title: Classification of Pectus Excavatum According to Objective Parameters From Chest Computed Tomography.
abstract: BACKGROUND
  Previous classification systems of pectus excavatum have been based on subjective morphologic characteristics. We sought to suggest a new classification system derived from objective variables.
  
  
  METHODS
  Patients who underwent surgical repair of pectus excavatum without a history of previous chest operations were included. Objective morphologic variables were measured from chest computed tomography scan images, and classification was performed by hierarchical clustering of measured indexes. Clinical relevance of the suggested classification was also verified.
  
  
  RESULTS
  Included were 230 patients who underwent operation for pectus excavatum from January 2001 to August 2013. These patients were classified into two major groups: typical (group I; 197 [85.7%]) and atypical (group II; 33 [14.3%]). Group I was further classified into three subgroups according to flatness and symmetry of the chest wall. Group II was further classified into four subgroups according to the severity of sternal torsion and sternal angulation. Two unique types of deformity were identified in group II: the double distortion subgroup (group IIa; 8 [3.5%]) and the reverse torsion subgroup (group IIc; 16 [7.0%]). Scoliosis was more frequently associated with group IIa (p = 0.008).
  
  
  CONCLUSIONS
  Morphologic classification obtained from computed tomography indexes hierarchical clustering identified seven distinct subtypes of pectus excavatum.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Dongguk University Ilsan Hospital, Goyang-si, Gyeonggi-do, Republic of Korea.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: In Kyu
authors.initials: IK
authors.lastname: Park
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Woo Sun
authors.initials: WS
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul, Republic of Korea. Electronic address: chkang@snu.ac.kr.
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Kang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D005660:Funnel Chest / Q000145:classification* / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult