Scapular, Parascapular and Pectoralis Flaps Ian Maxwell Summer anatomy July 4, 2013

Mathes and Nahai muscle flap classification

Mathes and Nahai classification of fasciocutaneous flaps:

Cormack and Lamberty classification of fasciocutaneous flaps:

Parascapular and scapular flaps

Triangular and Quadrangular spaces: Triangular space: – Borders are: Teres minor/subscap Teres major Long head triceps -CIRCUMFLEX SCAPULAR ARTERY Triangular interval – Borders are: Teres major Long head triceps Lat head tripceps/humerus - PROFUNDA BRACHII ARTERY - RADIAL NERVE Quadrangular space – Borders are: Teres minor/subscap Long head triceps Lat head triceps/ humerus Teres major -POSTERIOR HUMERAL CIRCUMFLEX ARTERY -AXILLARY NERVE

Classification: Mathesand Nahai = Type B septocutaneous Cormack and Lamberty = Type B single fasciocutaneous perforator Arterial Supply: Scapular Flap = Transverse branch of Circumflex Scapularartery Parascapular Flap = Descending branch of Circumflex Scapularartery Venous Drainage = venaecomitantes NOTE: SubscapularVein not paired Nerve: No reliable cutaneous nerve

Skin Paddle Scapular = 10cm x 25cm Parascapular = 15cm x 25cm Larger if STSG donor… not ideal Pedicle Length/Diameter Transverse branch = 4-9cm/ mm Descending branch = 4-6cm/ mm Circumflex Scapular = 7-10cm/ mm Subscapular = 11-14cm/ mm NOTE: can combine scapular and parascapular paddles if both vessels included

Bone Flap 2cm wide x 10 cm long At least 2cm from glenoid Include muscle to preserve periosteal blood supply Tip is supplied by angular branch from thoracadorsal artery

Flap Applications Local Pedicled Flap Shoulder Axilla Free Flap Head, neck, oral cavity/mandible Upperextremityand hand Lowerextremityand foot Chimeric flap Skin Fascia Muscle Bone

Flap Elevation Scapula Flap Mark flap to include triangularspace Dissect medial to lateral, suprafascial Incise fascia to protect pedicle

Flap Elevation Scapula Flap Foradditional pedicle length and vessel caliber must dissect through triangularspace to subscapularartery

Flap Elevation Parascapulra Flap Mark flap to include triangularspace Dissect inferior to superior suprafascial Incise fascia to protect pedicle

Flap Elevation Parascapula Flap Foradditional pedicle length and vessel caliber must dissect through triangularspace to subscapularartery

Pectoralis Flaps:

Classification Mathes and Nahai type V (segmental and dominant) Variations: – Muscle flap (most common) – Musculocutaneous – Osteomusculocutaneous (rib or sternum) – chondromusculocutaneous

Applications Face, Oral cavity, Neck, Sternum/mediastinum, Axilla and shoulder Upper extremity functional muscle transfer Reconstruction of – mandible, esophagus, breast, functional muscle for elbow

Pectoralis Major Muscle anatomy Origin: – Sternal head: first 7 ribs and sternum and aponeurosis of external oblique – Clavicular head: medial head of clavicle Insertion: – Lateral lip of bicipital groove of humerus

Arterial supply of Pec Major flap: Major pedicle – Pectoral branch of thoracoacromial artery Length = 4.5cm Diameter = 2-3mm Minor/segmental pedicles – Medially: Intercostal perforators 1-6 Usually pedicled off first 2 (deltopec flap) – Length = 1-2cm – Diameter <1mm – Laterally: pec branch of lateral thoracic artery Length = 3cm Diameter = 1-2mm Venous drainage via venae comittantes

Innervation Medial pectoral nerve (motor) Lateral pectoral nerve (motor) Intercostal nerves 2-7

Pec branch of Thoracoacromial artery Sternocostal head Clavicular head Lateral thoracic artery Clavicular Branch of thoracoacromial a.

Flap harvest: Incision: – Midline sternotomy: for sternum reconstruction – Subclavicular: usually for head and neck coverage – Through skin island if one is planned Dissection: through pre-pectoral plane  raise skin and subcu tissue off of pec

Flap Harvest Turnover (for sternum) – Divide through pec laterally – Dissect under pec lateral to medial until sufficient turnover possible based on IMA perforators Skin paddle – Axis of rotation is line from acromion to xiphoid – Skin paddle of 8x10 cm usual limit for 1 o closure, design over pec muscle, +/- dopplering of perforators

Skin paddle cont. Dissection proceeds as for turnover: – Divide lateral pec and insertion at ext oblique (including lateral pec artery) – Divide medial sternocostal origin – Dissect pec major away from pec minor and chest wall inferior to superior – Pedicle lies medial to pec minor on underside of pec major – Flap is tunneled to desired location

Functional muscle transfer Incision along anterior axillary line and dissect skin off muscle An innervated portion of muscle outlined Divide origin at sternum and clavicle Preserve thoracoacromial pedicle and motor nerves Tunnel muscle through axilla and suture to biceps tendon

Deltopectoral flap Fasciocutaneous flap based on 2 nd or 3 rd perforating branches of IMA More commonly used for head and neck recon given medial pedicle

References Microsurgeon.org Serafin, d. Atlas of microsurgical tissue transplantation Wei, Mardini. Flaps and reconstructive surgery Halifax flaps manual Ash’s scapular/parascapular talk last year