WP Chung O T in in Flaps in Plastic and Reconstructive Surge

1 C H A P T E R

Section I: Mandibular Surgery

Osteocutaneous Parascapular Flap for Mandibular Reconstruction

Ravi K. Garg and John W. Siebert

DEFINITION

Axillary artery

■■ The parascapular osteocutaneous free flap serves as a ver- satile reconstructive option for composite head and neck defects involving the mandible. ■■ The lateral border and angle of the scapula are the most commonly used osseous flap components, although harvest of the medial scapular border has also been described. ■■ Soft tissue elements that may be incorporated into the flap include skin, fat, fascia, muscle such as the serratus and latissimus, and nerves, including the thoracodorsal nerve. ANATOMY ■■ The parascapular osteocutaneous free flap is based on the subscapular system emerging from the distal third of the axillary artery. ■■ The circumflex scapular artery branches from the subscap- ular artery and serves as the primary blood supply to the parascapular osteocutaneous flap. ■■ The circumflex scapular artery can be reliably identified in the triangular fossa, which is bound by the teres major and minor muscles as well as the long head of the triceps ( FIG 1 ). ■■ The thoracodorsal artery also branches from the subscapu- lar artery and sends a branch to the scapular angle either directly or as a side branch of the serratus muscle branch. ■■ The angular artery can be useful for augmenting the blood supply of the scapular border or can be used to harvest the scapular angle as a separate osseous flap. PATIENT HISTORY AND PHYSICAL FINDINGS ■■ Determine if the patient has had previous head and neck surgery that would limit recipient vessel options or donor sites for microsurgical reconstruction. ■■ Assess the patient’s level of function and which donor site will result in the least morbidity. ■■ A scapular flap may be advantageous for older patients with compromised mobility who will have greater difficulty ambu- lating after surgery if a lower extremity donor site is chosen. 1 ■■ Inspect the patient’s dental occlusion and determine whether any diseased dentition needs to be managed perioperatively and whether dental rehabilitation will be performed. 2 IMAGING ■■ Preoperative CT angiography may be useful to exclude lower extremity flap options such as the fibular flap in a patient with claudication and suspected peripheral vascular disease. ■■ Virtual surgical planning may be helpful for complex head and neck reconstruction. A three-dimensional reconstruction

Cutaneous branch

Subscapular artery Circumflex scapular artery

Scapular flap

Thoracodorsal artery

Latissimus dorsi muscle

of the recipient and scapula donor sites can be produced using CT imaging. Osteotomy sites at both the recipient and donor scapula locations may be planned preoperatively and a cutting jig developed to facilitate scapular contouring and inset. 3 SURGICAL MANAGEMENT ■■ The parascapular osteocutaneous flap is particularly use- ful for composite tissue defects with a large soft tissue component. ■■ Multiple skin paddles and muscle flaps, including the latissi- mus and serratus, can be transferred with scapular bone based on the circumflex scapular artery, 2,4 enabling reconstruction of some of the most complex three-dimensional defects. ■■ This flap is unique among other choices used for man- dibular reconstruction including fibula, iliac crest, and radial forearm free flaps, because the lateral scapular bone FIG 1  • Demonstration of the cutaneous branch of the circumflex scap- ular artery exiting the triangular fossa defined by the teres major, teres minor, and long head of triceps. The versatility of the scapular osteocu- taneous flap relates to the multiple soft tissue elements including skin, fat, fascia, and the latissimus and serratus muscles that can be elevated with the flap based on the subscapular system. Additionally, the lateral scapular border is perfused by both the circumflex scapular and angular arteries, enabling separate bone flaps to be harvested.

Chung-Flaps1e9781975129491-P1-ch001.indd 2

2/19/2019 3:11:06 PM