Pectus Excavatum Classification and external resources
An example of a severe case.
ICD-10	Q67.6
ICD-9	754.81
OMIM	169300
DiseasesDB	29401
MedlinePlus	003320
eMedicine	ped/2558
MeSH	D005660

Pectus excavatum (a Latin term meaning hollowed chest)^[1] is the most common congenital deformity of the anterior wall of the chest, in which several ribs and the sternum grow abnormally. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings Q00-Q89 - Congenital malformations and deformations (Q00-Q07 Nervous system ( Anencephaly and similar malformations The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them The Diseases Database is a free Website that provides information about the relationships between medical conditions Symptoms, and Medications. MedlinePlus, with the MedlinePlus Medical Encyclopedia, is a website network containing Health information from the world's largest medical Library eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely two medical doctors Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. A congenital disorder is a disease or disorder that is present at birth In Vertebrate Anatomy, ribs ( Latin costae) are the long curved Bones which form the ribcage. The sternum (from Greek στέρνον sternon, "chest" or breastbone) is a long flat Bone located in the center of the thorax (chest This produces a caved-in or sunken appearance of the chest. The chest is a part of the Anatomy of humans and various other animals sometimes referred to as the Thorax. ^[2] It is usually present at birth and progresses during the time of rapid bone growth in the early teenage years, but in rare cases does not appear until the onset of puberty. ^[3]

Pectus excavatum is sometimes considered to be cosmetic, however it can impair cardiac and respiratory function, and cause pain in the chest and back. The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic In living organisms a respiratory system functions to allow Gas exchange. ^[4] People with the abnormality may experience negative psychosocial effects, and avoid activities that expose the chest. The term psychosocial refers to one in Psychological development in and interaction with a Social environment. ^[5]

Pectus excavatum is sometimes referred to as cobbler's chest, sunken chest, funnel chest or simply a dent in the chest. ^[6][7][8]

Signs and symptoms

The hallmark of the condition is a sunken appearance of the sternum. A hallmark is a mark or series of marks struck on items made of precious metals &mdash Platinum, Gold, Silver and in some nations Palladium The heart is displaced (and rotated). Mitral valve prolapse may also be present. Mitral valve prolapse (MVP is a Valvular heart disease characterized by the displacement of an abnormally thickened Mitral valve leaflet into the left atrium Base lung capacity is decreased. ^[9]

Causes

Researchers are currently unsure as to the actual cause of pectus excavatum but hypothesize genetic defect. ^[4] Approximately 37% of individuals with pectus excavatum have a first degree family member with the condition. ^[2] Physiologically, increased pressure in utero, rickets and increased traction on the sternum due to abnormalities of the diaphragm have been postulated as specific mechanisms. Rickets is a softening of the bones in children potentially leading to fractures and deformity The sternum (from Greek στέρνον sternon, "chest" or breastbone) is a long flat Bone located in the center of the thorax (chest ^[2] Pectus excavatum is also a relatively common symptom of Marfan syndrome. Marfan syndrome (or Marfan's syndrome is a genetic disorder of the Connective tissue. ^[10]

Pathophysiology

Because the heart is located behind the sternum, and because individuals with pectus excavatum have been shown to have visible deformities of the heart (seen both on radiological imaging and after autopsies), it has been hypothesized that there is impairment of function of the cardiovascular system in individuals with pectus excavatum. The heart is a muscular organ in all Vertebrates responsible for pumping Blood through the Blood vessels by repeated rhythmic The sternum (from Greek στέρνον sternon, "chest" or breastbone) is a long flat Bone located in the center of the thorax (chest While some studies have demonstrated decreased cardiovascular function in pectus excavatum, there has been no consensus reached based on newer physiological tests (such as echocardiography) of the presence or degree of impairment in cardiovascular function in people with pectus excavatum. An echocardiogram is a Sonography of the Heart. Also known as a cardiac ultrasound it uses standard ultrasound techniques to image two-dimensional slices of Similarly, there is no consensus on the degree of functional improvement after corrective surgery. ^[2]

Diagnosis

An x-ray showing pectus excavatum

Pectus excavatum is initially suspected from visual examination of the anterior chest. Auscultation of the chest can reveal displaced heart beat and valve prolapse. There can be a heart murmur occurring during systole caused by proximity between the sternum and the pulmonary artery. Murmurs are abnormal Heart sounds that are produced as a result of turbulent blood flow which is sufficient to produce audible noise The pulmonary arteries carry Blood from the Heart to the Lungs. ^[11]

Lung sounds are usually clear yet diminished due to decreased base lung capacity. ^[9]

Many scales have been developed to determine the degree of deformity in the chest wall. Most of these are variants on the distance between the sternum and the spine. One such index is the Backer ratio which grades severity of deformity based on the ratio between the diameter of the vertebral body nearest to xiphosternal junction and the distance between the xiphosternal junction and the nearest vertebral body. The xiphoid process, also known as the xiphisternum is a small cartilaginous extension to the lower part of the Sternum which is usually ^[12] More recently the Haller index has been used based on CT scan measurements. The Haller index, created in 1987 by Dr Haller Dr Kramer and Dr Computed tomography (CT is a Medical imaging method employing Tomography. The Haller index is the ratio between the horizontal distance of the inside of the ribcage and the shortest distance between the vertebrae and sternum. ^[13]

Chest x-rays are also useful in the diagnosis. A chest X-ray, commonly abbreviated CXR, is a projection radiograph ( X-ray) taken by a Radiographer, of the Thorax which is used The chest x-ray in pectus excavatum can show an opacity in the right lung area that can be mistaken for an infiltrate (such as that seen with pneumonia). Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal ^[14] Some studies also suggest that the Haller index can be calculated based on chest x-ray as opposed to CT scanning in individuals who have no limitation in their function. The Haller index, created in 1987 by Dr Haller Dr Kramer and Dr ^[15]

Pectus excavatum is differentiated from other disorders by a series of elimination of signs and symptoms. Pectus carinatum is excluded by the simple observation of a collapsing of the sternum rather than a protrusion. Pectus carinatum, also called pigeon chest, is a deformity of the chest characterized by a protrusion of the Sternum and Ribs. Kyphoscoliosis is excluded by diagnostic imaging of the spine, where in pectus excavatum the spine usually appears normal in structure. Kyphoscoliosis describes an abnormal curvature of the spine in both a coronal and Sagittal plane

Treatment

Medical treatment is limited to surgery and ensuring defects involving the heart and/or lungs are controlled. Before operation several tests are usually to be performed. These include, but are not limited to, a CT scan, pulmonary function tests, and cardiology exams (such as auscultation and ECGs). Computed tomography (CT is a Medical imaging method employing Tomography. Spirometry (meaning the measuring of breath) is the most common of the Pulmonary Function Tests (PFTs measuring Lung function specifically the measurement Cardiology (from Greek grc καρδίᾱ kardiā, "heart" and grc -λογία -logia) is the branch of Internal medicine ^[4] After a CT scan is taken the Haller index is measured. The Haller index, created in 1987 by Dr Haller Dr Kramer and Dr The patient's Haller is calculated by obtaining the measurement of inside left to inside right of the ribcage and dividing that by the distance from the sternum to the spine. A Haller Index of greater than 3. 25 is generally considered severe, while normal chest has an index of 2. 5. ^{[13] [16] [17]} The cardiopulmonary tests are used to determine the lung capacity and to check for heart murmurs.

Surgery

Surgical correction has been shown to repair any functional symptoms that may occur in the condition, such as respiratory problems or heart murmurs, provided that permanent damage has not already arisen from an extremely severe case. ^[4]

Ravitch technique

The Ravitch technique is an invasive surgery that was developed in the 1950s to treat the condition. The 1950s Decade refers to the years of 1950 to 1959 inclusive This procedure involves creating an incision along the chest through which the cartilage is removed and the sternum detached. A small bar is then inserted underneath the sternum to hold it up in the desired position. The bar is left implanted until the cartilage grows back, typically about 6 months. The bar is subsequently removed in a simple out-patient procedure. The Ravitch technique is not widely practiced because it is so invasive. It is often used in older patients, where the sternum has calcified, when the deformity is asymmetrical, or when the less invasive Nuss procedure has proven unsuccessful.

Nuss procedure

Main article: Nuss procedure

Lung exerciser, used after corrective surgery

Since then, Dr. The Nuss procedure is a Minimally-invasive procedure invented by Dr Donald Nuss, based at Children's Hospital of The King's Daughters (CHKD) in Norfolk, Virginia, has developed a technique that is minimally invasive. Children's Hospital of The King's Daughters ( CHKD) is a 186-bed non-profit Children's hospital located in Norfolk, Virginia. Norfolk is an Independent city in the Commonwealth of Virginia in the United States ^[18] The Nuss procedure involves slipping in one or more concave steel bars into the chest, underneath the sternum. The bar is flipped to a convex position so as to push outward on the sternum, correcting the deformity. The bar usually stays in the body for about two years, although many surgeons are now moving toward leaving them in for up to five years. When the bones have solidified into place, the bar is removed through outpatient surgery. Outpatient surgery, also referred to as ambulatory surgery, same-day surgery or day surgery, is Surgery that does not require an overnight

Vacuum Bell

Main article: Vacuum bell (medicine)

A relatively new alternative to surgery is the vacuum bell. The vacuum bell is a medical device used in the treatment of Pectus excavatum, one of the most common Chest wall defects It consists of a bowl shaped device which fits over the caved-in area; the air is then removed by the use of a hand pump. The vacuum created by this lifts the sternum upwards, lessening the severity of the deformity. As it is such a recent device there is currently no information as to whether it is effective in the long term. ^[19]

Cosmetic and light treatments

The cosmetic appearance of pectus excavatum can be treated with a dermal filler called Bio-Alcamid. Polyalkylimide is a Polymer which belongs to the family of acryl derivatives ^[20] However, as this does nothing to alleviate the actual deformity it will not prevent any physiological symptoms caused by the condition.

Mild cases have also reportedly been treated with corset-like orthopedic support vests and exercise. A corset is a Garment worn to mold and shape the Torso into a desired shape for Aesthetic or medical purposes (either for the duration of wearing it or ^[21]

There are also prosthetic implants available to 'fill the depressed area'. Solid silicone implants have been successfully used for many years with excellent results. More recently a porex implant has been used which is a similar material used to replaced 'skull' in brain surgery and severe head injuries.

Magnetic Mini-Mover Procedure

The Magnetic Mini-Mover Procedure (3MP) is a technique used to correct pectus excavatum by using two magnets to realign the sternum with the rest of the chest and ribcage. ^[22] One magnet is inserted 1cm into the patients body on the lower end of the sternum, the other is placed externally onto a custom fitted brace. These two magnets generate around 0. 04 Tesla (T) in order to slowly move the sternum outwards over a number of years. The tesla (symbol T) is the SI derived unit of Magnetic field B (which is also known as "magnetic flux density" and "magnetic The maximum Tesla that can be applied to the body safely is around 4T, making this technique safe from a magnetic viewpoint. ^[22] The 3MP technique's main advantages are that it is more cost-effective than major surgical approaches such as the Nuss procedure and it is considerably less painful postoperatively. One potential adverse effect of 3MP is inactivation of implanted devices such as an artificial pacemaker. For other uses see Pacemaker (disambiguation A pacemaker (or artificial pacemaker, so as not to be confused with the heart's natural pacemaker Since the 3MP is still in a trial period it is unknown whether long term wearing of the magnet will affect the skin or other vital organs.

Epidemiology

Pectus excavatum occurs in an estimated 1 in 150-1000 births, with male predominance (male-to-female ratio of 3:1). Occurrences of the condition in family members have been reported in 35% to 45% of cases. ^[9][23]

In Animals

Pectus excavatum is also known to occur in animals, e. g. the Munchkin breed of cat. The munchkin is a relatively new breed created by a Mutation that causes Achondroplasia, or more probably Hypochondroplasia as the skull ^[24] Some procedures used to treat the condition in animals have not been used in humans, such as the use of a cast with sutures wrapped around the sternum and the use of internal and external splints. A splint is a medical device for the immobilization of limbs or of the spine. ^[25][26] These techniques are generally used in immature animals with flexible cartilage. ^[27]

References

External links