With the widespread availability of prenatal ultrasound, more and more hydrocele is being detected in the fetal period, which is a great historical advancement and wins the possibility of early management after birth.
Grading of fetal hydronephrosis. The top row shows the diagram and the bottom row shows the ultrasound image.
After an anxious pregnancy, the baby is born, the newborn eats and sleeps well, and the family enjoys happiness, which seems to make the matter of hydronephrosis faintly forgotten. However, it may not be that simple.
Follow-up visits are important!
Most of the fetal hydrocele will gradually improve after birth, and intermittent ultrasound follow-up is sufficient. In a few cases, it is not so easy, and if it is moderate, severe or persistently worsening after birth, you should not take any chances.
Above: hydronephrosis due to obstruction of the ureteral junction of the renal pelvis, shown in the picture is the left hydronephrosis (pictures of medicine such as no special labeling, are from the perspective of the doctor looking across the patient)
Our primary and secondary school education is multiple choice, any one option is either right or wrong, but medicine is a combination of many uncertainties, and there may be aspects of each option that are advantageous, aspects that are disadvantageous, and many unknown aspects. In addition to a fixed point in time state, one has to look at changing trends.
It is an extremely controversial topic as to when treatment is needed and what treatment is needed for hydronephrosis due to obstruction of the pelvic ureteric junction in neonates. Therefore, what I have said here is only a family opinion and not a guideline. One of the more commonly accepted criteria is that immediate surgery is not necessary for those with fractional renal function of 40% or more.
What is fractional renal function?
Simply put, both kidneys are normal, each doing about 50% of the work; now one kidney is hydronephrosis and the other is normal, the hydronephrosis kidney can still do 40% of the work, and the other normal kidney has to do 60% of the work; in an extreme case, one kidney is almost non-functional (can only do 10% or less of the work), and the other kidney has to do 90% of the work. If both kidneys have problems, this ratio is just a ratio.
Fractional kidney function is something that can only be obtained through a nuclear scan, and is by far the most accurate way to evaluate kidney function. Of course, nuclide also looks at more than just fractional kidney function; it can also evaluate urinary tract obstruction and even reflux if requested. Generally speaking, the heavier the hydronephrosis, the larger the kidney, the thinner the kidney cortex, the longer it lasts, and of course the worse the kidney function. Sometimes there are exceptional cases where the fluid is not heavy on ultrasound, the kidney is not very large (or even small), and the cortical thickness seems acceptable, but the fractional kidney function is surprisingly low, and these kidneys may also have problems with the development of the kidney itself.
Those with renal function above 40% are still in need of continued ultrasound follow-up.
This fractional kidney function is more accurate, but not everyone needs to have it done. Things go back to how to make the initial determination based on ultrasound results. How to perform tests other than ultrasound, such as MR, CT and nuclear, at an appropriate time will be different for each doctor. While it is a fact that most newborns with hydronephrosis will gradually improve, it is also a fact that 15-33% will still show persistent worsening of hydronephrosis and deterioration of the kidney function of the affected kidney. Even though successful surgery will stop the worsening of hydronephrosis and the continued loss of kidney function, some may improve, but in about half of the cases, the lost portion of kidney function will not be restored.
For neonates and infants with moderate to severe hydronephrosis, because of the special period and low resistance, the chance of urinary tract infection is relatively high, and many people recommend the prophylactic use of antibiotics to reduce the possibility of kidney parenchymal damage and fibrosis caused by urinary tract infection. The flow of water does not rot, and the household pivot is not worm-eaten. In those with moderate to severe effusion, urinary tract infection is a matter of time. Personally, I think the more important concern for these children is whether to take active measures to clear the drainage of urine in the kidney.
For diseased kidneys with less than 10% fractional renal function, many doctors will recommend direct removal of the kidney. It is painful to remove the kidney, and there will not even be any complications such as urinary tract infections, and if the kidney is removed laparoscopically, there will not be a large incision, which is “perfect”. But personally I am still conservative and prefer to give this dying kidney another chance. That would be percutaneous renal puncture and drainage, where a tube with a curved end like a pig’s tail is inserted into the renal pelvis through the skin of the waist under anesthesia by an ultrasound interventionalist under ultrasound guidance to drain the urine directly. The kidney is observed for at least three to five days to see if the urine volume of this side of the kidney is restored, and the specific gravity of the urine of this side of the kidney is measured to determine if the kidney that was to be removed has really recovered. If the function cannot be effectively restored, it is not too late to cut it again.
Schematic diagram of percutaneous renal puncture and drainage
Percutaneous renal puncture and drainage can only be used as a temporary measure, but not as a long-term treatment, because there are two problems.
1, the tube is difficult to fix, and the silk thread sewn to the skin often loosens or cuts the skin, making care difficult and inevitably pulling, twisting, folding, or even dislodging the drainage tube in daily life.
2, the renal pelvis through the tube, the gap between the tube and the surrounding tissues, all with external traffic, bacteria into the pelvis, causing infection within the pelvis.
For fractional renal function in 10% to 40% of the fluid, severe hydronephrosis, thinning of the renal cortex, repeated urinary tract infections, active surgical treatment to save kidney function, probably this is more widely accepted. Surgery should be an option for children of large months or age. However, for neonatal hydronephrosis, there is no objection to observation for mild cases; for moderate to severe cases, should we continue to observe, or actively investigate, or take other measures, such as placing a tube for drainage by renal puncture, or placing a double “J” tube retrograde to the ureter under cystoscopy, or actively perform pyeloplasty? This may be a matter of disagreement.
Diagram of double J tube placement
If such a tube can be placed successfully to temporarily solve the problem of urine drainage, it will undoubtedly effectively reduce the pressure in the kidney and reduce the damage to the renal cortex. Waiting for the ureter to grow a bit with the child and then coming back for surgery is not a bad option. Whether the tube is externally inserted or internally placed, in addition to the possible failure of placement, almost all of them have to face the problem of infection.
The sparrow is small, but it has all the organs. The diameter of the ureter in a neonate is also only about 2-3 mm, the surgery is difficult and the chance of anastomotic problems after surgery is higher than in children of other ages, perhaps that is why many doctors are very cautious. It is no exaggeration to say that neonatal hydrocele surgery is “microsurgery”, so a surgical magnifying glass is necessary.
Schematic diagram of a disconnected pyeloplasty
For moderate hydronephrosis and above, I recommend further investigation and close follow-up. For severe neonatal hydrocele, I personally prefer early surgical solution. 1.5 cm or less incision, extraperitoneal route, postoperative anesthesia awake for feeding, and microsuture technique is used for surgery. With proper double J-tube, sutures, and surgical skills, age can be no problem.
The surgical incision for neonatal hydronephrosis is within 1.5 cm in length, which is about the width of an adult index finger
This is a controversial topic, and I have no intention of quelling the controversy. Medicine is not a right-or-wrong multiple-choice question as taught in elementary and secondary schools. For those with moderate to severe hydronephrosis after birth or persistent exacerbation, all options are possible, but waiting passively without any options and without aggressive and effective management is probably not.