Pectus Carinatum

Pectus carinatum is a term used to describe a spectrum of protrusion abnormalities of the anterior chest wall (see the image below).

Pectus carinatum. Photograph courtesy of K. Kenigsberg, MD.

The deformity may be classified as either chondrogladiolar or chondromanubrial, depending on the site of greatest prominence. Lateral deformities are also possible.

Hippocrates described the carinatum deformity as a "sharply pointed chest" and reported that patients became "affected with difficulty breathing." Symptomatic patients report dyspnea and decreased endurance. Some develop rigidity of the chest wall with decreased lung compliance, progressive emphysema, and increased frequency of respiratory tract infections.[1] Many affected patients have no physical complaints; however, concerns about body image have been associated with low self-esteem and a decreased mental quality of life.[2] Cosmetic concerns can be significant factors in opting for correction.

Barrel chest deformities with increased anteroposterior chest diameters can be seen in obstructive forms of chronic pulmonary disease, such as cystic fibrosis and untreated or poorly controlled asthma.

Until recently, most cases of pectus carinatum deformity were thought to be asymptomatic. However, little is known about the cardiopulmonary function. In 1989, Derveaux reported a series of patients with no significant preoperative or postoperative respiratory compromise.[3] However, some patients develop a rigid chest wall, in which the AP diameter is almost fixed in full inspiration. In these patients, respiratory efforts are less efficient. Vital capacity is reduced, and residual air is increased. Alveolar hypoventilation may ensue, with arterial hypoxemia and the development of cor pulmonale. As the lungs lose compliance, incidence of emphysema and frequency of infection are increased. Fonkalsrud (2008) reported his personal experience of 260 patients, all of whom were symptomatic.[4] Symptoms that were reported included dyspnea, exertional tachypnea, and reduced endurance.

In 1990, Iakovlev and colleagues studied the cardiac functions of 70 patients with pectus carinatum deformity.[5]  Mitral valve prolapse was identified in 97%. Rhythm disturbances and decreased myocardial contractility were less frequently observed, along with other cardiac and hemodynamic changes. Cardiac and hemodynamic changes were more commonly observed in patients with chondromanubrial prominence.

While the etiology of pectus carinatum deformity is still debated, current theories focus on defective metabolism or a developmental disorder with maturation disturbances of the sternocostal cartilage.[6] Park et al identified longer costal lengths and short rib lengths in a series of patients with symmetric pectus carinatum, leading them to suggest that the etiology of pectus carinatum is multifactorial.[7]

United States

Pectus excavatum is more common than the carinatum deformity. The overall prevalence of pectus carinatum is estimated at 0.06%.[8] Fonkalsrud (2008) reported that at least 25% patients have a positive family history of chest wall deformity.[4] Pectus carinatum can also be seen in association with Marfan syndrome, Noonan syndrome, and congenital heart disease.

International

The percentage of chest wall deformities represented by pectus carinatum are greater in reports from Brazil[9] and Argentina.[10]

Race

The conditions is more frequent in whites and is uncommon in blacks and Asians.

Sex

Males are affected 4 times more frequently than females. Because this deformity may occur either in isolation or as part of a syndrome, identifying a single etiology for the male predominance is difficult.

Age

Although pectus carinatum has been described at birth, it is most frequently identified in mid childhood. The deformity often worsens during the adolescent growth spurt.

Psychological and cosmetic concerns are the most prominent reasons for initial consultation. However, Fonkalsrud (2008) reported that surgical repair is rarely performed only for cosmetic reasons.[4] Morbidity in later years includes cardiac and hemodynamic changes.

In prepubertal children with pectus carinatum who are compliant with bracing, success rates are excellent (up to 80%).

Excellent results (97.4%) have been reported by Fonkalsrud (2008) in patients who underwent surgical correction using a very limited resection of deformed cartilage and immediate chest stabilization.[4] In addition, he reported less postoperative pain, shorter hospital stays, lower complication rate, and decreased cost. Furthermore, he reported satisfactory cosmetic results with the less extensive repair, as well as a high rate of improvement in exertional symptoms compared with more extensive open surgical procedures.

Recurrences are rare.

Responses to quality-of-life questionnaires in patients who had undergone minimally invasive repair of their pectus deformity supported a positive impact on psychosocial function.[11]

Common concerns in individuals with pectus carinatum, especially those with severe deformities, include the following:

• Body image, which can affect self-esteem
• Exercise symptoms, including fatigue and shortness of breath

Parents or the patient may report that pectus carinatum has been present since birth or early childhood, but most children present at age 11-15 years.

The degree of deformity may worsen during adolescence, and most patients are asymptomatic.

Once adult growth has occurred, the severity of the deformity generally remains stable.

Symptomatic patients report exertional dyspnea and tachypnea as well as decreased endurance. In one series, asthmatic symptoms were reported by 22% of patients.[4]

Musculoskeletal chest pain and tenderness when lying in the prone position can also occur.[12]

Patients may be affected by low self-esteem, poor body image, and decreased mental quality of life.[2]

Fokin et al have proposed the following classifications for pectus carinatum deformities[13] :

• Keel chest (chondrogladiolar variant, most frequent): This is protrusion of the lower third of the sternum, most prominent at the level of the sternoxiphoid junction. It is sometimes associated with lateral depression of the ribs. It may be symmetric or asymmetric. It is also known as pyramidal chest.
• Lateral pectus carinatum (asymmetric variant): This is unilateral protrusion of the elongated costal cartilages, often with concomitant rotation of the sternum towards the opposite side.
• Pouter pigeon breast (costomanubrial variant): This is protrusion of the manubriosternal junction and the adjacent ribs.

Postural abnormalities can occur.

Look for signs of genetic syndromes associated with pectus carinatum. For example, Turner syndrome and Noonan syndrome have been associated with Pouter pigeon breast.

See the image below.

Pectus carinatum. Photograph courtesy of K. Kenigsberg, MD.

Lower quality of life and poor body image have been associated with pectus carinatum deformities.[2] Other complications can include the following[14] :

• Exercise intolerance
• Scoliosis, especially when the pectus is asymmetric
• Decreased maximal Inspiratory and expiratory pressures

Also see Complications in the Treatment section.

A general approach to individuals with pectus carinatum is described below; however, evaluation and testing is individualized depending on the severity, associated findings, and anticipated treatment plan.

The patient should be assessed for the following:

• Body image
• Cardiopulmonary symptoms at rest (generally uncommon)
• Exercise tolerance and exercise related symptoms
• If genetic syndrome suspected, appropriate information about relevant findings
• Clinical characteristics of the chest wall
• Posture
• Physical features and findings of genetic syndromes

Pulmonary function testing should include body plethysmography, prebronchodilator and postbronchodilator spirometry, maximal inspiratory and expiratory pressure measurements, and cardiopulmonary exercise testing.[14]

The cardiovascular evaluation should include electrocardiography and echocardiography.

Imaging studies are individualized, with consideration for radiation exposure

Genetic testing may be warranted.

Plain chest films may be done initially.

A chest radiograph of a patient with pectus carinatum is shown in the image below.

Chest radiograph of a patient with pectus carinatum. Radiograph courtesy of A. Fruauff, MD.

CT and MRI imaging are the most common techniques used to evaluate deformities of the chest wall. A preliminary report from Lain et al (2017) describes their experience with a radiation-free external three dimensional scanning technique to evaluate and follow children and adolescents with chest wall deformities.[15] While this technique has limitations and does not currently replace CT or MRI studies in children with severe malformations, the development of imaging techniques without radiation exposure is important because of the increased susceptibility of children to the effects of ionizing radiation.

CT scanning of the chest in an individual with pectus carinatum (see the image below) reveals an increased anteroposterior chest wall diameter.[16]

CT scan of a patient with pectus carinatum. CT courtesy of A. Fruauff, MD.

The Haller method may be used to determine severity index, as follows: width of the chest divided by distance between the sternum and spine at the same level; this may help to predict those individuals who will benefit from surgical intervention.

In patients with pectus carinatum, pulmonary function studies may be tailored to address concerns about clinical symptoms and the appearance of the chest wall upon examination. Data on pulmonary and exercise physiology in patients with pectus carinatum deformities are limited. However, children with barrel chests usually have obstructive ventilatory defects. This underscores the importance of preforming complete pulmonary function testing, including prebronchodilator and postbronchodilator spirometry, lung volumes, and diffusion capacity. Exercise testing may complement these studies.

In 1982, Castile described one patient who reported exercise intolerance in his series of symptomatic pectus deformities.[17] His pulmonary function studies revealed flow rates and lung volumes within the reference range. Derveaux's 1989 series also reported a patient with no significant respiratory compromise at the time of his study.[3]

Progressive exercise studies may also be helpful in evaluating the exercise-related symptoms and exertional tolerance.

Electrocardiography and echocardiography may be considered if congenital heart disease is suspected. Iakovlev's study reported 70 patients with pectus carinatum deformity. Of these, 97% had echocardiographically documented mitral valve prolapse.[5] Hemodynamic and cardiodynamic changes were also observed in some patients, as well as decreased myocardial contractility. These abnormalities were more frequently observed in the patients with pigeon breast.

Scoliosis series may be considered if clinical features are suggestive of this diagnosis.

Chromosomal analysis and metabolic testing may also be considered if other dysmorphic signs are identified.

Most motivated patients with pectus carinatum, especially those younger than 18 years with malleable chest walls, benefit from orthotic bracing, and this is generally the first line of therapy.[18, 19]  Success rates of 65-80 % and long-term outcomes with orthotic bracing alone are encouraging.[12]

A study by Lee at el (2012) describes the preliminary results of 98 children treated using the Calgary Protocol, which involves a self-adjustable, low-profile bracing system used in 2 phases. The first phase involves 24 h/d bracing until correction is achieved. The second phase is a maintenance phase during which the brace is worn only at night until axial growth is complete. Twenty-three children completed treatment with good patient satisfaction and improved appearance, suggesting that when used in this fashion, it is an effective treatment for pectus carinatum. Therapy failed in 42 children, owing to either noncompliance or they were lost to follow-up. Two required surgical intervention after bracing failed to correct the problem. Additional studies and follow-up of the children still on protocol is important.[20]

A study by Wahba et al reported that less intensive bracing (< 12h/day) is associated with higher patient compliance (89.6% vs. 81.1%) with a similar time to correction (7.3 vs 7.1 months) and success rate (85.3% vs. 83.5%) when compared to more intensive bracing (≥12h/day).[21]

For older patients with more rigid chest walls, bracing may not be effective and surgery may be the initial consideration.

Casting followed by bracing or bracing alone eliminates the risks of surgery and anesthesia and does not preclude surgery if unsuccessful.

Endoscopic resection of costal cartilage with a sternal osteotomy

Because many corrections are performed for cosmetic reasons, decreasing the size of incisions is important.

In 1997, Kobayashi reported 2 patients in whom the pectus carinatum deformity was corrected with limited incisions using an endoscopic approach.[20] They suggest that this approach is better indicated in preschool-aged children because of their skin quality and tone, as well because of the increased ease of costal dissection compared with adult patients.

In 2008, Fonkalsrud reported a series of 260 patients who underwent surgical correction of pectus carinatum deformities over a period of 37 years.[4] He concluded that, over time, the trend towards less extensive open techniques has resulted in "low morbidity, mild pain, short hospital stay and very good physiologic and cosmetic results." His study included both pediatric and adult patients.

Open surgical repair

Various methods have been described. The reader is referred to Del Frari and Schwabegger (2011)[22] and Cohee et al (2013)[23] for further details.

Minimal access repair

A comparative analysis of 12 different surgical techniques for minimal access repair was published by Muntean et al.[24]

Pectus carinatum has been associated with congenital heart disease. In these patients, and in those with suspected or identified cardiac pathology, preoperative cardiology evaluation is recommended.

Exercise testing may be performed in consultation with either a cardiologist or a pulmonologist.

Symptomatic patients with exertional dyspnea, tachypnea, or decreased endurance, as well as those with asthma symptoms, benefit from a pulmonology evaluation.

Individuals with pectus carinatum who have significant concerns about their body image or low self-esteem can benefit from psychological counseling.

Symptomatic patients may report decreased exercise tolerance and exertional dyspnea, which may limit activity. Fonkalsrud's series (2008) reported improvement in exertional symptoms and endurance in all symptomatic patients within 3-6 months of surgical repair.[4]

Fonkalsrud's recommendations for postoperative activity include the following[4] :

• Use incentive spirometer and encourage periodic deep breaths.

• Limit twisting movements of the chest for at least 4 months postoperatively.

• Avoid rapid elevation of the arms overhead for at least 4 months postoperatively.

• Encourage lower extremity exercise (may begin within first 2 wk after surgery).

• Light weights may be used to strengthen biceps and deltoids; the use of chest and abdominal muscles may be increased later (after 3-4 wk).

• Gym classes are not indicated for 5 months after surgery in school-aged children.

• Long-term recommendations include stretching exercises that involve pulling the shoulder blades posteriorly to improve posture.

Complications vary according to treatment selection.

Ill-fitting braces can be associated with skin irritation and skin breakdown.

Shamberger reported a 3.9% complication rate with open surgical repair.[25] Complications include pneumothorax (2.6%), wound infection (0.7%), atelectasis (0.7%), and local tissue necrosis (0.7%). The mean postoperative stay was 5.8 days.

Fonkalsrud (2008) reported shorter hospital stays (mean, 2.6 d), mild postoperative pain, and low complication rate with limited resection and immediate chest stabilization.[4]

Also see Complications in the Presentation section.

Drug therapy currently is not a component of the standard of care in pectus carinatum. See Treatment.