confused

[kb781]

My 15 yr old son had spinal fusion surgery for scoliosis 6 times. He contracted a deep wound mrsa infection which resulted in 10 weeks of Zyvox along with drainage: his symptoms returned immediately when the antibiotics were finished.  This resulted in 2 debridement surgeries where all the hardware was removed.  He was on 6 weeks of IV Vanco and Rifampin which seem to end the infection.  6 weeks ago the went back in to redo the spinal fusion as his scoliosis was still severe and he had become very kyphotic well into his lumbar spine.  This was a long and difficult surgery (15 hours) with high blood loss (transfused 7 units during surgery and three post surgery).  He was moderately hypertensive throughout his hospital stay so they did a 24 hour urine collection and a renal sonogram.  He had a renal sonogram 4 weeks earlier as an MRI of his spine showed a renal cyst.  The results of the first sonogram stated right kidney 10.6 cm and lef 11cm.  Mild left sided hydronephrosis and a cyst of the right renal pole 1.3 x 1.4 cm.  Otherwise negative.  I was told prior to this surgery that it was an incidental finding and not to worry about it at this time.  The sonogram taken in the PICU seems like it is on a different kid: it states: right kidney 7.3 cm left kidney 11.2 cm.  Increase in renal echogenicity bilaterally.  No evidence of hydronephrosis.  Cyst in upper pole of right kidney 1.4x1.1x1.7cm.I can not understand the major difference in these studies.  Also, they are now telling me that he needs to see a nephrologist and his pediatrician is suggesting that his kidneys are scarred.  Can this be happening due to all the surgery and strong medications he has been on?  What exactly is this suggesting?  There is poly cystic kidney disease on his father's side. Please let me know if this is potentially serious and what I should expect when I take him to the Nephrologists.

[Enoch Choi, MD]

i really can't.  a nephrologist needs to review the lab tests (blood & urine), radiographs (CT scans and ultrasounds) and give you some insight.  it takes more information to know what's going on...  hard to shed light without information...

[kb781]

Thank you for responding but I still don't understand what this might be indicating.  He does not currently show signs of infection but he remains on Zyvox as a precaution as return of the mrsa with his spine in the condition that it is could be catastrophic.  Can you shed any light on what might be happening in his kidneys?

[Enoch Choi, MD]

i can't tell you what the nephrologists will say, but i can confirm that previously enlarged (hydronephrosis) kidneys can later shrink if scarring occurs.

this can happen from infection, blockage from stones or anatomy.