Final answer:
A vertical incision 4 cm lateral to the midline of the abdomen is a paramedian incision.
Step-by-step explanation:
The vertical incision described in the question, which is 4 cm lateral to the midline of the abdomen, is an example of a paramedian incision. This type of incision is commonly used in surgery to access the abdominal cavity. It is made slightly to the side of the midline to minimize potential damage to important structures in the center of the abdomen.