Pediatric Urology

Diagnostic algorithms, surgical techniques, and clinical management protocols in pediatric urology are standards aimed at ensuring the appropriate treatment of anomalies in the kidneys, bladder, and reproductive organs from infancy through adolescence in light of modern medical data. This comprehensive field of expertise includes planning laparoscopic interventions, robotic surgery solutions, and microsurgical methods applied to preserve the genitourinary system in accordance with the delicate physiology of children. The main principle in pediatric urology practice is to ensure that children experience a healthy developmental process by preserving organ functions at the highest level through minimally invasive approaches and evidence-based follow-up processes.

When Should Postnatal Ultrasonography Be Performed in Infants?

Ultrasonography is the most commonly used method for examining the kidneys and urinary tract of infants. Since ultrasonography does not contain radiation and works with sound waves, it is considered a highly reliable imaging tool for infants. However, the most critical point here is on which day this examination should be performed. Families may usually expect an ultrasound to be performed immediately on the day after birth when a problem is suspected, but the fluid balance in the baby’s body undergoes very significant changes during the first days. The kidneys of a baby newly separated from the womb undergo a physiological adaptation process during the first 48 hours after birth. During these first two days, babies excrete very small amounts of urine from their bodies. An ultrasound performed during a period when urine production is so low will not reflect the amount of fluid inside the kidneys. Even if there is actually an enlargement in the renal pelvis, this enlargement may be hidden on ultrasound because there is not enough urine flow, and it may create the false impression that the problem is much milder than it actually is.

In the later days of the first week, the exact opposite physiological situation occurs. Babies’ kidneys suddenly begin to produce a great deal of urine. This intense urine flow can create an instantaneous and temporary fullness in the renal ducts, making even a very mild enlargement appear on ultrasound as if there were a very serious obstruction. Therefore, unless there is a condition requiring urgent medical intervention, such as the baby being unable to urinate or having significant abdominal swelling, there is an ideal period that should be waited for to obtain the most accurate ultrasonographic assessment. The ultrasonographic evaluation providing the most reliable and clear results after birth is generally performed between the 7th and 10th days of the baby’s life. During these days, the fluid balance in the baby’s body has returned to normal, and urine production has become regular. In this ultrasound, the size of the kidneys is measured in millimeters, the thickness of the kidney tissue is examined, the diameter of the urinary ducts is evaluated, and the amount of urine remaining in the baby’s bladder after urination is carefully calculated. All these obtained data form the basis of the roadmap to be followed in the future.

In Which Situations Is Scintigraphy Showing Kidney Function Requested?

Although ultrasonography provides comprehensive details about the anatomical structure, shape, and size of the kidneys and urinary tract, it may not always show with certainty how well the kidney performs its filtering function or whether there is a hidden obstruction within the urinary ducts. The fact that the shape of an organ appears normal does not mean that it is functioning at full capacity. Scintigraphy tests, which are nuclear medicine applications, are used to evaluate in detail the functional condition of the kidneys, their filtering capacity, and the rate at which urine passes from the kidneys to the bladder. These tests are based on the principle of monitoring the movement of very low-dose, special, and safe substances reaching the kidneys in the body with special cameras.

The main nuclear medicine methods used to evaluate kidney functions in children are as follows:

• DMSA (Renal parenchymal scintigraphy)
• MAG3 (Dynamic renal scintigraphy)
• DTPA (Measurement of filtration capacity)

Among these tests, the method called DMSA is used to determine whether there is permanent damage or scarring in the fleshy tissue of the kidney (parenchyma). It is particularly preferred to see the extent to which kidney tissue has been affected by infection in children who have experienced severe, febrile urinary tract infections. MAG3 scintigraphy is a very important test that dynamically shows how quickly the kidneys filter urine and whether there is an obstruction in the urinary tract. Since the kidneys of newborn babies are not fully mature, the baby is expected to complete the 4th or 6th week after birth in order to obtain the most accurate result from the MAG3 test. The DTPA test is another dynamic examination method that measures the kidneys’ ability to filter blood. As a result of these scintigraphies, the working percentages of both kidneys are mathematically calculated. In a healthy condition, each kidney undertakes approximately half of the total workload. If the working capacity of one of the kidneys has fallen below forty percent, this is an important indicator that the organ has begun to lose function and guides the physician in determining the need for surgical intervention.

How Is Kidney Enlargement (Hydronephrosis) Detected in the Womb Monitored?

One of the issues families hear most frequently and worry about most during routine ultrasound examinations performed during pregnancy is that there is enlargement or dilation in the baby’s kidneys. This condition, medically known as antenatal hydronephrosis, is actually one of the most common developmental abnormalities seen in babies in the womb. When such an enlargement is detected in the womb, there is no need to panic immediately, because this condition covers a very broad spectrum, and a significant portion of cases may tend to improve over time after the baby is born.

Some important ultrasound findings that are carefully monitored in the management of this process are as follows:

• Renal pelvis width (Pelvis AP diameter)
• Condition of the intrarenal chambers called calyces
• Renal parenchyma (fleshy tissue) thickness

To understand the severity of the enlargement, the anteroposterior diameter of the pelvis where the kidney collects urine (AP diameter) is measured in millimeters. In addition, the pressure on the smaller chambers inside the kidney (calyces) is evaluated. After birth, when the baby is taken under urological follow-up, a staging system ranging from zero to four (SFU Grading) is used according to these findings.

In babies with stage 0 and stage 1, there is only very mild stretching in the renal pelvis, and this condition often returns completely to normal as the baby grows. However, in high-grade conditions such as stage 3 and stage 4, the accumulated urine begins to enlarge the inner chambers of the kidney as well and, most dangerously, causes thinning of the actual fleshy tissue of the kidney (parenchyma), which performs the filtering function. Thinning of the kidney tissue is an important sign that the kidney is under high pressure and at risk of damage. These babies are monitored much more frequently and meticulously with both ultrasound and, when necessary, scintigraphy tests, and even the slightest change in kidney functions is recorded.

When Is the Decision for Surgery Made in Cases of Kidney Swelling (Hydronephrosis)?

The vast majority of infants followed due to enlargement in their kidneys are monitored only with ultrasound examinations performed at regular intervals, and it is seen that this problem completely disappears over the years. The aim of the follow-up process is to distinguish physiological enlargements that do not harm the kidney from conditions that create a true obstruction and damage the kidney. The decision for surgical intervention is generally not made solely based on a few millimetric measurements in the ultrasonography report. Surgical intervention comes into play when it becomes a mandatory step to protect the long-term health of the kidney.

The main criteria supporting the decision for kidney outlet obstruction surgery (pyeloplasty) are as follows:

• Kidney function falling to a critical level (Below 40% on scintigraphy)
• Continuous and significant increase in enlargement during ultrasound follow-up
• Recurrent febrile kidney infection attacks
• Development of kidney stones

First of all, when the working capacity of the obstructed kidney falls below 40% in scintigraphy results or when a loss of more than ten percent in organ function is detected in consecutive tests, the surgical option strongly comes to the agenda. In addition, if the enlargement in the kidney continues to increase at every check and the fleshy tissue surrounding the kidney becomes thinner like paper day by day, waiting may now lead to complete loss of the kidney. The child frequently having to be hospitalized due to kidney infections or the urine accumulated in the kidney turning into stones and causing severe pain are also factors that make surgery inevitable. The basic principle of pyeloplasty operations is to cut out and remove the narrowed section of the duct causing the obstruction and to reattach the healthy duct to the renal pelvis in a wider manner. In this way, urine is allowed to flow freely, and the high pressure on the kidney is eliminated.

Why Does Urine Flow Back to the Kidneys in Children (Vesicoureteral Reflux – VUR)?

A healthy urinary system has a perfectly functioning one-way valve mechanism. Urine produced in the kidneys flows downward through thin, long tubes called ureters into the bladder. When the bladder fills or contracts while the child urinates, a natural valve system located where the ducts enter the bladder comes into play and largely prevents urine from flowing backward toward the kidneys. In Vesicoureteral Reflux (VUR), however, the tunnel through which these urinary ducts pass within the bladder wall is congenitally too short, or the valve mechanism has not developed. As a result, each time the child urinates, high-pressure and sometimes infected urine inside the bladder shoots backward through the urinary tubes and reaches the kidneys.

This disease is one of the greatest hidden dangers underlying recurrent urinary tract infections in infancy and childhood. Urine that continuously flows backward toward the kidneys can, over time, cause permanent damage to kidney tissue, the formation of scars, cessation of kidney growth, and even very serious problems extending to high blood pressure and kidney failure at later ages.

The most prominent factor in the development of the disease is genetic. If a child has been diagnosed with urinary reflux, the likelihood of the same structure being present in that child’s siblings is also very high. In fact, if the mother or father had this disease during childhood, the risk of genetic transmission increases by half. Because of this strong genetic connection, it is vitally important for the protection of kidney health that all children with a family history of urine reflux to the kidney undergo specialist evaluation even if they have no complaints.

What Are the Diagnostic and Treatment Methods for VUR?

One of the most effective and widely used imaging methods for determining whether urine flows backward to the kidneys in children is the examination known in medical terminology as Voiding Cystourethrography (VCUG). During this procedure, the bladder is reached through the child’s urinary tract using a very thin catheter, and a special liquid that appears on X-rays is slowly administered. Images are taken while the child’s bladder is filling and especially during urination. If there is upward reflux in the urinary ducts, this liquid is seen very clearly on the X-ray. The disease is graded from one to five according to how high the reflux reaches and how much it enlarges the kidney (Grade 1 is the mildest and Grade 5 is the most severe form). As the grade increases, the risk of kidney damage rises, and the likelihood of spontaneous resolution decreases.

The treatment options planned according to the severity of the disease are as follows:

• Prophylactic antibiotic use
• Endoscopic bulking agent injection (STING / HIT methods)
• Ureteral reimplantation surgery

If the child is young and the urine reflux is low-grade, the body is generally expected to repair itself and the urinary tract to lengthen as it grows and form a natural valve. During this waiting period, a very low dose of prophylactic antibiotic is given every day to protect the kidneys from infection. However, if the reflux does not improve despite the passing years, minimally invasive or open surgical methods are used.

In the minimally invasive endoscopic injection method, a thin instrument called a cystoscope is inserted through the urinary tract without making any incision, and a special biological substance is injected directly beneath the opening where the urine refluxes, creating an artificial mound in that area. This mound acts as a valve and prevents urine from flowing upward, and the child can return home the same day. However, in wide ducts where this method may not be sufficient, reimplantation surgeries with a high success rate are performed, in which the ureter is detached from the bladder and reattached by creating a longer tunnel.

How Dangerous Is Posterior Urethral Valve (PUV) Seen in Male Infants?

Posterior Urethral Valve (PUV) is a congenital anomaly that occurs exclusively in male infants and constitutes one of the most serious and severe obstruction conditions in pediatric urology. While the male baby develops in the womb, thin, sail-like membranous structures that should not normally exist form within the channel (urethra) that exits the bladder and carries urine out of the body. These membranes block the outflow path of urine almost like a plug. When the bladder fills, it has to contract very forcefully in order to expel the urine inside. The urine trapped inside causes enormous pressure, the bladder wall thickens as if it were a heavily exercised muscle, and over time this massive pressure strikes backward toward the kidneys, causing the kidneys to swell and become damaged even before the baby is born.

During ultrasound follow-up in the womb, the “keyhole appearance” caused by a thickened bladder wall and enlargement at the beginning of the urinary tract is highly typical for this disease. After birth, these babies urinate with great difficulty, drop by drop, or intermittently. A hard, unemptied bladder mass can be felt in the lower abdomen, and because urine cannot be expelled, the baby may face severe urinary tract infections or even a fatal condition called sepsis, in which microorganisms enter the bloodstream.

As soon as these babies are born, a thin catheter must be inserted into the urinary tract without delay to reduce the high pressure in the kidneys. The definitive treatment is to enter the urinary tract with very thin camera-equipped instruments and completely cut and eliminate the obstructive membranes using laser or electrical energy (Valve ablation). Even after the obstruction is relieved, the thick bladder tissue, which has been exposed to high pressure for months and has lost its elasticity, has the potential to cause lifelong permanent problems. Therefore, the kidney functions and bladder development of these children must be monitored very closely for many years.

How Does Hypospadias Surgery and the Recovery Process Proceed?

Hypospadias, popularly known as prophet’s circumcision, partial circumcision, or being born circumcised, is an anatomical difference that occurs as a result of the tube carrying urine out of the body failing to complete its development in boys. Under normal conditions, the urinary opening, which should be located at the very tip of the penis, is positioned at any point on the underside of the penis along the line extending toward the scrotum. In addition to the opening being located lower than normal, there is a downward curvature of the penis, known as chordee, which becomes much more prominent especially during erection, and the foreskin surrounding the head of the penis is completely undeveloped on the underside and gathered like a hood on the upper side. Since this condition can cause both an inability to urinate forward and serious sexual function disorders at later ages, it must be surgically corrected. It is recommended that this surgery be completed ideally between the sixth and eighteenth months of life, before the child becomes aware of their sexual identity and is psychologically affected by the condition.

Possible undesirable conditions (complications) that may occur after this delicate surgical procedure are as follows:

• Urine leakage from the new urinary tract (Fistula formation)
• Narrowing of the urinary opening (Meatal stenosis)
• Disruption of tissue integrity (Opening of the surgical site)

The main purpose of the surgery is to move the urinary opening to where it should be, significantly correct the curvature of the penis, and achieve the most natural appearance possible when viewed externally. During the surgery, a new channel, a kind of tunnel, is constructed from the location of the urinary opening to the tip using surrounding tissues. Since the healing and fusion of these newly created tissues take time, a silicone tube (catheter) is placed inside the urinary channel to prevent urine from damaging the fresh sutures, and this catheter is kept in the body for approximately one to two weeks. Especially in small babies, protecting the surgical area from urine and stool is very important to minimize the risk of infection. For this purpose, families are taught the double-diapering method. The inner diaper is selected in a small size, and a hole is made in its center so that the baby’s penis and catheter can be brought out through this hole, completely preventing stool from reaching the area, while the larger outer diaper collects the urine and ensures that the surgical site remains completely clean.

Why Is an Undescended Testis Important and When Should It Be Brought Down into the Scrotum?

The developmental journey of the testes, the most fundamental organs of reproductive function in male infants, begins in the womb in the area just below the kidneys. As pregnancy progresses, these organs begin a long journey downward and pass through the inguinal canals in the weeks close to birth, descending into their permanent home, the scrotal sacs. However, in some babies, this journey cannot be completed, and one or both scrotal sacs are found to be empty at birth. Sometimes the testes become trapped in the inguinal canal, and sometimes they remain deep within the abdominal cavity without ever entering the canal. In premature babies, this descent process may continue spontaneously during the first six months after birth. However, after the sixth month, the likelihood of the testes descending into the scrotum spontaneously without intervention is quite low.

The risks that may arise at later ages in testes that are not brought into place on time are as follows:

• Infertility problems
• Risk of testicular cancer (Especially in intra-abdominal location)
• Unnoticed trauma or testicular twisting (torsion)
• Serious psychological effects

There is one main physiological reason why the testes are located outside the body in the scrotum: they require an environment cooler than body temperature. In order for the testes to produce sperm and maintain healthy cellular structure, they must remain in an environment approximately two degrees lower than normal human body temperature. When a testis remains in the abdomen or groin and is continuously exposed to high body temperature, irreversible structural deterioration and loss begin in the sperm-producing stem cells from the moment the child reaches one year of age. This condition is one of the most important causes of infertility in adulthood.

Moreover, testes that remain at body temperature have a many times greater risk of developing cancer cells than normal testes. If the testes cannot be felt in the groin during physical examination, the abdomen is entered using laparoscopy, a minimally invasive surgical method, and they are searched for with a tiny camera. Once found, they are brought down into the scrotum and fixed in place before the valuable window between the sixth month and the first year of life closes (Orchiopexy surgery).

How Can Kidney Stone Formation in Children Be Prevented and How Are Stones Broken?

Kidney and urinary tract stones seen in children differ greatly from stone disease in adults both in terms of their causes and the course of the disease. While stone formation in adults is often associated with insufficient fluid intake and environmental factors, a metabolic disorder, meaning an imbalance in the substances excreted in the urine, underlies a very high proportion of stones in children. In the urine of these children, substances such as calcium, uric acid, or oxalate that crystallize and form stones may be excreted in much higher amounts than normal, or conversely, the production of protective substances such as citrate, which prevents stone formation and keeps crystals from sticking together, may be insufficient. If this underlying abnormality is not identified and corrected, even if the stones are completely removed surgically, they will recur with the same severity in a very short time, and the child will have to undergo repeated operations.

The modern surgical methods applied according to the size and location of the stones are as follows:

• External shock wave lithotripsy (SWL)
• Laser fragmentation with flexible instruments (RIRC / Flexible URS)
• Surgery through a small opening in the back (Mini-PNL / Percutaneous Nephrolithotomy)

The first step in treatment is to completely remove the stone from the body, while the second and longest-term step is to prevent the formation of new stones through medications and dietary adjustments. If the stones in the child’s kidney are not very large, the non-surgical method of breaking them using externally applied shock waves is frequently preferred. Since children’s body structures are smaller and their tissues are more flexible, these sound waves reach the kidney more easily and turn the stones into sand with a much higher success rate, allowing them to be passed through the urine. However, if the stone is very hard or located in the lower chambers of the kidney, methods performed by entering through the natural openings of the urinary tract are used. Hair-thin, snake-like flexible optical instruments are advanced deep into the kidney and into all its chambers, and the stones are fragmented with laser beams until they are turned into dust. These state-of-the-art methods, which require no incision in the child’s body, allow children to return quickly to their normal lives without damaging the kidney tissue.

Is Bedwetting in Children (Nocturnal Enuresis) a Disease and How Is It Treated?

The condition in which a child over the age of five who has completely completed daytime toilet training wets the bed by involuntarily urinating during sleep is medically called nocturnal enuresis. Families often feel helpless in the face of this condition that continues for many years and tend to attribute the problem to the child’s laziness, stubbornness, or deep sleep. However, the most important fact to know is that bedwetting is not a behavior performed by the child’s own will, but an entirely physiological, hormonal, or bladder-capacity-related organic problem. The child must never be punished, blamed, or shamed; otherwise, a treatable condition may turn into much deeper psychological trauma.

The main scientific treatment steps applied to solve the problem are as follows:

• Regulation of nighttime fluid intake (Urotherapy and behavioral training)
• Bedwetting alarm device (Conditioning therapy)
• Hormonal medications that reduce urine production (Desmopressin)

For treatment to be successful, the actual cause of bedwetting must first be identified. The family is asked to record, hour by hour for several days, all fluids the child drinks and the amount of urine produced. The physiological amount of urine the child’s bladder can store is also calculated using a special formula. The child’s age is taken as a whole number, one is added, and when the resulting number is multiplied by thirty, the approximate number of milliliters of urine the child’s bladder can hold is determined. If the child’s bladder capacity is completely normal but the kidneys produce much more urine during the night than the bladder can hold, a special medication that dissolves under the tongue is given before bedtime to slow the nighttime activity of the kidneys. If the problem is that the child’s bladder capacity is small and the brain cannot perceive the sensation of fullness, a small wetness-sensitive alarm device placed in the underwear is used. The loud alarm sounds as soon as the first drop of urine touches the underwear and wakes the child. Over the course of months, the brain may establish a connection between the sounding alarm and the filling bladder, develop a conditioned reflex, and the child may improve significantly and begin waking up dry.

What Is the Role of Robotic Surgery and Advanced Technologies in Pediatric Urology?

The rapid development of surgical technologies has changed the fate of many complex kidney and urinary tract operations in childhood. In particular, with the development and adaptation of robotic surgery systems called da Vinci, which have been used in adults for many years, to children’s anatomy, the boundaries of minimally invasive surgery in pediatric urology have been advanced much further. In the past, large and extensive incisions had to be made in the abdominal region to repair kidney duct strictures or prevent urine from flowing backward into the kidneys, whereas today, thanks to robotic systems, all these major procedures can be performed with great precision by entering the abdomen through only a few millimetric openings as thin as the tip of a pencil.

Robotic systems are not devices that make decisions on their own; they are advanced technological intermediary systems that transfer the hand and finger movements of an experienced surgeon sitting at a special console in the room to miniature instruments inside the abdomen simultaneously and with high precision. This system shows the patient’s organs to the surgeon in magnified, three-dimensional form and at a resolution so high that it cannot be seen with the naked eye. By filtering out the natural tremor of the human hand to a great extent, this device helps complex sutures to be placed with minimal tissue damage through tiny arms that provide maneuverability in narrow spaces. Since the abdominal muscles are not cut, children feel almost no pain during the postoperative period. Their need for painkillers is reduced to almost none, the risk of infection is minimized, and instead of staying in the hospital for days after major open surgeries, they can return home within a few days, running and playing.

Frequently Asked Questions