Duplex Kidney

I took my son to the Urologist for daytime and night time wetting concerns only to find out he has Kidney Duplication or "Duplex Kidneys".  It looks on the ultrasound like a kidney within a kidney but in reality is just two tubes (ureters - tubes that carry urine from the kidneys to the bladder) instead of just one coming from the kidney.  His right kidney is perfect, his left kidney is the Duplex Kidney.  (See the right side of the image below).  A duplex collecting system can result in frequent urinary tract infections, backflow of urine into the kidney and sometimes kidney damage.

We had an ultrasound done today that detected this as well as bladder wall thickening and a little fluid in the kidney.  We are scheduled to have an MRI (magnetic resonance imaging - a non-invasive scan) probably next week.  The MRI is to determine if he has "tethered cord" which is a condition where the spinal cord becomes stretched and damaged due to tissue that doesn't belong there.  It can cause urination control issues. It can also cause nerve damage if not treated. (See image below.)  The doctor suspected this when she noticed a crooked crease at the top of his buttocks.  

The fluid in the kidney can be a result of reflux (VUR - vesicoureteral reflux - an abnormal flow of urine from the bladder into the ureters or kidneys) but because he hasn't had urinary tract or kidney infections the doctors aren't worried at this point.  If concern develops a VCUG (voiding cystourethrogram - an x-ray examination of the bladder and lower urinary tract that uses a special form of x-ray called fluoroscopy; a catheter is used to fill the bladder with a liquid contrast to see if it flows backwards into the kidneys confirming VUR)  would be ordered for further analysis and treatment.

The duplex kidney, thickened bladder wall and possible tethered cord can all contribute to daytime / night time wetting.  He can't help the "leaking" or accidents.  For now we are using a timer watch set for every 2 hours as a reminder to potty and Miralax to make sure stools can easily move out of the body.  If after the watch and Miralax he still has problems there is medication he can take to help relax the bladder wall.  We'll wait for the MRI results to decide "next steps".  Next steps can be do nothing or do surgery or something in between depending on severity.

TIPS:  If you're child can't stay dry try a "potty watch" (recommended reminder set for every 2 hours; www.pottymd.com makes a "potty watch" that looks like a regular watch so it's not embarrassing for an older child to wear) and daily dose (usually 1/4 - 1/2 cap) of Miralax.  Sometimes constipation is the cause of leaks and accidents.  If there are still concerns see a pediatric urologist.