Pectoralis Major Musculocutaneous Flap:

A New Flap in Head and Neck Reconstruction

Edward H. Withers, MD, Nashville, Tennessee

John D. Franklin, MD, Nashville, Tennessee

James J. Madden, Jr, MD, Nashville, Tennessee

John 6. Lynch, MD, Nashville, Tennessee

Traditionally, reconstruction of the head and neck after extensive resections for cancer has been ac- complished by the use of forehead flaps, deltopec- toral flaps, and shoulder flaps. Various musculocu- taneous flaps have been developed that appear to offer distinct advantages in immediate reconstruc- tion in patients with head and neck cancer. [1,2]. The recent description of the pectoralis major musculo- cutaneous flap by Ariyan [3] has added a new capa- bility in head and neck reconstructions. Musculo- cutaneous flaps appear to have improved vascularity, provide bulk, and may be raised without a delay; frequently the donor site may be closed primarily. A series of patients have undergone immediate recon- struction with the pectoralis major musculocuta- neous flap, which appears to offer promise for one- stage reconstruction in patients with head and neck cancer.

Anatomy

The pectoralis major muscle is a thick fan-shaped muscle arising from the anterior surface of the sternal half of the clavicle and the anterior surface of the sternum, from the cartilages of all the true ribs with the frequent exception of the first and seventh ribs, and from the aponeurosis of the external oblique muscle (Figure 1). From this extensive origin, the

From the department of Plastic Surgery, Vanderbilt University Hospital, and the Divisions of Head and Neck Suraerv and Plastic Suraerv. Veterans Ad- ministration Hospital, Nashville, T&n&see.

_ _.

Reprint requests should be addressed to Edward H. Withers, MD, De- partment of Plastic Surgery, Vanderbilt University Hospital, Nashville, Tennessee 37232.

Presented at the Twenty-Fifth Annual Meeting of Ths Society of Head and Neck Surgeons, Pittsburgh, Pennsylvania, April 1-4, 1979.

fibers converge toward their insertion into a flat tendon about 5 cm broad which is inserted into the crest of the greater tubercle of the humerus [4]. The major blood supply of the pectoralis major muscle is from the thoracoacromial artery, which is a branch of the subclavian artery. The thoracoacromial artery courses laterally under the clavicle for several cen- timeters after leaving the subclavin artery before taking an oblique course which is parallel to the muscle bundles of the mid-portion of the pectoralis major muscle (Figure 2). The thoracoacromial artery is accompanied by its corresponding venae comi- tantes and the major motor nerve of the pectoralis major muscle, the lateral pectoral nerve. These ves- sels along with the lateral pectoral nerve, pectoralis muscle, and the overlying skin constitute an axial pattern musculocutaneous flap.

Figure 1. Pectoralis major muscle with blood supply.

Volume 139, October 1979 537

Withers et al

F(gure 2. Angiogram demonstrating the thoracoacromial artery.

Operative Technique

The pectoralis major musculocutaneous flap is elevated depending on the type of defect to be reconstructed. In general, the muscle is approached through an incision along the lateral aspect of the pectoralis major muscle or a few centimeters medial to it (Figure 3). The pectoral fascia is incised and the muscle medial to the incision is then rapidly elevated using blunt finger dissection. Retractors are

538

Figure 3. Flap with neurovascular supply.

placed along the medial border of the pectoral incision and the neurovascular bundle can usually be found by palpa- tion or direct vision. During the entire elevation of the pectoralis major musculocutaneous flap, the neurovascular bundle should be continually identified either by direct vision or palpation. The inferomedial and medial aspect of the incision is then made, depending on the defect to be reconstructed. The lateral and medial proximal branches of the thoracoacromial artery and vein are divided and li- gated as needed to continue flap elevation and to provide exposure and length. The proximal muscle fibers may be sharply dissected off the clavicle to provide further mo- bility and exposure of the neurovascular bundle. If a true “island” musculocutaneous flap is to be made, the lateral tendinous portion of the pectoralis major muscle can be sharply divided (Figure 4). The neurovascular bundle may

Figure 4. “‘Island” musculocutaneous flap.

The American Journal of Surgery

Pectoralis Major Musculocutaneous Flap

Figure 5. Primary closure of the donor site.

be further dissected at its junction with the subclavian vein and artery to provide additional length. When skeleton- izing the neurovascular bundle, care must be taken to prevent any damage to these vessels.

The donor site is then closed primarily by mobilization of the medial and lateral skin of the chest wall (Figure 5).

Suction catheters are placed in the chest wall defect prior to closure.

Clinical Material

Case 1 is a 60 year old black man who presented with a T,NpMo squamous cell carcinoma of the right pyriform sinus. There was skin invasion of the right anterior neck from bulky (9 cm) cervical metastasis. The patient was treated preoperatively with 4,600 rads with dramatic shrinkage in the pyriform sinus primary and right cervical lymphadenopathy. After radiation, the patient underwent incontinuity laryngopharyngectomy and radical neck dissection. A substantial amount of right neck skin was resected due to skin invasion of that area (Figure 6A). The right neck defect was resurfaced with a 10 by 14 cm “island” pectoralis major musculocutaneous flap. The patient’s postoperative course was entirely satisfactory. He has been offered the opportunity for return of the nipple areolar complex to his chest but, to date, has refused (Figure 6R).

Case 2 is a 58 year old white man from the mountains of East Tennessee with an 8.5 by 9.5 cm ulcerated squamous cell carcinoma of the left cheek. Physical examination re- vealed fixation to the underlying structures with a large amount of surrounding erythema and induration sugges- tive of peripheral skin invasion (Figure 7A). Several sus-

Volume 130, October 1979

Figure 6. A, msectbn of the skb8 of the right neck. S, “IstaW pectorab major musculocutaneous flap.

539

Withers et al

Figure 7. A, deeply invasive squamous cell carcinoma of the cheek. B, “island” flap with distal paddle.

picious anterior cervical and preauricular nodes were pal- pable. The patient underwent wide local excision of the primary lesion with incontinuity superficial parotidectomy, resection of the body of the zygoma, and left radical neck dissection. All gross tumor was removed, and frozen section control revealed negative margins. An “island” pectoralis major musculocutaneous flap with a distal 17 by 12 cm paddle was raised primarily to resurface the cheek and upper neck defect (Figure 7B). A small hematoma that developed beneath the flap was evacuated on the first postoperative day, but the patient’s cheek and neck defect healed completely. His postoperative recovery and result have been satisfactory.

Case 3 is a 63 year old white man admitted with a long history of adult onset diabetes with several episodes of

ketoacidosis. Physical examination revealed a large neck abscess with necrosis of the posterior neck skin extending behind and superior to the right ear (Figure 8A). Surgical debridement required resection of the posterior belly of the digastric muscle, the upper portion of the sternocleido- mastoid muscle, and necrotic skin and subcutaneous tissue of the neck. Ten days after debridement, an “island” pec- toralis major musculocutaneous flap with an 11.5 by 10.5 cm distal paddle was used to resurface the upper neck de- fect (Figure 8B). The postoperative course was entirely satisfactory and the patient is pleased with his recon- struction.

Case 4 is a 52 year old black man with a T*NrMe squa- mous cell carcinoma of the right pyriform sinus. After la- ryngopharyngectomy and right radical neck dissection,

Figure 8. A, extensive ab- scess of the neck with skin and muscle Inss. B, ‘Wand” pectoral/s major musculo- cutaneous flap with distal paddle.

The American Journal of Surgery

Pectoralis Major Musculocutaneous Flap

only 1 cm of posterior hypopharyngeal and upper esoph- ageal mucosa remained. Immediate reconstruction of the hypopharyngeal and esophageal defect was accomplished with a tubed “island” pectoralis major musculocutaneous flap with a 9 by 10 cm distal paddle (Figure 9A). The “island” pectoralis major musculocutaneous flap was passed beneath the neck flaps and tubed to the remaining pharyngeal and esophageal mucosa (Figure 9B). The pa- tient’s swallowing was satisfactory 12 days postoperatively. (Figure SC). He is presently undergoing radiation therapy.

Case 5 is a 57 year old black man who had previously undergone composite resection of a TsNsMc squamous cell carcinoma of the floor of the mouth. At that time, he un- derwent immediate reconstruction with a dorsalis pedis free flap. After failure of the dorsalis pedis free flap, a controlled orocutaneous fistula was established. Six months after the resection there was no evidence of re- current squamous cell carcinoma and the patient was readmitted to the hospital for closure of a 4 by 5 cm right submandibular orocutaneous fistula. He underwent closure of the orocutaneous fistula with an 18 by 14 cm “island” pectoralis major musculocutaneous flap for cover which was completely inset into his neck. Lining was provided by

a turnover “book” flap surrounding his fistula. His post- operative course was uneventful and the patient was able to swallow and eat adequately. The pectoralis major musculocutaneous flap filled the defect created by resec- tion of the sternocleidomastoid muscle on that side (Figure 10).

Figure 10. Closure of orocutaneous fistuia.

Volume 138. October 1979 541

Withers et al

Case 6 is a 56 year old white man with extensive cervical metastasis (9 by 11 cm) from squamous cell carcinoma of the lung. The left cervical mass was partially fixed to the underlying structures, and skin erosion ?nd fixation had occurred. A palliative debulking procedure was performed in an attempt to enhance the planned palliative radiation therapy. The debulking procedure required resection of the neck skin and the resultant defect was closed with a 15 by 18 cm transposition pectoral% major musculocutaneous flap. Palliative radiation therapy was begun 2 l/2 weeks after this operation.

Case 7 is a 65 year old white man who presented with a TINiMe squamous cell carcinoma occupying the entire base of his tongue, as well as clinically positive nodes in the left side of the neck. Because the resection would require total glossectomy, radiation therapy was advised; however, the patient and his family insisted on surgical resection of the lesion. The patient underwent total glossectomy and left radical neck dissection with mandibulectomy. The floor of the mouth was resurfaced with an “island” pectoralis major musculocutaneous flap with a 10 by 9.5 cm distal paddle. An intact skin bridge at the base of the flap was de-epithelialized. Postoperatively, venous hypertension developed in the flap, and on re-exploration the vascular pedicle may have been compromised by its position over the clavicle. At the time of removal of the pectoralis major musculocutaneous flap, the distal half of the pedicle had undergone necrosis and a controlled orocutaneous fistula was created.

Case 8 is a 50 year old white man with an advanced 9 by 5 cm mucoepidermoid carcinoma of the right parotid gland with extensive cervical metastasis. The skin overlying the

parotid tumor was grossly involved and the facial nerve on that side was completely paralyzed (Figure 11A). A total parotidectomy with incontinuity resection of the facial nerve and overlying skin and a radical neck dissection with a hypoglossal facial nerve transfer were performed. Im- mediate reconstruction was accomplished after determi- nation of clear microscopic margins with an “island” pec- toralis major musculocutaneous flap with a 9 by 11 cm distal paddle (Figure 11B). The postoperative course was satisfactory except for a 1 by 2 cm rim of flap necrosis, which did not jeopardize the cover for the nerve transfer. A secondary skin graft was performed to hasten the pa- tient’s discharge from the hospital.

Case 9 is a 25 year old white man who had previously sustained extensive third degree burns of the chest, the entire neck, and most of the face. The entire chest, neck, and lower face including the exposed mandible were ini- tially covered with split-thickness skin grafts. After grafting of the neck and chin, there was a severe burn scar contracture of the anterior neck and a loss of chin contour and prominence. Restoration of the chin contour and prominence as well as release of the burn scar contracture of the neck was accomplished in a single stage with an “island” 10 by 28 cm pectoralis major musculocutaneous flap. The skin overlying the pectoralis major muscle con- sisted completely of split-thickness skin graft and scar. The flap was completely inset into the neck and chin, which satisfactorily released the burn scar contracture of the neck and restored the chin contour. The grafted skin and scar overlying the pectoralis major muscle was completely viable. To the best of our knowledge, this is the only mus- culocutaneous flap raised where the skin overlying the

542

Figure 11. A, extensive skin involvement from mucoep- idermoid carchmma of the parotld gland. B, “island” pectoral/s major musculo- cutaneous f/ap with distal paddle.

The American Journal of Surgery

Pectoralis Major Musculocutaneous Flap

muscle consisted entirely of split-thickness skin grafts and scar. Further reconstructive procedures are planned in the future.

Comments

Frequently, reconstruction-in the head and neck area after radical resection for malignancy has been accomplished with deltopectoral flaps. This flap is limited in that the donor site requires a skin graft for closure and the flap may not provide enough bulk to fill large defects. Its length is traditionally limited to areas no higher than the zygoma unless a previous delay has been performed. When the deltopectoral flap is used for oropharyngeal reconstruction, the patient is committed to a two-stage reconstruction and a controlled salivary fistula [5]. The deltopec- toral flap occasionally shows poor vascularity at the tip when used as a direct flap, and minor wound complications are frequent.

The trapezius musculocutaneous flap appears to be a well-vascularized flap, and we have used it suc- cessfully in head and neck reconstructions. The disadvantages of this compound flap are that the donor site frequently needs to be skin grafted and the morbidity from loss of muscle function and shoulder pain can be significant. Patient acceptance of the skin-grafted shoulder has not been good. The ster- nocleidomastoid musculocutaneous flap is useful in resurfacing small defects but is limited by its narrow width and may not provide adequate bulk in the re- construction of large defects.

Ariyan [3] has shown that the pectoralis major musculocutaneous flap has sufficient length as a di- rect flap to reach the orbital cavity as well as the frontal, parietal, and temporal regions. The pectoralis major musculocutaneous flap has excellent vascu- larity due to its axial vessel pattern and appears to have the potential to nourish fascial grafts in patients undergoing craniofacial resections. It has been ob- served that when musculocutaneous flaps undergo radiation they maintain excellent vascularity to their overlying skin [3]. The pectoralis major musculocu- taneous flap has the potential to provide orophar- yngeal lining in one stage, eliminating the necessity for a temporary orocutaneous fistula. Secondary

procedures to close the fistula and return the un- needed portion of the flap are not necessary. It has been our clinical impression that the pectoralis major musculocutaneous flap has better vascularity than the standard medially based deltopectoral flap. We do not hesitate to use angiography if there is any doubt as to the patency of the thoracoacromial ar- tery. It also appears that the preservation of the lat- eral pectoral nerve prevents later atrophy and con- traction of the flap.

An additional advantage of this flap is that the neck contour is restored by the transfer of the pec- toralis major muscle beneath the overlying skin. De-epithelialization of the buried skin flap or a muscle flap with a distal skin paddle eliminates the need for a later pedicle division and return of the flap. A major advantage of the pectoralis major musculo- cutaneous flap is that all donor sites are closed pri- marily, even in patients with severe burn scar con- tractures of the chest.

Summary

The pectoralis major musculocutaneous flap de- scribed by Ariyan has great potential in single stage reconstructions of the head and neck. The advan- tages of the flap are greater length, improved vas- cularity, bulk, and one-stage reconstruction of oro- pharyngeal defects. The flap was used successfully in eight patients to reconstruct large defects in the head and neck area. Experience to date indicates that this flap has greater versatility than the deltopectoral flap in one-stage head and neck reconstructions.

References

1. &Craw J, Dibbell D: Experimental definition of independent myocutaneous vascular territories. Plast Reconsfr Surg 60: 212,1977.

2. f&Craw J, Dibbell D, Carraway J: Clinical definition of inde- pendent myocutaneous vascular territories. P/ad Reconstr Surg 60: 341, 1977.

3. Ariyan S: The pectoralis major myocutaneous flap: a versatile flap for reconstruction in the head and neck. Plasf Reconstr Surg 63: 73, 1979.

4. Gray H: Anatomy of the Human Body, 27th edition. Philadelphia, Lea & Febiger, 1959, p 489.

5. Bakamjian VY: A two stage method for pharyngoesophageal reconstruction with a primary pectoral skin flap. ~%st/?econ.sfr Surg36: 173, 1965.

Volume 139, October 1979 543