In urology, the incidence of congenital malformations is significant. Such pathologies present characteristics in both the diagnosis and the treatment, besides specific handling in the case of pediatric patients.

The clinic has complete pediatric endoscopic and urodynamic equipment needed for diagnosis and treatment. It also provides adequate radiological structure for children under anesthesia.

MASTER CLÍNICA relies on specialized professionals and has improved in the area of pediatric laparoscopy, enabling the correction of several urologic malformations through this surgical technique that does not require incisions and provides less postoperative pain, shorter period of hospital stay and early recovery.



Phimosis can be defined as a narrowing of the opening of the prepuce (foreskin) (skin that covers the glans, which is the head of the penis). This narrowing will not allow the foreskin to be retractable, which makes it difficult or impossible to expose the glans. Every boy, at birth, has physiological or natural phimosis, but around the age of 3, 90% of them will already have the problem solved spontaneously.

At 12 months of age, it may be indicated to the boys who do not yet have a complete exposure of the glans, a treatment with the corticosteroid based ointment, which accelerates the opening of the foreskin. For those who do not show improvement with the use of the ointment, surgery (called circumcision) is indicated, performed immediately after the boy no longer wears diapers (between 2 and 3 years of age).

Surgery is performed under general anesthesia, under an outpatient basis (check out on the same day) and a fast postoperative recovery, when performed at the ideal age.

Possible complications of untreated phimosis: balanoposthitis, paraphimosis, urinary tract infection, associated with penile cancer and sexually transmitted diseases (in adulthood).


Vesicoureteral Reflux (VUR)


VUR is the backflow of urine from the bladder to the upper urinary tract (kidneys), generally congenital and related to the embryological development. The urinary reflux facilitates the migration of bacteria to the kidneys, thus predisposing the occurrence of infection (pyelonephritis). An immune inflammatory response caused by the pyelonephritic infection can result in kidney damage and renal scar formation.

When we study groups of children with urinary tract infection (UTI), the prevalence of VUR is approximately 30%.
This is one of the most common childhood illnesses and when not treated properly it has high morbidity and may result in kidney damage with consequent arterial hypertension and chronic renal failure.

The intensity of the reflux is determined in degrees from I to V through a radiological exam called voiding cystourethrography.

The appearance of VUR can occur during pregnancy, being detected through prenatal ultrasound (it is associated with antenatal hydronephrosis).
The cases of VUR not detected during pregnancy can manifest themselves through episodes of urinary tract infection, abdominal pain, bleeding in the urine, urinary calculi, and palpable abdominal masses or, in more severe cases, kidney failure.

Imaging methods performed in a VUR evaluation are divided between those which aim to diagnose the reflux and those who evaluate the upper urinary tract, in search of renal scarring. Additional exams also allow for the diagnoses of other associated anomalies.

Voiding cystourethrography (VCUG) is the main exam for the diagnosis and grading of VUR.
Ultrasonography of the kidneys and the urinary tract is the initial evaluation method of the upper urinary tract; it can detect associated malformations.
Renal scintigraphy with DMSA (dimercaptosuccinic acid) evaluates the tubular kidney function and detects the presence of cortical scarring.
The main therapeutical modalities are clinical and surgical treatments (conventional, endoscopic and laparoscopic).

The clinical treatment consists of antibiotics in low daily doses (prophylaxis) and, as an alternative, a surgical correction has been proposed, based on the fact that in most children with lower grades of the illness, the resolution of the reflux can be spontaneous during the growth period.

In the surgical treatment, the goal is to prevent the infected urine from rising to the upper urinary tract, in order to reduce the likelihood of new episodes of pyelonephritis. The indication for the VUR surgical treatment is individualized and depends on extensive investigation.


Pyeloureteral Junction Stenosis (PJS)


In order to understand what the PJS stenosis is, it is best to first understand how the kidneys produce urine and how it drains through the renal pelvis and ureters, which are affected by this disease.

The kidney has the function of filtering the blood, removing the waste products from the body’s metabolism and producing urine. The urine produced is collected by the kidney pelvis and then transported to the bladder through a channel known as the ureter. The PJS is the connection between the kidney pelvis and the ureter.

The term stenosis means narrowing or thinning. PJS stenosis is a kidney malformation, when narrowing of this junction occurs. This causes an obstruction of the urine passage, resulting in an accumulation in the affected kidney and consequent dilatation (hydronephrosis).

Stenosis of the JUP can already be detected during pregnancy, through morphological ultrasound. The alteration found is an antenatal hydronephrosis (ANH), which, soon after birth, should be evaluated and investigated by a specialized urologist.

Among the investigation exams, the most important are the ultrasound of the urinary tract and the renal scintigraphy.

The surgery (pyeloplasty) basically consists in removing the narrowed region (PJS) and “joining” the healthy segments again.
Pyeloplasty can be performed openly, the conventional way (a “cut” in the abdomen), or through a more modern technique called laparoscopy.
Through laparoscopy, the surgeon accesses the kidney through small incisions (3-5 mm) that allow the entry of an optical system with a camera and mini laparoscopic instruments.
This technique, considered minimally invasive, offers a number of advantages to the patient: less trauma, less bleeding and faster postoperative recovery.
Master Clínica, a pioneer in laparoscopic technique, also offers this type of treatment for pediatric patients.


Urinary Infection


Urinary tract infection (UTI) is common during childhood. It is estimated that 8% of girls and 2% of boys will have at least one episode of UTI before reaching 7 years of age.

Clinical manifestations vary according to age and to the affected urinary tract segment (if it involves the kidney or if it is limited to the bladder). In infants and young children, the UTI can be manifested through nonspecific signs and symptoms (fever, irritability, decreased appetite, vomiting, diarrhea and prostration). The presence of a fever with no apparent focus at the clinical examination is the main evidence in this group.

Older children, who no longer wear diapers, may present more localized complaints, such as pain when urinating, loss of urine during the day or night, back or abdominal pain.
Urinary tract infection is often caused by micro-organisms from feces, and Escherichia coli is the isolated pathogen in 80% to 90% of the cases, and may be associated with abnormalities of the urinary tract and often requires a more detailed investigation on the possible cause of infection.

When a child has a fever and is suspected of having a urinary tract infection, early diagnosis is extremely important, as it will allow proper treatment, reducing the risk of renal scarring formation, which are infection sequelae that enable the development of high blood pressure and future chronic kidney disease.

Inguinal Hernia / hydrocele


It is a disorder characterized by painless swelling (bulging) in the girls’ groin area (inguinal) or in the boys’ inguinoscrotal region.

The most common age for the symptom onset is between 3 and 4 years of age, but may occur at any age, even shortly after birth. The swelling in the groin area, most commonly at the end of the day, intensifies with crying and physical exertion. In general, the child with a hernia does not feel pain in the region; when pain is present, it is possible that this is an incarcerated hernia. In that case, the child should be urgently evaluated by a surgeon (preferably a specialist).

The treatment is surgical (inguinal hernia) and the surgical correction must be programmed soon after the diagnosis. The more the treatment is postponed, the greater the risk for hernia entrapment, a serious complication which increases the risk of surgery.




One of the most common congenital abnormalities in male newborns is the result of malformations in the development of the urethra, which causes the orifice through which the urine comes out (meatus), not to be located in the usual position, that is, at the top of the penis. The urethra can then be opened in any position along the ventral (bottom) part of the penis.

The urethral orifice can be located from the part nearest to the head of the penis (glans), passing through the scrotum (testicular bag) until the part near the anus (perineum). The farther the urethral orifice is from the penis glans, the more severe is the clinical picture, due to the complexity of the treatment. Fortunately, the most distal hypospadias (urethral orifice near the glans penis) constitute the large majority of cases (about 70%).

The treatment for hypospadias is surgical. In general, the hypospadias closest to the glans are treated at once, while the hypospadias farthest from the glans need more surgeries for their correction (surgery in stages).

The ideal time for surgery must be between 6 months and 2 years of age, because in this period the child already has functional maturity of the body to bear the whole anesthetic/surgical process and has not yet reached the recognition phase of the genitalia, decreasing the probability of developing psychological trauma.
For the success of the surgery, in addition to the surgical technique used, the bandaging still performed in the operating room and in the postoperative period, besides the use of a urethral catheter to drain the urine is also important.

The postoperative complication rate is high, reaching up to 30%. The main complications are: opening of the new urethra (fistula of the neourethra), obstruction (stenosis) of the neourethra, and opening of the sutures (dehiscence) of the glans, among others.

Antenatal Hydronephrosis


The term antenatal hydronephrosis (ANH) or pyelocaliceal ectasia refers to dilation present in the kidney of a fetus, which may compromise one or both kidneys. It corresponds to 15% of all defects detected still in the pregnancy period.

During the prenatal care of pregnant women, the antenatal hydronephrosis can be identified through morphological ultrasonography, performed routinely to evaluate in detail the development of the baby and the early detection of possible structural malformation of the fetus.

The main causes of antenatal hydronephrosis are ureteropelvic junction stenosis (most common), vesicoureteral reflux, posterior urethral valve and megaureter.

Even before the birth of the child, a urologic evaluation can be made, which is basically to clarify to the parents about major causes and their treatments, possible after birth. There are no interventional intrauterine treatments with effective scientific evidence.

After birth, the child should be evaluated by experts (pediatric urologist and pediatric nephrologist) to reach specific diagnosis and adequate treatment.
Most cases (about 70%) will develop favorably, not requiring any surgical intervention.




It refers to an abnormal ureter due to the fact that it presents dilation and eventual tortuosity. This condition is usually associated with some obstructive factor – functional or mechanical – to the urine flow. Conceptually, one can say that ureters with a 7 mm caliber or more are considered dilated.

The coming into view of the megaureter can occur during pregnancy; it is of the primary kind when it is related to congenital abnormalities of the ureter itself, or of the secondary kind, when it is related to obstructive abnormalities of the bladder or urethra.

The megaureter is detected through a prenatal ultrasound. However the non-identified cases during pregnancy can manifest themselves as episodes of urinary tract infection, abdominal pain, bleeding in the urine, urinary calculi, palpable abdominal mass or, in more severe cases, kidney failure.
The tests of choice for its detection and monitoring are ultrasonography, voiding cystourethrography and renal scintigraphy.

Treatment is initially clinical, with surgery indicated in cases of persistent pain, recurrent infection, hematuria (elimination or presence of blood in the urine) and worsening of the renal function, which occurs between 9% and 28% of the cases.

Clinical treatment consists, primarily, of preventive antibiotic therapy (daily use of low doses) and follow ups with imaging exams.

But surgery treatment has, as a principle, the removal of the diseased distal part of the ureter, the reduction of the ureteral caliber and the ureteral reimplantation. The success of surgery is between 75% and 95% of the cases.




It is characterized by a failure in the testis descent to the scrotum (testicular bag) during the fetal development. After its appearance (in the retroperitoneum, through abdominal topography), the testicles migrate down through the inguinal canal (in the groin) and at birth should already be settled within the testicular bag. It may, however, occur that one or both testicles have an incorrect descent.

The cryptorchid testes may be located both in the inguinal canal and inside the abdomen (intra-abdominal). Through the physical examination, one can notice a hypoplastic scrotum (empty) and can palpate a testicle in the inguinoscrotal region. In 20% of the cases, the testicles are not palpable, and may indicate that they are in an abdominal position.

Until the child is 1 year old, there is a likelihood of the cryptorchid testes to continue their migration movement to the scrotum.
After this period, surgical treatment is recommended. There are clinical treatment protocols with the use of hormones for the stimulation of the testicular descent, all without proof of clinical efficacy.


Neurogenic Bladder


The function of the urinary bladder is to store urine to a certain capacity (variable according to the child’s age), until voluntary micturition (urination) occurs in a socially appropriate time, always with low pressure inside the bladder (in order to avoid damage to the urinary tract).

The neurogenic bladder refers to a group of diseases that affect the normal function of the bladder due to neurological lesions, both in the central nervous system (encephalon, marrow) and in the peripheral nervous system (bladder innervation).

The main pediatric diseases that evolve with neurogenic bladder are: myelomeningocele (defect in the closure of the backbone), occult spinal dysraphisms (non-visible spine pathologies), diseases which affect the central nervous system (cerebral palsy), among others.
The neurogenic bladder can manifest itself in two ways: hypercontractile bladder and hypocontractile bladder.

The hypercontractile bladder (hyperactive) has thicker walls and low storage capacity. It is manifested by involuntary and frequent bladder contractions, causing the patient to increase the trips to the bathroom, sometimes presenting urinary incontinence (urine loss in the underwear).

The hypocontractile bladder (underactive) has thin walls, increased storage capacity and decreased sensitivity. It manifests itself with the filling of the bladder beyond what is expected for the age and can cause overflow urinary incontinence. In addition, during urination, the child cannot properly empty the bladder (due to the low contraction strength of the bladder muscle), increasing the presence of urine residue, which is a risk factor for urinary tract infection.

The proper diagnosis of neurogenic bladder requires specific tests, such as urodynamic study, voiding cystourethrography (VCU) and ultrasound of the urinary tract.
Master Clínica has all the suitable diagnostic methods which are adequate to the pediatric population. It also has a clinical staff qualified in Pediatric Urology and Nephrology for the optimal monitoring of children with neurogenic bladder.


Nocturnal Enuresis


Nocturnal enuresis (bedwetting) is the involuntary habit of urinating during sleep. About 15% of children around 5 years of age have nocturnal urine leakage and it is more common in boys. It is at the beginning of school life that most parents and doctors start worrying about the nocturnal continence, because of the negative impact that bedwetting can play in a child’s socialization.

When the symptom manifests by itself, it is called Monosymptomatic nocturnal enuresis, and children of parents who used to lose urine in bed have increased chances, between 44% and 77%, of also suffering from nocturnal enuresis.

When realizing that bedwetting is associated with daytime symptoms characterized by increased urinary frequency, loss of urine during the day and weak urine stream, one should evaluate the child to investigate anatomical urinary tract diseases or neurological impairment.

Treatment options vary according to the aspects of the problem and the child’s profile. The behavioral modification therapy, which introduces a voiding reeducation, is a good therapeutic option aiming to change inappropriate behaviors that contribute to the persistence of enuresis (eg, drink fluids before going to sleep and not urinate regularly during the day). After careful evaluation, a drug therapy can be used in search of a better result.

Posterior urethral valve (PUV)


The most common cause of congenital urethral obstruction in children is on the PUV, with an incidence of 1 case per 3000-8000 live births, affecting only boys. Currently, the diagnosis for 60% to 80% of the cases is still done at the prenatal exams.
The valve is characterized by a membranous structure, originating from the floor lining of the prostatic urethra, which blocks the flow of urine.
The obstruction of urinary flow causes dilation, lengthening of the posterior urethra and thickening of the bladder muscle, as shown in the following figure.
In older children, the most obvious symptoms are: urinary incontinence, urinary urgency, squirt changes and dripping.

Voiding cystourethrography(VCU) is the best available test (gold standard) for the diagnosis of PUV, especially when associated with secondary vesicoureteral reflux (VUR).
The association with the urinary tract infection appears in more than 50% of children over one year of age suffering from PUV.
The overall evaluation of the newborn is extremely important, with special attention to the pulmonary and renal functions, and possible connection with the urinary tract infection.

After confirming the PUV, the initial approach, usually with a short stay, must be the bladder urinary drainage through a gavage.
A final treatment for VUP should be considered for boys born at term with normal weight, good general condition and absence of infection, through valve endoscopic cauterization.

Vesicostomy, which is a temporary deviation of the urine, by making a small surgical subumbilical incision, is indicated for patients with small diameter ureters, urinary tract infection or even sepsis, disorder of the excreta eliminated by the kidneys and renal failure.

In neonates with severe renal impairment, a higher urinary diversion may be indicated – ureteral or renal pelvis.


Voiding Dysfunction (VD)


VD is very common in children. It is a bladder dysfunction characterized by an abnormal pattern in its filling or emptying. The voiding function control in childhood is acquired starting at the age of two and it can occur until they are 4 years old. This disorder is present in 15% of seven-year-old children and is more common in girls. It is the cause of urinary tract infection in children after 4 years of age, and when left untreated, it also causes low self-esteem, social isolation and behavioral changes.

It can manifest itself with urine loss during the day, bedwetting, urinary urgency, abdominal pain, irregular or unfrequent urination (retention), intestinal constipation, urine and/or feces residue on clothing, a feeling of no vesical emptying, vulvovaginitis or untreatable rash, recurrent urinary tract infections, secondary vesicoureteral reflux (return of urine from the bladder into the kidneys), among others.

Early diagnosis is critical for the proper treatment, in order to improve the child’s social condition and prevent the formation of renal scars in children affected by urinary infection.

Pyeloureteral Duplicity

Minimally Invasive Surgery

Its origin is linked to complex embryological mechanisms. This is a duplication of the ureter on the same side, forming the upper and lower renal units. It may be incomplete, when the tubes (ureters) of these units merge before reaching the bladder, or complete, when the tubes of the units enter the bladder separately. In this case, it can present distinct problems of obstruction or reflux of urine.

The treatment is surgical and must be individualized for each situation. In an obstructive case with preserved kidney, a drainage procedure will be performed within the bladder, through the channel, using endoscopic equipment.

In case of a refluxing ureter, a more complex procedure may be required – the ureteral reimplantation, which is described in VUR.

If there is loss of organ function, removal of the renal part (heminephrectomy) may be the indicated treatment. We can perform this procedure through the laparoscopic technique, in order to minimize surgical trauma and offer a fast recovery period.

Master Clínica has skilled professionals specialized in the identification and treatment of this complex pathology.


Testicles intra-abdominal

Minimally Invasive Surgery

The testes that are palpable or visible in the inguinal region through an image examination are attached in the scrotum through open surgery(orchidopexy).
Patients whose testicles do not appear in the examination should be treated through laparoscopic treatment (video surgery without cuts), with the initial diagnostic purpose of location and then therapeutic for the scrotal fixation.

A one-time treatment may occur when the vessels are long enough for achieving the testicular positioning in the scrotal sac or a two-time treatment should be done when the vessels are short. In this case, the testicle is temporarily attached in the inguinal path and then there is a minimum waiting period of six months, for the development of collateral circulation (organ autonomization) and at the second time, the final scrotal fixation is done.



Minimally Invasive Surgery

The ureterocele is a congenital disease that consists in the presence of a membrane in the terminal segment of the ureter at the junction with the bladder, causing obstruction of that renal unit’s urinary flow. As a result, it may cause recurrent urinary tract infection, dilation and even loss of kidney function.

The treatment may be performed through the urinary duct (urethra) using a set of endoscopic equipment, camcorder, and laser unit to promote the opening of the obstructive membrane.

In some situations, a more complex treatment technique may be required, like a ureteral reimplantation at the bladder level. This method is traditionally performed through open surgery. However, more recently, laparoscopy was developed, bringing a lot of advantages to the child, because it is minimally invasive.


Posterior Urethral Valve (PUV)

Minimally Invasive Surgery

The PUV, by its destructive potential to the renal units and considering that it is not always easy to identify, makes it necessary for the diagnosis and therefore the treatment to be as fast and effective as possible.

The urethral endoscopic approach (bladder canal), which is usually the treatment of choice, consists in using a high-definition camera system attached to the endoscopic instruments (suitable for an infant patient), equipped with a laser unit for the fulguration (cauterization) of the valve, thereby removing the obstructive component.
The child has a fast postoperative recovery, being discharged from the hospital the day after the procedure.


Vesicoureteral Reflux

Minimally Invasive Surgery

The endoscopic treatment is based on the submucosal injection of synthetic substances that block the backflow of urine, below the entrance of the ureter, achieving very satisfactory results (up to 80% efficiency). Because it does not cause many complications, the endoscopic injection may be considered a good option, especially in patients with less severe refluxes (grades I, II and III).In cases of higher degrees of reflux (IV and V), the efficiency drops to approximately 50%.

The most advanced cases of reflux, or those in which the clinical and endoscopic treatment made no difference, can be solved through conventional open surgery or through a more effective technique which is laparoscopy.

Master Clínica, a pioneer in performing minimally invasive surgery, offers this type of treatment for VUR. Some of its advantages are: less tissue trauma, less postoperative pain and faster recovery.

Ureteropelvic Junction Stenosis (UPJ)

Minimally Invasive Surgery

The narrowing of the kidney channel (also known as UPJ stenosis) obstructs the flow of urine coming from the kidneys. It should be treated surgically when it begins to damage the kidney function.

This narrowing can be corrected through the endoscopic technique (endopyelotomy), by means of an equipment set like video camera, medical instruments, and laser unit, where the narrowing region is expanded to normalize the passage of urine.

The procedure, considered the first choice due to its great results, is the mini-laparoscopic technique, in which the kidney is accessed through 3 to 4 incisions of 3 to 5 mm in diameter. In this surgery, called pyeloplasty, the narrowed segment is extirpated and a reconstruction of the ureter and kidney is done, thus eliminating the obstructive factor.


Doctor’s office


Children, usually accompanied by their parents, are cared for in a large room, decorated with children’s theme, in order to make the environment cozy and suitable for the clinical evaluation. In the same manner, the waiting period occurs in a room provided with audiovisual resources which aims the patient’s full entertainment. Next to it, we also offer a bathroom with a diaper changing table for the mothers’ convenience, but mostly for the comfort of children.

Alex Sato Tanaka MD


Gustavo Marconi Caetano Martins MD


Mariana Araújo Barbosa Tanaka MD / Consultant


Graduated in Medicine from the North Juazeiro Medical School

Residency in Pediatrics at Children’s Hospital Albert Sabin

Specialist in Pediatrics by the Brazilian Society of Pediatrics

Residency in Pediatric Nephrology at the Federal University of São Paulo (UNIFESP)

Specialist in Pediatric Nephrology by the Brazilian Society of Nephrology and the Brazilian Society of Pediatrics

Master of Science Applied to Pediatrics, Federal University of São Paulo (UNIFESP)

Pediatric ultrasonography


Ultrasonography is an excellent image examination for children, as it allows for the diagnosis of major diseases, which affect the urinary and genital tract, without the use of radiation.

Master Clínica offers ultrasounds of the whole abdomen, the urinary tract, the inguinal region, the testicular bag with Doppler, and others.

We conduct the examinations on children of all ages (from a few days old to teenagers). The examinations are conducted by the pediatric urologists themselves, Dr. Alex Tanaka and Dr. Gustavo Marconi, ultrasound specialists, qualified to treat the pathologies diagnosed in exams.

In order to perform the examinations, we offer a propitious environment with audiovisual resources, which distract the children and a heated gel is used (especially on cold days).

Urethrocystography voiding with sedation


Voiding cystourethrography (VCU), also known as Micturating cystourethrography (MCU), is an examination suitable for children under the age of 3 with a single proven episode of urinary tract infection, and for children over 3 with recurrent urinary tract infection. Currently, it is the only test capable of diagnosing and grading the vesicoureteral reflux (urine return from the bladder into the kidneys), allowing for proper treatment. It is also recommended for patients suspected of having posterior urethral valve (a membrane in the urethral canal which blocks urine output).

At Master Clínica this procedure is carried out under sedation (anesthesia), as it allows for a better examination quality with less discomfort for the patient. We have our own team of anesthesiologists, specialists in child anesthesia.




It is an examination used to evaluate the bladder function in children with symptoms such as urinary incontinence, urinary urgency, increase in urinary frequency and nocturnal enuresis. The urodynamic is also indicated when the child has recurrent urinary tract infection.

A computer program (software) is used, which allows the study of urination dynamics by filling the bladder through a catheter.

The examinations are conducted by our pediatric urologists, Dr. Alex Tanaka and Dr. Gustavo Marconi, experts in treating diseases that affect a child’s bladder.

For a higher quality examination, we use audiovisual resources that make the process more comfortable for small patients.


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