Sunday, July 5, 2015
Non-functioning Left Kidney with Lithiasis
I used to have recurring UTI since I started getting pregnant in 1998. My OB Gyn recommended I have kidney ultrasound and we found out I have a smaller left kidney. It has been getting smaller over the years. My last GFR scan showed it is functioning just a little over 12%; the right kidney compensates and my total GFR rate is over 86%. However, my recent ultrasound shows a .5cm stone (lithiasis?) on my damaged left kidney. My nephrologist referred me to a urologist. One urologist just prescribed a medicine, with the hope that the stone will be dissolved in about 3 months. I got a 2nd opinion w/c was extremely different. He recommended either to take off the stone through laser treatment or the whole left kidney as this may cause further infection in the future. Which recommendation is healthier and more practical? I am turning 41 years old.
The situation is complex.
Recommendation 1): Assuming that the stone is uric acid (uric acid stones are detectable on CT scan but not on plain films), alkalinization of the urine can dissolve that type of stone. However, with a poorly functioning kidney, the excretion of the alkalinizing medication (typically sodium bicarbonate or uro-cit-K) may not be effective. This recommendation is harmless but might fail.
Recommendation 2): Laser treatment which requires either ureteroscopy or percutaneous nephrostolithotomy (or ESWL if the stone is visible on plain Xray) entail an anesthetic and the possibility of failure to retrieve or pulverize the stone which is small. Removing the kidney can be done laparoscopically and resolves any issues regarding future complications of the failing kidney.
Neither recommendation addresses the link between stone and infection. Most stones are not infected. The association between infection and stone can be established by performing cultures from that kidney and comparing to cultures from the opposite kidney. The situation you describe could be due to vesico-ureteral reflux which is back-flow of urine from the bladder to the kidney when the "valve" in the bladder wall is not functioning properly.
Ultimately, if the kidney is causing problems that require surgery (no response to alkalinization of the urine), then removal is the more definitive treatment in an essentially non-functioning kidney.
I hope this information is helpful.
James F Donovan, Jr, MD
Professor of Surgery
Director of UC Urology
College of Medicine
University of Cincinnati