Lower-leg wound healing requires creativity, skill
Indianapolis — In healing persistent surgical or other wounds of the lower leg, says Jeffrey E. Petersen, M.D., it's dermatologists' understanding of the fine balance required for wound healing — and how to manipulate this balance — that "allows us to walk where others fear to tread."
For example, he says that excess inflammation and edema can turn acute healing into a chronic wound process. Additionally, "We must balance maceration versus moisture, pressure versus necrosis and when to cut or cure," says Dr. Petersen, who is a dermatologist in private practice in Indianapolis.
Overall, Dr. Petersen says, "I have to get the leg better before I can get the wound better." To that end, "It may not always be necessary to cut."
For example, Dr. Petersen says the chemowrap technique proves helpful for surgery-averse patients and for those whose diffuse lower extremity squamous cell carcinoma (SCC) and actinic keratoses aren't well-suited for surgical removal (Mann M, Berk DR, Petersen J. J Drugs Dermatol. 2008;7(7):685-688).
"It is not meant to replace common clinical sense, but it is a tool for improving patient outcomes and results, including restoration of the integument," he explains.
The technique involves thoroughly washing the area to be treated with soap and water, then applying a thick coat of 5-fluorouracil (5-FU), starting distally on the midfoot and extending to the upper calf. "A 45 g tube should last two visits, treating both legs," Dr. Petersen says.
Next, Dr. Petersen recommends placing lubricated gauze at the angle of the foot to minimize friction. "You then apply a zinc-impregnated gauze (Unna's paste) with a 50 percent overlap. If you don't have the overlap, the 5-FU will come through the gauze and won't penetrate into the skin."
Additional layers include Kerlix (Kendall) with minimal overlap, followed by six-inch Coban (3M) or self-adhering veterinary wrap, which he says costs less.
"The patient removes the chemowrap in one week," he says. "I tell them to scrub it in the shower, and don't worry if it bleeds — that's normal. Then they return for reapplication" weekly as needed. Some people complain of discomfort with this treatment; however, he says this stems not from the 5-FU, but from incorrect application of the "boot."
Generally, Dr. Petersen says, "I don't do extensive amounts of Mohs surgery on the legs. I usually wrap them, reduce the tumor burden, get the leg better, then just operate on what's left."
However, Dr. Petersen says that if dermatologists must excise tumors or other lesions, "Provide a healing environment for the wound." In one case he treated, a patient who had undergone Mohs surgery for SCC had a postsurgical defect that extended down to the Achilles tendon. For this patient, "We did compression therapy for five weeks. We needed to get granulation tissue to form on and around the tendon. Granulation tissue will form on tendon and bone very easily if it's given proper care," he says.
After five weeks, Dr. Petersen applied a full-thickness skin graft rather than a split-thickness graft, which he says would have created tethering and skin contraction.
Whenever he operates on a lower extremity, he says he wraps the area afterward.
"Patients get two to six weeks of compressive therapy following surgery, whether they're healing by second intention, graft or primary closure. If you do this, it eliminates the vast majority of complications," he says.
Compression wraps also prevent patients from scratching wounds, which they otherwise may do in their sleep without knowing it.
His final piece of advice for dermatologists is this: "Don't let an acute wound become chronic. To heal a chronic wound, make it an acute wound."
In one case involving a nonhealing Mohs defect with tendon exposure due to extensive necrosis, he says he gently curated the dead tissue off the tendon, then applied compression therapy to eliminate inflammation and edema.
"This turns it back to an acute-phase wound that can heal itself if given the proper supportive care," he says.