Prostate development in prune belly syndrome (PBS) and posterior urethral valves (PUV): etiology of PBS--lower urinary tract obstruction or primary mesenchymal defect?

Fertility prospects for the prune-belly patient: A scoping review

INTRODUCTION

With advances in medical care and assisted reproductive technologies (ART), fertility prospects for prune-belly syndrome (PBS) men may be changing. This review aims to identify the factors influencing fertility and optimization of reproductive health for PBS patients.

MATERIAL AND METHODS

A scoping review was performed on all records published over 70 years (1952-2022) analyzing fertility in PBS males. Records were summarized in a table and narrative describing cryptorchidism, orchiopexy, testicle histology; prostate characteristics; sex hormone function; semen analyses, ART, and conception ability. This review was registered on Open Science Framework (OSF) and conducted using PRISMA methodology.

RESULTS

827 articles were identified and 83 were selected for data extraction. Before 2000, there were 0.85 publications/year whereas after 2000 there were 1.95 publications/year. Orchiopexy successfully relocated 86 % of PBS testicles into the scrotum. Testicular histology demonstrated 50 % of patients had no spermatogonia, while 47.2 % and 2.7 % had reduced or normal numbers respectively. Leydig hyperplasia and Sertoli only histology were found in 19.4 % of patients. Prostatic hypoplasia and prostatic urethral dilation were found in 93.6 % and 91.4 % of patients respectively. Testosterone, Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) were normal in 93.9 %, 87.7 % and 77.9 % of patients respectively. Azoospermia and oligospermia was found in 75.7 % and 21.6 % of patients respectively while 60.7 % had antegrade ejaculation. ART successfully extracted sperm in 6 instances and resulted in 4 conceptions, while natural conception was reported twice.

CONCLUSIONS

Data analysis indicates increased attention to fertility prospects for PBS males with evaluation of PBS patient's hormonal function, semen analyses, ART, and conception ability. The reviewed data suggest that PBS males may father biological offspring with contemporary management and also demonstrate the need for consistent reproductive management approaches to maximize their fertility prospects.

Gonadal Function and Reproductive System Anatomy in Postpubertal Prune-Belly Syndrome Patients

OBJECTIVE

To gain insight into the causes of infertility in Prune Belly Syndrome (PBS) by evaluating reproductive system anatomy and gonadal function in a cohort of postpubertal PBS patients.

METHODS

We contacted all PBS patients 14 years old or older treated and followed at our institution. Age at orchiopexy, type of orchiopexy (with or without ligation of gonadal vessels), testicular volumes and positions were evaluated. Pelvic magnetic resonance imaging (to assess prostate size, seminal vesicles, and vas) and hormonal profile were ordered. Sperm analysis and analysis of urine after masturbation were performed after informed consent.

RESULTS

Fifteen patients were included in this study. Mean age was 19.2 years. Mean age at orchiopexy was 18 months. Fourteen patients (93.3%) had normal and orthotopic testes. Mean testicular volume was 6.9 cc. Eight patients collected semen, 5 of them (62.5%) had spermatozoa in the specimen and motile sperm was found in 4 (50%). Mean hormone levels were LH: 5.3 mg/dL, FSH: 6.9 mg/dL, testosterone 531 mg/dL. Magnetic resonance imaging revealed hypoplastic prostates in 66.6% and unilateral seminal vesicle absence in 66.6%. No vasal abnormality was noted.

CONCLUSION

Patients with PBS may have normal sexual hormonal levels. Motile spermatozoa were found in half of the patients. Our study highlights a high prevalence of prostate and seminal vesicle abnormalities that may represent an important cause for their infertility.

Congenital Disorders of the Human Urinary Tract: Recent Insights From Genetic and Molecular Studies

The urinary tract comprises the renal pelvis, the ureter, the urinary bladder, and the urethra. The tract acts as a functional unit, first propelling urine from the kidney to the bladder, then storing it at low pressure inside the bladder which intermittently and completely voids urine through the urethra. Congenital diseases of these structures can lead to a range of diseases sometimes associated with fetal losses or kidney failure in childhood and later in life. In some of these disorders, parts of the urinary tract are severely malformed. In other cases, the organs appear grossly intact yet they have functional deficits that compromise health. Human studies are beginning to indicate monogenic causes for some of these diseases. Here, the implicated genes can encode smooth muscle, neural or urothelial molecules, or transcription factors that regulate their expression. Furthermore, certain animal models are informative about how such molecules control the development and functional differentiation of the urinary tract. In future, novel therapies, including those based on gene transfer and stem cell technologies, may be used to treat these diseases to complement conventional pharmacological and surgical clinical therapies.

Posterior urethra: Anterior urethra ratio in the evaluation of success following PUV ablation

INTRODUCTION

There are conflicting reports on the criteria with which to determine success following posterior urethral valve (PUV) ablation. The aims of this study were to assess the value of the posterior urethra: anterior urethra ratio (PAR) in predicting successful PUV ablation.

MATERIALS AND METHODS

All neonates and infants with confirmed PUV on voiding cystourethrogram (VCUG) were included. Initial PAR was computed by dividing maximum posterior urethral diameter by anterior urethral diameter. Distances were measured by an on-screen distance measurement tool in the Radiology department, to avoid error. Only oblique images with good voiding phases were used for assessment. All patients underwent cystoscopy and PUV ablation using cold knife. Postoperative VCUG and cystoscopy were performed at 3 months follow-up. Success was defined as cystoscopic resolution of obstruction, in addition to biochemical and radiological improvement, and this was compared with PAR findings. An equal number of age-matched control patients who had a normal VCUG (as a part of evaluation of antenatal hydronephrosis) were also analyzed.

RESULTS

A total of 56 patients (median age 15 days, range 3-250 days) were analyzed between 2013 and 2016. The mean PAR was 1.5 (0.42) in controls and 3.42 (0.75) in those with PUV at diagnosis (P = 0.001). In those with successful PUV ablation (n = 51) the mean PAR was 1.8 (0.21), and in those with residual PUV/stricture (n = 5) the mean PAR was 3.16 (0.54). The difference between these two groups was statistically significant (P = 0.0001). Applying the value of mean + 2 SD of successful PUV ablation, an upper limit of PAR >2.2 was proposed to predict failure. Using this cut-off, 4/7 with PAR >2.2 had confirmed failure, while 48/49 with PAR <2.2 had successful resolution (P = 0.001) CONCLUSION: Whenever the posterior urethra is more than 2.2 times the diameter of the anterior urethra (PAR >2.2) on repeat VCUG following a PUV ablation, a cystoscopy check is essential to rule out residual PUV/stricture.

Prune-belly syndrome: case series and review of the literature regarding early prenatal diagnosis, epidemiology, genetic factors, treatment, and prognosis

Prune-belly syndrome (PBS) is a rare congenital syndrome characterized by deficient abdominal muscles, urinary tract malformation, and in males, cryptorchidism and has an estimated incidence of 1 in 35,000 to 1 in 50,000 live births. The syndrome might be due to severe bladder outlet obstruction or to abdominal muscle deficiency secondary to a migrational defect of the lateral mesoblast between weeks 6 and 7 of pregnancy. The current review of the medical record reports a special focus on epidemiology, genetic factors, early prenatal diagnosis clusters, treatment, and prognosis of PBS.

Fetal megacystis: differential diagnosis

The purpose of our retrospective observational series was to determine whether the sonographic characteristics of fetal megacystic bladders can be used to reliably establish the most likely diagnosis in fetuses with this condition. The sonographic records of pregnant patients referred to our institutions over a 10-year period who were found on initial 2-dimensional sonography to be carrying fetuses with megacystis were examined for evidence of a keyhole sign, bladder thickness, amniotic fluid index, and fetal sex. When available, 3-/4-dimensional sonography, Doppler angiography, tomographic ultrasound imaging, virtual organ computer-aided analysis, and automatic volume calculation were used as part of the detailed fetal anatomic survey. Twenty fetuses with megacystis were identified. Seventeen were male; 2 were female; and 1 had ambiguous genitalia. All male fetuses with megacystis originally had a diagnosis of prune belly syndrome. The diagnosis for 10 male fetuses with a keyhole sign was changed to megacystis secondary to posterior urethral valves. The fetus with ambiguous genitalia had prune belly syndrome. One of the female fetuses had a diagnosis of urethral atresia, and the diagnosis for the other female fetus was megacystis-microcolon-intestinal hypoperistalsis syndrome. In conclusion, in fetuses with megacystic bladders, it is possible to distinguish between cases with prune belly syndrome, posterior urethral valves, urethral atresia, and megacystis-microcolon-intestinal hypoperistalsis syndrome by a detailed anatomic survey using 2- and 3-/4-dimensioinal sonographic techniques.

Kallikreins on steroids: structure, function, and hormonal regulation of prostate-specific antigen and the extended kallikrein locus

The 15 members of the kallikrein-related serine peptidase (KLK) family have diverse tissue-specific expression profiles and putative proteolytic functions. The kallikrein family is also emerging as a rich source of disease biomarkers with KLK3, commonly known as prostate-specific antigen, being the current serum biomarker for prostate cancer. The kallikrein locus is also notable because it is extraordinarily responsive to steroids and other hormones. Indeed, at least 14 functional hormone response elements have been identified in the kallikrein locus. A more comprehensive understanding of the transcriptional regulation of kallikreins may help the field make more informed hypotheses about the physiological functions of kallikreins and their effectiveness as biomarkers. In this review, we describe the organization of the kallikrein locus and the structure of kallikrein genes and proteins. We also focus on the transcriptional regulation of kallikreins by androgens, progestins, glucocorticoids, mineralocorticoids, estrogens, and other hormones in animal models and human prostate, breast, and reproductive tract tissues. The interaction of the androgen receptor with androgen response elements in the promoter and enhancer of KLK2 and KLK3 is also summarized in detail. There is evidence that all kallikreins are regulated by multiple nuclear receptors. Yet, apart from KLK2 and KLK3, it is not clear whether all kallikreins are direct transcriptional targets. Therefore, we argue that gaining more detailed information about the mechanisms that regulate kallikrein expression should be a priority of future studies and that the kallikrein locus will continue to be an important model in the era of genome-wide analyses.

Urethral ratio on voiding cystourethrogram: a comparative method to assess success of posterior urethral valve ablation

OBJECTIVE

To develop a simple, objective and reproducible quantitative measurement to assess success of posterior urethral valve ablation.

METHOD

In 30 patients with posterior urethral valves the diagnosis was confirmed by voiding cystourethrogram (VCUG). Our protocol was to perform valve ablation, and repeat VCUG at 12 weeks postoperatively. Urethral ratio was calculated by dividing the posterior urethral diameter by the anterior urethral diameter. Thirty males undergoing VCUG for urinary tract infections were evaluated as normative controls.

RESULTS

Median age of controls was 12 months (2 days-6 years) and of study group was 13 months (1 day-11 years). Mean urethral ratio in pre-fulguration group was 4.94 (+/-2.97) and in post-fulguration group was 2.134 (+/-1.19) (P<0.001). The mean urethral ratio in the control group of 1.73 (+/-0.577) was significantly different from the pre-fulguration group result (P<0.001), but not significantly different in comparison to the post-fulguration group (P=0.104).

CONCLUSION

Calculation of urethral ratio on VCUG as a method of assessment of outcome of fulguration is objective, reproducible, and allows preoperative and postoperative VCUG from different facilities to be compared. A post-fulguration urethral ratio of 2.5-3 represents an acceptable result postoperatively.

Imaging the Pediatric Prostate

The prostate gland is not often the target of imaging in children but may be imaged during investigation of symptoms related to the lower genitourinary tract such as hematuria, urinary retention, dysuria, and incontinence or during an evaluation for suspected congenital anomalies. Ultrasound and voiding cystourethrography are useful for initial evaluation of congenital and neoplastic disorders of the prostate. MR imaging and CT are useful in delineating more detailed anatomy before surgical planning and in determining the organ of origin in a patient who has a large pelvic mass.

A method to assess posterior urethral valve ablation

PURPOSE

There are few published reports addressing the assessment of posterior urethral valve ablation. This study was performed to provide a ratio to measure successful treatment of posterior urethral valves.

MATERIALS AND METHODS

A total of 35 patients with posterior urethral valves were treated by a single surgeon between 1995 and 2004. Of these patients 23 were younger than 1 year at diagnosis and were selected for this study. A urethral ratio was calculated by dividing the posterior urethral diameter by the anterior urethral diameter. A total of 31 males undergoing cystography for urinary tract infections were evaluated as normative controls. The urethral ratio was also measured and calculated for these patients.

RESULTS

Median patient age was 1.5 months. In 13 patients preoperative cystograms were available and in 20 patients postoperative cystograms were available for review. Measurements were made of the posterior urethral and anterior urethral diameters. Median preoperative ratio in 13 patients was 8.6. This ratio decreased postoperatively to 3.1 in 15 patients who only required 1 ablation and 8.0 in 5 patients who required a second ablation. After a second ablation the ratio decreased to 3.1. The 5 cases requiring a second ablation were initially managed by cystoscopy and a flexible electrode. None of the patients treated initially with a resectoscope required a second ablation. Urethral ratio was 2.6 in 31 normal males undergoing cystogram for investigation of a urinary tract infection.

CONCLUSIONS

Calculating urethral ratio in patients with posterior urethral valves allows objective measurement of the technical success of valve ablation.

Initial management of complex pediatric disorders: prunebelly syndrome, posterior urethral valves

Prunebelly syndrome and posterior urethral valves are conditions of detrusor dysfunction associated with antenatal urethral obstruction. The resultant severe hydroureteronephrosis and renal dysplasia initiate a sequence potentially leading to renal failure. This article reviews clinical features and explores neonatal evaluation and treatment for both conditions. A comprehensive approach to initial management aimed at optimal renal preservation and bladder rehabilitation is proposed.

Assessment of serum prostate specific antigen in childhood

OBJECTIVE

To investigate serum prostate specific antigen (PSA) levels with age and sex in childhood.

SUBJECTS AND METHODS

This prospective study included 205 children (123 boys, 82 girls; mean age 59.27 months, sd 3.78, range 2 days to 204 months) with no urogenital or endocrine disorders. PSA levels were measured using a highly sensitive, "third-generation" PSA (time-resolved immunofluorometric) assay, able to detect PSA levels of > or = 1 ng/L (0.001 ng/mL). Children were divided into four groups by age, i.e. A (0-12 months; 34 boys/20 girls); B (13-48, 37/21); C (49-144, 41/32); and D (> 144, 11/9). The data were analysed statistically using analysis of variance.

RESULTS

An accurate measurement of PSA was possible in both sexes using the assay. The median (sd, range) PSA level in boys was 38.41 (1.318, 1-2768) ng/L, and in girls 4.059 (1.392, 1-287) ng/L. There were no significant differences between girls at all age groups, or between the sexes for groups A-C, but levels were significantly higher in boys in group D (30 times that in girls), at 142.59 (1.53) and 4.85 (1.58) ng/L (P < 0.01).

CONCLUSIONS

PSA levels do not differ significantly between boys and girls until 12 years old, after which there is a significant and steep increase in PSA in boys, reflecting the development of the prostate. Assessing PSA in children could be used as a potential marker in the diagnosis and follow-up of urogenital disorders.

Congenital obstructive uropathy: its origin and contribution to end-stage renal disease in children

Most children with end-stage renal failure are born with abnormal kidneys, with fetal obstructive uropathy accounting for about half these cases. Posterior urethral valves (PUV) is overwhelmingly the most common, specific diagnosis, and is confined to boys. In general, the condition is sporadic, although familial cases have been reported, perhaps suggesting that genetic factors play a role in pathogenesis. PUV can present antenatally, detected on routine fetal ultrasonography, or postnatally, when it is associated with renal failure and bladder dysfunction. Advances in postnatal surgery and medical management have reduced the mortality in PUV, but it is uncertain whether antenatal diagnosis or treatment (eg, with vesicoamniotic shunts) improves long-term renal outcome. Other disorders associated with human fetal obstructive uropathy are urethral atresia, the prune belly syndrome, and multicystic dysplastic kidney. The nephropathy associated with fetal obstructive uropathy is renal dysplasia and comprises undifferentiated and metaplastic tissues. Several studies in animals and in humans suggest that fetal urine flow impairment causes deregulation of renal precursor cell turnover and expression of growth factor/survival and transcription factor genes. Furthermore, some of these morphologic and molecular changes can be ameliorated experimentally by fetal surgical decompression or administration of specific growth factors.

Urethral atresia: long-term outcome in 6 children who survived the neonatal period

PURPOSE

Urethral atresia is incompatible with life unless an alternative communication between the bladder and amniotic sac exists. Although antenatal intervention may improve perinatal mortality, clinical consequences remain. We outline the outcome after treatment of 6 patients born with urethral atresia.

MATERIALS AND METHODS

We reviewed the charts of 6 patients with urethral atresia treated at the Children's Hospital of Michigan between 1982 and 1999. Patient age ranged from 3 to 17 years (mean 9). All patients were males (46 XY) and presented at birth or in early infancy.

RESULTS

Oligohydramnios was demonstrated in 4 of the 6 patients (67%). A vesico-amniotic shunt had been placed in 2 patients (at more than 30 weeks of gestation and in 1 at 17 weeks of gestation). The remaining 3 patients presented at birth with either a vesicocutaneous fistula or patent urachus. Bilateral or unilateral hydronephrosis was identified in 4 patients while 2 had severe renal dysplasia. Cystography identified moderate to high grade vesicoureteral reflux in all patients, and 5 (83%) had the prune belly syndrome. Mean serum creatinine at age 1 year was 1.3 mg/dl (range 0.5 to 2.1). Renal failure occurred in 5 patients (83%) before age 10 years and 4 of them have received a renal transplant. An average of 7.8 (range 9 to 14) urological procedures were performed on each patient. Progressive urethral dilation was not successful in the majority of our cases and ultimately 67% required some form of supravesical diversion.

CONCLUSIONS

Our study demonstrates that urethral atresia is not necessarily fatal. Prenatal decompression allows survival and in some cases may even lead to normal bladder and renal function. A complicated clinical course requiring extensive reconstruction is to be expected.

Urethral atresia: long-term outcome in 6 children who survived the neonatal period

PURPOSE

Urethral atresia is incompatible with life unless an alternative communication between the bladder and amniotic sac exists. Although antenatal intervention may improve perinatal mortality, clinical consequences remain. We outline the outcome after treatment of 6 patients born with urethral atresia.

MATERIALS AND METHODS

We reviewed the charts of 6 patients with urethral atresia treated at the Children's Hospital of Michigan between 1982 and 1999. Patient age ranged from 3 to 17 years (mean 9). All patients were males (46 XY) and presented at birth or in early infancy.

RESULTS

Oligohydramnios was demonstrated in 4 of the 6 patients (67%). A vesico-amniotic shunt had been placed in 2 patients (at more than 30 weeks of gestation and in 1 at 17 weeks of gestation). The remaining 3 patients presented at birth with either a vesicocutaneous fistula or patent urachus. Bilateral or unilateral hydronephrosis was identified in 4 patients while 2 had severe renal dysplasia. Cystography identified moderate to high grade vesicoureteral reflux in all patients, and 5 (83%) had the prune belly syndrome. Mean serum creatinine at age 1 year was 1.3 mg/dl (range 0.5 to 2.1). Renal failure occurred in 5 patients (83%) before age 10 years and 4 of them have received a renal transplant. An average of 7.8 (range 9 to 14) urological procedures were performed on each patient. Progressive urethral dilation was not successful in the majority of our cases and ultimately 67% required some form of supravesical diversion.

CONCLUSIONS

Our study demonstrates that urethral atresia is not necessarily fatal. Prenatal decompression allows survival and in some cases may even lead to normal bladder and renal function. A complicated clinical course requiring extensive reconstruction is to be expected.

Prune belly syndrome: early antenatal diagnosis

A case of prune belly syndrome diagnosed by ultrasonography during the thirteenth week of gestation is described. Pathogenic data and the importance of antenatal diagnosis are discussed.

The prune-belly syndrome: current insights

The prune-belly syndrome comprises a constellation of well-established physical findings, yet the cause and management remain controversial. This review focuses on the current understanding of its pathogenesis and characterizes the fetal and neonatal diagnosis and management. Other associated anomalies are discussed to understand better the factors affecting treatment and prognosis as these patients grow into childhood and beyond.

Fetal bilateral obstructive uropathy: a series of nine cases

Bilateral obstructive uropathy is increasingly diagnosed in early pregnancy by ultrasound examination. Termination of pregnancy presented an opportunity to study uropathy in nine cases between 18 and 24 weeks of gestation. En bloc dissection of the urinary tract and subserial sectioning of the urethra revealed obstruction at the level of the membraneous urethra in all cases. No structural obstruction could be demonstrated in three cases, and urethral valves caused partial obstruction in two cases. The urethra was distorted by a fibrous band in one case. In three cases overriding urethral lumens appeared to represent incomplete or faulty canalization at the angled junction of the developing posterior and anterior urethra. Urethral obstruction is considered the major etiologic factor in the development of bilateral fetal uropathy and presumably the prune-belly phenotype.

Lethal congenital non-spherocytic, non-immune hemolytic anemia with genital and other anomalies in two brothers

Non-consanguineous healthy parents had 2 boys with severe, non-spherocytic, nonimmune hemolytic anemia, abnormalities of their external genitalia, flat occiput, dimpled earlobes, deep plantar creases, and increased space between their first and second toes. The birth of these children was separated by a spontaneous abortion at 3 months and delivery of a normal girl. We propose that these boys have a heretofore undescribed autosomal or X-linked recessive syndrome.

Lower mesodermal defects: a common cause of fetal and early neonatal death

Among the first 1,130 referrals to the Wisconsin Stillbirth Service Program 17 infants have been recognized to share phenotypic characteristics involving the genital, urinary, lower gastrointestinal, and axial skeletal systems. The pattern of abnormalities identified appears to be limited to structures sharing a common embryologic origin. These features, for the most part, are shown to be non-randomly associated. No clearly definable sub-groups within this population are demonstrable. The pattern of abnormalities is defined to include abnormalities of the following structures as pathogenetically primary features: lumbosacral vertebrae, kidneys, ureters, uterus/fallopian tubes, vagina, bladder, urethra, adrenals, gonads, anorectum, external genitalia, and umbilical arteries. An embryologic mechanism is proposed which explains this non-random association as arising secondary to disruption of structures derived from the lower portion of the primitive intraembryonic mesoderm. The Lower Mesodermal Defects Sequence appears to be a rather common (and under-recognized) cause of stillbirth and immediate neonatal death.