Silk Urethral Catheters- The Gateway to Nurses Performing Procedures

Urologists can pull some truly terrifying instruments from their bag of tricks; sounds, bougie-a-boules, dilators, resectoscopes, and filiforms come to mind.  Some items are best lost in history, such as  urology tools that were rigid, unyielding, and only for use by the very experienced physician. I recollect a truly terrifying instrument, the Kollman dilator that deserves a separate post.

It took years of experience to successfully and safely pass old time metal urethral catheters without damaging the prostrate or wreaking havoc with tender urethral mucosa. I have  vivid memories of a story an aging urologist told me about the time he inadvertently transected a hypertrophied prostate while attempting to relieve a distended bladder by using a metal urethral catheter. The notion of a metal catheter plowing through very sensitive  tissue with an awake patient arouses primal fear in everyone. I suspect that really does smart!

Ram-rodding rigid metal catheters into a highly innervated

orifice lined with delicate mucosa is not my idea of a fun time.
It's time to page the doctor to pass these steely stiletto-like
catheters, unless, you have one of those newfangled nurse
friendly, slippery and  flexible silk catheters.

Old time urethral catheters also were made of glass. whenever glass objects are inserted in a body cavity, the potential for breakage is always present. I have heard anecdotal accounts from older nurses relating that glass catheter breakage was the impetus for the development of silk catheters.

One glass catheter story involves a difficult labour that necessitated a Cesarean Section. While having a glass urethral catheter inserted, the patient had a very robust uterine  contraction breaking the glass catheter off in the bladder. After the baby was delivered the physician was faced with the difficult task of removing the glass catheter without causing injury.

The very first silk catheters were constructed by using a glass catheter as a sort of template. The silk was woven around a glass catheter and a varnish like substance applied to maintain the shape of the catheter. I'm not sure when the first silk catheter was constructed, but by the mid 1930's, silk urethral catheters were in widespread use. Natural silk has an off-white color and silk urethral catheters were often dyed by applying Methylene blue prior to the varnishing stage. The end result was a flexible, pretty blue urethral catheter.

If you are interested in perusing an unusual Methylene blue story, just type "A Blue Finger Bigot" into the search box on this blog. Someday I will get around to figuring out links! It's hard for an oldfoolrn to learn new tricks and so easy to stray from the task at hand....My apologies. Now it's time to return to the tale about silk catheters.

Our instructors in nursing school loved to show off the school's collection of silk urethral catheters. They differed from modern flexible Silastic or rubber catheters in that the wall of the silk catheter was very thin. An 18 FR. silk catheter probably had the same sized lumen as a modern 20 or 22FR catheter. While modern catheters are inelegantly  packaged by sandwiching them between a piece of paper  and a plastic-like covering, the old time silk catheters were individually packaged in an elaborate  long thin felt lined blue box that exuded class. They certainly don't worry about fancy packaging today.


I  have never used a silk catheter, but every older nurse sang their praises. The silk catheters had just the right amount of rigidity for insertion, but were very soft and forgiving to urethral mucosa. They were much less traumatic than a rigid metal catheters and nurses began to routinely perform catheterizations.

I guess everyone has to start somewhere and these silk catheters opened the door to other nursing procedures such as starting IVs. Oldfoolrns just called the procedure an IV start, but I see you whippersanapperns have coined the fancy terminology of "initiating a peripheral intravenous cannulation." That sounds much more sophisticated and I wish I had thought that one up. My old school terminology sounds pretty dumb. It's a good thing we were not as dumb as we sounded.

The next time you are starting an IV (OOPS.. I mean initiating an intravenous cannulation.) or setting up an arterial line take a moment to reflect on that old time nurse that started the nurses on the path to performing procedures with the silk urethral catheter.



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