Funnel chest

Funnel chest (pectus excavalus) is a developmental defect in the form of a depression of the sternum and ribs, accompanied by various functional disorders of the respiratory and cardiovascular systems.

The funnel chest was first described by G. Bauhinus in 1600. Abroad, the first operation on a patient with a similar deformation was performed by A. Tietze in 1899, who performed a resection of the altered lower part of the sternum.

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Causes funnel chest

Funnel chest is usually a congenital malformation. The expanded classification of etiopathogenetic concepts of the occurrence of funnel chest deformity combines four main groups of theories,

• The first group of theories associates the development of funnel-shaped deformation with uneven growth of the bone-cartilaginous formations of the chest, as well as the xiphoid process, due to the embryonic inferiority of the apophyseal and epiphyseal growth zones. The sternum and cartilaginous parts of the ribs lag behind in their development. The formation of the chest is uneven. It changes its shape, volume and size, which is manifested by a decrease in the sternovertebral distance and flattening of the chest itself.
• The second group is represented by theories that explain the formation of funnel-shaped deformation by congenital changes in the diaphragm: shortening and delay in the development of its sternal part, the presence of a shortened sternodiaphragmatic ligament. The ribs have an excessive inclined or oblique direction, as a result of which the position of the chest muscles changes, as well as the diaphragm, especially its anterior sections at the point of attachment to the costal arches.
• The third group includes theories that suggest that the funnel chest is a consequence of imperfect development of the sternum in the embryonic period, dysplasia of connective tissue, which in turn leads to anatomical-topographical and clinical-functional changes not only in the chest itself, but also in the respiratory and cardiovascular systems, and is manifested by metabolic disorders in the whole body. Some authors highlight reliable dysplastic signs indicating the congenital nature of the disease. These include Mongoloid eye shape, arachnodactyly, high palate, hyperelasticity of the skin, dysplasia of the auricles, dolichostenomelia, scoliosis, mitral valve prolapse, umbilical hernia, and sphincter weakness. It is also noted that the presence of more than four of the above signs in patients is an unfavorable prognostic sign.
• The fourth group included eclectic theories that explain the formation of funnel-shaped deformation by the incorrect position of the fetus in the uterine cavity with oligohydramnios or infectious processes in the mediastinum.

There is no doubt that in some patients with funnel chest, this deformation is a hereditary defect. Thus, H. Novak examined 3000 schoolchildren and found the deformation in 0.4%, and among their relatives, funnel chest was found in 38% of those examined. The congenital nature of the disease is confirmed by its combination with other congenital developmental defects.

Currently, funnel chest is in most cases associated with dyschondroplasia. In the early stages of the embryonic period (first 8 weeks), the development of cartilaginous cells of the ribs and sternum is delayed. As a result, by the time of birth, embryonic cartilage is preserved, characterized by fragility due to excessive development of soft tissue structures and a quantitative deficiency of cartilaginous cells. O.A. Malakhov et al. (2002) consider the main factor in the formation and progression of chest deformation to be dyshistogenesis of hyaline cartilaginous tissue, leading to uneven development of chest elements due to the accelerated growth of the ribs with subsequent disruption of blood circulation and respiratory biomechanics.

Funnel chest deformity reduces the volume of the chest, which leads to hypertension in the pulmonary circulation, chronic hypoxemia, functional disorders of the internal organs of the chest cavity, changes in the acid-base balance and water-salt metabolism with the formation of a vicious circle. On the other hand, changes in the attachment points of the muscles involved in the act of breathing cause their atrophy, loss of elasticity, tone and degenerative degeneration, which is confirmed by electromyography of the respiratory and accessory muscles examined at rest and during exercise tests, as well as by histological examination during surgery. Such changes lead to a decrease in the elasticity and mobility of the chest, a decrease in its excursion, and the development of persistent paradoxical breathing. In addition, compression of the bronchi, displacement of the mediastinum and torsion of large vessels are noted, which disrupts the activity of the respiratory system and the pulmonary circulation.

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Symptoms funnel chest

Funnel chest is noticeable in newborns as a small depression. A characteristic sign in infants is the "inhalation paradox" symptom: when inhaling, and especially when children cry or scream, the depression of the sternum and ribs increases. G. I. Bairov points out that in half of children, the deformation of the chest and paradoxical breathing disappear in the first months of life. And only in the second half, as they grow, does the depression of the sternum increase. During this period, the edges of the costal arches and the groove formed under it begin to protrude. When rising, the edges of the ribs push the rectus abdominis muscles forward, creating the impression of its enlargement. These changes are mistaken for symptoms of rickets.

An increase in deformation already in the first half of the year can lead to dysfunction of the chest organs, a tendency to respiratory diseases of the upper respiratory tract, and chronic pneumonia.

Some children have stridor breathing - a difficult wheezing breath is accompanied by great tension in the respiratory muscles, retraction of the jugular notch, epigastric region and intercostal spaces, which is caused by increasing negative movement in the chest cavity. As a rule, no changes are found on the ECG in infants.

Funnel chest becomes especially noticeable after the age of 3. By this time, the gradual transition to a fixed curvature of the sternum and ribs is usually complete. The appearance and posture acquire the typical appearance of funnel chest.

Thoracic kyphosis increases, less often the back becomes flat. Lateral curvatures of the spine may occur. Upon examination, the drooping shoulders and protruding belly are noticeable. The chest is flattened, a funnel-shaped chest is determined in the sternum area.

The depth and volume of the funnel may vary within different limits depending on the severity of the pathology and the age of the patient. The depth of the funnel is measured by the distance from the plane connecting both edges of the depression to the top of the funnel. In addition, its size can be determined by the amount of fluid it contains. The volume of the funnel with minor deformations is 10-20 cm ³, and with pronounced ones - up to 200 cm ³ and more in adult patients.

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Stages

N.I. Kondratin developed a classification of funnel chest deformity, in which patients are conditionally divided into groups according to the clinical course of the disease, form, type and severity of the deformity.

There are three degrees of deformation of the sternum, taking into account the depth of the funnel and the degree of displacement of the heart:

• I degree - depth of the funnel up to 2 cm, no displacement of the heart;
• II degree - deformation depth up to 4 cm, displacement of the heart within 2-3 cm;
• Grade III - the depth of deformation is more than 4 cm, the heart is displaced by more than 3 cm.

The degree of deformation of the sternum determines the clinical course of the disease.

In this regard, compensated, subcompensated and decompensated stages of the disease are distinguished.

• In the compensated stage, only a cosmetic defect is detected, there are no functional disorders or they are minimal. As a rule, this stage of the disease corresponds to the first degree of chest deformation.
• The subcompensated stage of deformation corresponds to the second degree of deformation. In this case, mild functional disorders of the heart and lungs are noted,
• In the decompensated stage, grade III funnel-shaped deformation with significant functional impairment is detected.

Distinguishing deformations by shape, we distinguish between normal and flat-funnel-shaped, and by appearance - symmetrical and asymmetrical (right-sided, left-sided).

• Pectus excavatum is in most cases the result of progression of deep pectus excavatum.
• The symmetrical form of deformation is characterized by uniform development of both halves of the chest,

Some authors, supplementing the classification of N.I. Kondrashin, distinguish the following forms of the sternum with funnel-shaped deformation: flat, hook-shaped, and a sternum with an osteophyte.

Diagnostics funnel chest

To assess lung function, an electromyographic study of the respiratory (intercostal) and accessory (sternocleidomastoid and trapezius) muscles is performed.

Electromyographic examination reveals structural changes in the respiratory muscles and chest in half of patients with funnel chest. Such indicators are an argument in favor of dysfunction of spinal cord motor neurons.

Children with severe chest deformation are asthenic, lag behind in physical development, have a weak muscular system and vegetative-vascular dystonia, since a sharp decrease in the vital capacity of the lungs (15-30%) and pronounced manifestation of cardiac and pulmonary insufficiency complicates blood gas exchange. Patients often complain of rapid fatigue and stabbing pains in the heart. A decrease in the excursion of the chest and diaphragm, a violation of the function of external respiration lead to a change in oxidation-reduction processes in the body. This is manifested in a violation of carbohydrate, protein and water-salt metabolism, as well as acid-base balance.

To objectively assess the condition of the internal organs in patients with funnel chest deformity, the function of external respiration, vital capacity of the lungs, and reserve volume of inhalation and exhalation are examined using a special technique.

Funnel chest is characterized by insufficient expansion of the lungs, which reduces the "pulmonary membrane" through which gas exchange occurs. Due to incomplete expansion of the lungs, the "anatomical dead space" increases and alveolar ventilation decreases. To compensate for these disorders, the body increases lung perfusion, which leads to hypertrophy of the right ventricle of the heart. Functional disorders of the cardiovascular and respiratory systems in patients with funnel chest lead to tissue hypoxia, changes in enzymatic and metabolic processes.

Vital capacity (VC) within the normal range was noted only in 21% of patients with grade II chest deformation. Moderate VC deviation was observed in 45%, significant decrease - in 6%. In patients with grade III deformation, normal VC values were not noted. As a rule, funnel chest deformation is associated with deformation of the anterior chest wall and impaired respiratory function. The trend is unidirectional: the higher the degree of deformation, the more pronounced the impairment of the ventilation function of the lungs.

Electrocardiographic examination revealed various deviations from the norm in most patients (81-85). Thus, in 40% of cases, right bundle branch block, sinus arrhythmia (10%), deviation of the electrical axis of the heart to the right and left (9%), left ventricular hypertrophy (8%) and other deviations were noted.

Echocardiographic examination revealed mitral valve prolapse and abnormal location of the chord in the left ventricle.

Analysis of ECG and EchoCG data allows us to conclude that with an increase in the degree of deformation, the frequency of cardiovascular disorders increases.

In addition to the clinical examination method, they use the X-ray method, which is the most accurate.

Based on the X-ray examination data, the degree of funnel-shaped deformation and the degree of kyphosis of the thoracic spine are assessed. The method also helps to identify the nature of changes in the chest organs. X-ray examination is performed in two standard projections: anteroposterior and lateral. For better contrast of the sternum, a wire or strip of radiopaque material is fixed along the midline. The degree of deformation is assessed using the Gizycka index (Gizicka, 1962). It is determined on lateral radiographs by the ratio of the smallest size of the retrosternal space (from the posterior surface of the sternum to the anterior surface of the spinal column) to the largest. The quotient obtained by dividing 0.8-1 (the norm is 1) characterizes deformation of the 1st degree. from 0.7 to 0.5 - II degree, less than 0.5 - III degree.

The Gizhitskaya index remains the simplest radiographic indicator to date for determining the degree of chest deformation and deciding on surgical intervention. In some patients, lateral radiographs reveal exostotic growths on the inner wall of the sternum, its thickening, which significantly reduces the retrosternal space. In these cases, a discrepancy is noted between the magnitude of deformation and functional disorders.

To assess the quantitative relationships of the respiratory capacity of different parts of the lungs, V.N. Stepnov and V.A. Mikhailov use the method of X-ray pneumography.

During X-ray examination, the degree of thoracic spine kyphosis is assessed before and after surgical correction. 66% of patients with funnel chest deformity have grade II kyphotic deformity, and 34% have grade III kyphosis.

The first report on the study of the structure of the chest and thoracic cavity in patients with funnel chest deformity using X-ray computed tomography appeared in 1979 (Soteropoulos G, Cigtay O., Schellinger P.). This method is of great value for thoracic surgery, especially when it is necessary to visualize the organs of the chest cavity.

Ultrasound examination using the method of multi-position scanning in longitudinal and transverse planes is widely used to assess the condition of not only the internal structures of the chest cavity, but also as a method for assessing the bone and cartilage structures of the chest both before and after surgical interventions.

One of the main preoperative examinations of patients with sunken chest is a psychological examination, since, according to various authors, from 78.4 to 100% of patients suffer from an inferiority complex. Especially with age, indicators that adversely affect the development and growth of the child increase: apathy, shyness and alienation in relationships with peers, negativism and indifference towards parents. The combination of a pathological psychological state and physical and functional insufficiency does not allow children to lead a full social life.

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Treatment funnel chest

Conservative treatment of funnel chest

Physiotherapy exercises, breathing exercises, chest massage, physiotherapy, hyperbaric oxygenation, therapeutic swimming do not relieve the patient from chest deformation, but conservative measures must be taken. In order to prevent the progression of deformation, strengthen the muscular frame and physical development of the child, prevent the development of spinal deformations, normalize posture, increase the vital capacity of the lungs.

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Surgical treatment of funnel chest

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Indications for surgery

Most orthopedists who perform thoracoplasty for funnel chest deformity adhere to the indications for surgical intervention proposed by G. A. Bairov (1982). Functional, orthopedic and cosmetic indications for surgical intervention are distinguished.

• Functional indications are caused by dysfunction of the internal organs of the chest cavity.
• Orthopedic indications are caused by the need to change poor posture and spinal curvature.
• Cosmetic indications are related to the presence of a physical defect that disrupts the aesthetics of the physique.

Using modern methods of examination and attaching great importance to the psychological status of the patient. A.V. Vinogradov (2005) proposed indications and contraindications for surgical treatment of children with chest deformities, including post-traumatic and congenital defects.

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Absolute indications for surgery

• Funnel chest deformity grades III and IV,
• Congenital and acquired deformities of the chest that do not cause functional disorders of the respiratory and cardiovascular systems, but cause disturbances in the patient’s psychological status.
• Poland syndrome, accompanied by a bone-cartilaginous defect of the chest and a resulting decrease in its skeletal and protective properties.
• Congenital clefts of the sternum in children of all age groups.

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Relative indications for surgery

• Deformations of the chest without defects in the bone-cartilaginous framework of the chest, which do not cause any functional or psychological disorders.
• Acquired deformities of the chest after injuries, inflammatory diseases and surgical interventions.

Despite the simplicity and clarity of indications for surgical treatment of funnel chest, many orthopedic surgeons consider grade II-III deformation with the presence of functional disorders to be the main indication for surgery.

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Contraindications to surgical treatment

• Severe concomitant pathology of the central nervous, cardiovascular and respiratory systems.
• Mental retardation of moderate, severe and profound degree.

There are no clear recommendations on the age of patients requiring thoracoplasty for funnel chest. Orthopedists mainly cite data on surgical interventions in adolescents, citing the fact that functional abnormalities are not detected in younger children. Funnel chest has serious functional disorders in puberty and adolescence, since the high compensatory capabilities of the child's body maintain close to normal respiratory and cardiovascular function for a long time. This circumstance often leads to the erroneous conclusion about refusing surgery in younger children.

As surgical treatment of patients with funnel chest deformity improved, classifications of surgical treatment methods were proposed that are still used today.

A classification of operations for funnel chest deformity that is convenient for practical use was proposed by V.I. Geraskin et al. (1986), dividing the methods of thoracoplasty and fixation of the sternocostal complex into the following groups.

1. Radical operations (thoracoplasty):

By the method of mobilization of the sternocostal complex:

• subperichondral resection of deformed costal cartilages, transverse sternotomine;
• double chondrotomy, transverse sternotomy;
• lateral chondrotomy, T-sternotomy
• combinations and other rare modifications.

By the method of stabilization of the sternocostal complex;

• using external sternal traction;
• using internal metal fasteners;
• using bone grafts;
• without the use of special fixators of the sternocostal complex.

2. Operations with 180 degree rotation of the sternocostal complex:

• free rotation of the sternocostal complex:
• reversal of the sternocostal complex with preservation of the superior vascular pedicle;
• reversal of the sternocostal complex while maintaining connection with the abdominal muscles.

3. Palliative operations:

There are three most common methods of mobilizing the sternocostal complex in pectus excavatum.

• Subperichondral resection of costal cartilages, transverse sternotomy.
• Lateral chondrotomy, T-sternotomy.
• Double (parashernadial and lateral) chondrotomy, transverse sternotomy.

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Postoperative complications of funnel chest

The most frequent complications after thoracoplasty are hemothorax (20.2%), suppuration of the skin wound (7.8%), pneumothorax (6.2%), subcutaneous hematomas (:1.7%), postoperative pneumonia (0.6%), pleurisy (0.9%). Along with the listed complications, without statistical clarification, mediastinitis, sepsis, osteomyelitis of the sternum, migration of fixators, secondary bleeding, skin necrosis, intestinal paresis, hemopericarditis, pericarditis, myocarditis, keloid scars are distinguished.

In the early postoperative period, hemodynamics, respiration, diuresis and the general condition of patients are monitored for timely detection of complications. Usually, after restoration of independent breathing, the patient is transferred to the intensive care unit, where symptomatic treatment of funnel chest is carried out for 3-5 days. Antibacterial treatment is prescribed from the first day. Many surgeons consider drainage of the retrosternal space with active aspiration according to Redon for 3 days to be mandatory. The retrosternal space is drained with a polyethylene tube. After transferring the patient to a specialized department, a set of therapeutic exercises and breathing exercises are prescribed to improve the function of the cardiorespiratory system. During this period, A.F. Krasnov and V.N. Stepnov, using a specially proposed technique, use hyperbaric oxygenation in combination with physiotherapy and electrical stimulation of the respiratory muscles.

Patients with funnel chest should be monitored for a long time. Children after surgery should be sent to a sanatorium for health treatment.

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Effectiveness of treatment of funnel chest

The funnel chest after surgery is assessed on the following scale: good, satisfactory and unsatisfactory.

• A good result is the absence of complaints about cosmetic defects, the Gizhitskaya index (GI) is 1.0, and the anatomical shape of the anterior chest wall is completely restored.
• Satisfactory result - complaints of residual deformations of the anterior chest wall (slight depression or protrusion of the sternum, local depression of the ribs), IG is 0.8.
• Unsatisfactory result - complaints about a cosmetic defect, relapse of deformation to the original value, IG less than 0.7,

The most effective and objective assessment of different methods of surgical interventions for funnel chest deformity is given by Yu. I. Pozdnikin and I. A. Komolkin.

Over the years, the authors have used four different surgical methods to correct pectus excavatum:

• thoracoplasty according to G.I. Bairov;
• thoracoplasty according to N.I. Kondrashin;
• Paltia thoracoplasty;
• tunnel chondrotomy (Pozdnikin Yu.I. and Komolkin I.A.).

Due to its significant effectiveness and pathognomonicity, the table of remote results of surgical treatment of patients with funnel chest deformity should include reconstructive combined bone and muscle plastic surgery of the chest according to A.F. Krasnov and V.N. Stepnov.

Restorative treatment of funnel chest is a topical issue in orthopedics and thoracic surgery. Foreign and domestic surgeons have proposed a significant number of fairly effective methods of surgical correction, combining tendon-muscle plastic surgery, bone transplantation, and fixation of the sternocostal complex with metal plates. Funnel chest should be treated with the method that is optimal given the patient's physiological condition.