Chest Reconstruction, Chest Wall Reconstruction

History of the Procedure

The history of chest wall reconstruction illustrates the challenges associated with this type of repair. In 1778, Aimar resected the first osteosarcoma of the ribs. In 1820, Cittadini reported a case of bony chest wall tumor resection. Parham, in 1899, was the first in the United States to report resection of a bony chest wall tumor involving 3 ribs. This apparently caused a pneumothorax, which was controlled with soft tissue coverage. In the early 1900s, Fell and O'Dwyer described intubation techniques and positive-pressure ventilation.

In 1906, Tansini used the latissimus dorsi myocutaneous flap, apparently for the first time, for coverage of radical mastectomy defects. Hutchins and Campbell shared this approach. Graham and Singer were the first to successfully perform a pneumonectomy in the early 1930s. In the 1940s, Watson and James used the fascia lata for closure of skeletal wound defects. Bisgard and Swenson described the use of ribs for closure of sternectomies.

Pickrell offered techniques in chest wall resection for breast cancer, and Maier described his use of cutaneous flaps for patients with breast cancer postresection. The 1950s and 1960s included refinement of the reconstructive techniques and the implementation of multistaged procedures. Other pioneers of mention include Arnold and Pairolero, whose studies concluded that chest wall reconstruction is safe, durable, and associated with long-term survival. For the past 25 years, chest wall reconstruction has undergone a vast growth in technique and alternatives. Flaps often used for this task are the latissimus dorsi, pectoralis major, serratus anterior, rectus abdominis, external oblique, and omentum.

The congenital defect of the thorax, Poland syndrome, was described by Sir Alfred Poland in 1841. He noted restricted musculature on one side of the thorax on a single autopsy. In his report entitled "Deficiency of the pectoralis muscle," he described absence of the sternocostal portion of the pectoralis major, an absent pectoralis minor, and a severely hypoplastic serratus anterior and external oblique. de Haan associated the defects of Poland syndrome to the overlooked concomitant deformities of the ipsilateral upper extremity and hand.

Etiology

One of the most common acquired chest wall deformities is sequela from infection. This may be the result of mediastinitis, trauma, or empyema. The resulting defects, from debridement of the chest wall or the pleural space and its contents, may require fill procedures with flaps of thoracic or abdominal origin, sterilization procedures, or collapse procedures as in thoracoplasty. Tumor radiation injury promoting scar and nonfunctional tissue also may require debridement and reconstructive measures. Resection of large chest wall, pulmonary, or mediastinal tumors, as well as defects created by trauma, may merit chest wall reconstruction.

The etiology of Poland syndrome, a congenital defect of the chest wall, is unclear, yet the current theory describes hypoplasia of the ipsilateral subclavian artery in utero. The subclavian artery supply disruption sequence (SASDS) described by Parker et al illustrates the kinking of the upper extremity artery as the ribs grow forward and medially. The reduction in lumen diameter and thus flow impedes distal growth, which supports the theory that more proximal blocked flow results in more severe deformity. The incidence of Poland syndrome is 1 in 30,000. The right side in Poland syndrome is affected twice as often as the left and it is considered to be autosomal dominant with low penetrance.

Möbius syndrome involves the anomalies observed in Poland syndrome in addition to bilateral facial paralysis and the inability to abduct the eyes. Möbius syndrome is observed in 1 individual per 500,000.

The etiologies of pectus excavatum and pectus carinatum are unknown. Pectus excavatum is the most common congenital anomaly of the chest (90%). The male-to-female ratio is 3:1.

Pathophysiology

The muscles of inspiration, an active action, involve primarily the diaphragm, which contracts inferiorly and creates a negative intrapleural pressure, thus inducing inhalation. Secondary muscles involved in inspiration are termed accessory muscles and are the sternocleidomastoids, which aid in raising the sternum superiorly and outward; the scalene muscles, which elevate the upper ribs; and the external intercostal muscles, which elevate all the ribs.

Expiration is a passive process. The intrinsic elasticity of the lung and musculature promotes exhalation. The muscles mentioned above relax and initiate the expiratory phase of breathing. Pulmonary function tests that measure forced expiratory volume in 1 second (FEV-1), tidal volume, and the ratio of FEV-1 to forced vital capacity ratio also are beneficial, yet these values are not critical in the face of mandatory surgical intervention. Lung disease takes on two broad categories, obstructive and restrictive. With obstructive disease, expiration is impeded by proximal obstruction of the bronchioles and bronchi, causing air trapping, increased functional residual capacity and residual volume, and decreased FEV-1 and vital capacity.

Restrictive lung disease is an interstitial process that causes lung tissue to be less compliant, thus reducing the ability of the lung to expand. This promotes reduced lung volumes. Flail chest refers to a segment of chest wall, usually 5 cm in diameter, which loses continuity with the surrounding chest wall, resulting in a paradoxic respiratory pattern and inefficient ventilation. Adequate fixation of this segment is necessary to correct this phenomenon and restore proper respiratory physiology and ventilation.

The size of the defect above which bony stabilization is required is not clear. Two-rib segmental loss may be repaired with soft tissue reconstruction. While Dingman cautions that a 4-rib loss results in flail, Arnold argues that complete sternectomy or resection of 4-6 ribs at the cartilage level does not result in flail or respiratory instability. McCormack and Picciocchi et al agree that defects less than 5 cm in diameter or resection of 3 ribs or fewer do not merit skeletal stabilization.