Functional urinary tract obstruction developing in fetuses with isolated gastroschisis.

OBJECTIVE: To evaluate the frequency and natural history of urinary tract abnormalities developing in fetuses presenting with initially isolated gastroschisis. METHODS: Serial ultrasounds were performed prospectively on fetuses identified by our prenatal diagnosis program as having a gastroschisis. When abnormalities in the urinary tract were identified prenatally, newborns were evaluated by a pediatric urologist. RESULTS: Over a 1-year period four out of 12 fetuses with gastroschisis developed deformations of the urinary tract. In three fetuses the bladder herniated through the abdominal wall defect. Two also had upper tract dilatation. A fourth fetus developed bilateral hydronephrosis with a normally situated bladder. Once the gastroschisis was repaired none of the newborns had evidence of structural obstruction of the urinary tract, however, hydronephrosis with or without reflux persisted for several months. CONCLUSIONS: Deformations of the fetal urinary tract can develop secondary to gastroschisis. They do not appear to represent separate malformations and evaluation with fetal karyotyping may not be indicated. When hydronephrosis is present ongoing urologic evaluation of the neonate is indicated.     

胎儿泌尿系畸形的超声随访监测与临床对比观察

目的对孕期超声监测到胎儿泌尿系统畸形者的妊娠结局和患儿以后的肾脏功能进行评估.方法对1993年1月～2003年12月所有产前超声检查怀疑泌尿系先天畸形的患儿进行产前死亡率、产后超声诊断、产后处理、肌酐清除率进行回顾性分析,以评估以后的肾脏功能.结果 74例产前超声怀疑为泌尿系畸形者,18例考虑到泌尿系畸形可能为致命性病变而终止妊娠,15例患儿于产前或产后1个月内死亡.至今存活者,21例肾脏功能良好、5例肾功能欠佳、3例肾功能极差,12例胎儿于出生后超声证实不是畸形,他们的肾功能良好,产前怀疑双侧泌尿系畸形和合并其他相关畸形患儿预后较差.结论产前诊断泌尿系畸形预后依靠特有的异常发现,染色体组型异常、合并其它相关畸形、累及双侧的先天泌尿系畸形预后较差.     

Spontaneous remission of urinary tract obstruction and ascites in a fetus with posterior urethral valves.

We report a case of posterior urethral valves with its typical sonographic findings. The initial diagnosis of an infravesical obstruction was made at 18 weeks gestation based on the finding of an enlarged fetal bladder and bilateral dilated renal pelves. Weekly observations showed no change in bladder size until 27 weeks gestation. At this time there was a significant increase in dilatation, the bladder wall was thickened and at 28 weeks a large amount of fetal ascites was diagnosed, but there was no oligohydramnios. Fetal urine investigations following ultrasound-guided puncture of the fetal bladder revealed hypotonic urine and adequate renal function. Hence no vesicoamniotic drainage was performed. At 32 weeks, spontaneous remission of ascites and reduction of the bladder dilatation were noted. The fetus was delivered vaginally at term. Follow-up of the newborn during the 1st year of life is reported. At the age of 1 year the infant shows good renal function with a serum creatinine of 0.33 mg/dl. This case shows that spontaneous remission of fetal urinary tract obstruction as a consequence of posterior urethral valves is possible. The sequence of events leading to spontaneous remission and the favorable outcome is discussed.     

Transvaginal sonography (TVS) of the fetal urinary tract

Examination of the fetal urinary tract is an integral part of routine sonographic examination in the second trimester of pregnancy. Malformations of the urinary tract are being detected at an ever-increasing rate, mostly because they are associated with two easily visualized sonographic markers: the cystic accumulation of fluid and a change of the amniotic fluid volume. Detailed evaluation of the fetal urinary tract and identification of anomalies were considered to be difficult before the 18th week from the last menstrual period (LMP) before the use of transvaginal sonography (TVS). Transvaginal sonography (TVS), owing to its proximity to the maternal pelvic organs at early gestation, enables earlier determination of both normal and abnormal findings in the fetal urinary system such as: renal agenesis, polycystic and multicystic kidneys, hydronephrosis, and bladder extrophy. The TVS enables earlier and more accurate diagnosis and identification of fetal urinary tract anomalies as compared with abdominal ultrasound.     

Sonography of fetal micturition.

OBJECTIVE: To describe the sonographic visualization of fetal micturition and its role in the diagnosis of posterior urethral valves and hypospadias. METHODS: This was a prospective study of 25 male fetuses (21 with bilateral pyelectasis, one whose bladder was being studied because of ureterocele and three with hypospadias), and five female fetuses (with bilateral pyelectasis). A midline sagittal scan of the fetal pelvis, perineum and external genitalia was obtained and observed continuously during fetal micturition. RESULTS: In 19 of the 21 male fetuses and the five female fetuses with bilateral pyelectasis micturition was normal, with visualization of urinary bladder contraction, slight fluid distention of the urethra and a urinary stream from the external urethral meatus. In three male fetuses, two with bilateral pyelectasis and the one with ureterocele, the posterior urethra was normal at rest and it ballooned out during micturition, diagnostic of posterior urethral valves. In the three male fetuses with hypospadias the ventral jet of the urinary stream was visualized. CONCLUSION: Fetal micturition can be visualized on sonography. It may be of value in the diagnosis of posterior urethral valves and hypospadias.     

Enlarged fetal bladder: Differential diagnosis and outcomes

The sonographic finding of an enlarged fetal bladder may simply be a transitory normal variant, but it may also be secondary to reflux or to obstructive, neurogenic, or myopathic causes. In this report, we describe the cases of 3 fetuses with an enlarged bladder, each of which had a different cause. The first fetus had posterior urethral valve obstruction, the second, a ruptured neurogenic bladder, and the third, megacystic-microcolon-intestinal hypoperistalsis syndrome. When sonographic examination reveals an enlarged fetal bladder, the ureter, kidneys, genitalia, and spine should be evaluated carefully. Although sonography is good at identifying urinary tract abnormalities, it often cannot provide the specific diagnosis or cause. We recommend frequent sonographic monitoring to evaluate such fetuses for persistence of or changes in bladder enlargement and for changes in the volume of amniotic fluid because these signs may be indicators of abnormalities of renal function and risk factors for a poor prognosis. Analysis of fetal electrolyte levels can also aid in determining the prognosis and whether the condition is amenable to therapeutic intervention.     

神经源性膀胱合并上尿路扩张患者尿动力学检查的护理

目的探讨神经源性膀胱合并上尿路扩张患者尿动力学特点及检查过程中的护理配合。方法回顾性分析150例神经源性膀胱合并上尿路扩张患者膀胱功能测定的护理配合要点、检查结果和并发症发生情况。结果上尿路扩张患者多表现为膀胱低顺应性、逼尿肌过度活动、高逼尿肌漏尿点压、相对安全容量显著降低、残余尿量显著增多、膀胱活动低下等,尿动力学检查后患者并发泌尿系感染的风险和严重程度明显增加。结论神经源性膀胱合并上尿路扩张患者行尿动力学检查时需加强相关的护理配合,如严格控制膀胱充盈速度及重复检测次数、及时留置导尿管持续引流尿液或进行清洁间歇导尿、预防性使用抗生素等,以保证检查结果的准确性,并有效预防检查后泌尿系感染的发生。     

The antenatal sonographic visualization of cloacal dysgenesis

Hydronephrosis associated with a septated cystic structure in the fetal pelvis in the absence of an otherwise identifiable fetal bladder should alert the sonographer to the possibility of a persistent cloaca. Problems associated with compromised urinary tract drainage and the associated oligohydramnios occurring early in gestation as well as frequent association of anomalies with other organ systems must be addressed. Squamous epithelia in fetal bladder aspirate is further supportive evidence for the diagnosis.     

Significance of nonvisualization of the fetal urinary bladder.

The fetal urinary bladder was visualized sonographically in 1254 (94%) of 1335 consecutive fetuses of 14 weeks of development or older, but it could not be seen in 81 cases (6%). Five of these cases were lost to follow-up and were excluded from the study. Of the remaining 76 cases, 69 (91%) of the pregnancies progressed to term, and the infants were normal at birth and at 6 week perinatal follow-up. Seven (9%) of the fetuses had a variety of associated obstetrical abnormalities that resulted in fetal demise or termination of the pregnancy (oligohydramnios, hydrops, intrauterine growth retardation [IUGR], ventriculomegaly, diaphragmatic hernia, cystic hygroma, and triploidy). Notably, none of these were renal tract anomalies. We concluded that (1) nonvisualization of the fetal urinary bladder with an otherwise normal sonogram, including normal volume of amniotic fluid and normal renal areas, is of no clinical concern and does not require follow-up, and (2) nonvisualization of the fetal urinary bladder in the setting of associated obstetrical abnormalities may be secondary to renal tract anomalies or may only be a consequence of the associated abnormalities.     

Complementary Roles of Sonography and Magnetic Resonance Imaging in the Assessment of Fetal Urinary Tract Anomalies

Objective. The purpose of our study was to determine whether fetal magnetic resonance imaging (MRI) provides additional information that might affect the obstetric management of pregnancies complicated by sonographically diagnosed fetal urinary tract anomalies. Methods. Fetal MRI and sonography were used to study 39 women with suspected fetal urinary tract anomalies in the second and third trimesters of pregnancy. Results. In 24 of 39 cases (61%), fetal MRI confirmed the sonographic diagnosis. In 14 cases (36%), fetal MRI modified the initial sonographic diagnosis and counseling but did not change obstetric management. In 1 case (3%), the addition of fetal MRI resulted in a substantial change in the management of the pregnancy. Conclusions. During the second and third trimesters of pregnancy, fetal MRI showed fetal urinary tract anomalies in excellent anatomic detail. Fetal MRI is a useful complementary tool in the assessment of sonographically diagnosed fetal urinary tract anomalies. In a small percentage of cases, it can have a substantial impact on obstetric management.     

胎儿泌尿系畸形的产前超声诊断及预后评估

目的 探讨超声诊断胎儿泌尿系畸形的声像图特征及其临床实用价值。 方法 按产科超声常规检查胎儿，发现胎儿泌尿系统异常者，根据声像图特征评估处理。 结果 52例产前超声可疑为泌尿系畸形患者中，13例考虑到泌尿系畸形可能为致命性病变而终止妊娠，10例因一侧肾病变而自愿引产，12例胎儿出生后随访肾盂积水消失，7例胎儿肾盂扩张大于1．5cm，考虑输尿管狭窄出生后经手术治疗，1例胎儿单侧肾囊肿因合并心脏严重畸形出生后死亡，8例胎儿一侧肾脏异常、另一侧形态及结构未发现异常后均自然分娩，1例胎儿于孕24周可疑婴儿型多囊肾后经复查排除。 结论 产前超声诊断胎儿泌尿系畸形，依靠特有的声像图改变及合并其他畸形，对胎儿预后判断、临床及早采取措施提供依据，这对优生优育及新生儿早期治疗有重要临床实用价值。     

Noradrenaline content in canine lower urinary tract tissue

To examine the distribution of sympathetic nerve fibers in the lower urinary tract, the noradrenaline content was measured in the urinary bladder dome and base, and proximal and distal urethra of the male and female dogs, using high pressure liquid chromatography-electrochemical detection (HPLC-ED). The noradrenaline content was the highest in the proximal urethra and the lowest in the urinary bladder dome in both sexes. The noradrenaline content of the proximal urethra was significantly higher in the male than in the female, whereas the content of the urinary bladder base and the distal urethra was lower in the male than in the female. These data suggest that sympathetic innervation is the richest in the proximal urethra in the lower urinary tract and that there is a sex difference in the sympathetic innervation in the lower urinary tract.     

Host defense mechanisms in the pathogenesis of urinary tract infection

Certain microorganisms have a propensity for causing urinary tract infection, and the route (either ascending or hematogenous) by which microorganisms contaminate the urinary tract from external sources is frequently characteristic of the microorganism. There are local defense mechanisms both in the urine and at each anatomic site in the urinary tract (urethra, bladder, ureter, and kidney). The defense mechanisms at one site may have opposing effects on microbial growth at other sites in the urinary tract. The outcome following entrance of microorganisms into the urinary tract is a result of competing forces, which consist of these local urinary defense mechanisms, the initial numbers of microorganisms contaminating the urinary tract, and microbial virulence factors.     

Megacystis-microcolon-intestinal hypoperistalsis syndrome: in utero sonographic appearance and the contribution of vesicocentesis in antenatal diagnosis.

OBJECTIVE: The purpose of this report is to describe the in utero sonographic appearance of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) and examine the role of vesicocentesis. METHODS: Two cases of the sonographic appearance of MMIHS were reviewed. We performed vesicocentesis in 2 fetuses with MMIHS and performed vesicoamniotic shunting in 1 of them. The sonographic findings after these procedures were compared with those before puncture. RESULTS: In both cases, ultrasound examination showed a massively enlarged fetal bladder and bilateral hydroureteronephrosis with a normal amount of amniotic fluid. Fetal urinary sodium and chloride concentrations were within normal limits in both cases; this suggested normal fetal renal function. Generally, it is difficult to detect the dilated fetal bowel in MMIHS, probably because of the disturbance caused by a large bladder. In our cases, however, the ultrasound examination clearly showed fetal bowel dilatation after these procedures; this made the antenatal diagnosis of MMIHS more definite. CONCLUSIONS: The sonographic features after vesicocentesis may be helpful in confirming the antenatal diagnosis of MMIHS.     

Guidelines for preventing urinary retention and bladder damage during hospital care

Aims and objectives. To develop evidence‐based guidelines for adult patients in order to prevent urinary retention and to minimise bladder damage and urinary tract infection. Background. Urinary retention causing bladder damage is a well known complication in patients during hospital care. The most common treatment for urinary retention is an indwelling urinary catheter, which causes 80% of hospital‐acquired urinary tract infections. Appropriate use of bladder ultrasonography can reduce the rate of bladder damage as well as the need to use an indwelling urinary catheter. It can also lead to a decrease in the rate of urinary tract infections, a lower risk of spread of multiresistant Gram‐negative bacteria, and lower hospital costs. Design. An expert group was established, and a literature review was performed. Methods. On the basis of literature findings and consensus in the expert group, guidelines for clinical situations were constructed. Results. The main points of the guidelines are the following: identification of risk factors for urinary retention, managing patients at risk of urinary retention, strategies for patients with urinary retention and patient documentation and information. Conclusion. Using literature review and consensus technique based on a multiprofessional group of experts, evidence‐based guidelines have been developed. Although consensus was reached, there are parts of the guidelines where the knowledge is weak. Relevance to clinical practice. These guidelines are designed to be easy to use in clinical work and could be an important step towards minimising bladder damage and hospital‐acquired urinary tract infections and their serious consequences, such as bacteraemia and the spread of multidrug‐resistant bacteria in hospitals.     

Bladder neck obstruction in the female

Bladder neck dysfunction is a rare cause of obstruction in women. The symptoms are nonspecific and diagnosis relies on video-urodynamic evaluation. In this case study, a woman presented with urinary retention, recurring urinary tract infections, and bilateral hydronephrosis, in whom video-urodynamics revealed bladder neck obstruction. Her clinical presentation, as well as the pertinent literature on the diagnosis and treatment of bladder neck obstruction in women, are reviewed.     

The necessity of voiding cystourethrography in children with prenatally diagnosed hydronephrosis

The postnatal persistence of fetal hydronephrosis requires further evaluation to establish whether pathological abnormalities are present. This study determined the necessity for voiding cystourethrography (VCUG) to identify vesicoureteral reflux (VUR) in children (n = 195) with prenatally diagnosed hydronephrosis. Among the study population, the prevalence of VUR was 17.4% (24 males, 10 females). There was a poor correlation between the severity of hydronephrosis, ureteral dilatation, presence of bilateral hydronephrosis and presence of VUR. Except for the frequency of urinary tract infections and the presence of renal damage on (99m)Tc-dimercaptosuccinic acid scans, VCUG was the only reliable method for confirming VUR in this study. The diagnosis of VUR is important for the early detection of renal damage. Further information is needed to develop the optimal approach to the evaluation of prenatal hydronephrosis, with reliable parameters that avoid invasive procedures such as VCUG.     

脊柱裂患者的影像尿动力学特点分析

目的分析脊柱裂患者的影像尿动力学特点，探讨其发生上尿路损害的尿动力学危险因素。方法33例脊柱裂患者采用非完全同步影像尿动力学方法评估患者的膀胱尿道功能，了解膀胱的感觉、稳定性、顺应性、相对安全容量、逼尿肌漏尿点压力、有无膀胱输尿管返流等储尿功能参数，以及排尿期逼尿肌压力、有无逼尿肌内外括约肌协同失调（DSD）等排尿功能参数。将患者按照有无肾积水或返流、肾功能损害分为上尿路损害组和非损害组，统计比较各组中尿动力学参数的差异。结果脊柱裂患者上尿路损害的发生率约为51％（17／33），其中膀胱输尿管返流发生率为33％（11／33），无返流性肾积水发生率为18％（6／33）。在肾积水患者中，64．7％具有膀胱输尿管返流。上尿路损害组的膀胱顺应性和相对安全容量等参数与非损害组相比差异具有显著性（P〈0．05）。结论脊柱裂患者具有较高的上尿路损害发生率，其中膀胱输尿管返流占较大比例。膀胱顺应性下降及相对安全容量小可能是患者发生上尿路损害的主要尿动力学危险因素。     

Correlation between ultrasound and anatomical findings in fetuses with lower urinary tract obstruction in the first half of pregnancy.

OBJECTIVE: The prognosis of fetal lower urinary tract obstruction (LUTO) depends upon renal function and also upon the underlying etiology. Precise identification of the latter remains a challenge antenatally. Our objective was to examine the underlying pathology in male fetuses with sonographic evidence of severe and isolated LUTO. METHODS: Detailed postmortem examination was carried out after termination of pregnancy in 24 male fetuses presenting before 25 weeks of gestation with ultrasound evidence of isolated severe LUTO. RESULTS: All fetuses had megacystis and hyperechogenic kidneys. There was anhydramnios/oligohydramnios and pelvicalyceal dilatation in 20 and 15 cases, respectively. Posterior urethral valves (PUV) were suspected antenatally in 20 cases and urethral atresia was not suspected antenatally. However, postmortem examination of the urethra demonstrated atresia in six cases, severe stenosis in eight cases, PUV in nine cases and an apparently normal urethra in one case. Renal dysplasia was found in all cases but one. Urethral atresia was the most common urethral anomaly at 12-17 weeks. Hydronephrosis was more frequent in cases with PUV (8/9) and urethral stenosis (6/8) than with urethral atresia (0/6). In LUTO presenting in the first and second trimester, hyperechogenic kidneys were predictive of renal dysplasia in 95% of cases. The association of a sagittal diameter of the bladder of at least 40 mm with hydronephrosis before 28 weeks was predictive of PUV with a positive (PPV) and negative (NPV) predictive value of 44.4% and 66.6%, respectively. Absence of hydronephrosis and a sagittal diameter of the bladder of less than 40 mm were predictive of urethral atresia or stenosis with a PPV and NPV of 100% and 47.6%, respectively. The absence of hydronephrosis was predictive of urethral atresia with a PPV and NPV of 66.6% and 100%, respectively. CONCLUSION: LUTO in a male fetus presenting with megacystis in the first or second trimester of pregnancy is as likely to reflect urethral atresia or stenosis as it is PUV. The size of the bladder and the presence of hydronephrosis should be considered in order to improve prenatal diagnosis and counseling.     

彩色多普勒超声结合导尿管法对女性膀胱出口梗阻的诊断及治疗价值

目的探讨彩色多普勒超声（CDFI）结合导尿管法对女性膀胱出口梗阻（FBOO）的诊断及治疗价值。 方法常规超声扫查发现膀胱颈部病变疑为FBOO者，予置导尿管通过CDFI观察病变与尿道的解剖关系，对确诊病例，定期进行尿道扩张治疗。 结果32例患者超声下均表现为环绕导尿管的球形或管形病变，开放导尿管后可见彩色尿流回声从病变中间穿过，所有病例均经膀胱尿道镜及尿流动力学检查确诊，用导尿管进行定期尿道扩张治疗后，患者排尿困难症状均明显改善或消失。 结论CDFI结合导尿管法对于女性膀胱出口梗阻具有较高的诊断及鉴别诊断价值，并可辅助进行尿道扩张治疗。