The exact pathology of hypospadias is not fully understood. It is probably caused by an incomplete virilization of the penis, leading to the incomplete fusion of the urethral folds. It is important to check that a child with hypospadias is not an overvirilized female or an XY/XO mosaic. This can usually be done by palpation of the testes; if only one testicle is palpable then an XY/XO must be considered. If no testes are present then an overvirilized female must be excluded. In any case of doubt, investigation into ambiguous genitalia should be done.
Treatment for hypospadias is through corrective surgery. The age of surgery is generally left to the surgeon’s preference, but it is usually done between 9 and 12 months of age. The further along the penis the meatus is, the easier a successful outcome is. The most common form of operation is the MAGPI (meatus advancement and glanduloplasty incorporated), used in the treatment of coronal hypospadias. No matter what form of hypospadias is present, the aim is create a terminal meatus on a well formed glans and penile shaft which is straight on erection (achieved by release of the chordee) together with a good cosmetic result.
Autosomal dominant polycystic kidney disease (ADPKD):
This congenital abnormality is often described as the ‘adult’ form of polycystic kidney disease and accounts for 5-10% of end-stage renal failure world-wide.
Generally, this disease is not symptomatic during childhood (around 2% present with severe cases of disease in childhood). The usual age of onset for a person with ADPKD is in the third and fourth decade of life, however it can occur at any time. 60-70% of sufferers present with hypertension. One of the most common problems is chronic pain, usually in the back or side and sometimes the stomach. Some patients suffer from continuous sharp pain in the same regions. Fatigue is a common symptom amongst sufferers. Almost 50% of people with ADPKD suffer from blood in the urine (hematuria) at some stage. People with ADPKD have an increased chance of having kidney stones and suffering urinary tract infections (UTIs).
ADPKD also affects other organs. 70% suffer from liver cysts, which is shown by an enlarged liver. Other areas commonly affected are the heart, intestines, pancreas and cerebral arteries.
There are three different mutations that give rise to ADPKD:
It is not entirely sure why the cysts form but it is thought to be either due to the collecting duct and the nephron not properly joining in the embryo, or because of cystic dilation in the earliest generation of nephrons which would usually degenerate and disappear.
Cyst formation begins with excess cell proliferation on the walls of the cyst in comparison with normal kidney cells. This is followed by fluid secretion by cyst cells, which fill the cyst. The cysts take up space in the kidney and block the arteries bringing blood in for filtration, preventing the kidneys functioning correctly. This eventually leads to end stage renal disease, which is caused by the kidneys’ inability to filter out waste products the body produces (uremia).
At present there is no cure for ADPKD, however research has shown that following a healthy diet and doing regular exercise can slow cystic development. Treatment is usually aimed at the symptoms of the disease:
Some sufferers of ADPKD develop kidney failure. In such instances, the use of dialysis is used. If a suitable donor can be found, a kidney transplant can be performed.
Ureteropelvic junction (UPJ) obstruction
This congenital anomaly affects 1 in 1500 live births and affects males more often than females. In UPJ obstruction, the junction between the ureter and the renal pelvis gets blocked preventing urine from leaving the kidney.
One of the commonest symptoms of UPJ obstruction is enlargement of the kidney due to fluid build up in the kidney (hydronephrosis), which can be seen in a prenatal ultrasound scan. Pain in the back and the side (caused by the swollen kidney) is often felt, especially after consumption of excess fluid. UTIs accompanied by fever are often seen because the urine trapped in the kidney becomes stagnant. This can also lead to infection of the kidney (pyelonephritis). Other symptoms exhibited are hematuria and kidney stones.
There are several factors that lead to UPJ obstruction. Underdevelopment of the ureter may lead to an abnormal peristaltic action of the ureter preventing normal urine flow. Furthermore, if the muscles around the proximal ureter are not symmetrical peristalsis is inhibited. Another cause of UPJ obstruction is when the ureter is inserted into the kidney in an abnormal fashion or in an elevated position. This effects the arrangement of the ureter causing backward pressure. The ureter can also become narrowed by a vessel going to the lower pole of the kidney, thus hindering urine flow.
The only form of treatment for this condition is through surgery. When a child is born with a known UPJ obstruction, they are put on antibiotics to prevent UTIs. In children, the most favoured operation is an Anderson-Hynes dismembered pyeloplasty. The obstructed segment is completely removed, with reattachment of the renal pelvis and ureter in a dependent funneled fashion. A stent (small piece of tubing over repair) may be used in the initail healing. Newer techniques being employed now include laparoscopic pyeloplasty. This has the advantage of being minimally invasive compared with open surgery, but it makes delicate parts of the operation a lot harder. In adults, endoscopic repairs can be performed with great success.
