The diabetic foot. The biggest non-traumatic cause of limb amputation; some would say the biggest AVOIDABLE cause of lower limb amputation. It’s a battle, and a global one at that. As diabetes becomes more prevalent it is going to become more of a problem unless the multiple disciplines of medicine and surgery develop a solution to the lethal triad of ischaemia, infection and neuropathy. Two events prompted this blog post (well three but the third is simply the fact I’ve not posted recently anything remotely medical). Firstly, a recent article in Vascular News (http://tinyurl.com/oyoalug) about a new pan European trial for assessing the efficacy of minimally invasive attempts at revascularisation using software developed by Phillips. The assumption is that revascularisation leads to limb preservation. Not unreasonable, but there’s much debate among vascular surgeons at least on what the outcome measurement outcome should be for treatment of diabetic foot disease. Wound healing? Resumption of ADLs? The traditional ‘amputation free survival’? Besides, we’re not even sure that the assumption holds true. There are plenty of diabetic feet that are surgically amputated with clinically, and radiographically, normal vascular supply (that is not to say normal vascularity), or supply that has been restored optimally without any discernible benefit. I think the trialists will find that the software predicts tissue perfusion, but I believe the results for clinical success by limb salvage, or however it is measured, will be disappointing. There are just too many other variables to consider, the other two prongs of the triad at least. The second reason for posting is a recent case; and this is part of the problem in the real world of clinical management of the diabetic foot. A patient with neuropathy, decent vascular supply who presented with an infected necrotic toe a few months ago had the toe amputated and sutured closed. Just one stitch to approximate the edges and speed the skin closure. He was even seen to have (mostly) healed his wound in the wound clinic three weeks later. The tell tale was in the notes. The wound review described a well healed wound with a small non-healed edge at one side exuding a small amount of fluid. Two weeks later I see this in the clinic and the remnant bones of the amputated and ‘healed’ toe have decomposed on X-ray.
In this case the foot was saved by further debridement and removal of the infected tissues and bone and the WOUND LEFT OPEN to drain; to heal by secondary intention. A week down the line and the situation could have been considerably worse with a septic patient and a limb threatened and threatening.
Attempts to close these wounds must be avoided. I bang on about this but it is still done, and the inevitable recurrent infection still occurs. The wounds look clean but they are not and, particularly in diabetic patients, the microcirculation, the immune response, and the awareness is inadequate to prevent adequate primary healing. So, while new software might give us reassurance that the pictures are good, it’s the people on the ground doing the work and owning the disease that need to learn both how to prevent the initial insult and how to prevent deterioration, and recurrence, that will make the biggest impact on how frequently diabetic foot disease will lead to major amputation. One positive aspect to this sea of defeatist talk is the fact that for the first time to my knowledge a major player in the health industry is investing in diabetic foot research, albeit perhaps recognizing it as an area of growth and potential profit, and it is likely now that others will follow. Hopefully on the back of big pharma money there will be a multi pronged approach to the epidemic that is approaching rather than tinkering at the high tech (high return) edges
In the meantime, for those with an interest who might find themselves with a suture in hand and a lovely looking toe amputation wound begging to be closed my measage is: just don’t, please.