Muscle Flaps

Muscle Flaps:

Muscle Flaps Trefor Nodwell MD CM Dr. D. Lalonde, FRCSC Dr. W. Parkhill, FRCSC

Outline:

Outline Review Basic Anatomical and Physiologic Review Reconstructive Goals & Principles Classification Schemes with examples Muscle Flaps Only Common Examples Type/Pattern of Circulation Applications Anatomy and Elevation

Outline:

Outline Precautions/Pitfalls Brief overview of Less Common (but applicable) flaps Discussion

The Basics - Anatomy:

The Basics - Anatomy Motor nerves are always accompanied by vascular pedicles Pedicles Dominant – can sustain entire muscle on its own Minor – maintains only a portion of the muscle Segmental –nourishes small segment of the muscle Allows for a classification scheme

The Basics- Physiology:

The Basics- Physiology Arc of Rotation Standard – extent of reach of the muscle based on its dominant pedicle Reverse (distally based) – restricted by secondary pedicles

The Basics- Physiology:

The Basics- Physiology Choke arteries Small caliber vessels allowing bidirectional flow Oscillating veins No valves, allows reversal of flow Perforators Vessels pass through muscle to supply overlying skin Identified preoperatively

The Basics:

The Basics Balance reconstructive needs and sacrifice of normal function Reconstructive Ladder versus Triangle Defect analysis Location Size Physical Components Environment –host factors

The basics – Goals & Principles:

The basics – Goals & Principles Safety - successful wound coverage Identify and protect pedicle Conservative skin territories Tension- at pedicle or inset site Form- normal shape or contour Restoration at defect Preservation at donor site

The basics – Goals & Principles:

The basics – Goals & Principles Function – stability of closure, specialized functions. Hair growth Sensibility Skeletal Support Locomotion (or animation)

Classification:

Classification

Classification:

Classification According to mode of innervation (Taylor) Type I – single unbranched nerve enters muscle. Type II- Single nerve, branches prior to entering. Type III – Multiple branches from same nerve trunk. Type IV – Multiple branches from different nerve trunks. Affects suitability for functioning muscle transfer

Classification:

Classification Vascular Supply (Mathes and Nahai, PRS, 1981) Type I – Single vascular pedicle Type II – Dominant pedicle, minor pedicle(s) Type III – Dual dominant pedicles Type IV – Segmental Pedicles Type V – Dominant pedicle with secondary segmental pedicles

Examples – Type I:

Examples – Type I Single Vascular Pedicle Tensor fascia Lata Gastrocnemius Genioglossus Stylogossus Anconeus First Dorsal Interosseus Abductor Digiti Minimi (hand) Abductor Pollicis Brevis Vastus Lateralis

Examples – Type II:

Examples – Type II Dominant Vascular Pedicle and Minor Pedicles Gracilis Trapezius Soleus Rectus femoris Coracobrachialis Biceps Femoris Triceps SCM Platysma Brachioradialis Abductor digiti minimi (foot)

Examples – Type III:

Examples – Type III Two Dominant Pedicles Gluteus Maximus Rectus abdominus Serratus Temporalis Pectoralis Minor Intercostal Orbicularis oris

Examples – Type IV:

Examples – Type IV Segmental Pedicles Sartorius Tibialis Anterior External Oblique Extensor Hallucis Longus Flexor digitorum longus Flexor hallucis longus

Examples – Type V:

Examples – Type V Single Dominant and secondary segmental pedicles. Latissimus Dorsi Fibula Pectoralis Major Internal oblique

Common Examples:

Common Examples Each reviewed in terms of Applications Features – Location, size, origin, insertion Classification Nerve supply – motor and sensory Function Anatomy – vascular Arc of rotation Elevation

Tensor Fascia Lata:

Tensor Fascia Lata

Tensor Fascia Lata - Type I:

Tensor Fascia Lata - Type I Applications- Coverage of lower abdominal wall, perineum, ischium and sacrum. Free flap. Small thin, flat. 5X15cm. Origin – ASIS and crest. Behind sartorius Insertion – Iliotibial tract of Fascia Lata. Innervation Superior Gluteal T12 and lateral femoral cutaneous

Tensor Fascia Lata - Type I:

Tensor Fascia Lata - Type I Function - flexes and abducts the thigh Vascular Anatomy Ascending branch lateral circumflex femoral (off Profunda femoris) Pedicle: length – 7cm, Diameter 2-3mm Arc of Rotation Anterior – abdominal wall, groin, perineum Posterior – greater trochanter, ischium, perineum, sacrum.

Tensor Fascia Lata - Type I:

Tensor Fascia Lata - Type I Musculocutaneous V-Y advancement Fasciocutaneous Precautions Distal end less reliable (consider delay) Donor site closure – possible thigh compartment syndrome Donor site often requires grafting

Gastrocnemius - Type I:

Gastrocnemius - Type I

Gastrocnemius - Type I:

Gastrocnemius - Type I Applications – coverage of inferior thigh, knee, contralateral leg. Location – superficial posterior calf. Medial and lateral heads. 20X 8 cm. Origins – medial and lateral femoral condyles Insertion – calcaneus via Achilles tendon

Gastrocnemius - Type I:

Gastrocnemius - Type I Pedicles Major - Medial and Lateral sural arteries Minor – paired anastomotic sural vessels\ Innervation Tibial nerve Saphenous (medial), Sural (lateral) Function – plantar flexion of the foot.

Gastrocnemius - Type I:

Gastrocnemius - Type I Vascular Anatomy - medial and lateral muscles Arc of rotation - Medial Standard - suprapatellar thigh, knee, upper 1/3 tibia. Extended – by 5-8cm Distally based – middle third of leg. V- Y advancement to Achilles

Gastrocnemius - Type I:

Gastrocnemius - Type I Skin territories – Vertical and transverse islands. 10 X 23 cm Elevation Supine or lateral decubitus position. Stocking seam incision Pedicles in popliteal fossa entering deep surface, near origins superior to popliteal crease Popliteal vein and tibial nerve – superficial to popliteal artery

Gastrocnemius - Type I:

Gastrocnemius - Type I Precautions Preserve soleus Tourniquet recommended – avoid nerve injury Standard flap leaves better scar Preoperative angiography Relative contraindication – recent DVT

Gracilis – Type II:

Gracilis – Type II

Gracilis – Type II:

Gracilis – Type II Applications – groin, perineum, abdomen, ischium. Vaginal reconstruction. Facial reanimation. Location – medial thigh. Pubis to medial knee Thin, flat 6X24 cm. Adductor longus and sartorius anteriorly Semimembranosus posteriorly. Origin – Pubic symphysis Insertion – Medial Tibial condyle

Gracilis – Type II:

Gracilis – Type II Innervation Motor – anterior branch of obturator Sensory – anterior femoral cutaneous (L2-3). Function – thigh adductor.

Gracilis – Type II:

Gracilis – Type II Vascular Anatomy Dominant Ascending branch of medial circumflex femoral. Length – 6 cm, Diameter – 1.6 mm. Minor one or two branches of superficial femoral Length – 2 cm, Diameter – 0.5 mm

Gracilis – Type II:

Gracilis – Type II Arc of Rotation Standard – groin perineum vagina, anus and ischium Distal – requires delay, arc to knee. Skin territory Pubis to junction of middle and lower third between rectus anteriorly and biceps posteriorly. 16X18cm

Gracilis – Type II:

Gracilis – Type II Flap Elevation Draw line from Symphysis to medial femoral condyle – cut 3cm posterior to this. Pedicle location – 10cm inferior to pubic tubercle. Retract the adductor longus to expose. Muscle superficial to adductor magnus Medial to adductor longus Anterior to semimembranosus

Gracilis – Type II:

Gracilis – Type II Precautions Selective arteriography if prior vascular surgery Confirm skin island position often Special case- Functional muscle transplant Mark muscle resting length with sutures prior to disinsertion Dissect out obturator nerve Vaginal reconstruction – paired flaps

Trapezius – Type II:

Trapezius – Type II

Trapezius – Type II:

Trapezius – Type II Applications – Skull, head and neck, Oral cavity, posterior trunk and shoulder. Mandible facial reanimation. Location – large, flat, triangular. Superficial. 34 X 18 cm Origin – external occipital protuberance, medial third of sup. nuchal line, ligamentum nuchae, spinous processes of C7 to T12 Insertion – lateral third of clavicle, spine of scapula, acromion.

Trapezius – Type II:

Trapezius – Type II Vascular anatomy Dominant Transverse cervical artery Length 4 cm, diameter 1.8 mm Minor Branch of Occipital artery Length 3 cm, diameter 1mm Dorsal Scapular artery Length 4 cm, diameter 1.6mm.

Trapezius – Type II:

Trapezius – Type II Innervation Motor – CN XI (spinal accessory) Sensory - #rd and 4 th cervical nerves, intercostals Function Rotates scapula, elevates shoulder during abduction and flexion of arms

Trapezius – Type II:

Trapezius – Type II Arc of Rotation Standard – Posterior skull, cervical and thoracic vertebral column, midface and neck. Reverse – midline of trunk Skin territory 20 X 8 cm.

Trapezius – Type II:

Trapezius – Type II Elevation Mark midline, scapular border, midportion of scapula. Midpoint between scapular tip and PSIS Position prone or lateral decubitus Pedicle – Vertical flap - vertical component TCA. Deep surface of middle fibers, over superior rhomboid Lateral flap – ascending branch of TCA identified in posterior neck

Trapezius – Type II:

Trapezius – Type II Vertical Flap

Trapezius – Type II:

Trapezius – Type II Precautions Preserve superior fibers Selective ateriography if radiated or radical neck dissection. Use Doppler to identify segmental vessels in reverse flap Shoulder immobilization post op to avoid tension on closure.

Soleus – Type II:

Soleus – Type II

Soleus – Type II:

Soleus – Type II Applications – coverage of middle third +/- lower third of leg Location large, broad, bipennate, deep to gastroc. Medial and lateral bellies. Fused proximally. 8X28 cm (Flap dimensions 7-12 cm) Origin Lateral posterior head and body of fibula Medial middle third of medial border of tibia Insertion Calcaneus via Achilles tendon

Soleus – Type II:

Soleus – Type II Innervation Motor – posterior tibial and medial popliteal nerves Function- plantar flexion of the foot

Soleus – Type II:

Soleus – Type II Vascular Anatomy Dominant Proximal two branches of popliteal artery (Length 0.5-1 cm, diameter 1-1.5mm) Proximal two branches of posterior tibial artery (Length 1-2 cm, diameter 1-2 mm) medial belly Proximal two branches of peroneal artery (Length 1-2 cm, diameter 1-2 mm) lateral belly Minor 3-4 segmental branches of posterior tibial (L 1-1.5 cm, D 0.5 1mm)

Soleus – Type II:

Soleus – Type II Arc of rotation Standard – middle third of tibia Distal – distal third of tibia, based on minor pedicles. (Distal hemisoleus, more reliable)

Soleus – Type II:

Soleus – Type II Elevation Landmarks – medial border of tibia, fibula laterally. Extends below gastrocs and plantaris. Pedicle Deep surface (Post tib medial, peroneal laterally) Minor segmentals – distal medial border

Soleus – Type II:

Soleus – Type II Standard Flap Medial incision, transposed laterally. Lateral approach Hemisoleus – medial and lateral. Pedicle length cannot be extended

Soleus – Type II:

Soleus – Type II Precautions Congenital adhesions Distally based lateral hemisoleus has less reach than medial.

Gluteus Maximus – Type III:

Gluteus Maximus – Type III

Gluteus Maximus – Type III:

Gluteus Maximus – Type III Applications – Sacrum , Ischium, Trochanter, breast reconstruction. Location – large, quadrilateral, most superficial. 24X24 cm Origin – gluteal line of ilium and sacrum Insertion – Greater tuberosity of femur, iliotibial band.

Gluteus Maximus – Type III:

Gluteus Maximus – Type III Vascular Anatomy Dominant Superior gluteal artery (Length 3 cm, diameter 2.5 mm) Inferior Gluteal artery (Length 3 cm, diameter 2.5 mm) Minor First perforator of Profunda femoris (L 5 cm, D 1.5mm) Intermuscular branches of lateral circumflex femoral (length 1 cm, diameter, 0,6 mm)

Gluteus Maximus – Type III:

Gluteus Maximus – Type III Innervation Motor – inferior gluteal nerve (L5 to S1-2) via sciatic foramen at level of piriformis Sensory – Posterior divisions of L1-3 laterally, S1-3 medially) Function Extends and laterally rotates the thigh

Gluteus Maximus – Type III:

Gluteus Maximus – Type III Arc of Rotation Standard Axis edge of sacrum Covers sacrum and ipsilateral ischium Reverse (Inferior half) Divide origin and inferior pedicle To posterior lateral thigh Segmental transposition

Gluteus Maximus – Type III:

Gluteus Maximus – Type III Elevation Easily identified Standard flap Superior half –cover sacrum Inferior half – cover ischium

Gluteus Maximus – Type III:

Gluteus Maximus – Type III Donor closure Recommended, V-Y advancement may facilitate this. Precautions Not expendable Denervation atrophy Piriformis – key to division of midportion Sciatic nerve – inferior flap

Rectus Abdominus – Type III:

Rectus Abdominus – Type III

Rectus Abdominus – Type III:

Rectus Abdominus – Type III Applications – Thorax, abdomen, perineum, Breast, head and neck upper and lower extremities. Location –vertical, costal margin to pubis, long flat, three tendinous intersections.. Length 25X6 cm. Origin – crest of pubis, symphysis Insertion – 5 th to 7 th ribs

Rectus Abdominus – Type III:

Rectus Abdominus – Type III Innervation Motor – segmental 7 th to 12 th intercostal nerves Sensory – 7 th to 12 th intercostal nerves Function Flexes vertebral column, tenses abdominal wall.

Rectus Abdominus – Type III:

Rectus Abdominus – Type III Vascular anatomy Dominant Superior epigastric (L 2cm, D 1.8 mm) Inferior epigastric (L 5 cm, D 2.5 mm) Minor Subcostal and 6-7 intercostal arteries

Rectus Abdominus – Type III:

Rectus Abdominus – Type III Arc of rotation Standard – two Superior epigastric – Anterior thorax Inferior epigastric – Groin Perineum and inferior trunk Skin territory Vertical standard or island Transverse ipsilateral or TRAM

Rectus Abdominus – Type III:

Rectus Abdominus – Type III Elevation Landmarks – costal margins to pubic ramus Easily palpable Leg raising maneuver Standard muscle flap – numerous modifications Donor closure Critical to prevent herniation Avoid tension on pedicle base

Rectus Abdominus – Type III:

Rectus Abdominus – Type III Precautions Previous abdominal surgery - Kocher, Pfannenstiel Prior LIMA/RIMA surgery Segmental flap elevation may not preserve function Marlex mesh reinforcement Direct donor site closure preferred.

Serratus Anterior –Type III:

Serratus Anterior –Type III

Serratus Anterior –Type III:

Serratus Anterior –Type III Applications – head and neck, Thorax, axilla, posterior trunk, breast reconstruction and free tissue transfer Thin, broad, multidigitated. 15X20cm. Origin – outer surface upper nine ribs Insertion – ventral surface of medial border of scapula.

Serratus Anterior –Type III:

Serratus Anterior –Type III Innervation Motor – Long thoracic N. (C5-7 roots) Sensory – T2-4 segmental intercostals Function – pulls medial border of scapula anteriorly. Prevents winging.

Serratus Anterior –Type III:

Serratus Anterior –Type III Vascular anatomy Dominant Lateral thoracic (L 6-8 cm, D 2-2.5 mm) Branches of Thoracodorsal (L 6-8 cm, D 2-2.5 mm) – enters posterior to Lat. Thoracic.

Serratus Anterior –Type III:

Serratus Anterior –Type III Arc of rotation Standard - chest wall, shoulder, axilla, back. Extended – divide one of the two pedicles. Combined Serratus-Latissimus dorsi flap.

Serratus Anterior –Type III:

Serratus Anterior –Type III Elevation - Standard Mark Lat. dorsi and Pec. major Scapular tip Elevate skin flaps anteriorly and posteriorly Pedicles Lateral Thoracic – upper 3-5 slips, deep to pec Thoracodorsal – 6 cm lateral and below LT pedicle

Serratus Anterior –Type III:

Serratus Anterior –Type III Identify lower 3-4 slips (on TD pedicle) Identify Nerves Lateral thoracic – superficially, at 6 th rib with TD pedicle Long Thoracic Divide vessels to latissimus. Donor site closed primarily.

Serratus Anterior –Type III:

Serratus Anterior –Type III Precautions Identify thoracodorsal pedicle early to speed dissection Prevent winging – 3-4 segments, prevent denervation. Tunneling – potential for vascular compromise.

Latissimus Dorsi – Type V:

Latissimus Dorsi – Type V

Latissimus Dorsi – Type V:

Latissimus Dorsi – Type V Applications – among the most varied Location – large flat, triangular, postero-inferior trunk. Deep to trapezius. 25X35cm. Origin – aponeurosis to thoraco lumbar fascia, T7-12 spinous processes, sacrum, post iliac crest Insertion – scapular tip. Intertubercular groove of humerous.

Latissimus Dorsi – Type V:

Latissimus Dorsi – Type V Vascular anatomy Dominant Thoraco dorsal artery (L 8 cm, D 2.5mm) Secondary Segmental Lateral Row (L2-3cm, D 2.5 mm) Medial Row (L 1-2 cm, D 0.5 mm)

Latissimus Dorsi – Type V:

Latissimus Dorsi – Type V Innervation Motor – Thoracodorsal (C6-8) – enters with dominant pedicle Sensory – Lateral intercostal cutaneous nerves (divided) Function – adducts, extends and rotates the humorous

Latissimus Dorsi – Type V:

Latissimus Dorsi – Type V Arc of Rotation Standard Axis at posterior axilla Posterior – neck, occiput, parietal skull. Anterior – hemi thorax, sternum, mid face, upper abdomen. Extended 5-10 cm more Reverse – off segmentals

Latissimus Dorsi – Type V:

Latissimus Dorsi – Type V Elevation -Standard muscle flap Posterior axillary incision 5-10cm Pedicle – in posterior axilla deep to muscle. 10-15 cm below insertion. Proceed from inferior/medial to superior/lateral Divide insertion only after pedicle is isolated Donor site closure – direct 5-7cm.

Latissimus Dorsi – Type V:

Latissimus Dorsi – Type V Precautions Relative contraindication contra-lateral shoulder girdle is paralyzed Denervated muscle is difficult to dissect Do not divide branch to serratus until subscapular-thoracodorsal system is identified. Adhesions with serratus Identify segmental vessels prior to reverse transposition.

Pectoralis Major – Type V:

Pectoralis Major – Type V

Pectoralis Major – Type V:

Pectoralis Major – Type V Applications Coverage, Reconstruction, Functional transfer, Free flap. Location – flat, fan shaped. 15X23 cm. Origin – Medial clavicle, anterior sternum, upper seven costal cartilages, ext. oblique aponeurosis. Insertion – Lateral lip of bicipital groove.

Pectoralis Major – Type V:

Pectoralis Major – Type V Vascular Anatomy Dominant Pectoral branch of Thoracoacromial artery (L 4cm. D 2-2.5 mm) Minor Pectoral branch of lateral thoracic (L 3-4 cm, D 1-2 mm) Minor Segmental Internal mammary perforators (L 1-2 cm, D 1-2mm) Intercostal perforators, 5-7 th (L 1-2 cm, D <0.5mm)

Pectoralis Major – Type V:

Pectoralis Major – Type V Innervation Motor Lateral (Superior) Pectoral nerve – deep surface near dominant pedicle. Medial (Inferior) Pectoral nerve – via pec minor to posterolateral pec major. Sensory 2-7 th intercostal nerves Function – arm adduction and medial rotation.

Pectoralis Major – Type V:

Pectoralis Major – Type V Arc of rotation Standard Head and neck, sternal defects Extended 3-5 cm – Inferior orbital rim, intrathoracic cavity Reverse (turn over) Sternum and mediastinum

Pectoralis Major – Type V:

Pectoralis Major – Type V Elevation Standard (Thoraco acromial pedicle) Midline incision – elevate skin flaps then muscle Identify pedicle – deep surface, junction of middle and lateral thirds of clavicle. Minor pedicles cauterized. Incise origin – island muscle flap

Pectoralis Major – Type V:

Pectoralis Major – Type V Precautions Less reliable as vascularized bone flap (5 th -6 th rib) Bulky in head and neck reconstruction Donor deformity (loss of axillary fold) – minimized with segmental transpositions.