Vascular Wounds
To treat a wound successfully, the provider must first know what type of wound it is. Of course, there are many different types of wounds, but the most common types seen in a typical wound care clinic are venous ulcers, diabetic ulcers of varying etiologies, pressure injuries, arterial injuries, burns of various types, and skin tears. Any of these types of wounds may or may not be clinically infected and may be acute or chronic (more than 30 days old). This article addresses venous and arterial ulcers.
VENOUS ULCERS
Venous insufficiency ulcers are common and generally found on the lower leg, on the medial ankle, or in the so-called “gaiter area” of the calves. (“Gaiters” have been around for hundreds of years and are still used in US military uniforms. This is the thick fabric that goes over army boots and extends several inches up the calf.) Venous wounds are often painful and malodorous and are susceptible to infection. The underlying, generally incurable venous insufficiency, usually visible as varicose veins, makes healing difficult, as does the fact that patients often spend most of the day sitting with their legs hanging down, instead of elevated. Because of that, gravity makes the problem worse.
The mainstays of treatment are elevation of the legs level with or above the heart as much as possible and compression bandages or support hose. Application of multilayered (usually 4 layers) compression bandages is a specific skill. The dressing needs to be started at the toes and continued up to the knees, maintaining an even pressure consistently. Package inserts will provide instruction on maintaining the correct pressure. Bony prominences need to be padded with orthopedic wool to avoid creating a pressure injury. Health care providers must also be cognizant of maintaining the arterial circulation to the lower leg. In general, no patient should have compression bandages or compression stockings before they have had an ultrasonic ankle-brachial index (ABI) evaluation to rule out any significant arterial insufficiency; the ABI should be 0.8 or higher.1
Many patients with venous ulcers also have some level of peripheral edema, making it hard to determine whether they have adequate dorsalis pedis and/or posterior tibial pulses in the foot and medial ankle; therefore, an ABI evaluation is mandatory, because the compression bandages can turn severe peripheral vascular disease (ABI less than 0.8) into critical peripheral vascular disease, leading to critical leg ischemia and amputation. The skin breakdown area typically also needs a nonadherent dressing, such as paraffin gauze, plus a secondary dressing, as discussed below.
The following are my opinions about appropriate dressings. There have been very few good studies comparing one type of dressing with another, so it is difficult to present actual proof.2
For necrotic venous ulcers, hydrogel or hydrocolloid dressings with the application of collagenase ointment (SANTYL; Smith + Nephew) on the wound surface is indicated. According to the package insert, this ointment is compatible with multiple antibacterial dressings, creams, or powders, such as silver, iodine, or Manuka honey products. Sharp debridement is often needed to remove necrotic tissue.1
For a heavily draining or bleeding venous ulcer, alginate dressings are a good choice because they can absorb a large quantity of drainage and help control bleeding.
A healing ulcer is marked by granulation tissue, for which polyurethane foam dressings are a good choice.
Collagen dressings are helpful when the wound is almost healed and has started to epithelialize.2
An Unna boot is a zinc oxide-impregnated gauze wrapping similar to a cast but more flexible. This therapy has been around for about 200 years. It can work well but can also cause significant cellulitis, and, for me, does not seem to work any better than regular compression. In my practice, I have not seen it used often for venous ulcers and never in our wound care clinic.
Venous ulcer infection. Infection and biofilm formation on a venous ulcer are common and not always obvious. Results of swab cultures are not particularly helpful because of the inevitable contaminants. In my opinion, one can reasonably assume that any wound of any type that has been present for more than 30 days is infected.
Iodofom guaze is an effective antimicrobial and helps with debridement of necrotic tissue.3 Silver-impregnated dressings are commonly used, and I have not noted a problem with significant antimicrobial resistance.
If a patient does not regularly elevate the legs at least to the level of the heart, venous ulcers are unlikely to heal and are likely to recur if they do heal. Zero-gravity chairs are available, comfortable, and reasonably priced.
ARTERIAL ULCERS
Arterial ulcers, also called ischemic ulcers, are usually a consequence of peripheral vascular disease, in which an area of skin dies and breaks down because of a lack of blood supply. Characteristics of peripheral vascular disease include absent ankle and pedal pulses, cool feet that turn pale upon leg elevation, and a history of intermittent claudication (when a patient can walk only a short distance before having to stop because of calf pain).
The lesions are commonly found on the foot, especially the toes, but may occur elsewhere. They are usually deep and have a round appearance in contrast to venous ulcers, which are generally shallow and irregular in shape. In general, arterial ulcers do not bleed, for the obvious reason that there is no blood supply to the wound.
These patients should never have support hose or compression dressings applied. In addition, the patients would not be able to tolerate prolonged leg elevation. Indeed, many of these patients will sleep in a chair so that their legs can be much lower than the heart to maximize the peripheral circulation.
In general, ischemic ulcers should not be debrided because the debrided area may not heal, making the wound worse. Wound dressing choices are essentially the same as for venous ulcers. The goal is to try to prevent the wound from becoming infected.
The mainstay of treatment of arterial ulcers is to improve the circulation with stents or arterial bypass surgery. This is a surgical problem outside the scope of a wound care center.
Arterial foot wounds frequently occur in patients with diabetes, often starting as a minor foot injury that never heals. The reason for this is that many patients with diabetes have peripheral neuropathy and cannot feel their feet, so they cannot feel that a shoe is on too tightly or a small stone is in the shoe. Unfortunately, the end-result is frequently amputation, starting with the toes, then the foot, and then a below-the-knee or above-the-knee leg amputation. Currently about 150 000 nontraumatic amputations are performed yearly in the United States.4 This number is increasing rapidly, mostly because of uncontrolled diabetes and especially in African Americans, who have 4 times the amputation rate of White Americans.5 By contrast, I cannot recall ever seeing a venous leg ulcer that ending with an amputation.
I welcome readers’ comments and experiences on the huge and growing problem of vascular leg wounds.
Dr Davey is a mostly retired wound physician with more than 24 years of practice treating many different types of wounds at the HCA Edward White Hospital Wound and Hyperbaric Medicine Center in St. Petersburg, FL. He can be contacted at drchrisdavey@outlook.com and welcomes all feedback. The opinions and statements made here are not necessarily those of Wound Management & Prevention or HMP Global. This article was not subject to the Wound Management & Prevention peer-review process.
REFERENCES
1. Nair B. Compression therapy for venous leg ulcers. Indian Dermatol Online J. 2014;5(3):378–382. doi:10.4103/2229-5178.137822
2. Dabiri G, Damstetter E, Phillips T. Choosing a wound dressing based on common wound characteristics. Adv Wound Care (New Rochelle) 2016:5(1)32–42. doi:10.1089/wound.2014.0586
3. O’Donnell TF, Passman MA, Marston WA, et al. Management of venous leg ulcers: clinical practice guidelines of the Society for Vascular Surgery® and the American Venous Forum. J Vasc Surg. 2014;60(suppl 2):3S–59S. doi:10.1016/j.jvs.2014.04.049
4. Creager M, Matsushita K, Arya S, et al. Reducing nontraumatic lower-extremity amputations by 20% by 2030: time to get to our feet: a policy statement from the American Heart Association. Circulation. 2021;143(17): e875–e891.
5. Mosti G. Wound care in venous ulcers. Phlebology. 2013;28(suppl 1):79–85. doi:10.1177/0268355513477015
SUGGESTED READINGS
Geiss LS, Li Y, Hora I, Albright A, Rolka D, Gregg EW. Resurgence of diabetes-related nontraumatic lower-extremity amputation in the young and middle-aged adult U.S. population. Diabetes Care. 2019;42(1):50–54. doi:10.2337/dc18-1380
Mizokami F, Murasawa Y, Furuta K, Isogai Z. Iodofom guaze removes necrotic tissue from pressure ulcer wounds by fibrinolytic activity. Biol Pharm Bull. 2012;35(7):1048–1053. doi:10.1248/bpb.b11-00016
