Q: I am C5-6 complete quad. Up until now I have been voiding naturally and using convenes (external catheters) with no problems since my injury eight years ago. Recently I started getting recurring UTIs. A urodynamics test last week confirmed that something needs to be done. The urologist gave me a choice of either a surgical sphincterotomy or a suprapubic catheter, neither of which I am keen on. My wife is now doing intermittent catheters every night and morning for me until I can get something done.
 
I read about a urethral sphincter stent and am wondering if this may be an option for me. Other than this, I feel my preferred choice would be to try the chemical sphincterotomy. However, would either of these options shrink my bladder?
— David

A: David, your question is a good reminder to those of us with spinal cord injuries to continue regular follow-up visits with a urologist. The fact that your bladder situation changed eight years after injury underscores this. Your question also points out the importance of doing research and discussing pros and cons (including possible complications) with your urologist before having any type of procedure. I suggest you read about the suprapubic catheter option in the August Bladder Matters. In this column I will discuss pros and cons of the other three procedures you mention.

All three procedures — sphincterotomy, chemical sphincterotomy, and sphincter stent — open up the urethral sphincter (the muscle that holds the urine in the bladder). When researching information about bladder management and SCI you will come across an important term: detrusor-sphincter dyssynergia (DSD). In layperson’s terms DSD means the detrusor muscle (the muscle that contracts the bladder in order to void) contracts — but the sphincter muscle remains tight and doesn’t release urine, which creates high bladder pressure — not good. High bladder pressure causes bladder scarring, and reflux — urine backing up into the kidneys, which can cause permanent kidney damage. And dyssynergia means impairment of voluntary movement — meaning you can’t voluntarily contract detrusor muscle and relax the sphincter muscle to void.

The goal of each of these procedures is to achieve low Leak Point Pressure (LPP) and low residual volume of urine in the bladder. LPP is the pressure in the bladder when urine starts to flow. A tight sphincter muscle causes LPP to go up. Even if the detrusor muscle isn’t contracting the bladder, a tight sphincter muscle without catheterization enables the bladder to overfill which can result in scarring and reflux.

Residual volume is the amount of urine left in the bladder after voidi