3 Overview Classification: Mathes and Nahai type I muscle flap Pedicle length: up to 10cmPedicle calibre: mm (artery)UsesGroinIschiumPerineumLower abdomenSacrumTrochanter
4 Anatomy Origin: Insertion: Blood supply: Innervation: anterior iliac crestInsertion:illiotibial tractBlood supply:ascending branch of the lateral circumflex femoral arteryInnervation:Sensory: lateral cutaneous sensory nerve of the thighMotor: distal branch of the superior gluteal nerveThe TFL muscle takes origin from the anterior iliac crest in an arc and inserts into the iliotibial tract. The vascular pedicle enters the TFL muscle at the level of the junction of the proximal and middle thirds of an axis drawn from the anterior superior iliac spine to the lateral patella.The TFL muscle flap is supplied by the ascending branch of the lateral circumflex femoral artery. The descending branch supplies the anterolateral thigh and rectus femoris flaps. The descending branch can be harvested with the anterolateral thigh skin to enlarge the perfused vascular territory of the TFL flap. Taking a large width of flap can create a significant aesthetic donor deformity, especially if skin grafting is required to close the defect. The lateral femoral cutaneous nerve of the thigh travels through the flap skin and fat proximally to supply distal flap sensation.
6 Variations Bone (ASIS) +/- TFL muscle Neurosensory Include lateral sensory branch of T12 or lateral femoral cutaneous nerveExpanded or transverse skin paddlePerforator flapV-Y advancement
7 Surgical MarkingsMark a line from ASIS to the lateral patella (anterior axis)Pedicle is located anywhere from 8-12 cm below ASISAxis of femur marks posterior aspect of flapThe patient is prepped and draped supine with a bump under the ipsilateral hip. The anterior part of the flap runs along the axis of the septum between the vastus lateralis and the rectus femoris. A line drawn from from the anterior superior iliac spine to the lateral patella locates this anterior landmark. The entry point of the pedicle is at the level of the junction of the proximal and middle third of the aforementioned line. The posterior aspect of the TFL is denoted by the axis of the femur. The flap is marked as an ellipse over the axis of the TFL muscle and to incorporate the pedicle proximally.
8 Dissection Elevate flap from distal to proximal More proximally, retractor placed between rectus femoris and vastus lateralisFirst identify descending branch of LFCA, then identify ascending branch more superiorlyIsolate pedicle course to TFLPedicle can be traced to lateral femoral circumflex vessels/profundus to gain calibre and lengthThe flap is elevated from distal to proximal. The skin and deep fascia are incised together and the plane deep to the iliotibial tract fascia is elevated sharply while coagulating small perforators. As one ascends proximally, the space between the rectus femoris and vastus lateralis is retracted with a self retaining retractor to identify the descending branch of the lateral femoral circumflex artery. The ascending branch is then identified as one proceeds in a superior direction.With the ascending branch identified, its course to the TFL can be isolated. The proximal flap is then divided by electrocautery while protecting the pedicle. The pedicle can be traced to the origin of the lateral femoral circumflex vessels to gain length and caliber.
13 Overview Reliable blood supply and motor innervation Classification: Mathes and Nahai type 2 (dominant and minor arterial supply)Major disadvantages are:Not a particularly expendable musclePedicle can be affected by atherosclerosisCoverage of lower abdomen, groin, ischium, trochanteric region, functional muscle transplantation
14 Anatomy Origin: iliac portion of acetabulum and ASIS Insertion: patellaArterial supply:Dominant = descending branch of lateral femoral circumflex arteryMinor = ascending branch of lateral femoral circumflex artery and muscular branch of SFAVein = venae commitantesPedicle length/calibre = 5cm/2mmNerve = motor branch from femoral nerve
15 Variations With or without skin paddle Innervated functional muscle Most perforators within middle third of thighInnervated functional muscle
16 Surgical MarkingsDraw line from ASIS to mid patella for longitudinal axisLazy S incision over musclePedicle just proximal to junction of proximal and middle thirds of thigh (8-10 cm below AIIS)Length limited to middle 1/3rd of thighA line drawn from the anterior superior iliac spine to the mid aspect of the patella denotes the longitudinal axis of the muscle. The incision is made in a lazy-'s' fashion to expose the required length of muscle. The pedicle arises just proximal to the junction of the proximal and middle thirds of the muscle. A skin paddle can be harvested with the width determined by ability to close the thigh with a pinch test, while the length is limited to middle third of the thigh. Cutaneous perforators can be determined with the pencil Doppler.
17 Flap dissection Incise through skin paddle (if required) Through muscular fasciaSartorius and rectus femoris identifiedSartorius retracted mediallyLateral femoral circ vessels lie here on proximal portion of musclePedicle is 8-10cm below AIISMuscle freed from medial, lateral, distal fascial attachmentsRaised on pedicle
20 Overview Workhorse flap Used for pedicled coverage of groin, vaginal/groin reconstructionUsed as free innervated functional muscle for facial reanimationSegmental motor nerve supply allows muscle to be sectioned (3 branches: anterior, mid, posterior)Mathes and nahai type 2 muscle flapPedicle length/calibre = 6cm/1-2mm
27 Flap dissection Incise over axis of muscle proximally Optional distal incision to disinsert distal insertionDissect down to fascia over gracillis and adductor longus until septum reachedRetract these muscles apart from each otherPedicle lies hereProximal origin divided, pedicle dissected