Elliptical Or Fusiform Excision
“Doctor, I’m concerned. My pet had surgery today to remove a mass under the skin one inch in diameter, but his surgical incision is six inches long. Why is that?”
The surgical technique for removing masses such as the one illustrated in the photograph at right is called excision. The term stems from the Latin excisio, which is made up of the prefix “ex,” meaning “out,” and the root “caedere,” meaning “to cut.”
In other words, the patient has material that must be removed or excised.
How do we go about that?
If the mass is round, we could draw a circle around it, big enough to provide clean margins, and cut around the circle.
That would work if one didn’t care what the resulting closure looked like. However, the only way to close a round surgical incision is by purse string suture. Just as in the purse illustration above, the result is none too pretty and the resulting scar would be unacceptable.
Instead, an elliptical excision is used, with the points of the ellipse sitting on opposite sides of the mass. The sharp points and sweeping lines of an ellipse can easily be adjusted by the surgeon to pass as close to or as far
from the mass as necessary, depending on the perceived risk of neoplastic contamination near the palpable and/or visible parts of the mass. The result can be a wide excision or narrow excision, as needed. The standard formula is for the shape to be three times as long as it is wide. Doing so gives an approximate 30-degree angle at each end of the ellipse, avoiding a bunching-up of tissue commonly referred to as a “dog-ear.”
Another name for elliptical excision is fusiform excision. Fusiform comes from the Latin “fusus,” meaning “spindle.” Thus, an elliptical excision is spindle-shaped.
When closed, the two edges of the excision are sutured together to make a single line. That line may be straight or curved, depending on the shape of the mass removed , the body part affected and the availability of sufficient skin for closure.
One might reasonably ask whether the smaller round excision might hurt less than the longer elliptical excision. In actuality, it doesn’t. At least not to a degree we can measure. And almost no one would find the proud, puffy scar of a purse string closure to be something they would want to look at for the rest of their pet’s life.
See you tomorrow, Dr. Randolph.