George T. Klauber

Minimal Hydronephrosis in the Fetus: Clinical Significance and Implications for Management

PURPOSE We further define the natural history and management of minimal fetal hydronephrosis. MATERIALS AND METHODS Experience with minimal fetal hydronephrosis (renal pelvic diameter 4 to 10 mm. before 20 weeks of gestation and 5 to 10 mm. from 20 to 24 weeks) was reviewed for 18 months at New England Medical Center. RESULTS The incidence of minimal fetal hydronephrosis was 2.2% in the 5,900 fetuses screened by ultrasound. In 63% of cases prenatal ultrasound was done more than once, and revealed that dilatation of the urinary tract was stable during gestation in 31 (25%), and became normal in 35 (29%) and worse in 11 (9%). A total of 63 patients (103 renal units) followed for up to 1 year underwent postnatal sonography. Those with abnormalities were screened with a voiding cystourethrogram and renal scan, including 40 with normal postnatal ultrasound and no changes on subsequent evaluation. Of the 23 patients with abnormal findings 4 had functionally significant ureteropelvic junction obstruction and 1 had severe vesicoureteral reflux. A retrospective analysis of the sonograms of patients with minimal fetal hydronephrosis and persistence or progression of hydronephrosis revealed calicectasis, progression of minimal fetal hydronephrosis in utero and/or abnormal renal echogenicity in each fetus. CONCLUSIONS Our study shows that in a small but significant number of fetuses minimal fetal hydronephrosis will progress, whereas in most it will resolve.

Prenatal Diagnosis and the Pediatric Surgeon: The Impact of Prenatal Consultation on Perinatal Management

PURPOSE Pediatric surgeons are increasingly called on by obstetrical colleagues to counsel parents about the implications of a prenatal ultrasound finding. Our understanding of the natural history of many prenatally diagnosed surgical conditions has grown significantly in recent years. Whether prenatal surgical consultation can influence perinatal course had not been investigated. METHODS During an 21-month period, 12,865 prenatal ultrasound studies were performed on a total of 4,551 patients, and 221 prenatal surgical consultations were obtained through a newly established fetal treatment program at a tertiary care prenatal diagnostic center. To evaluate the impact of prenatal pediatric surgical consultation on perinatal course, the authors reviewed changes in management including termination of pregnancy, in utero intervention, and altered site, mode, or timing of delivery. RESULTS Two hundred twenty-one fetuses were referred for consultation; their 234 congenital anomalies included genitourinary (36%), thoracic (16%), intraabdominal (14.5%), abdominal wall (10.6%), neurological (9%), skeletal (6%), and head and neck (2.5%) defects; 2.5% had tumors and 2.5% were twin pregnancies. Pregnancy was terminated in 9.5% of cases, because of patient request, chromosomal abnormality, or dismal prognosis. In 3.6%, the decision to terminate was changed as a result of consultation. Site of delivery was changed as a result of consultation in 37% to facilitate postnatal evaluation and initiate immediate treatment. Mode of delivery was changed in 6.8% to prevent dystocia, hemorrhage into a tumor, as in sacrococcygeal teratoma, or to provide an emergency airway, as in cervical teratoma. The timing of delivery was changed in 4.5% to avoid further damage to fetal organs in cases of obstructive uropathy, gastroschisis, sacrococcygeal teratoma with high-output failure, and hydrocephalus. Five percent (11) underwent treatment in utero for fetal hydrothorax, obstructive uropathy, twin-twin transfusion syndrome, or lymphangioma. The overall perinatal mortality rate was 2.5%. CONCLUSION Prenatal pediatric surgical consultation may have a significant impact on the perinatal management of the fetus with a surgically correctable congenital anomaly. Providing obstetric colleagues and families with valuable insight into the surgical management of anomalies allows fetal intervention when appropriate, and delivery in an appropriate setting, by the safest mode of delivery, and at the gestational age appropriate to minimize effects of the anomaly.

Molecular characterization of the androgen receptor gene in boys with hypospadias

Development of male external genitalia is dependent on androgens, and karyotypic males lacking appropriate levels of androgens or functionally normal receptors may show abnormal virilization. Mutations in the androgen receptor gene cause abnormal receptor function and diverser mutations may be associated with heterogenous clinical signs of androgen insensitivity. In this study, we have searched for the existence of androgen receptor gene mutations carried by some patients with hypospadias. Genomic DNA samples from peripheral blood leucocytes from 21 patients with different degrees of hypospadias were studied. Analysis of the androgen receptor gene was performed by exon-specific amplification using polymerase chain reaction, single strand conformation polymorphism analysis, and direct genomic sequencing. Although a silent polymorphism was identified in exon 1 of the androgen receptor gene, the majority of patients studied (20/21) did not carry androgen receptor gene mutations. One patient with severe hypospadias and bilateral cryptorchidism was found to carry a point mutation in exon 8. We conclude that mutations in the androgen receptor gene may be carried by subset of patients with genital ambiguity presenting primarily with hypospadias, but this is not the underlying cause in the majority of cases. Characterization of this genetic defect may be important for classification and subsequent conservative therapeutic approaches for these patients.

Renal cell carcinoma in association with tuberous sclerosis in children

Tuberous sclerosis, a genetically transmitted multisystem neurocutaneous disorder, is associated with renal lesions in 50% of cases. The expected lesions are angiomyolipomas or renal cysts; renal cell carcinoma has been encountered in adults who have tuberous sclerosis, but is very rare in children. The authors report the case of a 5-year-old girl with tuberous sclerosis for whom atypical computed tomography findings led to the diagnosis of renal carcinoma at an early age. This experience suggests that children with tuberous sclerosis may need earlier screening.

Sacral agenesis: Analysis of 22 cases

Sacral agenesis is a rare congenital anomaly of the spine and is usually associated with urologic abnormalities. Twenty-two patients are reviewed. Twenty-one had other congenital and developmental abnormalities in addition to sacral agenesis. Physical examination showed flattening of the buttocks, loss of the gluteal cleft, widely spaced buttock dimples, and a palpable sacral defect. Lateral views of the spine are essential when anteroposterior views suggest an absence of sacral segments. Seven patients had a significant familial history of diabetes mellitus. All patients with involvement of more than one sacral segment had neurogenic bladder dysfunction with incontinence. The degree of neurologic deficit could not be predicted from the radiologic appearance of the sacrum.

Von Hippel-Lindau Disease and Renal Cell Carcinoma in a 16-Year-Old Boy

Von Hippel-Lindau disease is a rare autosomal dominant disorder. Kidney lesions occur in the majority of cases, with renal cell carcinoma noted in 40% and renal cysts in 60%. Renal cell carcinoma in von Hippel-Lindau disease is usually bilateral and occurs at an earlier age than in patients with sporadic renal cell carcinoma. We report on a 16-year-old boy who, to our knowledge, is the youngest patient to present with von Hippel-Lindau disease and renal cell carcinoma. Controversy currently exists regarding the nature of renal cysts in von Hippel-Lindau disease and the optimal therapeutic approach (that is radical versus parenchymal sparing surgery). We review the histology of renal cysts and carcinoma, and discuss the rationale for selecting parenchymal sparing surgery.

Critical Evaluation of the Crede Maneuver: A Urodynamic Study of 207 Patients

The efficacy of Credés maneuver to promote voiding was evaluated prospectively in 207 patients with a variety of lower urinary tract disorders. The normal response to Credés maneuver was a contraction of the external urethral sphincter (the Credé effect), an increase in urethral pressure and maintained closure of the vesical neck. Relaxation of the external urethral sphincter and synchronous opening of the bladder neck during Credés maneuver were seen in only 4 patients (2 per cent). We conclude that Credés maneuver is an inefficient method of bladder emptying in the majority of patients and even when voiding is accomplished with Credés maneuver it usually is grossly inefficient and associated with significant urethral obstruction.

The Biological Behavior of Autologous Collagen Injected into the Rabbit Bladder

Growing interest in the endoscopic treatment of vesicoureteral reflux and urinary incontinence has led to the development of safe reliable techniques that use an injectable bulking agent. A variety of injectable materials has been studied, such as polytetrafluoroethylene, fat and bovine collagen. We evaluated autologous collagen extracted from the dermis of skin for potential use in the urinary tract. Therefore, an animal model was developed to study the biological behavior of autologous collagen within the bladder. Collagen was extracted from the skin of rabbits and radiolabeled with 125iodine. An aliquot of radiolabeled autologous collagen was injected submucosally in the bladder. The animals were monitored weekly under a gamma camera. The decay of the radiolabeled collagen was recorded during 50 days. The animals were then sacrificed and the bladder wall at the site of injection was studied histologically and on electron microscopy. Decay of the injected collagen within the urinary tract was similar to control material, indicative of good stability within the bladder. A mild inflammatory response with fibroblastic and vascular invasion of the collagen implant was observed. These preliminary data suggest that autologous collagen injected endoscopically can provide a safe reliable bulking material that could be used to treat urinary incontinence and lower grades of vesicoureteral reflux in children.

Congenital Ureteral Valves—An Abnormality of Ureteral Embryogenesis?

Congenital ureteral valves are a rare cause of obstructive uropathy and the majority of cases are diagnosed only at surgery or autopsy. A case of congenital ureteral valve associated with an incompletely duplicated kidney is reported and the literature on ureteral valves is reviewed. Modern uroradiological and endoscopic diagnostic techniques should result in a more precise preoperative diagnosis. The high incidence of associated genitourinary anomalies, particularly duplication anomalies, suggests abnormal ureteral embryogenesis as an etiological factor in congenital ureteral valve formation.

Computer assisted tomography of urachal abnormalities.

Three examples of urachal abnormalities are presented: two urachal cysts and one urachal carcinoma. These cases demonstrate the value of computed tomography in detecting urachal abnormalities, particularly if there is no communication between the bladder and the urachal remnant. The embryonic development of the bladder is discussed, particularly with reference to the development of urachal abnormalities.