Diabetic Foot Ulcers, PAD, And The COVID-19 Pandemic: Continuing The Fight Against Delays In Care
Peripheral artery disease (PAD) is a frequent complicating factor in patients with diabetic foot ulcers. Almost 50 percent of those with foot wounds will have significant ischemia requiring some type of intervention. Sufficient perfusion is a prerequisite for wound healing. But even before the COVID-19 pandemic, there was not optimal care for those with PAD and wounds. A study conducted of over one million Medicare inpatients found that an angiogram reduced the odds of amputation by 90 percent, but only 27 percent of patients with critical limb ischemia actually received an angiogram.1
In 2019, the world’s vascular societies, including the Society for Vascular Surgery (SVS), created the Global Vascular Guidelines.2 David G. Armstrong, DPM, MD, PhD and I were co-authors representing podiatry. The guidelines helped to standardize terminology and provided evidence-based recommendations on the diagnosis and treatment of PAD. As such, the guidelines recommend the use of the term chronic limb-threatening ischemia (CLTI) as an alternative to critical limb ischemia. The definition of CLTI is a more severe stage of PAD where there is either rest pain, tissue loss, or gangrene in the presence of PAD.2
Where Are We With Limb Preservation During The COVID-19 Pandemic?
The COVID-19 pandemic negatively impacted care for those with chronic diseases. This appears to disproportionately affect patients with wounds. We reported on the increasing amputation rates as a consequence of the disruption in care of those with diabetic foot wounds, which created a “pandemic within a pandemic.”3 But, one thing is pretty consistent in these reports of increasing amputation rates. Treatment of patients with ischemia is taking place later and at more severe stages.
Caruso and colleagues4 in Italy found that patients admitted to the hospital for diabetic foot ulcers were more likely to have gangrene during the pandemic than the year before, and the number of amputations during this time doubled. Schuivens and team5 found that patients admitted to the vascular service of an academic hospital in the Netherlands suffered three times the number of amputations during the pandemic than in the year before. The authors noted that the Rutherford class of the patients’ ischemia was significantly worse during the pandemic, as well. Both studies surmised that patients were presenting later due to a fear of interacting with the health care system and the risk of contracting COVID-19.
Key Diagnostic Considerations To Implement Today
Understanding the high prevalence of PAD and having a high index of suspicion are key in making an early diagnosis.6 The patient may have a history of other vascular diseases, such as coronary artery disease or cerebrovascular disease. Masking of expected symptoms may be present due to sensory neuropathy in a patient with diabetes. They rarely present with claudication or rest pain. The clinical exam is often not sufficient to uncover the extent of the PAD. Pulse palpation alone is not a good indicator of sufficient perfusion.6
The Global Vascular Guidelines recommend an objective non-invasive test in all patients with suspected CLTI, including any patient with a lower extremity ulceration.2 The ankle-brachial index (ABI) is a frequently used and recommended test for PAD7 despite its lack of reliability in patients with diabetes due to calcification and incompressible vessels.7 Adding a toe-brachial index (TBI) and evaluating the pulse volume recording (PVR) waveforms can improve the reliability of the exam. This exam is quick, easy, and available in almost any health care setting.
However, due to the unreliable nature of the ABI, one could employ other modalities such as skin perfusion pressure, transcutaneous oxygen measurement, or near-infrared spectroscopy (NIRS). In my experience, skin perfusion pressure is becoming a less frequent option since the manufacturer of the United States-based devices ceased operations and the disposables are no longer available. Transcutaneous oxygen measurements are time consuming and have a high degree of fluctuation of interrater reliability. NIRS is a newer technology.
Pertinent Treatment Pathways You Should Know
The Global Vascular Guidelines recommend urgent referral to a vascular specialist for any patient with confirmed or suspected CLTI.2 In my experience, delay is probably the largest contributing factor to limb loss. But let me be clear, in patients with infection and ischemia, infection management should be immediate and take priority as it is limb- and life-threatening. A podiatrist should not seek “vascular clearance” to surgically manage an infected extremity. The vascular consultation should take place following the urgent management of infection.6
In patients with a diabetic foot ulcer and PAD (technically defined as CLTI), both the Global Vascular Guidelines and an earlier clinical practice guideline from the SVS and APMA published in 20167 recommends revascularization by open bypass or endovascular means. In patients with a diabetic foot ulcer that fails to respond in four to six weeks of management, the SVS-APMA guideline suggests using hyperbaric oxygen therapy.7
In Summary
The APMA and the SVS created an “Alliance” in 2010 with the goal of improving the multidisciplinary care of the patient with lower extremity ischemia. As part of the Alliance, we wrote about the “Toe and Flow” team model which includes a podiatrist and vascular surgeon at its core.8 The podiatrist’s role on that team is vital. Validation of this model took place in an evaluation of care rendered in Alberta, Canada where one provincial zone included podiatry with vascular surgery in care plans and another did not.9 The zone including podiatry had a 45 percent lower rate of major amputation, providing strong evidence for the Toe and Flow model. Dozens of other studies highlight the effect of team care on reducing amputations.10 Specifically, a team that includes a podiatrist can reduce costs,11 reduce hospitalizations,12 and reduce amputations.13
At the beginning of the pandemic, we warned of its effect on patients at risk for amputation.14 We recommended a triage system to help prioritize the setting and the urgency of care for those with diabetes and foot problems. Especially now, during the continued pandemic and its surges, we cannot lose focus on what really works to prevent amputations in patients with diabetic foot ulcers; early diagnosis and intervention of PAD.
Dr. Rogers is the Chief of Podiatry in the Department of Orthopaedics at the University of Texas Health Science Center in San Antonio, Texas.
1. Henry AJ, Hevelone ND, Belkin M, Nguyen LL. Socioeconomic and hospital-related predictors of amputation for critical limb ischemia. J Vasc Surg. 2011;53(2):330-339. e1.
2. Conte MS, Bradbury AW, Kolh P, et al. Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia. Eur J Vasc Endovasc Surg. 2019;58(1S):S1-S109.e33.
3. Rogers LC, Snyder RJ, Joseph WS. Diabetes-related Amputations: A Pandemic within a Pandemic. J Am Podiatr Med Assoc. Published online November 3, 2020. doi:10.7547/20-248
4. Caruso P, Longo M, Signoriello S, et al. Diabetic Foot Problems During the COVID-19 Pandemic in a Tertiary Care Center: The Emergency Among the Emergencies. Diabetes Care. 2020;43(10):e123-e124.
5. Schuivens PME, Buijs M, Boonman-de Winter L, et al. Impact of the COVID-19 Lockdown Strategy on Vascular Surgery Practice: More Major Amputations than Usual. Ann Vasc Surg. 2020;69:74-79.
6. Rogers LC, Conte MS, Armstrong DG, Lavery LA, Mills JL, Neville RF. The Significance of the Global Vascular Guidelines for Podiatrists: Answers to Key Questions in the Diagnosis and Management of the Threatened Limb. J Am Podiatr Med Assoc. Published online March 17, 2021. doi:10.7547/20-217
7. Hingorani A, LaMuraglia GM, Henke P, et al. The management of diabetic foot: A clinical practice guideline by the Society for Vascular Surgery in collaboration with the American Podiatric Medical Association and the Society for Vascular Medicine. J Vasc Surg. 2016;63(2 Suppl):3S - 21S.
8. Rogers LC, Andros G, Caporusso J, Harkless LB, Mills JL Sr, Armstrong DG. Toe and flow: essential components and structure of the amputation prevention team. J Am Podiatr Med Assoc. 2010;100(5):342-348.
9. Basiri R, Haverstock BD, Petrasek PF, Manji K. Reduction in Diabetes-Related Major Amputation Rates After Implementation of a Multidisciplinary Model: An Evaluation in Alberta, Canada. J Am Podiatr Med Assoc. 2021;111(4). doi:10.7547/19-137
10. Musuuza J, Sutherland BL, Kurter S, Balasubramanian P, Bartels CM, Brennan MB. A systematic review of multidisciplinary teams to reduce major amputations for patients with diabetic foot ulcers. J Vasc Surg. 2020;71(4):1433-1446.e3.
11. Sloan FA, Feinglos MN, Grossman DS. Receipt of care and reduction of lower extremity amputations in a nationally representative sample of U.S. Elderly. Health Serv Res. 2010;45(6 Pt 1):1740-1762.
12. Skrepnek GH, Mills JL, Armstrong DG. Foot-in-wallet disease: tripped up by “cost-saving” reductions? Diabetes Care. 2014;37(9):e196- e197.
13. Schmidt BM, Wrobel JS, Munson M, Rothenberg G, Holmes CM. Podiatry impact on high-low amputation ratio characteristics: A 16-year retrospective study. Diabetes Res Clin Pract. 2017;126:272-277.
14. Rogers LC, Lavery LA, Joseph WS, Armstrong DG. All Feet On Deck-The Role of Podiatry During the COVID-19 Pandemic: J Am Podiatr Med Assoc. Published online March 25, 2020. doi:10.7547/20-051
