Monday, July 08, 2024

by Dr. Jay Long, MD, Retired Vascular Surgeon, Medical Director – Semler Scientific, Inc. 

A major lower-extremity amputation has been reported to be the most feared complication by patients experiencing diabetic foot problems.¹ The statistics surrounding diabetic foot ulcers (DFU) and potential subsequent amputations are staggering.

• Foot ulcers are present in 1 out of 10 patients with diabetes²
• Underlying neuropathy contributes to more than 60% of diabetic foot ulcers³
• A foot ulcer is the initial event that leads to over 85% of major amputations among people with diabetes⁴
• Patients with both diabetes mellitus and peripheral arterial disease (PAD) are four times more likely to undergo an amputation than those with PAD alone. ⁵   

Patients with diabetes experience a significantly higher rate of major limb amputations compared to non-diabetics. The disparity in amputation rates between these cohorts underscores the critical need for comprehensive management of diabetes and its associated risk factors.

Primary care practitioners play a crucial role in helping diabetic patients with non-healing wounds by identifying and managing peripheral neuropathy and peripheral arterial disease, both of which are major contributors to wound progression.

While implementing tighter control of A1C levels, blood pressure, cholesterol, and other risk factors like smoking can contribute to long-term reductions in morbidity and mortality, they do not immediately improve wound healing. Acutely managing diabetic wounds by controlling the presence of infections and removing necrotic and infected material is critical. These steps have the potential to decrease the deterioration of the wound; however, neither will independently improve the likelihood of wound healing, especially with underlying PAD.

Additionally, screening for PAD by palpating pulses alone is not sufficient to confirm adequate blood flow for wound healing. The use of cuff-based ABI is a common tool to assist with diagnosing PAD, but it has limitations when measuring the characteristically non-compressible arteries of a diabetic patient. An alternative diagnostic tool that is not limited by arterial calcification is the QuantaFlo device which uses volume flow technology to produce a digital ABI reading and is an excellent screening test for PAD.

Referring patients to a dedicated specialty team can also significantly reduce complications and the risk of amputations for a non-healing wound. This team typically includes specialists in wound care, diabetes, podiatry, infectious disease, and vascular. Their collective expertise can provide comprehensive care tailored to the specific needs of diabetic patients with chronic wounds. PAD can be treated by rerouting blood flow, either with bypass surgery or through a minimally invasive procedure. Improving the flow of oxygen and nutrients to an ulcer within eight weeks of evaluation can enhance ulcer healing prospects.⁶

Diabetic foot ulcers are a serious complication of diabetes that can put patients at significant risk of amputation, particularly when combined with neuropathy and peripheral artery disease (PAD). Diabetic neuropathy increases the chances that a patient will develop a DFU due to the loss of protective sensation in the limb, making it difficult for the patient to notice the wound in a timely manner. Additionally, a diagnosis of PAD with a DFU is associated with numerous negative implications for the patient, including the need for advanced and intensive healthcare, risk of limb loss, and mortality.

This combined pathology poses significant challenges for healthcare systems struggling with increased prevalence of diabetes and its chronic complications. By addressing both neuropathy and PAD early on and involving a specialized care team, primary care practitioners can potentially improve outcomes and quality of life for diabetic patients with non-healing wounds.

References

1. Wukich, D.K., Raspovic, K.M., & Suder, N.C. (2018). Patients with diabetic foot disease fear major lower-extremity amputation more than death. Foot & Ankle Specialist, 11(1), 17-21. https://doi.org/10.1177/1938640017694722
2. Wu, S.C., Driver, V.R., Wrobel, J.S., & Armstrong, D.G. (2007). Foot ulcers in the diabetic patient, prevention and treatment. Vascular Health and Risk Management, 3(1), 65-76. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994045/
3. Clayton, W.J, & Elasy, T.A. (2009). A review of the pathophysiology, classification, and treatment of foot ulcers in diabetic patients. Clinical Diabetes, 27(2), 52–58.  https://doi.org/10.2337/diaclin.27.2.52
4. Brownrigg, J.R.W., Apelqvist, J., Bakker, K., Schaper, N.C., & Hinchliffe, R.J. (2013). Evidence-based management of PAD & the diabetic foot. European Journal of Vascular and Endovascular Surgery, 45(6), 673-681. https://doi.org/10.1016/j.ejvs.2013.02.014 
5. Barnes, J.A., Eid, M.A., Creager, M.A., & Goodney, P.P. (2020). Epidemiology and risk of amputation in patient with diabetes mellitus and peripheral artery disease. Arteriosclerosis, Thrombosis, and Vascular Biology, 40(8), 1808-1817. https://doi.org/10.1161/ATVBAHA.120.314595
6. Elgzyri, T., Larsson, J., Nyberg, P., Thörne, J., Eriksson, K-F., & Apelqvist, J. (2014). Early revascularization after admittance to a diabetic foot center affects the healing probability of ischemic foot ulcer in patients with diabetes. European Journal of Vascular and Endovascular Surgery, 48(4), 440-446. https://doi.org/10.1016/j.ejvs.2014.06.041