How to create a bi-lobed flap in the foot

How to create a bi-lobed flap in the foot


A bi lobed flap is very useful when surgically removing a large soft tissue mass, a tumor or a wart.

The following images are for surgical education purposes and training only.

The first image is of a large soft tissue mass that turned out to be a plantar verrucae. The lesion was taken out by another doctor and returned to grow much larger when the patient presented in my foot and ankle clinic. The advantage of placing a flap is primary closure of the surgical site.

The first part of creating a bi lobed flap is surgical planning. It is vital to know anatomy and skin tension lines. 

Pearl: I would advise not to place any local medication under the surgical site. An ankle block or general anesthesia is best. Local anesthetic will place too much tension on the skin and make it difficult to rotate the flap. 

Second Pearl: The width of flap B should be about the same as the soft tissue mass (C). The width of flap A should be about 40% smaller than flap B

In the above picture the relationship of the bi-lobed flap is 90 degrees (Black Lines). I would advise to make the flap relation around 80-65 degrees. 

Index:

A: Used to close flap defect

B: Used to close the soft tissue defect

C: Soft tissue mass

Step 1: Draw a circle around the soft tissue mass and make sure to take a clear margin.

Step 2: From the opposite corners of the circle create a cone. In the above picture the cone is made of one red line and one black line.The point of the cone is pointed up in the above picture. 

Step 3: Draw a 90 degree line from the red line- two lines should be about the same length

Step 4: Draw a 80-65 degree line from the black line - two lines should be about the same length

Make a full thickness incision. Undermine the entire flap. Undermine the skin around the other side of the incision. Be careful when handling the soft tissue. Be very delicate.

Rotate the entire flap and suture it down.  

Suture the flap down. 

Some areas might look slightly white. As long as the patient has good blood flow the skin color should return to pink. 

Finally, remain off the foot for 3 weeks.

For more information contact Dr. Kolodenker, Foot and Ankle Surgical Podiatrist in Orange County