When closing wounds created by surgical excision, key principles include minimizing skin tension, confining repairs within cosmetic units and matching skin characteristics when using flaps and grafts, an expert says.
Buenos Aires - After removal of a benign or malignant lesion, the choice of a primary closure, a flap or a graft depends on a variety of factors, an expert says.
"Depending on the wound's location and the anatomy where one has created the defect, there are certain principles one must observe," says Anthony V. Benedetto, D.O., F.A.C.P., clinical associate professor of dermatology at the University of Pennsylvania, Philadelphia.
First, key objectives of excisional surgery reconstruction include keeping the final scar short by minimizing the deformity in the direction of natural skin tension lines, Dr. Benedetto tells Dermatology Times.
Additionally, Dr. Benedetto says that with flaps and grafts, it's paramount to match skin characteristics, including texture, color, thickness, vascularity, mobility, elasticity, sebaceousness, pore size and contour.
Similarly, one should consider skin tension lines, which lie perpendicular to the direction of muscle contraction, and contour lines, which divide body planes and define cosmetic units.
"Avoid crossing cosmetic units and boundary lines," he says. Extending a line of closure into different cosmetic units will draw the eye in the manner that a cleft palate would, he says.
Regarding specific techniques, Dr. Benedetto says that if removal of a cyst in the middle of the patient's back leaves a rather deep hole, "Many times it's easy to simply stitch the two edges together. This will produce an elongated line, but it's closed."
Conversely, Dr. Benedetto says that if one is working near free margins such as the nasal openings, lips or eyelids, "One must be careful in which direction the closure is created - the stitched wound edge must lie perpendicular to the free edge, because if it's parallel, the vector of tension wants to separate the two closed edges."
Intuitively, one might think that creating the closure parallel to the free edge would help camouflage it, but, in fact, the vector of tension should run parallel to the free margin to avoid problems such as ectropion, he says.
In creating flaps for facial wounds, a key principle is to use natural reservoirs of tissue such as the glabella, cheeks and preauricular area, where there's minimal tension and maximum movement, he says.
Specific steps for creating a flap start with visualizing the flap - basically, looking at a defect and trying to imagine the best closure strategy.
Next comes outlining the flap. While physicians frequently use an ink pen or a dye for this purpose, Dr. Benedetto says, "One can just get a little cotton-tipped applicator and use the blood from the wound.
"It's expedient, you can wipe it away and you're not tattooing the skin," which can happen inadvertently if one inserts stitches before completely cleaning an ink or dye from the skin's surface.
Additionally, he cautions, "Do not excise the entire outline or length of the flap, or the Burrows triangles, until the total skin movement is assessed and undermining is completed. Wait until you have it all undermined - and the tissues shifted and edges brought together - before starting to cut those Burrows triangles, because a lot of them will disappear due to the tissue contour."
The proper depth of undermining depends on the anatomic location, he continues.
"In the scalp," Dr. Benedetto says, "it's the subgaleal area. In the forehead, it's above the muscle. In the central cheek, it's between the upper and middle one-third of the subcutaneous fat. In those areas, we can be guaranteed that there are enough blood supply and nerves to keep the flap alive."