Natural history of neonatal reflux associated with prenatal hydronephrosis: long-term results of a prospective study

PURPOSE: We have previously reported on patients with neonatal vesicoureteral reflux followed conservatively. The current study is a long-term followup of our prospective expectant management protocol for the overall cohort. MATERIALS AND METHODS: Between 1993 and 1998, 31 of 260 patients with prenatal hydronephrosis had vesicoureteral reflux and were followed prospectively. Outcome analysis was done on 25 patients, excluding 6 who underwent surgery, with the end point of complete resolution or improvement of reflux using our previously reported Kaplan-Meier survival curve, urinary tract infection, dysfunctional voiding, and changes in renal function or growth, somatic growth and hypertension. RESULTS: Of the 25 cases reflux was grades I to V in 7%, 20%, 34%, 16% and 23%, respectively. Reflux resolved in 13 patients (52%) and improved in 6 (24%). Grades I to V disease resolved in 100%, 77%, 53%, 28% and 40% of refluxing units, respectively. The improvement rate for grades III to V reflux was 13%, 14% and 30%, respectively. Breakthrough urinary tract infection occurred in 4 patients with grades IV and V reflux, and dysfunctional voiding developed in 5. Followup renal scans showed 19% and 17% decreased differential function in 2 units without new scars. There was no difference in renal length in patients with resolved versus persistent reflux or low versus high grade reflux. All patients had normal somatic growth at the 4-year followup and none had hypertension. CONCLUSIONS: Expectant management was effective in the majority of cases and associated with a low urinary tract infection rate. Neonatal vesicoureteral reflux resolved or improved in 76% of our patients by age 4 years without somatic growth retardation or hypertension. High grade reflux resolved or improved in 59% of the units and showed normal renal growth with expectant management.     

Natural history of bilateral mild isolated antenatal hydronephrosis conservatively managed

Background

The purpose of this study was to assess the prevalence and outcome of newborns with bilateral mild isolated antenatal hydronephrosis managed with neither antibiotic prophylaxis nor voiding cystourethrography (VCUG).

Methods

Inclusion criteria were ultrasonographic evidence of an anterior–posterior pelvic diameter (APPD) of 5–15?mm at the third trimester of gestation and on the first postnatal ultrasound sonogram. Exclusion criteria were an APPD?>15?mm, calyectasis, hydroureteronephrosis, or renal or bladder abnormalities. Ultrasound follow-up was performed. Parents were familiarized with the signs of urinary tract infection (UTI). If UTI was confirmed, VCUG was performed. The outcome was assessed as intrauterine resolution of hydronephrosis, total or partial resolution, stability, or progression.

Results

Hydronephrosis was bilateral in 98 of the 236 newborns (196 hydronephrotic kidneys) with mild isolated antenatal hydronephrosis enrolled in this study. Nine patients had UTI, and none showed reflux. After a mean follow–up of 15?months, 74 kidneys showed intrauterine resolution (38%), 82 (42%) showed total resolution, 13 showed partial resolution, 24 were stable, and 3 showed progression. Bilateral cases represented 42% of mild isolated antenatal hydronephrosis. During the first year of life, 80% of the kidneys showed total hydronephrosis resolution, 9% of patients had UTI, and none of the patients showed reflux.

Conclusions

Antibiotic prophylaxis and VCUG are not mandatory in newborns with bilateral mild isolated antenatal hydronephrosis, but clinical and ultrasound follow-up are recommended during the first year of life.     

Management of fetal hydronephrosis

Prenatally detected hydronephrosis has become a common diagnosis for both pediatric nephrologists and urologists. Hydronephrosis is most commonly assessed by the Society for Fetal Urology grading system or anterior–posterior diameter of the renal pelvis in the transverse plane. Some cases of bilateral obstruction, most commonly from posterior urethral valves, can be life-threatening and require close monitoring or, occasionally, fetal intervention. The majority are unilateral and of no threat to the growing fetus. The crux of postnatal management is the separation of the minority of patients whose renal function is at risk from the majority who will suffer no renal consequences. This management involves a regimen of ultrasounds, voiding cystourethrograms, and nuclear renograms for diagnosis and surveillance. Recent literature has been aimed at the timing and necessity of these studies in order to minimize extraneous studies without compromising renal function.     

胎儿肾积水的超声诊断及转归分析

目的用超声方法检测胎儿肾积水程度与出生后积水肾的转归情况。方法选择2000年9月至2007年6月我院门诊就诊的单胎孕妇，应用超声检查筛选并随访肾积水胎儿163例（221侧）积水胎肾，随访时间最长为2．5年，同期测量15孕周至40孕周正常胎儿肾脏，记录肾脏集合系统内径及肾皮质厚度。结果正常胎儿的肾脏在孕28—32周可以测量到7mm左右集合系统的分离，肾脏皮质厚度均在5mm以上；本组胎肾集合系统前后径分离值10～15mm者：Ⅰ组，165侧，其中皮质厚度在5mm以下者37侧，6侧手术治疗；集合系统前后径〉15mm者：Ⅱ组，56侧，皮质厚度〉5mm的42侧中3侧手术治疗，皮质厚度5mm以下14侧，其中11例手术治疗。结论产前胎儿肾积水大部分都是生理性的，可随着个体的发育而自发消退，对于生后仍存在肾积水的患儿，应定期随访观察；超声检查显示肾集合系统前后径〉15mm，肾皮质厚度〈5mm的胎儿肾积水往往存在病理性梗阻，应高度重视。     

MRI在胎儿肾积水诊断中的应用

目的:探讨磁共振成像(MRI)对胎儿肾积水的诊断价值.方法:回顾性分析60例肾积水随访胎儿的MRI,孕龄21～37周,平均29周,并将MRI、US结果与引产后或出生后随访结果对照.结果:双侧11例、单侧49例;轻度肾积水31例,中度肾积水12例,重度肾积水17例,其中双侧重度肾积水2例引产,余58例均出生,轻度积水的胎儿中有22例产后随访积水消失.结论:MRI是胎儿肾积水较有价值的产前影像诊断方法.能提供超声以外的信息,发挥超声的重补充作用,尤其是超声显示不清时.     

Incidental fetal hydronephrosis: clinical implication

Maternal ultrasonography performed after twenty weeks of gestation is able accurately to identify and diagnose fetal hydronephrosis. We believe this finding should serve to alert the obstetrician as well as the pediatrician to potential complications which may arise at the time of delivery or immediately thereafter. Urologic evaluation and definitive surgical repair may then be performed when indicated.     

Ultrasonographic diagnosis in a case of fetal hydronephrosis

A case of fetal hydronephrosis diagnosed by ultrasonography in the 32nd week of pregnancy is reported. The finding was confirmed by urography performed in the neonatal period. Early neonatal therapeutic intervention has been made possible by the prenatal detection of the abnormality.     

Ultrasonographic diagnosis of fetal hydronephrosis in utero.

Ultrasonography offers a noninvasive method to visualize antenatal or neonatal anatomy which will lead to early detection and treatment of abnormalities. In these 2 cases, ultrasound allowed prompt diagnosis of hydronephrosis despite normal physical examination and laboratory values at birth.     

Diagnosis of fetal hydronephrosis in utero using ultrasound

Detection of fetal hydronephrosis in utero, subsequent investigation, and surgical treatment is described. With the increasing use of ultrasound for obstetrical problems and greater experience with fetal sonography, more urologic abnormalities will be diagnosed prenatally.     

Correction of congenital hydronephrosis in utero. I. The model: fetal urethral obstruction produces hydronephrosis and pulmonary hypoplasia in fetal lambs

In an attempt to simulate congenital hydronephrosis secondary to urethral obstruction, we evaluated the consequences of obstructing the urethra in fetal lambs by several techniques. When the urethra was ligated before 108 days gestation, the bladder decompressed through the urachus and the upper-urinary tract developed normally. Ligation of both the urethra and urachus produced gross bilateral hydronephrosis, hydroureter, and megacystis, as well as severe pulmonary hypoplasia, and was associated with a high perinatal mortality. Intermittent urethral obstruction produced with a balloon constrictor or by diverting urine externally and pressure-limited obstruction produced with a Pudenz valve both proved unsatisfactory for producing congenital hydronephrosis. Finally, ligation of the urachus and progressive gradual obstruction of the urethra with an ameroid constrictor produced hydronephrosis and pulmonary hypoplasia. This model simulates urethral obstruction in the human fetus and produces a clinical and pathologic picture similar to that seen in infants born with congenital hydronephrosis.     

Early experience with open fetal surgery for congenital hydronephrosis

The fetus with severe bilateral hydronephrosis and associated oligohydramnios in the second trimester is doomed at birth by ongoing pulmonary and renal damage. Since decompression with percutaneously placed catheters anesthetic, surgical, and tocolytic techniques for open fetal anesthetic, surgical, and tocolytic techniques for open fetal urinary tract decompression in animals, and have now applied those techniques to a small group of five patients. One had bilateral ureterostomies and the subsequent four had marsupialization of the bladder. All pregnancies proceeded to cesarean delivery at 32 to 35 weeks' gestation. There was no long-term maternal morbidity, and two mothers have since experienced normal pregnancies. Three fetuses had return of normal amniotic fluid dynamics, and all three had adequate pulmonary function at birth, suggesting that fatal pulmonary hypoplasia associated with early severe oligohydramnios had been reversed. Two neonates died at birth with pulmonary hypoplasia. One had no amniotic fluid even after decompression, and the other had some amniotic fluid after decompression but a tiny chest cavity due to the long period of severe oligohydramnios before decompression. Of the three surviving infants, one had normal renal function when she died of unrelated causes at 9 months of age. One has normal renal function at 23 months and the third had failing renal function at 2 1/2 years and has grown and developed normally, but will require renal transplantation. We have now developed selection criteria that would exclude from treatment the two fetuses who died of pulmonary hypoplasia and the one who developed renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognostic factors in fetal hydronephrosis: a multivariate analysis

With the increasing use of obstetric echography fetal hydronephrosis has been reported more frequently. The purpose of this study was to identify prognostic factors associated with adverse outcome, such as renal failure and death, in fetal hydronephrosis. One hundred and forty-eight children with fetal hydronephrosis were admitted, submitted to a systematic protocol, and prospectively followed. Prognostic factors associated with fetal echography and clinical and laboratory findings on admission were studied. The median follow-up was 39 months. The analysis was conducted in two steps. In a univariate analysis, variables associated with adverse outcome were identified by the Kaplan-Meier method. The variables that were significantly associated with adverse outcome were then included in a multivariate analysis. This analysis, using the multivariate Cox’s model, was performed to identify variables that were independently associated with a worse prognosis. Only variables that remained independently associated with adverse outcome were included in the final model. After final adjustment by Cox’s multivariate model, three variables were identified as independent predictors of adverse outcome: oligohydramnios, prematurity, and glomerular filtration rate lower than 20 ml/min. Thus, in the presence of oligohydramnios, prematurity, and abnormal renal function, the medical team must plan appropriate follow-up for infants at health centers prepared to investigate and treat uropathies in newborns. Received: 24 August 1998 / Revised: 7 December 1998 / Accepted: 11 December 1998     

Natural history of adenomas

One-third of individuals over the age of 55 years have single or multiple colorectal adenomas. During a subsequent period of 10 years, 3–5% of adenoma-bearing individuals will probably develop a carcinoma. The rather low conversion rate from benign to malignant disease indicates that most individuals with adenomas will never develop colorectal carcinoma. More knowledge is required to predict the outcome of the individual adenoma in a given patient. This will probably be obtained by increasing progress within gene technology and through large prospective follow-up studies of adenoma-bearing patients.

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Resumen Una tercera parte de los individuos mayores de 55 años poseen adenomas Únicos o mÚltiples de la región colorrectal. En el curso del siguiente decenio, 3–5% de las personas con adenomas tienen la probabilidad de desarrollar un carcinoma. La relativamente baja tasa de conversión del adenoma benigno a neoplasia maligna indica que la mayoría de aquellas que tienen un adenoma jamás habrán de desarrollar carcinoma colorrectal. Se requiere mayores conocimientos para lograr predecir la evolución final del paciente con adenoma. Tales conocimientos probablemente serán obtenidos mediante el progreso en la tecnología genética y a través de amplios estudios prospectivos de seguimiento de los pacientes con adenomas.

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Résumé A partir de 55 ans, on voit se développer chez un tiers de la population un ou plusieurs adénomes colorectaux. Dans les 10 ans à venir, 3 à 5% de ces patients adénomateux deviendront cancereux. Le taux plutôt bas de passage de l'adénome au cancer signifie que la plupart des individus ayant des adénomes n'auront jamais de cancer colorectal. Il faut élargir nos connaissances pour prévoir le devenir de chaque patient adénomateux. On y parviendra probablement grâce au progrès constant dans la technologie des gènes et grâce aux grandes études prospectives de suivi des patients à adénome.