In the days before ultrasound was common, most children with hydronephrosis were detected because of back and abdominal pain, abdominal masses, hematuria, urinary tract infections, or even after the kidney ruptured. With the improvement and popularity of imaging technology and the emphasis on pregnancy tests, more and more hydronephrosis can be detected before the child shows symptoms, or even before birth.
To talk about hydronephrosis, we have to start from the embryonic period. The fetal kidney is usually detected by ultrasound at 13-14 weeks of gestation and the fetal bladder at 18-20 weeks of gestation, while the ureter and urethra are not normally detected by ultrasound. By 17-18 weeks of gestation, fetal hydronephrosis may be detected by ultrasound. Fetal hydronephrosis is detected in 2-5.5% of pregnancies and is more common in male than female fetuses. Fetal hydronephrosis is still considered very common.
Mothers-to-be with ultrasound results are often seen in pediatric surgery clinics. The detection of hydronephrosis in a baby that has not yet been born can cause anxiety for the mother-to-be who has just experienced joy. Statistics have been done, about 48% of fetal hydronephrosis are transient and about 15% are physiological, 63% of which cannot be considered as “disease” because they will get better on their own before or soon after birth. The remaining 37% are considered to be “sick” and only 5-10% are considered to require surgery after birth. That’s why the most important thing I tell mothers-to-be in the clinic is: don’t be nervous, most of them are fine, and don’t be careless, but continue to have regular ultrasound exams.
In the vast majority of cases, a fetus diagnosed with hydrocele does not require any treatment. In rare cases, reduced fetal urine outflow can cause low amniotic fluid, which in turn can affect fetal growth and development. At the current state of fetal surgery, the benefits of fetal surgery for non-fatal conditions versus the risks to the fetus and mother are still very controversial. We can only hope that future technological developments will bring us more surprises, but for now fetal hydronephrosis basically has to wait until the child is born before further evaluation and management.
To be precise, hydronephrosis can only be considered as a manifestation, not as a disease. Urine is produced on both sides of the kidneys and enters the bladder via the ureters on each side, where it is stored to a certain amount and then excreted through the urethra. An obstruction at any location in this channel will show dilatation and fluid accumulation above it, such as an obstruction at the ureteropelvic junction will result in hydronephrosis, such as an obstruction at the uretero-vesical junction will result in ureteral dilatation and hydronephrosis, and then an obstruction in the urethra will result in ureteral dilatation and hydronephrosis on both sides. Besides obstruction, another common cause is reflux, such as urine that enters the bladder is squeezed back into the ureter when the child urinates and the bladder contracts, and you will have ureteral dilatation and hydronephrosis. So whether the hydronephrosis is unilateral or bilateral, mild or severe, whether the ureter is dilated or not, whether the child is urinating smoothly, etc., all of these may mean that there are different reasons behind the hydronephrosis. The most common of these is obstruction at the pelvic-ureteral junction, followed by vesicoureteral reflux, but there are also giant ureters, ureteral cysts, duplicated kidneys, polycystic kidney dysplasia, posterior urethral valves, ectopic ureters, etc. Also hydronephrosis is not always congenital. Trauma or other diseases such as urinary tract stones, polyps, tumors, or pressure from outside can cause hydronephrosis. This makes hydronephrosis quite complex and each child should be evaluated individually.
There are several conditions that need urgent treatment only after the child is born, but of course these conditions are still very rare.
1. hydronephrosis of both kidneys with a full bladder, difficulty in urination and suspected urethral obstruction.
2, huge hydronephrosis causing respiratory depression and feeding difficulties
3, renal failure (solitary hydronephrosis or severe hydronephrosis on both sides).
4.Severe urinary tract infection soon appears. Treatment is also based on puncture fistula and drainage, and further surgery will be done after the situation is stabilized.
The vast majority of the rest of the children need only ultrasound follow-up observation. There is no standardized criteria for when to operate and in what cases, and each surgeon may have a different opinion on this. Generally speaking, it is necessary to be cautious and aggressive in cases of solitary kidney (only one well-developed kidney), recurrent urinary tract infections, bilateral lesions, and persistent worsening of hydronephrosis with thinning of the renal cortex. Personally, I think that the trend of changes is more important than the status alone in judging a hydronephrosis, so it is better to bring all the information of all time periods rather than a single report sheet when you visit the clinic.
For moderate to severe hydronephrosis, the doctor may order many ancillary tests, and there are many ways to combine the tests for hydronephrosis, in addition to many. This is because various tests have their own strengths and cannot completely replace each other.
1.The first choice is definitely ultrasound, which is cheap, non-invasive and can be done repeatedly. Some parents are particularly anxious and can’t wait to do ultrasound examination just a day or two after the birth of their child, and they are particularly excited when the result of hydronephrosis is much lighter than before birth or there is no more hydronephrosis, not knowing that the child is in a relatively dehydrated and oliguric stage at this time and the result is inaccurate. The first ultrasound after birth should be done after a week, or at least 3-5 days. Even if the first ultrasound after birth is normal, it is still necessary to review it again.
2. cystourethrography, which is most important to know the presence of reflux and urethral obstruction.
3, nuclear imaging, or ECT, to assess renal function on both sides
4. CT, which can look at both morphology and roughly function and takes a short time to examine.
5, MR (magnetic resonance), the examination time is on the long side, the sedation requirement is high, and it usually only shows the morphology, not the kidney function, with the advantage of no X-rays. Problems in the downstream of the urinary system can cause problems in the upstream, so one of the characteristics of urological diseases is to grasp the whole picture, and the combination that can clarify the problem is the optimal combination. Many parents worry about X-rays. My concept is that the disease is more harmful to the child, and you can’t just choke on it.
Once the examination is clear, the doctor will add a clearer diagnosis behind the hydronephrosis, and will give a more specific plan according to the cause and the degree of the disease. It should be clear: the purpose of treatment of hydronephrosis is not to eliminate the fluid, because the urine is constantly produced, surgery can only do is to unblock the channel, the fluid does not continue to aggravate the purpose of treatment, so do not ask me why there is still fluid after hydronephrosis surgery, remember: not aggravate is good. It is very likely that hydronephrosis will last a lifetime, and the follow-up is also lifelong.
The urinary tract is supposed to produce and discharge urine, and the urine itself is not harmful to the urinary tract, what has a harmful effect on the urinary tract in hydrocele is the high pressure of urine and infection. Mild and some moderate hydronephrosis are usually not enough to affect kidney function, while the kidney function of those with severe hydronephrosis may not necessarily return to normal after surgery. The earlier, more severe and longer the hydronephrosis appears, the more serious the damage to the kidney is, but if the total kidney function is still normal, the child can still live a normal life.
Etiology treatment.
1, obstruction at the ureteral junction of the renal pelvis. This is the most common pathological cause, generally not urgent immediate surgery, observation, mild can always be observed, moderate to severe with indications need surgery, if delayed on the kidney function is extremely harmful. The gold standard surgery is “disconnected pyeloplasty”. For those with extremely deteriorating renal function, if the fractional renal function is less than 10%, puncture and drainage is feasible, and if there is improvement, disconnected pyeloplasty is performed; if there is no improvement, it is removed.
2. Vesicoureteral reflux. In addition to hydronephrosis and ureteral dilatation caused by reflux, it is also easy to combine urinary tract infections, and the emergence of renal failure in reflux nephropathy is the most serious consequence. Prophylactic application of antibiotics is an important treatment. Because 65% of children can get better on their own at the age of 2 years, Deflux treatment is given to the ureteral opening first abroad (this drug is not available in China) before considering doing ureteral bladder reimplantation
3, ureteral bladder connection obstruction. The manifestation is also hydronephrosis and ureteral dilatation. Need for ureterobladder reimplantation.
4. primary giant ureter. Presentation is also hydronephrosis and ureteral dilatation. Primary means that the end of the ureter itself is unpowered, excluding the above two (reflux and obstruction) causes. Endangering the kidney function or need to consider surgery, traditional surgery is to do ureteral cropping and reimplantation.
5. ureteral cyst. Cutting together to do endoscopic incision, cysts with huge protrusion into the urethra should be removed as much as possible, if there is reflux then do reimplantation.
6, posterior urethral valves. Suitable for endoscopic electrocautery, posterior urethral valves have a great impact on bladder function and need to be treated early, delayed diagnosis will affect bladder function in the long term.
7, duplicate renal ureter. No treatment is needed if there are no symptoms. If there is fluid or ectopic opening of the ureter, surgery is required.
8, renal dysplasia. If there is no symptom, no treatment is needed. If there is effusion or ectopic opening of ureter also need surgery.
9.Polycystic kidney. Requires follow-up, and pediatric surgeons can do very little.
10.Horseshoe kidney. No treatment needed if asymptomatic. If effusion is present, surgical treatment is required.
11, neurogenic bladder. This is a complex disease that could be written in a book.
12, urinary stones, polyps, tumors and other causes of hydronephrosis, need to do treatment for the cause.
In summary.
1, hydronephrosis is very common, do not be nervous, and do not be careless. The conservative conservative, the surgery on the surgery.
2, ultrasound follow-up is usually necessary.
3, hydronephrosis are more specific causes, identified to help determine the treatment plan.
4.Mild hydrocele often does not require surgical treatment, while moderate or severe hydrocele is likely to require surgery.
5. the choice of timing of surgery is different for specific diseases
6.Surgery is not to eliminate the effusion, but to unblock the channel, not to aggravate is good.