Surgical Treatment of Chest Wall Deformities

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Surgical repair of pectus carinatum is considered medically necessary when there is documented evidence of significant physical functional impairment (e.g., cardiac or respiratory insufficiency), and the procedure is expected to correct the impairment.
Surgical repair of a chest deformity associated with Poland syndrome is considered medically necessary when rib formation is absent.

Not Covered
Magnetic Mini Mover Procedure (3MP) for the treatment of pectus excavatum is considered experimental, investigational or unproven.
Surgical repair of a chest wall deformity performed solely to improve or alter appearance or self-esteem or to treat psychological symptomatology or psychosocial complaints is considered cosmetic and not medically necessary. Under many benefit plans, Cigna does not cover breast reconstruction procedures performed in association with surgical repair of a chest wall deformity for Poland syndrome, pectus excavatum, or pectus carinatum, because each is considered cosmetic in nature and not medically necessary. Such reconstruction procedures include, but are not limited to the following: • breast reconstruction with latissimus dorsi flap or other technique • mastopexy • mammoplasty with or without prosthetic implant • nipple/areolar reconstruction • breast reconstruction with tissue expander • revision of reconstructed breast • insertion of breast prosthesis • reconstructive surgery to produce a symmetrical appearance

General Background
The thorax (i.e., chest cavity) is a rigid structure that protects the thoracic organs and supports the upper extremities. Commonly reported chest wall deformities include pectus excavatum (PE), pectus carinatum (PC) and Poland syndrome. In many cases, primarily cosmetic complaints without functional impairment are associated with the abnormality. However, abnormalities of the chest wall can lead to restrictive pulmonary disease, impaired respiratory muscle strength, and decreased ventilatory performance in response to physical stress (Boas, 2020). Cardiac or respiratory impairment may result in functional limitations, such as activity intolerance. Other symptoms may include mild to moderate exercise limitation, respiratory infections, and asthmatic symptoms as well as decreased stamina and endurance.

Pectus Excavatum
Pectus excavatum (PE), also referred to as a sunken chest or funnel chest, is the most common congenital chest wall deformity. The deformity may be deeper on the right side than on the left side and result in a rotation of the sternum. It is usually diagnosed within the first year of life, with wide variations in the degree of sternal depression. Although most patients are asymptomatic, during periods of rapid bone growth (e.g., puberty), the appearance of the chest may worsen and symptoms may develop. Moderate to severe deformities may displace the heart into the left chest, decreasing stroke volume and cardiac output. Chest deformities may also depress the sternal volume, adversely affecting the flow of air in and out of the lungs. Scoliosis, congenital heart disease and functional heart murmurs can also be associated with PE. Symptoms may include fatigue, dyspnea, chest discomfort and palpitations with mild exercise. The body generally compensates by increasing the heart rate with activity to overcome the decreased cardiac output and by more rapid, shallow breathing to compensate for the respiratory deficit. Pulmonary effects associated with PE generally include restrictive lung disease, atelectasis, and paradoxical respiration. Restricted lung disease is indicative when the total lung capacity (TLC) (forced vital capacity plus residual capacity) is less than 80% of the predicted value for an individual (Rakel, 2011; Johnson and Brunetta, 2005).

Pectus Carinatum
Pectus carinatum (PC) (i.e., pigeon breast or chicken breast) is a congenital chest deformity characterized by an anterior protrusion deformity of the sternum and costal cartilages. PC is typically not confirmed until after the growth spurts of early adolescence. This deformity produces a rigid chest and, while symptoms are uncommon, it may result in inefficient respiration as a result of the restrictive chest formation. Three types of PC-related defects have been identified in the literature: • anterior displacement of the body of the sternum and symmetrical concavity of the costal cartilages • lateral depression of the ribs on one or both sides of the sternum • pouter pigeon breast (the least common of the three): a defect that consists of an upper or chondromalacial prominence with protrusion of the manubrium and depression of the sternal body The degree of physiological impairment is related to the degree of chest deformity. Patients with PC may develop symptoms as a result of restricted air exchange; complete expiration of air from the lungs may not occur. In addition, pain may result from the secondary pressures that develop from the overgrowth of cartilage. Other conditions that may be associated with PC include frequent respiratory infections, asthma, rickets, mitral valve disease, Marfan's syndrome, scoliosis and other cardiac changes.

Poland Syndrome
Poland syndrome (i.e., Poland's anomaly, Poland's syndactyly), is a rare congenital disorder associated with lateral depression of the ribs on one or both sides of the sternum. The right side of the body is affected twice as often as the left. When the anomaly occurs on the left side of the body, the heart and lungs are vulnerable, because they may be covered only by skin, fascia and pleura. Although the anomaly is associated with a wide range of malformations, the condition is characterized by absence or hypoplasia of the pectoralis major muscle, absence or hypoplasia of the pectoralis minor muscle, absence of costal cartilages, hypoplasia of the breast and subcutaneous tissue, and a variety of hand and upper-extremity anomalies. In cases of severe cartilage deficiency, patients may develop lung hernia and paradoxical respiratory motion. In less severe cases, patients may develop a simple flattening of the anterior chest wall.

Diagnosis and Evaluation
The severity of the chest wall abnormality is dependent upon the depth, symmetry and width of the deformity. Chest radiographs are commonly used to determine the degree of chest wall deformity. Plain anteroposterior and lateral radiographs are used to determine the Haller index (a measurement of chest diameter). Crosssectional imaging such as computerized tomography (CT) scans and magnetic resonance imaging (MRI) may be used to evaluate the degree of cardiac compression (ventricular compression), pulmonary compression, and cardiac displacement. CT scan ratios that reveal transverse to AP diameter of greater than 3.25 are considered significant for pectus excavatum. A normal chest has an index of 2.5 (Malek, et al., 2003;Fonkalsrud, 2004).
Echocardiography and/or electrocardiography may also be used to evaluate cardiac status. Respiratory status can be determined with the use of pulmonary function studies. In some cases, pulmonary function studies may reveal a restrictive pattern (incomplete lung expansion) and a subsequent decrease in pulmonary volume and reserve. The forced expiratory volume (in one second) (FEV1), forced vital capacity (FVC), and total lung capacity (TLC) are reduced while the ratio of FEV1/FVC may be normal or increased in the presence of restrictive airway disease. TLC <80% predicted value signifies restrictive pulmonary disease.
The diagnosis of Poland syndrome is usually obtained by clinical examination. Chest wall abnormalities and determining the presence of latissimus dorsi muscles may require CT scans while chest radiographs may be utilized to evaluate rib formation.

Surgical Treatment
Indications for surgical correction are controversial and vary widely. Surgical repair is offered primarily as a method of improving cosmesis and psychological factors but may be necessary to improve cardiopulmonary function in some patients, as the disfigurement may be accompanied by physiologic impairment.
Pectus Excavatum/Pectus Carinatum: While the optimal age for surgical repair is generally between the ages of 11 and 18 years, and may be performed in adults, each case must be reviewed individually for the presence of impaired cardiopulmonary symptoms. Criteria that may be used to demonstrate severe PE and the need for surgical repair include two or more of the following (Goretsky, et al., 2004): • a Haller CT index greater than 3.25 • pulmonary function studies that indicate restrictive or obstructive airway disease • a cardiology evaluation, where the compression is causing murmurs, mitral valve prolapse, cardiac displacement, or conduction abnormalities on the echocardiogram or EKG • documentation of progression of the deformity with associated physical symptoms other than isolated concerns of body image • a failed Ravitch procedure • a failed minimally invasive procedure Surgery for PE may be performed using any one of several techniques, including a sternal osteotomy (i.e., a modified osteotomy that involves supporting, removing and repositioning the sternum) or implantation of a Silastic mold in the subcutaneous space to fill the defect without altering the thoracic cage. Surgical correction often employs a metal bar behind the sternum; the bar may be removed in one to two years, after remolding has occurred. The standard surgical procedure is the open Ravitch procedure, which involves extensive dissection, cartilage resection and sternal osteotomy. More recently, minimally invasive techniques, such as the Nuss procedure (i.e., a minimally invasive repair of pectus excavatum [MIRPE]), have been utilized. These procedures involve the insertion of a convex steel bar beneath the sternum through small thoracic incisions and do not require cartilage resection or osteotomy. Surgical repair may also be recommended for the treatment of PC. The initial surgical repair for PC involves removing the affected cartilages and mobilizing the skin and pectoralis muscle flaps. To straighten the sternum, any one of the following surgeries may be performed: • an osteotomy • a subperichondrial resection of the involved costal cartilages • a wedge-shaped osteotomy in the anterior sternal plate While orthotic bracing may be effective for correction of the chest wall deformity associated with PC, this type of treatment is often aimed at improving cosmesis. Compression orthotic braces exert pressure on the anteroposterior direction and may be recommended for skeletally immature children (e.g., < age 18 years) with mild to moderate chest deformities. Prolonged use of the orthotic device is often required for total correction and compliance is an important factor for successful remodeling. As a result candidates must be motivated to wear the brace (Goretsky, et al., 2004;Obermeyer, Gorestsky, 2012).
Poland Syndrome: Patients with Poland syndrome typically present for surgical reconstruction to improve physical appearance and correct breast asymmetry. Surgical procedures involving the breast and muscles to achieve symmetry are considered cosmetic since there is no significant impairment being corrected. Patients who present with absent ribs are considered candidates for surgical repair (Townsend, 2004). In such cases, operative reconstruction may eliminate paradoxical motion, improving respiratory impairment. For more severe conditions, reconstructive surgery also provides protection of the underlying heart and lung structures. While there are a variety of surgical techniques to correct the deformity, a common approach is to use the latissimus dorsi muscle with autologous rib grafts to reconstruct the chest wall.
Surgical treatment of Poland Syndrome often consists of reconstruction of the breast and nipple on the affected side by a plastic surgeon, in addition to surgical repair of the chest wall muscles and hypoplastic bone. Surgery is performed early (approximately age 13) in males, however, in females, reconstructive surgery is often deferred until breast development is complete. If there are rib abnormalities and paradoxical motion, the rib grafts or other chest wall stabilization may occur before breast development is complete. Generally, reconstruction of the breast involves tissue expansion, placement of permanent breast implants and may involve myocutaneous or latissimus dorsi flaps if there is an associated anomaly of the pectoral muscle. Nipple-areolar reconstruction is generally performed at a later stage. Consequently, for patients with Poland syndrome, treatment provided before complete breast development may involve the use of tissue expanders in the affected side which can be inflated periodically to match development of the unaffected breast. Expanders allow for tissue expansion and accommodation of a permanent implant and latissimus muscle upon completion of breast development. Once breast development is complete, the expander is removed and a permanent prosthesis is inserted and breast reconstruction is performed.
Surgical repair of the chest wall includes the reconstruction of the pectoral muscles and resection of deformed cartilages. This repair typically involves muscle transfers and/or flaps to match normal development of the unaffected side, reconstruction of the axillary line, and correction of infraclavicular flattening. If necessary, reconstruction of the rib cage may be performed at this time with autologous rib grafts.

Literature Review
Published evidence evaluating surgical repair of chest wall deformities consists of meta-analyses, case series, cross-comparison studies and prospective trials. The reported clinical outcomes are mixed; differences among outcomes may be related to patient selection criteria, the degree of severity of the deformity, the surgical technique utilized, and growth effects. Many authors evaluated and reported on the methods of surgical repair and improved cosmetic outcomes while some evaluated the impact of PE or PC on cardiopulmonary function. There is little consensus regarding the degree of cardiopulmonary impairment, if any, that is associated with these anomalies. The effects of surgery on exercise tolerance are not clearly established, however, data suggesting improvement in cardiovascular and/or pulmonary function and activity tolerance after surgical repair have been reported (Kelly, et  Outcome measures of these studies generally included total lung capacity (TLC), functional residual capacity (FRC), vital capacity,(VC), expiratory flow rate (EFR), and maximum expiratory flow rate (MEFR), exercise tolerance and endurance typically measured prior to surgery, immediately following surgery and three to six months postoperatively. Improvement was generally seen only with increased periods of exercise and not with routine pulmonary function testing at rest. The results of some meta-analyses and other published clinical studies in the medical literature are also mixed, some results tend to support improvement in cardiopulmonary function following surgery (Johnson, et al., 2008;Malek, et al., 2006a, Malek, et al., 2006b) while others do not (Zganjer and Zganjer, 2010;Castellani, et al, 2010;Guntheroth and Spiers, 2007).

Professional Societies/Organizations
Current professional society recommendations and policy statements, including the American Thoracic Society and the American Academy of Pediatrics, for the treatment of congenital chest wall deformities are lacking.

Centers for Medicare & Medicaid Services (CMS)
• Implantable breast prosthesis, silicone or equal S2066 Breast reconstruction with gluteal artery perforator (GAP) flap, including harvesting of the flap, microvascular transfer, closure of donor site and shaping the flap into a breast, unilateral S2067 Breast reconstruction of a single breast with "stacked" deep inferior epigastric perforator