Paediatric Respiratory Reviews 15 (2014) 246–255 Contents lists available at ScienceDirect Paediatric Respiratory Reviews CME article Chest Wall Abnormalities and their Clinical Significance in Childhood Anastassios C. Koumbourlis M.D. M.P.H.* Professor of Pediatrics, George Washington University, Chief, Pulmonary & Sleep Medicine, Children’s National Medical Center EDUCATIONAL AIMS 1. The reader will become familiar with the anatomy and physiology of the thorax 2. The reader will learn how the chest wall abnormalities affect the intrathoracic organs 3. The reader will learn the indications for surgical repair of chest wall abnormalities 4. The reader will become familiar with the controversies surrounding the outcomes of the VEPTR technique A R T I C L E I N F O S U M M A R Y Keywords: The thorax consists of the rib cage and the respiratory muscles. It houses and protects the various Thoracic cage intrathoracic organs such as the lungs, heart, vessels, esophagus, nerves etc. It also serves as the so-called Scoliosis ‘‘respiratory pump’’ that generates the movement of air into the lungs while it prevents their total collapse Pectus Excavatum during exhalation. In order to be performed these functions depend on the structural and functional Jeune Syndrome VEPTR integrity of the rib cage and of the respiratory muscles. Any condition (congenital or acquired) that may affect either one of these components is going to have serious implications on the function of the other. Furthermore, when these abnormalities occur early in life, they may affect the growth of the lungs themselves. The followingarticlereviewsthe physiology of the respiratory pump, providesa comprehensive list of conditions that affect the thorax and describes their effect(s) on lung growth and function. ß 2014 Published by Elsevier Ltd. INTRODUCTION ‘‘Chest wall abnormalities’’ refer to any abnormality that affects the normal structure and/or limit the function of the thorax. Chest The thorax comprises the upper body and it consists of multiple wall abnormalities are often referred to as chest or thoracic independent bony parts (spinal vertebrae, sternum, ribs) that form dysplasias or dystrophies. Although there is a certain overlap the rib cage, and several muscles that cover it from the outside and between these terms, in this article, dysplasia refers to abnormal separate it from the abdominal cavity. The rib cage provides the anatomic structures that result from the abnormal growth or ‘‘scaffolding’’ on which the muscles lay and connect, whereas the development of cells or tissues, and it is primarily used for bony muscles provide stabilization and movement to the rib cage. abnormalities (e.g. Spondyloepiphyseal dysplasia). The term Although, it is often viewed as just a ‘‘protective case’’ for the dystrophy is conventionally used for muscle abnormalities (e.g. various intrathoracic organs (lungs, heart, vessels, esophagus, muscular dystrophy). This article reviews in detail the common nerves etc), the thorax is in fact a dynamic apparatus (the so-called types of chest wall abnormalities and the effects they have on the ‘‘respiratory pump’’) that performs the actual function of breathing respiratory system. by, generating the movement of air in and allowing or forcing the movement of air out of the lungs). Thus, any condition that results TYPES OF CHEST WALL ABNORMALITIES in its malfunction will have significant repercussions on the function of the respiratory system and frequently on other Many of the chest wall abnormalities (especially the dysplasias) intrathoracic organs as well. are congenital but they can also develop later in life as a result of a disease (e.g. ankylosing spondylitis) or injury that can be accidental (e.g. flail chest secondary to trauma), or iatrogenic (e.g. thoracotomy). Specific genes and modes of inheritance have * Division of Pulmonary & Sleep Medicine, Children’s National Medical Center, been identified for many of the congenital dysplasias, whereas 111 Michigan Ave N.W., Washington DC 20010 Tel.: +001-202-476-3519; fax: +001-202-476-5864. others are assumed to be caused by accidental exposures. The E-mail address: [email protected]. chest wall abnormalities are either primary or part of a syndrome 1526-0542/$ – see front matter ß 2014 Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.prrv.2013.12.003 A.C. Koumbourlis / Paediatric Respiratory Reviews 15 (2014) 246–255 247 Table 1 Conditions associated with abnormalities of the thorax CONDITION THORACIC SHAPE STERNUM RIBS SPINE VERTEBRAE Aarskog syndrome PE/PC (X) (X) Achondrogenesis Small thoracic cage X Achondroplasia Small thoracic cage X Allagile Syndrome (arteriohepatic dysplasia) X X Beals syndrome X X Camptomelic Dysplasia Small thoracic cage X (X) X Cerebro-Costo-Mandibular syndrome Small thoracic cage X X Chondroectodermal dysplasia Small thoracic cage Chondroplasia punctate X (X) CHARGE syndrome (X) CHILD syndrome (X) Cleidocranial dysostosis Small thoracic cage (X) Coffin-Lowry syndrome PE/PC X X Cohen syndrome X X Diastrophic dysplasia Small thoracic cage X Down syndrome (PE/PC) (X) (X) Dyggve-Melchior-Clausen syndrome PE/PC X X Early Amnion Rupture sequence X Ehlers-Danlos syndrome (X) Escobar syndrome X (X) X Fetal Hydantoin Effects X Fetal Alcohol syndrome (X) (X) Fetal Aminopterin Effects (X) Fetal Valproate Effect (X) X Fibrochondrogenesis Small thoracic cage X Frontometaphyseal dysplasia X Generalized Gangliosidosis syndrome, Type I X (X) X Gorlin syndrome X X (X) Haldu-Cheney syndrome (X) X Homocystinuria syntrome PE/PC X Hunter syndrome X Hurler syndrome X X Hypophosphatasia Small thoracic cage Incontinentia PPigmenti syndrome X (X) Jarcho-Levin syndrome Small thoracic cage X Jeune syndrome Small thoracic cage X Klippel-Feil sequence (X) (X) X Kniest Dysplasia X X Kozlowski spondyloepiphyseal dysplasia PE/PC X Langer-Giedion syndrome X X Lenz-Majeswski hyperostosis syndrome X Lethal multiple pterygium syndrome Small thoracic cage Marfan syndrome PE/PC X (X) Marinesco-Sjogren syndrome PE/PC (X) Maroteaux-mucopolysaccharidosis X X X Melnick-Needles syndrome Small thoracic cage PE/PC X X Meningomyelocele X Metaphyseal chondrodysplasias Small thoracic cage X Metatropic Dysplasia Small thoracic cage X X Morquio syndrome X X X Mucopolysaccharidosis VII PE/PC X (X) Multiple synostosis X Multiple Lentigines syndrome PE/PC Multiple neuroma syndrome PE/PC (X) MURCS association (X) X Neurofibromatosis syndrome (X) (X) (X) Noonan syndrome PE/PC (X) (X) X Osteogenesis imperfect Small thoracic cage PE/PC X Oto-Palato-Digital syndrome (Small thoracic cage) PE/PC X X Pallister Hall syndrome (X) X Partial Trisomy 10q syndrome PE/PC X X (X) Poland anomaly X (X) Progeria syndrome (Small thoracic cage) X Proteus syndrome (X) X (X) Pseudoachondroplasia Sponyloepiphyseal dysplasia Small thoracic cage X X Pyle Metaphyseal Dysplasia X (X) X Rhizomelic Chondroplasia Punctuta X Robinow syndrome (X) X Rokitansky sequence X Rubenstein-Taybi syndrome (X) Ruvalcaba syndrome PE/PC X X Sanfilippo syndrome X X Seckel syndrome X (X) Short rib syndrome Small thoracic cage X Shprintzen syndrome (X) Shwachman syndrome Sponyloepiphyseal dysplasia congenita PE/PC X 248 A.C. Koumbourlis / Paediatric Respiratory Reviews 15 (2014) 246–255 Table 1 (Continued) CONDITION THORACIC SHAPE STERNUM RIBS SPINE VERTEBRAE Thanatophoric dysplasia Small thoracic cage X Trich-Rhino-Pharyngeal syndrome PE/PC Trisomy 8, 9, 9p Mosaic syndrome Small thoracic cage X X Trisomy 4p, 13 X X (X) Trisomy 18, 20 (X) X X Vater syndrome X X Waardenburg syndrome (X) (X) (X) Williams syndrome (PE/PC) XO, XYY, 18p, XXXXY syndromes PE/PC (X) (X) (X) Adapted from: Smith’s Recognizable Patterns of Human Malformation / Edition 5., Jones KL Elsevier Saunders, Philadelphia, PA, USA 1988 PE: Pectus Excavatum; PC: Pectus Carinatum; (X): abnormality only occasionally present Table 2 Chest wall abnormalities on each of the components of the thorax Abnormalities of the Sternum Abnormalities of the Ribs Abnormalities Abnormalities of the Muscles of the Spine Pectus Excavatum Fused ribs (e.g. Jarcho-Levin syndrome) Scoliosis Absent muscles (Poland Syndrome) Pectus Carinatum Narrow chest (e.g.Asphyxiating Thoracic Kyphosis Muscle weakness (e.g. spinal muscular atrophy) Dystrophy) Bifid Sternum Fractured ribs (e.g. Flail chest) Lordosis Defects (e.g. Congenital diaphragmatic hernia); gastroschisis) Absent ribs (e.g. resection of tumors) Abnormal vertebrae Paralysis (e.g, diaphragmatic paralysis) (Table 1). Most of the syndromes initially affect a specific spondylitis (that may cause ossification of the ligaments in the component of the thorax but because of the interrelationship spine and in the rib cage); fibrothorax (that causes fibrosis of the between the various components eventually the entire thorax may pleura that in turn limits the expansion of the rib cage), and become deformed. From a clinical standpoint the chest wall scleroderma (that limits the expansion of the rib cage due to the abnormalities can be categorized according to the part of the thickening of the skin that covers the thorax). thorax that is primarily affected (Table 2) and/or according to the causes as follows: Abdominal conditions Conditions such morbid obesity, accumulation of large amounts Congenital chest wall abnormalities of fluid or air in the peritoneal cavity (e.g. ascites or pneumoper- itoneum) or organ enlargement (e.g. significant hepatosplenome- a) Anomalies of the sternum (e.g. Pectus excavatum, bifid galy) may cause severe limitation in the function of the thorax by sternum) impeding the function of the diaphragm. Defects of the abdominal b) Anomalies of the ribs (e.g. Jarcho-Levine Syndrome) wall (e.g. gastroschisis, giant omphalocele) also impede diaphrag- c) Anomalies of the spine (e.g. Scoliosis) matic function, thus limiting the normal expansion of the thorax. d) Anomalies of the respiratory muscles (e.g. Poland syndrome, One could also include the normal pregnancy (although it neuromuscular disorders) obviously can ‘‘affect’’ only women of reproductive age) as a cause of temporary dysfunction of the thorax due to the pressure that the fetus and the amniotic sac exert on the diaphragm.