Chest Cavity, and Dorsal Spine Surgery


Funnel chest


Pigeon chest


Aplasia or dysplasia


Pectus excavatum


Pectus carinatum


Ectopia cordis

  

Cleft sternum

  

Poland’s syndrome

  

Asphyxiating thoracic dystrophy




Pectus Excavatum


Pectus excavatum is the anterior depression of the costal wall. It is the most common malformation of the chest cavity, with an incidence of 1 in 400 births. It is more common in men than in women, with a ratio of 5:1. It is more common in the white race, and it is more frequently presented from the first year of life, progressing and becoming more noticeable during the puberty growing phase. The mechanism that provokes it is not completely identified. Some histological studies have shown a weakening in the components of the costal cartilages, which would allow for posterior sternal migration. There is no chromosomal defect, but it has been reported in conjunction with Marfan syndrome, Ehlers–Danlos syndrome, osteogenesis imperfecta, syndactyly, and Klippel–Feil syndrome. Also, a genetic predisposition of approximately 40% of the patients has been detected, who report having a family member with medical history of being a carrier of a malformation of the chest wall.


Preoperative Evaluation


The objective of the preoperative evaluation is to define the morphology and seriousness of the deformation of the sternum, and its functional repercussions both in the lungs and the heart. It is also important to demonstrate that the subject is not allergic to the metallic compounds used when repairing the pectus excavatum, which is present in 2% of the cases.


Computerized tomography or magnetic resonance is used in the evaluation of the level of seriousness of the pectus excavatum when calculating the Haller index. This consists in the transverse diameter of the chest divided by the anteroposterior diameter of the point of the sternum with the greatest depression (Fig. 72.1).

../images/441522_1_En_72_Chapter/441522_1_En_72_Fig1_HTML.png

Fig. 72.1

Haller index (TAC)


In the lung evaluation, abnormalities in the lung function can be shown by measuring the forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow of 25–75% of the forced vital capacity.


Regarding the cardiac assessment, the echocardiographic assessment is important, which can show cardiac compression with alterations in the filling and emptying of the right ventricle, while showing deformations of the mitral ring, with prolapse and regurgitation of the mitral valve.


The symptoms produced in the patient are an important part of the preoperative evaluation. Symptoms, such as exercise intolerance, low endurance, and shortness of breath, are reported by the patients with pectus excavatum. Another important aspect is the cosmetic effect that this produces. It limits the normal life of some patients, because they avoid places where the chest deformity will have to be exposed, such as the beach or pools. It has been proven that patients with pectus excavatum have a lower quality of life and that the treatment statistically improves their bodily image.


Treatment


Surgical correction for pectus excavatum is recommended when the patient has one of the following criteria:


  1. 1.

    Computerized axial tomography or magnetic resonance that shows heart or lung compression with a Haller index of 3.25 or more.


     

  2. 2.

    Restrictive lung disease proven by a lung function test.


     

  3. 3.

    Heart compression with abnormalities in the mitral valve, either prolapse or regurgitation.


     

  4. 4.

    Exercise intolerance, decrease in endurance, and shortness of breath during exercise.


     

  5. 5.

    Recurrence after an open or minimally invasive surgery.


     

  6. 6.

    Cosmetic effect produced in patients.


     

The optimal correction age is between 10 and 14 years of age. In this period the chest cavity is more malleable, which allows for a lower rate of recurrence.


Today, the surgical treatments that are more widely used to correct pectus excavatum are the open technique or Ravitch procedure, and the minimally invasive repair technique or Nuss procedure. The Ravitch technique, described in 1949, consists in an open repair of the defect by a transverse inframammary incision, through which the malformed sternum and the costal cartilages are exposed. Through the anterior approach, costal cartilages are resected, preserving the perichondrium, and anterior sternal osteotomies are performed to correct the sternal depression defect. The wound is closed moving pectoral muscle flaps.


The minimally invasive surgery for pectus excavatum or Nuss procedure was described in 1998 by Dr. Donald Nuss. This technique allows the correction of the pectus excavatum without the need for a great incision in the skin or the resection of costal cartilages. In short, a lateral incision is performed in the thorax, through which, assisted by videothoracoscopy, a convex metal bar is inserted behind the sternum, which is exteriorized on the other side of the chest (Fig. 72.2). When the bar is flipped 180° the sternal defect pops up (Fig. 72.3). The bar is fixed to the ribs by stabilizers. This device is installed in the patient for 2–3 years.

../images/441522_1_En_72_Chapter/441522_1_En_72_Fig2_HTML.png

Fig. 72.2

Insertion of the retrosternal bar


../images/441522_1_En_72_Chapter/441522_1_En_72_Fig3_HTML.png

Fig. 72.3

Flipping of the retrosternal bar to pop out the sternal defect


Recently, a prospective, multicenter study was described in which the functional results were analyzed when correcting the pectus excavatum, whether by Ravitch technique or Nuss procedure. The results of this work show an important correction to Haller index and a significant improvement in the cardiac and pulmonary function tests (Table 72.2).


Table 72.2

Result of the surgical treatment of pectum excavatum




































 

Preoperative (average)


Postoperative (average)


Haller index


4.4


3.0


FVC (predicted %)


88.0


93.0


FEV 1 (predicted %)


87.0


90.0


TLC (predicted %)


94.0


100.0


VO2 during exercise (l/min)


3.18


3.50


Pulse oximetry during exercise (VO2/FC)


13.58


16.16



FVC forced vital capacity, FEV1 forced expiratory volume in 1 second, TLC total lung capacity, VO2 oxygen consumption


The complications of the surgical correction of pectus excavatum are uncommon, the most common being the displacement of the metallic devices, having to reoperate the patient to reposition the bar. Other more infrequent complications are wound infections, retrosternal hematomas, pneumothorax, hemothorax, myocardial lesions, and allergic reactions to metal. These complications tend to be more frequent after the Nuss procedure.


Pectus Carinatum


Pectus carinatum is the second most frequent congenital malformation of the costal wall. Like pectus excavatum, it is more frequent in men than in women, with a ratio of 4:1. It is more frequent to have a late consultation, because it tends to appear after age 11, worsening during puberty.


Preoperative Evaluation


Medical history and complete physical examination are necessary. The protrusion of the sternum with different morphologies will allow the classification of the malformation in its different types. Type 1 or chondrogladiolar is the one that protrudes in the gladiolus or sternal body and lower cartilages. Type 2 or chondromanubrial is less common. Here the manubrium sterni and the higher cartilages protrude. Type 3 or lateral deformities are those in which there is a unilateral protrusion or sternal rotation. There are also mixed forms. Most of the patients will not present symptoms, being mainly a cosmetic problem, which significantly influences the development of a negative body image. Some patients may report musculoskeletal pain in the thorax and epigastrium. The posteroanterior and lateral chest X-ray, and in some cases computerized tomography or magnetic resonance can be useful to have a surgical plan. Patients with a Haller index between 1.2 and 2.0 benefit from the correction of the deformity.


Treatment


Unlike pectus excavatum, the first line of treatment in pectus carinatum is the compressive therapy with orthosis according to the deformity type. In patients under 18 years of age, where the chest cavity is more malleable, the success rate varies between 65% and 80%. Dr. Marcelo Martínez-Ferro, a pediatric surgeon in Buenos Aires, developed a dynamic compression system that allows measuring the compression force electronically, with which he reports an 88% success rate (Fig. 72.4). Regarding the surgical treatment, it was initially described by Ravitch in 1952. The procedure is similar to the one for pectus excavatum, where the deformed costal cartilages are resected, keeping the perichondrium, and the sternal osteotomies are performed, depending on the type of information. Dr. Horacio Abramson, from Buenos Aires, published a paper in 2009 that described a minimally invasive technique to correct pectus carinatum. It is similar to the Nuss technique for pectus excavatum, but the bar goes through the sternum, allowing the retraction of the deformity (Fig. 72.5).

../images/441522_1_En_72_Chapter/441522_1_En_72_Fig4_HTML.png

Only gold members can continue reading. Log In or Register to continue

Nov 7, 2020 | Posted by in Uncategorized | Comments Off on Chest Cavity, and Dorsal Spine Surgery
Premium Wordpress Themes by UFO Themes