Ureteropelvic Junction Obstruction
What is Ureteropelvic Junction Obstruction?
Ureteropelvic junction obstruction occurs when the connection between the kidney at the renal pelvis and proximal ureter is blocked. The blockage stops or slows the flow of urine and causes urine to pool in the kidney, leading to kidney swelling (hydronephrosis).
Causes
There are a number of etiologies for this issue. Most often, UPJ obstruction is congenital, meaning children were born with it. Often, these are found on prenatal ultrasound. In adults, UPJ obstruction may occur after kidney stone, other ureteral/kidney surgery or swelling or infection of the ureter.
Symptoms
UPJ obstruction can cause a palpable abdominal mass, urinary tract infection, flank pain, kidney stones, blood in the urine, vomiting and poor growth in infants. Additionally, occasionally, a patient will develop flank pain only in relation to increased fluid intake.
Diagnosis
An ultrasound or CT scan may help in identifying that there is a problem in an affected kidney. With concern for UPJ obstruction, blood tests will be obtained to check renal function. A nuclear renal scan may be performed; this test measures proportionate function of each kidney and assesses for obstruction.
Treatment
If the patient is asymptomatic with normal kidney function, he/she may be able to avoid intervention. The mainstay of treatment is surgery, with an operation call Pyeloplasty. If infants and small children this is done open. In adults, there are minimally invasive options using laparoscopy or robot-assisted techniques to perform the pyeloplasty. During a pyeloplasty, the surgeon makes several small cuts in the abdomen to access the affected kidney and then reconstructs the renal pelvis to relieve the obstruction. Occasionally, if pyeloplasty is deemed too high risk, an endopyelotomy—where a surgeon endoscopically makes an incision through the obstruction—may be recommended.
After Treatment
Patients usually recover quickly after surgery. You will have a ureteral stent which allows for healing of the surgical site; this is typically removed 4-6 weeks after surgery. The doctor uses ultrasound a few weeks after surgery to check for hydronephrosis (swollen kidney). The appearance of the kidney will improve with time, though it will not look normal. Once the UPJ obstruction is fixed, it almost never comes back. Note that patients who have had UPJ obstruction may have a slightly greater risk of future kidney stones or infection. This is because the kidneys may still contain some pooled urine, even though overall drainage is improved. To learn more about UPJ obstruction, please click this https://www.urologyhealth.org/urology-a-z/u/ureteropelvic-junction-(upj)-obstruction