Pectus Excavatum is the most frequent congenital deformity of the thoracic cavity, since it represents almost 95% of cases. It is characterized by a depression of the sternum that gives a sunken appearance to the chest, also known as a funnel chest. The malformation is diagnosed in newborns and develops progressively during puberty. It is estimated to occur in approximately one in 500-1000 births and is generally more frequent in males (male: female ratio = 3: 1). The opposite deformity, also common among thoracic deformities, is known as Pectus Carinatum.
The etiology of the Pectus Excavatum remains unknown, although it can be considered as a hereditary condition. The suspicion is strong of an intrinsic disease on a molecular level of the cartilage of the costernal unions with a variable number and intensity. On rare occasions, the Pectus Excavatum is syndromic (Marfan, Morquio, Pierre Robin, Prune Belly, Poland, Jeune, etc.), although it usually occurs in isolation.
The deformity is visible already in the first year of life. The patient’s respiratory pattern should be carefully observed. If sternal sinking occurs with inspiration, there is what is called a reverse or paradoxical breathing. This is correlated with an unfavorable evolution of the case. Monitoring will be carried out with visits every six months, which can be made more frequent in the event that the patient presents more serious respiratory disorders that require being admitted to hospital. Until approximately the age of four, it is not necessary to do any additional physical exam, since this adds nothing new.
It allows a look at the sternal sinking in the lateral view and the possiblity to taking the AP diameter measurement as well as the cross one. A metal or barium marker can be placed at the bottom of the deepest part. It also allows to see associated malformations, such as scoliosis, hemivertebrae, rib fusion, etc.
Patients will undergo computed tomography (CT Scan or CAT) of the chest. Only a few funnel slices are requested, except in the case of a more complex deformity, in which case a helical CT scan may be used.
Conventional slices at the level of maximum subsidence allow to appreciate the degree of the Pectus Excavatum from the calculation of the Haller Index. This index is calculated by dividing the transverse axis (horizontal distance from the inside of the rib cage) by the anteroposterior axis (shorter distance between the vertebrae and the sternum) and correlates with the surgical indication when it is equal to or greater than 3.25 .
Other complementary tests
Cardiac and pulmonary evaluations will also be done through:
The monitoring of the patients requires in many cases to repeat some or all of the tests to assess stabilization or worsening evolution, and to prescribe the indication more accurately.
Approximately half of the affected cases of Pectus Excavatum will show clinical symptoms that will be due to the pathophysiological alteration of the deformity. Therefore, there will be a large population of patients with Pectus Excavatum who probably will not have symptoms nor will consequently have correction criteria.
In the affected cases, the shortening of the anteroposterior diameter of the thorax causes a deviation of the mediastinal viscera, generally towards the left hemithorax, which leads to a deviation of the cardiac axis to the left and a restrictive ventilatory pattern.
In these cases, deficits in blood filling can also be detected in the right chambers of the heart; cardiac displacement / rotation with a subsequent decrease in left ventricular ejection volume, and a reduced ability to pump efficiently; mitral valve prolapse; arrhythmias; or ventricular hypertrophy due to axial offset.
The presentation of the deformity is visual and is noticeable in the first year of life, although it goes unnoticed due to the absence of symptoms, which will become evident in prepubertal age. The cases detected early must be monitored at least until that time, since this is when sports activity begins and the deficiencies that Pectus Excavatum causes are revealed.
Patients suffering from this deformity may experience:
Many cases initially show a mild Poland sequence with chest hypoplasia of the breast and nipple, usually the right one, which is increased over time and worsens at puberty, especially in female patients.
TYPES OF PECTUS EXCAVATUM PATIENTS