Foot ulcers and wounds with kidney disease and dialysis

Why kidney disease puts your feet at risk

In a review of 30 studies of people on dialysis, the strongest warning sign for a new foot ulcer was a previous one.⁠^[7] Peripheral artery disease, diabetes, nerve damage and heart disease were also linked to higher risk.⁠^[7] Leg swelling, protein loss in the urine, ongoing inflammation and poor nutrition further weaken the skin and slow healing.⁠^[4] Chronic kidney failure also makes a foot wound more likely to become infected.⁠^[5]

Ulcers become more common as kidney function declines, often before dialysis begins.⁠^[4] In a Dutch study that accounted for diabetes, poor circulation, nerve damage (external site) and foot deformity, people on dialysis developed foot ulcers at about 7.6 times the rate of people with stage 3 kidney disease. Major amputation was also far more common.⁠^[1]

Poor circulation is common too. In one study of people with diabetes, those on dialysis were much more likely to have peripheral artery disease.⁠^[8]

Signs to watch for

Nerve damage, poor circulation and a weaker immune response can hide the usual signs of infection, so don’t wait for pain.⁠^[5] Check your feet every day for these changes:⁠^[6]

• a blister, crack or sore that isn’t getting smaller
• swelling, redness, warmth, tenderness, or pus-like drainage around a wound, which are signs of infection⁠^[5]
• a foot that feels cooler than the other, which can be a sign of poor circulation⁠^[3]

Calf pain when walking and foot pain at rest, the classic signs of blocked arteries, are often absent with diabetes, partly because nerve damage can mask pain.⁠^[3] International kidney experts (KDIGO) say routine foot checks make sense on dialysis and can be done during hemodialysis, so ask your dialysis team to look at your feet.⁠^[2]

How circulation is tested with kidney disease

The ankle-brachial index compares ankle and arm blood pressures. In kidney disease, calcium commonly builds up in the walls of the leg arteries (medial arterial calcification), making them hard to squeeze with a cuff.⁠^[2,8] The ABI can then read normal, or even high, when artery disease is present.⁠^[8,3] That is why KDIGO also advises checking the toe-brachial index at the same time.⁠^[2] Calcification raises ankle readings more than toe readings, so toe measurements are more reliable in calcified arteries.⁠^[3,8]

A toe pressure of 30 mmHg or more makes healing more likely. A lower reading raises the chance of major amputation and calls for an urgent vascular opinion. A very high ABI, above 1.3, is a warning sign of its own.⁠^[3]

We check the pulses in your foot at your first visit and do noninvasive circulation testing at our practice. Arterial duplex ultrasound or angiography, when needed, is arranged with vascular specialists.

Treatment: healing a wound around dialysis

Healing follows the same principles as for any diabetic foot ulcer: treat infection promptly, remove dead tissue regularly, take pressure off the wound, control blood sugar if you have diabetes, improve nutrition, and treat swelling and other health problems.⁠^[3]

Our Lyndhurst, Paramus and Millburn offices all offer wound care visits, usually every week or two while a wound heals. We measure the wound each visit, clear away callus and dead tissue in the office, and set up your dressings and offloading. When a total contact cast or other non-removable knee-high device is right for you, we fit the device and show you how to get around safely. For the wounds that need it, we also use negative-pressure wound therapy and skin substitutes. Dr. Efe Ozturk, a Foot and Ankle Surgeon, is board certified in wound care (FAPWH).

Long hours of sitting during dialysis, shifts in fluid and blood pressure, and a higher risk of falls may affect how well a wound heals and how easy offloading is to keep up.⁠^[4] Tell us your dialysis schedule, and we will fit offloading around it.

For infection, we base antibiotics on wound cultures. Hemodialysis is a risk factor for MRSA, a germ that resists common antibiotics. The choice and dose of antibiotic may also need adjusting for kidney function or dialysis.⁠^[5]

A rare wound of kidney failure: calciphylaxis

Calciphylaxis has been reported in 0.04% to 4% of people on dialysis. Calcium builds up in the walls of blood vessels and causes painful nodules and ulcers that won’t heal. A skin biopsy is the most reliable way to diagnose it. Treatment pairs pain control with wound care and changes to the risk factors behind it.⁠^[9] Tell both your foot and kidney doctors about a very painful sore that won’t heal.

When surgery helps save the foot

When wound care alone isn’t enough, limb salvage surgery is often the step that saves the foot. For moderate and severe infections, the international infection guideline suggests considering early surgery, within 24–48 hours and alongside antibiotics, to remove infected and dead tissue. In hospital studies of severe, deep infections, earlier surgery was linked to fewer major amputations and more healed wounds. When bone is infected, it suggests considering surgery to remove that bone, together with antibiotics. With both poor circulation and infection, it calls for urgent advice from surgical and vascular specialists on whether and when to drain the infection and restore blood flow.⁠^[5]

Dr. Ozturk performs the foot surgery itself: draining infection, removing dead tissue and infected bone, and correcting deformities that keep causing ulcers. For the wounds that need it, he also performs skin grafts and local flaps, and toe, ray, transmetatarsal or midfoot amputations that remove only what can’t be saved. Restoring blood flow is done by a vascular specialist; we arrange the referral and coordinate the timing with your wound care.

People with kidney and artery disease are less often considered for revascularization. Yet evidence suggests it helps save the leg at every stage of kidney disease.⁠^[2] If a wound hasn’t shrunk by about half after 4 weeks of good care, blood flow should be rechecked and a vascular specialist consulted.⁠^[3] If you’ve been told amputation is your only option, a limb salvage second opinion can help you weigh the choices.

Risks and limits. Procedures to restore blood flow carry a higher risk of complications with kidney disease.⁠^[2] In studies summarized by the international guideline, limb salvage one year after revascularization was around 70% with end-stage kidney disease. Most studies of people with diabetes report 80% to 85%.⁠^[3] Healed ulcers also return sooner with kidney failure, so prevention continues after the wound closes.⁠^[4]

Keeping your feet healthy on dialysis

For people with diabetes, the international prevention guideline rates end-stage kidney disease plus nerve damage or poor circulation as high risk, even without a past ulcer. It advises a professional foot check every 1–3 months.⁠^[6] We offer risk-based check-ups, therapeutic shoes and custom inserts; see diabetic foot care (external site) and keeping your foot in remission.

Plan foot and kidney care together: tell your dialysis team about any new wound, bring recent labs and your medication list to foot visits, and tell your kidney doctor before any surgery.

When to seek care

See us within a day or two for any foot wound that isn’t healing, especially if you have diabetes. If you have kidney disease, call us the same day for a new wound or blister, signs of infection such as a red, hot, swollen foot, a toe slowly turning dusky or purple, or new pain in the foot at rest.