Muscle and musculocutaneous flaps Flashcards
Describe the pec minor flap
Use: primary use for this pedicle is as a free functional muscle for facial reanimation.
Other uses: axilla, shoulder, inferior breast pole coverage, other free tissue transfer
Muscle type: MN III
Blood supply:
- D1: Pectoral branch of thoracoacromial (+ single vein); 8-10cm & 2mm diameter; enters on deep aspect proximally
- D2: Branch of lateral thoracic artery (+ single vein); 8-10cm & 1.5mm diameter; enters on lateral border
Innervation: medial pectoral nerve (C8-T1)
Muscle
- origin: ribs 3-5 near costochondral junction
- insertion: coracoid process
- action: stabilization of scapula and protraction of scapula on shoulder
Landmarks and markings: Mark the clavicle, the palpable lateral border of pec major and the coracoid process. Estimate the position of p. minor as it originates from ribs 3-5 underlying p. major
Advantages: small, thin muscle (no reduction req’d in facial rean), fan shaped and tendinous insertion ideal for peri-oral insertion
Disadvantages: shorter pedicle amenable to situations only w/ 2-stage & CFNG (would not reach neck in 1-stage to CN V), potential for congenital absence of muscle in mobeius and poland.
Describe pec major flap
Regional Uses: sterum, mediastinum, anterior chest (common), axilla, face/oral cavity, shoulder
Specialized uses: esophagus (2nd line), functional muscle (rare)
Type & Blood supply: type IV
- Dominant: pectoral branch of thoracoacromial (L 4cm, D 2-2.5mm) (enters deep surface usualy and jxn of medial 2/3 and lateral 1/3)
- Minor segmental: IMA perforators 1-6 IC spaces
- Minor pedicle: pectoral branch of lateral thoracic (L 3cm, D 1-2mm)
- Veins: single veins, 1-2mm
Innervation: medial and lateral pectoral nerves
Muscle: origin: medial 1/2 clavicle, anterior sternum, ribs 5-6; insertion: lateral lip of bicipital groove of humerus; action: adducts & medially rotates arm
Landmarks & markings: Clavicle, sternal border to 7th rib, anterior axillary border. Markings depend on indication (see image)
Steps for sternal wound
- bilateral advancement
- if using muscle only then dissect from overlying skin evelope in suprafascial plane (better for suturing)
- then muscle is released from sternal origin (and ribs 5,6)
- dissect in submuscular plane, ensure to stay on top of pec minor
- respect pedicle entering deep surface
- advance into sternal defect vest-over-pants wiht other muscle
- make incision along deltopectoral groove and release insertion (tendon) but sparing the pedicle
- for low sternal wounds, use a reverse turnover flap based on IM perforators, but causes relative hypovascularity to skin margins at sternal wound cutaneous closure
Describe the Mathes Nahai classification of muscle flaps
- Type I: single dominant pedicle - raise whole muscle on this vessel
- Type II: dominant pedicle and minor pedicle(s) - usually can raise whole muscle on dominant pedicle; sometimes distal flap less reliable
- Type III: 2 dominant pedicles - can raise whole/part of muscle on either pedicle reliably
- Type IV: segmental perforators - arise along length of belly of muscle for focal segmental perfusion, ligation of > 2-3 can alter perfusion and lead to necrosis/fibrosis
- Type V: dominant perforator and segmental perforators - flap can be raised entirely on dominant perforator, or part of flap on minor perforator
Give 5 muscle examples for each type of MN muscle flap
- TVGAF - tensor fascia lata, vastus lateralus, gastroc (M & L), ADB flap (hand), first dorsal interosseous
- GST, BRB: gracilis, soleus, trapezius, biceps femoris, rectus femoris, brachioradialis
- PIGROST: pec minor, intercostals, gluteus maximus, rectus abdominus, orbicularis oris, serratus anterior, temporalis
- ETS, FFEE: external oblique, tibialis anterior, sartorius, flexor digitorum/hallucus longus, extensor digitorum/hallucus longus
- LIP: latissimus dorsi, internal oblique, pectoralis major
List 5 MN type 1 muscles and name their blood supply according to the classification
TVGAF
- Tensor fascia lata - ascending branch of lateral circumflex femoral artery
- Vastus lateralis - descending branch of lateral circumflex femoral artery
- Gastrocnemius - medial or lateral sural artery
- ADM Hand - deep palmar artery, branch of (ulnar)
- First dorsal interosseous - branch of deep palmar arch (radial artery)
List 5 MN type II muscles and name their blood supply
GST, BRB
- Gracilis - D: medial circumflex femoral a (from profunda); muscular branches from superficial femoral
- Soleus - D1: branches of popliteal; D2: proximal branches of peroneal a; D3: proximal branches of posterior tibial a; m: segmental branches from posterial tibial
- Trapezius - D: transverse cervical artery; m: dorsal scapular artery (subscapular system)
- Brachioradialis - D: radial recurrent a; m: muscular branches of radial artery
- Rectus femoris - D: lateral circumflex femoral artery; m: branches of superficial femoral a
- Biceps femoris - D: 1st perforating branches of profunda femoris a; m: 2nd/3rd perforating branches, branch of inferior gluteal a, superior lateral genicular artery
List 5 MN type III muscles and name their vascular pedicles
PIGROST
- Pec minor: pectoral branches of D1: thoracoacromial D2: lateral thoracic (m: small direct branch off axillary)
- Intercostal: D1: anterior branch of posterior intercostal vessel; D2:
- Glutues maximus: D1: superior gluteal a; D2: inferior gluteal a
- Rectus abdominus: D1: deep inferior epigastric a; D2: superior epigastric artery
- Orbicular oris: bilateral superior and inferior labial arteries
- Serratus anterior: D1: serratus anterior branch of thoracodorsal; D2: lateral thoracic a
- Temporalis: D1: superficial temporal artery; D2: middle temporal artery
List 5 MN type IV muscles and name their vascular pedicles
ETS, FFEE
- External oblique - segmental lateral cutaneous branches of inferior 8 posterior intercostal vessels; m: ascending branch of deep circumflex iliac artery
- Tibialis anterior - segmental branches of anterior tibial artery, superolateral and inferolateral peroneal arteries (branches of anteiror tibial artery)
- Sartorius - segmental branches of superficial femoral
List 5 MN type V muscles and list their blood supply
LIP
- Latissimus dorsi - D: thoracodorsal artery; s: paraspinal lumbar perforators
- Internal oblique - D: DCIA s: subcostal/lateral cutaneous branches of posterior intercostal arteries
- Pectoralis major - D: thoracoacromial artery; s: perforating branches of IMA (2-5,6)
What is a choke vessel
a small calibre vessel allowing a connection and bidirectional flow between 2 adjacent angiosomes, supplied dominantly by different pedicles
What is the mathes classification of vascular supply to the skin
- A: direct cutaneous
- B: fasciocutaneous
- C: septocutaneous
What are mechanims to improve the blood supply to a skin paddle?
- Vascular delay
- External expansion
- Define perforators and keep them in flap
- Try to discard distal flap
List general indications for use of a muscle or myocutaneous flap
- Obliteration of dead space
- Fill contour and crevaces
- Poorly vascularized or previously infected or contaminated tissues
- Massive defects
- Compound wounds
- Functional sensorimotor flaps
List advantages to use of myocutaneous or muscle flaps
- bulk and fills deadspace
- address contour differences
- brings well vascularized tissue
- well defined and relaible vascular pedicle patterns
- possible resistance to infection
- can be functional
- can be combined w/ other tissue components or flaps
- Can cover vessels, have a long pedicle, be outside of zone of injury
- readily available
what are disadvantages to muscle flaps
- donor site morbidity
- scar
- weakness/dysfunction
- deformity
- scars
- HTS/KS/large
- possible need for skin graft for closure
- Drains
- muscle atrophy
- excess bulk
