significantly higher in postpubertal males (81.9 ± 239.5) than in prepubertal males and postpubertal females (25.8 ± 63.1 and 13.8 ± 7.7, respectively; p < 0.05 and p < 0.05, respectively). Our results suggest that glomerular injury may develop during adolescence predominantly in male patients with severe renal scarring. In contrast, renal damage indicated by urinary α1-microglobulon level appears to be ameliorated in female postpubertal patients. This gender difference may be attributed to sex hormones.

Vesicoureteral reflux in infants under one year old Follow-up study and consideration on development of renal scarring

In an attempt to clarify reflux nephropathy (RN), 67 infants aged under one year with vesicoureteral reflux (VUR) were retrospectively classified into two groups, non-surgical and surgical. They were evaluated on VUR grading, VUR spontaneous cessation rate, and incidence of scarring. As a whole, spontaneous cessation rate was 61 percent. The cessation rate was higher for infants with lower VUR grading. The average age at cessation was 2.5 years. Some patients showed no scarring at presentation despite severe VUR. However, most cases of renal scarrings at the time of presentation belonged to grade IV or V. Scarring advanced in 3 kidneys of the non-surgical group and in 13 kidneys of the surgical group. Of these 16 kidneys, 7 were rated as grade IV and 9 as grade V. An association between development of scarring and recurrent urinary tract infections was suggested.