A potential disadvantage of ultrasound-assisted lipoplasty is tissue burns. These may occur when the tip of the probe hits the undersurface of the skin. These "end hits" occur when the tip of the probe is vertically oriented to the skin surface, and they are more likely to happen when the surgeon is trying to go around the sides of the patient from centrally located access incisions.
To help avoid hitting the skin’s undersurface around the lateral aspect of an area being treated, a lateral meridian is drawn before surgery with the patient standing. The surgeon should not cross this lateral meridian when working in an anterior direction from the central access incisions with the patient in a prone position or when working in a posterior direction with the patient in a supine position. The prone position displaces this lateral line posteriorly, whereas the supine position displaces it anteriorly because the operating room table pushes up against the patient’s body.
The surgeon’s non-dominant hand assists by rolling tissue toward the probe so that its tip does not approach the skin in a vertical orientation. Early in my experience, I would sometimes push the probe too far around a contour. The surface orientation provided by the lateral line has helped prevent that problem so the tip of the probe is not perpendicular to the skin.
I limit access incisions to well-concealed sites. One or two incisions at the superior border of the escutcheon or umbilicus for the anterior abdomen and lateral flanks, and one at each of the lower lateral borders of the escutcheon for the inner and outer thighs have been adequate when the patient is in the supine position. Incisions on either side of the spine and in each buttock crease have sufficed to treat flanks and thighs with the patient in the prone position.