Meet Chow Chow and her "New Ureter"
Chow Chow is a 7 year old Miniature Schnauzer who came to VSH for treatment of a recurrent ureteral obstruction, or blockage between the kidney and the bladder.
When the VSH Veterinary Internal Medicine team met Chow Chow, her ureter was blocked by urinary stones as well as a migrated stent. The stent had previously been placed to help urine pass from the kidney to bladder. Unfortunately, one of the complications of ureteral stents is migration (the stent becoming dislodged and moving within the urinary tract). After stents migrate they are no longer functional and must be removed or replaced.
The IM team discussed all the options with the owners. The options for treatment of an obstructed ureter include removing the kidney, ureterotomy (opening the ureter and removing the obstruction), stents, and a subcutaneous ureteral bypass (SUB) device. We do not advocate taking the kidney out for obstructions, and ureterotomies are associated with high complication rates (leaking, stricture/scar formation, and re-formation of stones). Stents are a good option in dogs, and in female dogs they can be placed endoscopically, without surgery. The downside to stents is that they can have complications like migration, re-obstruction, hematuria, chronic infection, stone formation on the stent, and dysuria (abnormal urinations).
Sub-cutaneous ureteral Bypass (SUB) devices are artificial ureters. A catheter is placed in the kidney and another catheter is placed in the bladder; we leave the ureter alone. The two catheters are connected to a port under the skin. This device allows urine to pass from the kidney to bladder. These devices require long term management including flushing the system every 3 to 6 months to decrease the chance of stone formation. They can be flushed without anesthesia through the skin using a specialized needle. Unlike stents, the SUB device will not migrate, however there are a low number of other complications including chronic infection, hematuria and, without monitoring, stone formation within the device.
Due to the complications with the previous stent placement, Chow Chow's owners were reluctant to have another stent placed. Luckily for Chow Chow, Dr. Josh is one of very few specialists worldwide to have completed prestigious post-residency training in interventional procedures like SUB placement. A SUB device was placed, and Chow Chow did well in surgery, where the previously placed stent was removed. She was discharged 2 days later with no more evidence of ureteral obstruction.
X-ray showing Chow Chow's migrated ureteral stent
Post-operative X-ray of Chow Chow's new SUB device
Dr. Josh Steinhaus
MS, BVMS, DACVIM (SAIM)