Hi
@Jellytots, Sorry to hear of your troubles. It can really turn one off the idea of the pump!! From my experience on an insulin pump, not as professional advice or opinion:
Being from Australia and on a different pump I recall that
some Accucheck pumps connect to their infusion sets by a luer connection. Such a connection is used by various pump manufacturers so it may be possible to find a steel cannula infusion set in a different brand than Accucheck. The non-luer connection infusion sets are compatible only with one particular pump brand.
I have a luer connection which enabled me to find a steel cannula from a different brand as Tandem has only recently arrived in Australia and importation of their own steel cannulas had been held up.
My own experience has been more with plastic cannulas kinking but also some leaking. One thing I did find was that with tucking the 'spirals' of pesky plastic tubing in is that
the twist in the tubing can sometimes be enough to twist the cannula and its small adhesive patch of out of the skin. So I would tape over the cannula patch, But of course I had then to partly remove the extra white tape to release the tubing.
The advantage of the
steel cannulas I found was that
they do not kink. They also have the
detachable section in a separate part of the tubing to the needle cannula, so there are two adhesive patches instead of one. This means no likely pulling about of the cannula when detaching the tubing. The downside is that steel cannulas are recommended to be changed every 48 hours rather than the 72 hours max for the plastic cannulas. It seems that steel is less compatible with the body that the plastic.
I imagine the rep has gone through the importance of not having the cannula tip enter the muscle layer or being at the junction of muscle and subcutaneous tissue (tissue below the skin, in which the cannula ideally is placed) above it, particularly with 90 degree inserted cannulas. From anatomy books I gather there is a tough thin tissue layer at that junction.
I can only tell that having a cannula tip at this junction might be happening when the cannula is inserted in my tummy area and I feel a twinge which seems to spread from the area and is worse when I breathe out.
You can imagine that a plastic cannula tip being at that junction might have trouble releasing insulin causing back-pressure on the cannula, pushing it upwards or the contraction and relaxation of the muscle beneath could push the cannula upwards towards the skin. See also posts and diagrams in the thread "Needle port problems' in the Insulin Pump Forum.
In theory the cannulas inserted at 30 degrees being longer than the 90 degree ones should have a better chance of staying in because there is more length for friction to act on. Again this assumes the cannula tip is located above the junction of the subcutaneous tissue and muscle.
Also in the Needle Port Problems thread it is was mentioned that one person found more cannula problems with cannulas placed in the upper part of the tummy and if placed anywhere after a shower. I cannot say for sure why these things should be so except that maybe there is less depth of subcutaneous tissue high up in the abdomen than lower down and so hitting that pesky layer might happen more often, and that the skin and subcutaneous tissue might be more stretchy and less 'grippy' when warmed (and thus maybe less stretchy and more 'grippy' when cool).
The only other way I can see that one could know where a cannula and its tip are located might be by
performing an ultrasound.
I gather ultrasounds are used to locate splinters and such under the skin in subcutaneous tissue, muscle etc.. If your troubles continue perhaps you could approach your GP, DSN or specialist and see whether an ultrasound can be performed very soon after you insert a cannula (even if you have to do an extra one at the ultrasound rooms) to see where a particular cannula is located.
You might even have to insert the two or three of the most likely cannula candidates ( sounds like a matching show on TV) to see where each cannula tip is located and see how long each stays in (although this will not be quite the same as having a pump attached). Or the final option is rotating the pump connection between the sites so that they receive somewhat similar 'pump time'.
final point: I have been on insulin for 52 years. The last 7 on a pump. The rep thought that some of my cannula problems might be from
scar tissue built up over those years. I had been using 6 mm 90 degree plastic cannulas and maybe a cannula tip was hitting this scar tissue in some sites and not others. The scar tissue might only accept insulin infusion for a shorter while than unscarred tissue and thus cause problems such as kinking, leaking etc. The solution was to use steel cannulas and continue with 6 mm cannulas in new sites and if needing to revisit previous 'stabbing' grounds to try an 8 mm cannula , see if that would avoid the scar tissue. So far so good. I do hope the above can help you. Please ask your health team and rep to please pull out all the stops to help you. to 'nail' this one !!!
