Lateral Thigh Flap

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Lateral Thigh Flap

YUN XX, D.D.S., M.S.D.Dept. of Oral & Maxillofacial Surgery, College of Dentistry, XXXXX National University

History1983 Baek S.M.Two new cutaneous free flaps : the medial and lateral thigh flap

1984 Richard E. HaydenReconstruction of pharyngoesphageal defects

1995 Miller M.J.Anatomical study of the lateral thigh free flap

1998 Turelson J.M.Lateral thigh flap reconstruction in head and neck

AnatomyEncompassing skin and subcutaneous tissue of posterolateral thigh Ellipse, with the long axis resting over intermuscular septum between vastus lateralis and the long head of biceps femoris Skin island size : 27.0 14.0 cm 27. 14.

Blood supplyCutaneous branches of the perforators from the profunda femoris a. Principal supply : Third perforatorvery small minority of patients - fourth perforator

Secondary supply : Second or fourth perforatorCf. Cf.) Anterolateral thigh free flap (Koshima et al)Lateral circumflex femoral system

Profunda femoris a.Femoral a.3.5 cm below inguinal ligament

Profunda femoris a.Deep to the adductor longus

Third perforator

Piercing the fascia through linea aspera Branches to vastus lateralis and biceps femoris Pass the short head of the biceps femoris Intermuscular septum

Cormack et al(Plast. Reconstr. Surg. 75:342, 1985)

Primary blood supply of the lateral thigh skin came from the perforators of the profunda femoris a. Not dependent on perforators from underlying muscle or fascia Can be harvested with the flap to repair complex defects skull base

Michael J. Miller et al(Plast. Reconstr. Surg. 96:334, 1995)

Anatomic cadaver dissectionVessel came to skin level14. 14.5cm 3.5cm above the lateral femoral epicondyle

Pedicle length from superficial fascia level to the origin of the 3rd perforator6.1cm 0.9cm

57 of 61 cases pass through the short head of the biceps femoris

PerforatorsAn understanding of these four branches is critical to the safe harvest of the lateral thigh flap

Each perforator gives off three types branchesMuscular branches to the hamstrings Branches that run in a cephalocaudal direction to anastomose with branches of the other perforators Fasciocutaneous branches

The first perforatorPrimary blood supply to the adductorsBrevis, longus, and magnus

Terminal branchmain vascular pedicle of the gracilis muscle

Cutaneous branchupper medial thigh

Branches to gluteus maximus and greater trochanter

The second perforatorMuscular branchesSemimembranosus Long and short heads of biceps femoris Vastus lateralis

The nutrient artery of the femur

The third perforatorDominant nutrient supply to the lateral thigh flap Muscular branches to the biceps femoris and vastus lateralisThe short head of the biceps femoris : A flexor of the knee Pulsations within the filmy short head of the biceps femoris

The fourth perforatorTerminal portion of the profunda femoris Occasionally provide the dominant vascular supply to the lateral thigh skin Sacrificed in the process of harvesting a lateral thigh flap

Arterial diameterProfunda femoris a. : 3 to 5 mm Origin of the 3rd perforator : 2 to 3 mm Terminal cutaneous branch : 1 to 2 mm

Venous drainageVenae comitantesAlways two venae comitantes Traveling with the arterial perforator Join to become one large vein that ultimately accompanies the profunda femoris artery The diameter of the parent vein : 4 to 5 mm

Sensory supplyLateral femoral cutaneous nerveOriginate from the first three lumbar nerveSometimes from the femoral nerve

Passing under the inguinal ligament and anterior, posterior or through sartorius m. Divide into anterior and lateral branchSubdivide into the subdermal fat

Anatomic VariationsMajor arterial supply - fourth perforatorThe center of the skin paddle - more distally

The major problemMajor arterial supply - second perforatorEnsure the vascular supply to the muscles and the femur

Anatomic VariationsHayden15% 15% incidence of vascular variations Recommend to include a large fourth perforator to augment the cutaneous blood supply

BaekOne cadaver : the dominant vascular supply - from a branch of the superficial femoral artery The rudimentary profunda femoris

Clinical applicationsTotal pharyngectomy defectsThin, pliable flap qualityTube formation an epithelialized conduit

DeDe-epithelizationSkin island for monitoring flap viability

Very long pharyngeal defectsFrom nasopharynx to thoracic inlet

Clinical applicationsNearNear-total glossectomy defectsBulkier thigh flapswith more subcutaneous fat can provide sufficient tissue

Advantages of the subdermal fatless atrophy associated with denervated muscle

Clinical applicationsSensory reinnervation for oral cavity reconstructions Severe cervical burn contractures - suboptimal color match Large scalp defects with underlying fascia flap Facial augmentation with vascularized fat flap

Patient SelectionBody habitus and specific defect requirement No tourniquetLimiting worries of extremity eschemia

Minimal donor site morbidity No specific preoperative workup

WorkupQuestion about issues that disqualify surgery Evaluate previous injury or surgery to the thigh No specific lab studies or imaging studies Pinch test to determines the amount of fat Doppler device to locate the main perforator

Draping and Flap designSlight flexion of hip and knee Inward rotation of leglocation of pillow under the hip for rotation

Exposure of thighFrom the greater trochanter to the lateral epicondyle

Palpation and marking of intermuscular septumCenter of the line - Third perforator

Design : Ellipse with long axis along the line

Landmarks of femurGreater trochantergreater trochanter of the femur is a large, somewhat rectangular projection from the junction of the neck and the body. body. It provides an insertion for several muscles of the gluteal region. region.

Condylethe medial and lateral condyle of the femur are subcutaneous and easily palpable. Palpate them as you flex and extend your palpable. knee joint. At the center of each condyle is a prominent joint. epicondyle, to which the tibial and fibular collateral ligaments of the knee joint are attached. The medial and lateral attached. epicondyles are easily palpable. palpable.

Flap harvestIncision at the anterior aspect of ellipseThrough the skin and subcutaneous fat Down to the level of fascia overlying vastus lateralis

Easy distal approach to intermuscular septumProximal : overlying fascia lata

Third perforator identificationNear superior border of short head of biceps femoris Vessel may run on, under, or through the muscle This area is preserved for later dissection

Flap harvestMedial retraction of vastus lateralis m.Trace the vessel toward the femur Careful ligation of muscular perforatorsTo the vastus lateralis and biceps femoris

Demonstration of vascular pedicle piercing adductor fascia through a semilunar hiatusReleasing adductor attachment from linea aspera

Identification of profunda femoris a.Proximal dissection until the 2nd perforator level

Flap harvestSkin paddle mobilizationRelease from short head of biceps femorisAvoid direct dissection Two finger breadth section of biceps femoris m.

Posterior skin incision down to long head level and proximal dissectionSciatic n. protection during flap elevation

Flap harvestStaple back of flap until transferFurther practical test of flap viability Limits ischemia time for the flap Placement of flap in cool siline bath

Donor siteHemostasis & Suction drain insertion Primary closure - wide undermining of skin flap Occasional skin graftParallel relaxing incision on the anterior thigh area Primary closure at intermuscular septum and with splitsplit-thickness skin graft at medial relaxing wound To avoid potential skin graft loss at the intermuscular septum

Sensate lateral thigh flapLateral femoral cutaneous nerveArborize from the subcutaneous fat proximal to the anterior incision of ellipse Retrograde dissection : tedious and unsatisfying Second longitudinal incision at sartorius levelLateral tracing from the main nerve trunk Section of the branch to the anterior thigh Halt further dissection and harvest with subcutaneous fat Subdermal dissection and underlying fascia elevation

Aid Tips DetailsProper positioning Sufficient exposureAnatomic landmarks and postlateral thigh

Remember the exit of perforating artery Planned ellipseCenter on intermuscular septum

Relation of vascular pedicleTo the short head of biceps femoris

Most challenging aspect of the dissectionAdductor hiatus level

AdvantagesVascular pedicle : 8-10cm 10cm Large vessel diameter : 2-5mm Large available surfaceThin pliable flap - pharyngeal reconstruction Thicker flap - glossal reconstruction

AdvantagesTwo team approach Minimal donor site morbidity Favorable alternativeMore accepted fasciocutaneous free flapForearm flap - linear scar Scapular/parascapular flap

DisadvantagesBulkness in Obese patients HairHair-bearing skinEsp. Esp. in male Permanent depilatory effects of postpost-operative radiation therapy

ComplicationsFlap deathSuccess rate approaches 90-95% 90-95% Arteriosclerotic plaque Accidental vessel transection during dissectionThe posterior skin attachment may be left intact until the time of anastomosis The posterior subdermal and dermal vessels provide adequate blood flow to the skin flap. flap.

Donor site skin graft lossSeroma have a tendency to develop in this area

Future and ControversiesControversiesPFA itself Vs third perforatorShort pedicle length

PFA proximal to second pe