A 'mythectomy' for dermatologic surgery

"In dermatology and in medicine, in general, we have this historic divide between medicine and surgery. Dermatology is a somewhat unique field because it does both, as does ophthalmology," Dr. Spencer says.

"Medical treatments, such as new drugs, are extensively studied before they can be introduced in the marketplace. Refinements in surgical techniques often do not lend themselves to such trials. More often than not, surgical techniques are adopted because a respected expert said so - not because it is necessarily true or proven."

Common myth No. one

According to Dr. Spencer, plastic surgeons tend more than dermatologists to be fooled by this first myth: the belief that large surgical wounds - really any surgical wound - cannot be left open to heal by second intention.

Physicians tend to think that, particularly when it comes to wounds with exposed bone, healing with second intention will result in bone desiccation, putting the patient at risk for osteonecrosis and osteomyelitis.

"Most dermatologists, using the Mohs technique, have found that even very large surgical defects with exposed bone heal quite nicely with second intention," Dr. Spencer says.

Common myth No. two

When it comes to the necessity of excising dog ears, dermatologists tend not to know it is a myth, while plastic surgeons do.

"We were taught as dermatology residents that when you do a simple excision with primary closure - that the dog ears should be completely excised at the time of surgery or else they will be persistent and permanent," Dr. Spencer says. "The truth is that there are areas on the body - particularly on the backs of the hands - where smaller dog ears will settle and go away, naturally."

Dermatologists learn in school that, in order to avoid dog ears, the length-to-width ratio should be three-to-one or four-to-one.

"That is false," Dr. Spencer tells Dermatology Times. "Dermatologists should instead use their judgment and experience that each patient and each location is different and the best thing to do is put a stitch in the middle and take a look. When wrong, they should be willing to revise and go back and get it."

Common myth No. three

Dermatologists learn never to use lidocaine with epinephrine on distal sites, such as the fingertips, toes, penis or even the nasal tip.

The reason? The fear that the epinephrine would cause such vasoconstriction that the area would die from poor blood supply.

"That is false," Dr. Spencer says. "Someone finally got around to studying this in the modern era (J Am Acad Dermatol. 2004 Nov; 51[5]:755-759), and it turns out to simply not be true. In fact, it is absurd."

Common myth No. four

Dermatologic residents learn that in order to sew a primary closure together they need to use absorbable sutures inside and nonabsorbable - usually nylon - sutures on the outside.

Why not use the absorbable suture on the outside and avoid having to open two packs of sutures? The answer historically, Dr. Spencer says, was that the absorbable sutures have a braided configuration, which was thought to favor infection and cause inflammation. But researchers (Arch Facial Plast Surg. 2003 Nov-Dec; 5[6]:488-490) studied the topic and found that nothing adverse happens when doctors use absorbable sutures on the outside.

A fifth myth – or not?

One myth will never be truly dispelled:

It is a medical-legal fact that resurfacing should not be performed on patients who have recently taken Accutane (Roche), according to Dr. Spencer.

"This has never been studied. This notion is based on nine anecdotal case reports by centers doing thousands of dermabrasions and, in these nine cases, scarring arose," he says.

The cases are anecdotal and probably not true because, as a general principle, topical retinoids prior to wounding accelerate healing, according to Dr. Spencer. Still, it is accepted as fact and in the textbooks, he says.

"That is probably a myth, but no one is ever going to answer this question because no one is ever going to study this. There was one animal study done and Accutane had no effect on healing or propensity to scar," Dr. Spencer says.

"It is yet another case where surgery does not lend itself to true study."

For more information: Krunic AL, Wang LC, Soltani K, Weitzul S, Taylor RS. Digital anesthesia with epinephrine: an old myth revisited. J Am Acad Dermatol. 2004 Nov; 51(5):755-759; Parell GJ, Becker GD. Comparison of absorbable with nonabsorbable sutures in closure of facial skin wounds. Arch Facial Plast Surg. 2003 Nov-Dec; 5(6):488-490.