Gracilis Flap
These diagrams and illustrations have been designed to help you learn, memorise and recall key information.
INTRODUCTION
A type II Muscle flap supplied by the medial circumflex femoral artery.
It has 1 or 2 minor pedicles from the Superficial Femoral Artery (SFA) distally.
It provides ~ 5x20cm of good well vascularised muscle which can be innervated.
The donor sit is good with minimal functional deficit.
CLASSIFICATION
Type II Muscle Flap (Mathes & Nahai).
COMPOSITION
Muscle +/- skin.
KEY ANATOMY
The gracilis arises from the inferior pubic ramus.
It narrows inferiorly to insert into the medial side of the tibia (behind sartorius).
PEDICLE
Ascending branch of the medial circumflex femoral artery from the profunda femoris.
It enters the muscle on its deep surface ~ 10cm inferior to the pubic tubercle.
Runs posterior to adductor longus, but anterior to magnus.
Vein(s): Two venae
Pedicle length up to ~6-8cm.
SKIN PADDLE
Can be harvested with skin paddle eg TUG (transverse upper gracilis) Flap.
The skin paddle is said to be unreliable (esp in obese patients)
INNERVATION
Motor via Anterior branch of the obturator nerve. ~10-12cm of nerve is available.
The nerve enters on the medial side of the muscle just superior (~2cm) to the vessels.
The nerve trifurcates on enter to the muscle so the muscle can be split into slips.
COMMON USES
Pedicled - Coverage for perineum, pubis, groin abdominal wall or ischium.
Free - A good muscle flap for many defects. eg Following lower extremity trauma or for osteomyelitis.
Functional - Biceps, Finger flexors or facial reanimation.
TECHNIQUE
I position the patient supine with the leg abducted and externally rotated.
Add longus (easily palpable) & sartorius lie ant. to gracilis with semi-mebranosus posterior.
I design an incision ~3-4cm posterior to the adductor longus.
The long saphenous vein crosses the muscle and should be retracted anteriorly.
I raise the muscle (dividing any perforators to the overlying adductor longus).
The adductor longus can be retracted to expose the full length of the pedicle to its origin.
I locate the nerve on the medial side of the muscle just superior (~2cm) to the vessels.
I divide the muscle using McIndoe scissors to avoid contraction with diathermy.
I then perform the anastamosis and cover the flap with a SSG if required.
DISTALLY BASED GRACILIS (controversial)
Based on distal Minor pedicles (1-2 small vessels from the SFA)
Delay of the dominant pedicle prior to elevation is recommended.
