小儿先天性发育不良肾的临床特点和治疗

目的 探讨小儿先天性发育不良肾的临床特点、诊断和治疗.方法 总结分析1988年至2009年我科收治的83例单侧先天发育不良肾的临床资料.所有患儿术前均行多普勒超声、静脉肾盂照影和99mTc-DTPA肾脏扫描.35例患儿行增强CT检查,39例行IVP后延迟CT检查三维重建.所有病例均行发育不良肾切除,肾切除的指征包括无功能发育不良肾脏合并临床症状55例,无临床症状的无功能多囊发育不良肾,随访不消退或增大27例,无功能发育不良肾合并肾输尿管积水1例.结果 各项术前检查中IVP后延迟CT三维重建技术阳性诊断率最高,达100%.术后病理均提示为发育不良肾脏.4例因高血压行发育不良肾切除的患儿,术后2例仍然有高血压,其他患儿术后临床症状消失,没有恶变者.结论 儿童先天发育不良肾脏发育不良程度不一,合并畸形不同,临床表现各异.IVP后延迟CT检查三维重建技术诊断发育不良肾脏阳性率高.合并临床症状的无功能发育不良肾、多囊发育不良肾长期随访不消退者可手术治疗,随访过程中有明显消退的多囊发育不良可定期观察,有功能的非多囊发育不良肾可以保留.近19%发育不良肾脏可合并对侧肾脏畸形,应密切监测对侧肾脏功能及血压.     

先天性单侧肾发育不良的诊治体会(附23例报告)

目的总结先天性单侧肾发育不良的诊治经验。方法回顾性分析23例先天性单侧肾发育不良的临床资料。其中女20例,男3例。年龄2～14岁。合并肾位置异常2例,输尿管异位开口15例,双侧输尿管囊肿1例,输尿管积水3例,膀胱输尿管返流(VUR)1例。对侧重复肾并输尿管异位开口2例,膀胱输尿管返流1例。B超检查21例,IVP检查22例,输尿管逆行造影4例,膀胱镜检查10例,CT检查13例,VCU检查2例。均行手术治疗,其中肾切除19例;输尿管囊肿电切开窗1例;对侧重复肾切除2例;膀胱输尿管再吻合1例。结果全部病例随访6个月～3年,漏尿、发热及尿路感染等症状消失。结论临床症状结合影像学检查是诊断先天性单侧肾发育不良的有效方法,单侧肾发育不良常合并输尿管末端及对侧肾脏病变。治疗上主要是切除发育不良的肾。     

儿童肾发育不良的诊治分析

目的总结儿童肾发育不良的临床特点，探讨合理的诊治方法。方法回顾性分析我院1997年6月2006年6月间66例肾发育不良患儿的临床表现、影像学检查、治疗方法及预后情况。结果就诊年龄1个月～15．8岁，平均4．8岁，男20例，女46例，左侧38例，右侧28例，临床表现主要为正常分次排尿同时有排尿间滴尿，B超检查可以确定发育不良肾的位置、大小、形态，以及合并的其他畸形，静脉肾盂造影（IVP）检查多表现为患侧肾不显影、患肾无功能，65例患儿接受了发育不良肾及输尿管切除术，1例患儿因患侧肾与对侧正常肾融合而接受了患侧输尿管切除术，其中经腹腔镜切除32例，术中见发育不良的肾脏的大小、形态和位置异常，术后绝大部分预后良好。结论超声结合静脉尿路造影是诊断肾发育不良的有效影像学检查方法。对于有临床表现及体征的肾发育不良的患儿，肾和输尿管切除术是有效的治疗方法。腹腔镜微创手术在肾发育不良的治疗中具有一定优势。     

14例先天性单侧肾发育不良的临床研究

目的　发育不良肾可位于肾窝或盆腔内 ,可无症状 ,如伴有输尿管异位开口可致尿失禁。该文主要探讨先天性单侧肾发育不良的临床特点、诊疗方法以及病理分型。方法　回顾总结 14例单侧肾发育不良患儿的临床资料。其中女 10例 ,男 4例。左侧 11例 ,右侧 3例。主要临床表现为滴尿、反复尿路感染以及腹部包块等。术前均行静脉尿路造影 (IVU)、B超检查 ,7例行CT检查。术前确诊 9例。结果　 14例均采用手术治疗 ,术后所有症状消失。术中见发育不良肾脏的体积、形态和位置异常。 9例为体积较小的肾脏 ,5例为葡萄状发育不良肾。病理表现为镜下大量未成熟的扩张导管 ,异常排列的未成熟肾小球和肾小管。术后随访 1～ 2年 ,生长发育正常。结论　先天性单肾发育不良女孩多见 ,因无特异性临床表现 ,不易确诊。临床上影像学检查十分重要 ,手术治疗效果确切。     

小婴儿肾积水手术治疗及预后评价

目的 探讨小婴儿肾积水手术指征、治疗及预后.方法 总结40例小婴儿肾积水的手术治疗.全部病例术前均行彩超、IVP、静脉肾盂造影后三维CT重建及SPECT检查.所有患儿均行肾盂输尿管成形术,术后病理证实为肾盂输尿管交接处梗阻所致肾积水.术后常规随访,行彩超和SPECT检查.结果 所有患儿手术经过顺利,无手术并发症.术后3个月彩超示所有患儿肾盏扩张明显减轻,肾盂前后径和肾实质厚度均较术前好转,术前肾实质平均厚度为(4.37±1.57)mm,术后为(5.89±1.66)mm;两者比较有显著差异,P=0.000.术前.肾盂前后径为(4.20±1.66)cm,术后为(1.93±0.98)cm,两者比较有显著性差异,P=0.000.32例单侧肾积水术后25例肾脏功能稳定,7例有不同程度的恢复,没有恶化者.8例双侧肾积水较重侧手术,术后对侧积水均明显减轻.结论 小婴儿肾积水肾盂前后径增大并出现肾盏扩张、肾实质变薄者,即使肾功能正常也以手术为佳.肾功能恶化、肾积水加重或出现临床症状者应积极手术.肾盂前后径小于2 cm,肾功能在40%以上,但肾图为梗阻曲线者应密切观察.小婴儿肾积水手术效果良好,术后肾脏形态恢复显著,肾脏功能可以保存.     

儿童重复肾上肾输尿管膨出合并下肾膀胱输尿管反流的治疗体会

目的探讨儿童重复肾上肾输尿管膨出合并下肾或对侧肾膀胱输尿管反流合理的治疗方法。方法回顾分析2007年10月至2019年10月首都医科大学附属北京儿童医院收治的重复肾上肾输尿管膨出合并下肾或对侧肾膀胱输尿管反流24例患儿的临床资料。其中,男5例,女19例,就诊年龄7个月至9岁,平均2岁。重复肾左侧13例,右侧6例,双侧5例,上肾输尿管膨出左侧15例,右侧9例,无双侧,合并下肾膀胱输尿管反流左侧13例,右侧9例,下肾及对侧2例。泌尿系统感染17例,影像学检查发现6例,间断腹痛1例。上半肾无功能者22例行重复肾上半肾切除术;上半肾积水但有功能者2例,行上下输尿管吻合术1例,行上肾输尿管膨出切除上下输尿管膀胱再植术1例。结果 22例半肾切除患儿中19例患儿获得随访,3例失随访,术后下半肾反流消失11例(含对侧反流1例),减轻3例,反流无缓解无临床表现2例(术前Ⅳ级随访4个月,术前Ⅴ级随访2年),3例术后反流未消失合并泌尿系统感染再次手术治疗后治愈。保留上肾2例中,行上下输尿管吻合者术后4个月,无临床症状,尚未复查排尿性膀胱尿道造影,行上肾输尿管膨出切除上下肾输尿管膀胱再植术后复查反流消失无临床...     

先天性单侧肾发育不良合并输尿管异位开口27例报道

目的 总结先天性单侧肾发育不良合并输尿管异位开口的诊治经验。方法 对27例先天性单侧肾发育不良合并输尿管异位开口患儿的临床表现、诊治方法进行回顾性分析。结果 27例患儿均为女性。左侧18例,右侧9例。经B超、静脉尿路造影（IVU）、阴道逆行造影、CT、MRI等检查证实,17例输尿管异位开口于阴道壁,3例开口于尿道与阴道口之间。16例发现发育不良的肾脏。27例患儿均接受了发育不良肾及输尿管切除术。结论 先天性单侧肾发育不良合并输尿管开口异位通过病史、体格检查及影象学检查,可于术前得到确诊,手术切除发育不良的肾脏及输尿管,疗效满意。     

先天性单侧肾发育不良合并输尿管异位开口的诊治体会

目的 探讨先天性单侧肾发育不良合并输尿管异位开口的临床特点和诊治方法。方法 总结分析12例肾发育不良合并输尿管异位开口的临床资料。结果 12例肾发育不良均为女性。左侧7例，右侧5例，主要临床表现为点滴性尿失禁，静脉尿路造影患肾均不显影，对侧肾显示代偿性肥大。B超探查8例未探及肾脏，仅4例在盆腔探及发育不良肾组织，其中4例接受CT扫描。2例提示盆腔有发育不良肾，12例均接受了发育不良肾及输尿管切除，术中见肾脏体积小，形态及位置异常，术后“尿失禁”症状立即消失。结论 先天性肾发育不良女孩多见，常伴有输尿管开口异位，主要表现为点滴性尿失禁，B超多不能探及患肾，静脉尿路造影患肾均不显影而对侧肾肥大，易误诊为孤立肾。手术切除患肾及输尿管效果确切。     

重度肾积水保留肾脏的临床研究

目的 探索重度积水肾保留肾脏手术治疗的方法.方法 对20例IVP患肾不显影或极淡及SPECT检测患肾功能极差的肾积水患儿,先行经皮肾穿刺造瘘术.术后随诊1～3个月,再复查B超、CT、IVP及SPECT,决定是否保留患肾.结果 19例患肾功能均有改善,并成功实施离断性肾盂成形术;仅1例因分肾功能仍在10%以下患儿,行肾切除.结论 重度积水肾患儿先行经皮肾穿刺造瘘术后,结合手术前后肾实质厚度及分肾功能的变化,判断患肾功能恢复的状况,为尽可能保留患肾提供充分的依据.     

小儿重复肾畸形的早期诊断和治疗

目的 探讨小儿重复肾畸形的早期诊断和治疗方法.方法 回顾性分析本院1995年6月-2007年9月60例经手术治疗的小儿重复肾畸形病例的临床资料.60例均行B超检查,确诊55例,误诊为肾上极囊肿5例.60例患儿均行静脉肾盂造影(IVP)检查,均提示重复肾,其中2例上下肾部均有不同程度的肾盂积水和输尿管扩张,进一步行排尿性膀胱尿道造影,诊断下肾部膀胱输尿管返流、下肾部输尿管膀胱交接部梗阻各1例.结果 重复肾畸形患儿60例均行手术治疗,行上肾部切除及其输尿管切除58例,重复肾并上下肾部积水手术2例,其中1例下肾部输尿管末端梗阻致下肾部积水,上肾部输尿管囊肿,行上肾部及其输尿管切除,术后输尿管囊肿萎陷,下肾部输尿管末端梗阻解除,症状消失,术后6个月复查IVP,下肾部肾盏杯口清晰,无肾积水,肾功能良好,疗效满意;另1例为下肾部输尿管返流致下肾部积水,上肾部输尿管囊肿,行输尿管囊肿切除,双输尿管膀胱再植术,术后6个月复查排尿膀胱尿道造影,膀胱输尿管返流消失,排尿正常,无泌尿系感染.结论 术前诊断不明或误诊的原因多系患儿临床症状与其他疾病症状相类似而误诊为其他疾病,应强调对可疑征象的辅助检查.如重复肾畸形诊断明确,应早期手术治疗.     

Doppler sonography in congenital ureteropelvic junction obstruction and multicystic dysplastic kidneys

The accurate diagnosis of severe congenital ureteropelvic junction obstruction (UPJO) and the indications for surgical intervention are a matter of debate. Differential diagnosis from, for example, congenital cystic kidney malformations is important. In the present study we analysed the value of Doppler sonography (DS) for assessment of obstruction in congenital UPJO and its usefulness for differential diagnosis. A total of 138 infants and children were examined. Forty-three healthy infants and 24 children who had had a pyeloplasty at least 1 year previously served as control groups. Seventy-one children with UPJO and cystic kidney malformations underwent DS in addition to the usual examinations of intravenous urography and scintigraphy. Resistive Index (RI) was measured in both kidneys. Twenty infants showed decompensated UPJO and had needed an operation. Preoperatively all showed significantly increased RI (RI=74%), which returned to normal after operation (RI=68.3%). Thirty-nine children with UPJO could be managed conservatively, showing compensated obstruction on diuretic renography. On DS they had normal and symmetrical RI values (RI=67%). Eleven children had multicystic dysplastic kidneys; 4 underwent nephrectomy. On DS all showed either absence of perfusion signals or very low flow velocities with very high RI values (RI=90–100%) in the renal vessels. One child was found to be suffering from a cystic nephroma. DS was able to reveal quite normal vessel distribution in renal parenchyma with slightly elevated RI values (RI=80%). Our results indicate that DS a non-invasive, non-ionising method of investigation, may serve as an additional functional parameter for defining accurately the degree of obstruction in UPJO. DS can influence the indication for surgical treatment and improves the differential diagnosis of congenital cystic kidney malformations. It provides an adequate method for frequent monitoring in conservative treatment.     

Multicystic dysplastic kidney and contralateral vesicoureteral reflux. Renal growth

BACKGROUND: To evaluate if vesicoureteral reflux (VUR) contralateral to the multicystic dysplastic kidney can interfere with the compensatory renal hypertrophy. METHODS: Twenty-seven patients (17 males, 10 females) with multicystic dysplastic kidney (MDK) (14 on the right, 13 on the left) have been treated at the Nephrology Unit of the Pediatric Department of the University of Verona from birth up to the second year of life. All these patients were diagnosed as having MDK by prenatal ultrasonography. Seven children (4 males and 3 females) had VUR (5 monolateral, 2 bilateral), diagnosed at the end of the first month of life. After diagnosis children underwent antibiotic prophylaxis with beta-lactam compounds at low doses. Four patients underwent a surgical correction of VUR associated with nephrectomy within the second year of life. The remaining 3 patients were treated with antibiotic prophylaxis; a progressive resolution or downgrading of reflux grade took place respectively in 1 and in 2 of them. Only 6 children with MDK underwent nephrectomy. Renal growth was studied by serial echographic measurements of the longitudinal renal lenght (performed at birth, at 6 months, and at 2 years of life). RESULTS: Renal length was 5.68+/-1.24 cm, 6.72+/-0.88 cm, 8.56+/-1.27 cm in children without VUR, respectively at birth, 6 months and 2 years of life. Renal length was 4.65+/-0.63 cm, 6.70+/-0.64 cm, 7.07+/-1.14 cm in children with VUR, respectively at birth, 6 months and 2 years of life. A statistically significant difference was observed between the two groups at birth (p<0.05) and at 2 years of life (p<0.01). CONCLUSIONS: The conclusion is that VUR contralateral to the MDK is associated with small kidneys and reduced renal growth both at birth and at 2 years of life.     

Renal dysplasia in infants: Apperance on99mTc DMSA scintigraphy

Infantile renal dysplasias, including multicystic dysplastic kidneys (MCDK), are reported rarely to accumulate radiopharmaceuticals on renal scintigraphy.^99mTc DMSA is a highly sensitive tracer for detecting functioning renal cortical tissue and may be more suited to studying renal dysplasia than^99mTc DTPA. We reviewed the ultrasound studies and^99mTc DMSA scintigrams of 42 infants (age range 1–12 months) with known or suspected MCDK. Overall, uptake on^99mTc DMSA scintigraphy was evident in 6/41 (15%) dysplastic kidneys. Of the 18 patients who underwent nephrectomy, histopathological examination revealed that uptake correlated closely with the presence of mature renal cortical tissue in the affected kidney. Our study shows that a small, but significant number of MCDK will show low-grade uptake on DMSA scintigraphy. This finding may be relevant given the reliance placed on renal scintigraphy in planning treatment for infants with suspected MCDK, particularly with the increasing trend for the non-operative management of this condition.     

Study of the association between the BMP4 gene and congenital anomalies of the kidney and urinary tract

Objectiveto determine the frequency of different phenotypes for congenital anomalies of the kidney and urinary tract (CAKUT) in a Brazilian sample, and to evaluate the association between the CAKUT phenotypes and the BMP4 gene.Methodsin this study, 457 Brazilian individuals were analyzed in an attempt to establish the association between the BMP4 gene and the CAKUT diagnosis. A case-control sample was genotyped for three BMP4 gene polymorphisms.Resultsassociation data was established with CAKUT sample as a whole and with the three most important CAKUT phenotypes: multicystic dysplastic kidney disease (MDK), ureteropelvic junction obstruction (UPJO) and vesicoureteral reflux (VUR). When the sample was segregated in these three phenotypes, associations between the BMP4 gene were observed with UPJO and with MDK. Conversely, VUR was not associated to the polymorphisms of the BMP4 gene.Conclusionsthe present data suggest that Brazilian individuals with polymorphisms of the BMP4 gene have a higher risk to develop CAKUT, especially the malformations related to nephrogenesis and initial branching such as MDK and UPJO. Conversely, VUR appeared not to be related to BMP4 gene.     

The impact of vesicoureteral reflux on contralateral renal length in infants with multicystic dysplastic kidney

Purpose. The purpose of our study was to determine the influence of vesicoureteral reflux (VUR) on contralateral renal length in neonates and young infants with unilateral multicystic dysplastic kidney (MCDK). Material and Methods. We reviewed the imaging findings in 48 term neonates and infants (27 boys; 21 girls) who had unilateral MCDK (mean age at diagnosis 0.09 years; range 0–0.64 years). Each had renal ultrasonography (RUS), renal scintigraphy, and voiding cystourethrography before 1 year of age. The diagnosis of MCDK was based on characteristic imaging findings (i. e., an echogenic, cystic kidney at RUS that did not function at scintigraphy). None had contralateral hydronephrosis or cysts. We calculated an age-corrected z-score for contralateral renal length (at RUS) in each patient based on published standards. We examined the effects of gender, ipsilateral or contralateral VUR, and age at RUS on the contralateral renal length using multifactor ANOVA. Results. Nine patients (19 %) had VUR into the contralateral kidney. The refluxing kidneys were significantly shorter (renal length: median 5.1 cm, mean 5.07 cm; z-score: median − 0.43, mean − 0.58) than the nonrefluxing kidneys (renal length: median 6.2 cm, mean 6.08 cm; z-score: median 1.03, mean 1.04; P < 0.001). The contralateral kidney was more than 1 SD longer than the mean for age in none of the 9 patients with VUR on that side. By comparison, the contralateral kidney was more than 1 SD longer than the mean for age in 21 (54 %) of 39 patients with no VUR on that side, and more than 2 SD longer than the mean in 5 (13 %). Conclusion. VUR into the kidney contralateral to a MCDK is associated with smaller size of that kidney during the first year of life. Received: 16 January 1998 Accepted: 13 April 1998     

Prenatally detected ureteropelvic junction obstruction: clinical features and associated urologic abnormalities

Urologic congenital anomalies associated with ureteropelvic obstruction (UPJO) have been previously characterized; however, less data are available regarding these associations in a prenatally diagnosed population. A retrospective study was conducted to evaluate significant clinical features and urological anomalies associated with prenatally diagnosed UPJO. The records of 143 children with prenatally diagnosed hydronephrosis secondary to UPJO were retrospectively reviewed. The gender, side of obstruction, degree of hydronephrosis, associated clinical features, and urological anomalies were noted. Hundred and forty-three children (M/F = 2.7) with a total of 198 affected renal units (RU) presenting with unilateral (61%) or bilateral (39%) UPJO were enrolled. In cases of unilateral obstruction, the left side was affected in 60 children (68%). The grade of hydronephrosis was Grade 1 in 56 RU (28%), Grade 2 in 51 RU (26%), Grade 3 in 50 RU (25%) and Grade 4 in 41 RU (21%). Associated clinical features included prematurity (n = 7, 4.9%), twinning (n = 5, 3.5%) and presentation with renal failure (RF) (n = 2). Excluding contralateral UPJO, other urologic anomalies were encountered in 29 patients (20.3%). Associated vesicoureteral reflux (VUR) was encountered in 11 patients (7.7%, M/F = 2.7). Pyeloplasty was required more often in children with associated VUR (54.5 vs. 18.2%) (P = 0.01). Contralateral multicystic dysplastic kidney (MCDK) was encountered in six patients (M/F = 2), one of whom presented with RF. One child carried the diagnosis of Schinzel–Giedion syndrome (SGS), demonstrating severe developmental and neurological disorders and bilateral hydronephrosis. The more frequent occurrence of UPJO in males with predominantly left-sided location, association with VUR and MCDK, and increased frequency of bilaterality in our prenatally diagnosed patients were similar to historical reports. In addition, prematurity and twinning were independently associated with UPJO. The higher rate of pyeloplasty in patients with associated reflux warrants further investigation.     

Dysplastic multicystic kidney: should the classic treatment (nephrectomy) be changed after prenatal diagnosis?

We reviewed 60 cases of multicystic renal dysplasia managed in our institution during a 10-year period, 54 of which were prenatally detected; 59 were unilateral dysplastic multicystic kidneys (DMK) and 1 bilateral. The mean gestational age at diagnosis was 28.1 weeks. Associated anomalies were present in 17 cases; 4 of these infants died. In 19 cases, a nephrectomy was initially performed. Among the 37 infants initially managed nonoperatively, 4 were lost to follow-up. The DMK was removed in 17 instances after 18 months of age (mean age 26.8 months), and 16 children with spontaneous regression of the lesion were followed. In 9 cases, complete disappearance of the dysplastic kidney was observed. Of the 36 kidneys removed, most were of the dysplastic type; a ureter was present in 21 cases and no nodular renal blastema was found. When opacification of the specimen was performed, communication between cysts was the most frequent finding. The critical question of the harmlessness of nonoperative management of DMKs has to be answered by a large-scale, long-term, multicenter study. Correspondence to: E. Sapin     

Anderson-Hynes pyeloplasty in horseshoe kidney in children: is it effective without symphysiotomy?

Contemporary reports on surgery for horseshoe kidney (HK) still recommend isthmotomy and lateropexy to complete an open pyeloplasty. To evaluate whether simple Anderson-Hynes pyeloplasty without symphysiotomy is effective for relief of ureteropelvic junction obstruction (UPJO) in HK, we studied the records of ten children, two of whom had bilateral UPJO. Only one child presented with calculi; 11 units were operated upon for UPJO, 1 needed a partial nephrectomy. The surgical outcome was evaluated with emphasis on the changes in renal drainage and function assessed by ultrasonography and diuretic renal scans. Associated vesicoureteral reflux was observed more often (25%) than with UPJO in normal kidneys. Obstruction was caused by a crossing lower-pole vessel in three cases, a high ureteral insertion in two and narrowing of the UPJ 7. Postoperative follow-up (mean 5.5 years) revealed improved renal function and good drainage in all cases. Hydronephrosis vanished in 7, whereas grade 2 hydronephrosis remained in two children with former refluxive megaureter and grade 3 in one. All children are doing well and have no symptoms due to the persistent isthmus (Rovsing syndrome). It is concluded that simple Anderson-Hynes pyeloplasty via a flank incision is a highly effective and safe procedure for treating UPJO in HK. Accepted: 13 October 1998     

Multicystic dysplastic kidney: Impact of imaging modality selection on the initial management and prognosis

ObjectiveTo evaluate the impact of imaging modalities on the evaluation and prognosis of children with multicystic dysplastic kidney (MCDK) disease.Patients and methodsA retrospective analysis of all children with MCDK diagnosed from 2004 until 2012 was performed. The study included 63 patients for whom all postnatal imaging modalities were available: renal bladder ultrasound (RBUS), dimercaptosuccinic acid scan (DMSA) and voiding cystourethrogram (VCUG). Cases with major congenital abnormalities or incomplete data were excluded. Abnormalities in the contralateral kidney and the fate of MCDK were also addressed.ResultsAt diagnosis, the average age was four-and-a-half months. The majority of cases were detected antenatally (87%). Postnatal RBUS and DMSA scans established the diagnosis of MCDK in 92% and 98% of patients, respectively. DMSA showed photopenic areas in the contralateral kidneys in 10% of patients; all of them had hydronephrosis and were confirmed to have vesicoureteral reflux (VUR). Contralateral VUR was detected in 16 patients; 63% of them had hydronephrosis. After a mean follow-up of three-and-a-half years, involution occurred in 62% of patients and the involution rate was inversely proportional to the initial size.ConclusionsThe classical appearance of MCDK on RBUS was sufficient to establish the diagnosis in most patients. DMSA scan was more accurate in confirming the diagnosis and evaluating the contralateral kidney. Selective screening for VUR in patients with contralateral hydronephrotic kidney should be considered.