I was fitted via endovascular surgery at the Cleveland Clinic, two weeks ago, with an extension to my abdominal aortic stent graft to stabilize the left arm in the common iliac artery, which takes the stent closer to my hip joints; see this link for details. Here is my plan:
Shorter cranks (145 mm from Cobb).Raise saddle to max that works.Keep heels down at top of pedal stroke - won’t be easy, and worry about killing my tibialis anterior - will have to experiment with this.Ride standing as much as I can hack it, leaving something for the marathon (Placid again in July).Keep hips forward whilst standing.
If anyone has any other ideas, apart from a recumbent bike or my abandoning Ironman (NO WAY) that would be great.
Oh! Yes! I’m 70, so I’m slowing down a bit, but I’m not dead yet.
Shorter cranks should help quite a bit. Like possibly even 155mm? Probably a more forward saddle position as well. Go to a good fitter and work out a stack height and reach that’s as aero as possible while still pedaling comfortably. No shame is being upright for comfort, if that’s what it takes ot keep you out there enjoying the sport. It’s jsut a new challenge.
Get a power meter and good wheels to compensate for your positional inadequacies.
With the short cranks you may need to run a higher cadence and shorter gearing, so you might end up with a triple to get the gearing you needs for a hilly course like IMLP.
I’ve followed your posts with some interest, as I work for a medical device company* in the design and testing of aortic stent grafts similar to the one that you have implanted. In the blog post you link to you talk about using rigorous methodology to assess the risk/benefit scenario of adjusting your hip angle while cycling to reduce strain on the implanted iliac graft extension. Unfortunately, I am fairly confident in saying that no medical device manufacturer has assessed the fatigue performance of their iliac stent graft in response to the extreme angular flex you are talking about.
So while the basic hypothesis of ‘less angular flex is better’ may very well be true, there is no real way of saying ‘a reduction in hip angle of x degrees will result in a reduction in the probability of stent graft displacement by y%’. So there is no way of performing any type of rigorous risk/ benefit calculation for your situation - the necessary input data simply does not exist.
My point is, don’t fool yourself into thinking you’re being rigorous and safe when the necessary knowledge for your assessment does not exist. I personally* wouldn’t make major changes in cycling position or technique and risk other injury to chase a specific hip angle without any knowledge of how much that reduces risk of graft displacement. If you want to accept the (not quantifiable) risk of continuing in endurance sports, the most I would do* is work with your doctor to monitor the graft position and integrity at a higher frequency than the usual yearly follow up. i.e. if the repetitive motion of cycling is bad for the longevity of your stent graft, it is possible that graft movement or stent fracture could show up in follow-up imaging before it becomes a catastrophic leak issue. Of course, with a higher frequency of imaging you accept a higher risk of issues from radiation exposure (and a higher cost since it probably won’t be covered by your insurance).
*Disclaimers - I am not a doctor, my opinion posted here does not constitute medical advice or represent the official position of my company. Based on your previous postings, I do not work for the company that manufactured your implant, and do not have specific knowledge of their device test methodology and fatigue performance.
I agree 100% with J. It sounds like you are the thorough and curious type so I will suggest the following. Get several x-rays of your pelvis in the lateral position at different hip angles. I predict that you will see no movement at all of your iliac vessels or stent graft. You are talking about structures very deep in the pelvis and most modern stent grafts are very flexible and in fact tolerate millions of pulsations and small movements from your cardiac systole. I agree that changing your bike fit will likely lead to other health problems in knees, hips and back more likely then disrupt your graft. At a maximum increased surveillance would be all that I would do for myself or my patients and only then if they were worried about it.
Just my 2 cents as a vascular Doctor that places endografts daily.
PS - I am assuming that your grafts do not extend down into the common femoral arteries – that is a different situation and hip angle could certainly be an issues there – difference is of course these vessels cross the joint and are relatively fixed in the inguinal region.
As a cardiac surgery fellow who deals with endografts on the regular, I agree wholeheartedly with J and wdlong. Changing the position on the bike will lead to it’s own problems with hips, etc. You are a healthy, 70 year old, something many of our patients who we place these grafts in are not. Keep up the fitness and healthy lifestyle, and the grafts should keep you going
Hi Jam,
I very much appreciate your response. I don’t think I’m fooling myself as I’m still trying to collect data. A series of ultrasounds through the pedal stroke would be ideal, I think, using Doppler to look for effects on flow. My surgeon thought running would be fine, but wasn’t sure about cycling - I don’t think anyone is sure about anything until we collect some data. The math was just to make me think. It sure is an interesting conundrum. I know the Lake Placid course well, having undertaken it 7 times, and completed 5 times (best was the year I found my aneurysm, 13:34 at age 67 I think.
I’ll keep collecting input, thoughts, impressions and the like from radiologists, vascular surgeons and the like, and then I’ll make my decision about moving forward. Not on the bike yet, just recovering from surgery, and doing some gentle conditioning.
I seem to be an experiment with an ‘n’ of one, but then, my stent extension is part of a clinical trial, which is an experiment in itself.
Fooling myself? Hope not. I’m very careful about what I do, but I sure plan to chase down data.
Actually flexion isn’t my only concern, as there is clearly the potential for torsion around the root of the hypogastric and external iliac arteries where the branches of the extension come together - I need to study that object a little more closely
Off to Cleveland in two weeks for a scan, and I’ll pick brains and make plans for data collection as hard as I’m permitted.
Once again, thanks so much for your thoughts.
Cheers,
Kevin
Thanks wdlong1, much appreciated. Just into the external iliac and hypogastric, not the femoral. I hope to have images created from the scans soon, and I’ll post those. Thanks a million, and I’ll bring all these thoughts together as I work out what to do. Kind Regards, kevin
Thanks agf88, I really appreciate your input. Fascinating the responses. I’m glad I wrote this post. I’ll bring it all together on my Aortic Surgery To Ironman Training Diary once I see my surgeon again in a couple of weeks. Kind Regards, Kevin
