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767.e2 Pectus Excavatum

Pectus Excavatum
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• Cardiovascular auscultation sometimes reveals
BASIC INFORMATION
Treatment of comorbid conditions (e.g., respira-
○ Muffled heart sounds be sufficient, particularly in young patients.
Definition ○ Heart murmur tory infections) and ensuring adequate nutrition
Dorsal deviation of the sternebrae (usually • Severely affected animals may demonstrate are critical for case management.
caudal), results in dorsoventral compression failure to thrive compared with unaffected
of the thorax ± malpositioning/compression littermates. Acute General Treatment
of the heart and lungs. Clinical signs, if • Treatment for patients presenting in respira-
present, develop due to restricted ventilation Etiology and Pathophysiology tory distress (p. 879)
and cardiovascular compression. Cause is not well established; current theories • Treat comorbid conditions if identified (e.g.,
include congestive heart failure [p. 408], bacterial
Synonyms • Shortening of central tendon of the pneumonia [p. 795]).
Chondrosternal depression, funnel chest, diaphragm
sunken chest, Cobbler’s chest • Failure of osteogenesis/chondrogenesis Chronic Treatment
• Thickening of the cranial diaphragm and Treatment depends on the severity of disease:
Epidemiology substernal ligament • Asymptomatic patients: no treatment
SPECIES, AGE, SEX • Arrested sternal development necessary
• Cats > dogs • Chronic upper airway obstruction (acquired) • Mild clinical signs: external compressive
• No sex predisposition splinting or manual lateral-medial chest com-
• Most commonly a congenital defect, although DIAGNOSIS pressions may help improve conformation
clinical disease may not develop until later until animal reaches maturity (≈9 months).
in life (e.g., congestive heart failure [CHF]) Diagnostic Overview • Moderate to severe clinical signs: surgical
• Acquired form can be seen secondary to Diagnosis is based on physical exam. Changes correction may benefit patients with moder-
chronic upper airway obstruction at any age. noted on thoracic imaging can be used in several ate to severe clinical signs associated with
grading schemes (e.g., frontosaggital index pectus excavatum. Correction in animals <
GENETICS, BREED PREDISPOSITION [FSI], Backer ratio, Haller index, vertebral 4 months of age is associated with a more
Littermates are often affected, suggesting index). Scales developed to classify the degree favorable prognosis. A minimal surgical age
heritability; 37% of individuals with pectus of deformity typically involve evaluation of the of 8 weeks is recommended. These patients
excavatum have a first-degree family member distance between the sternum and spine. should be referred to a specialty center
with the disorder. Autosomal recessive pectus to address complications associated with
excavatum has been reported in a litter of setter- Differential Diagnosis pediatric thoracic surgery (e.g., hypothermia,
cross puppies. Burmese cats and brachycephalic • Trauma hypoglycemia, and need for positive pressure
dogs are predisposed. • Cardiac disease ventilation).
• Differentials for paradoxical breathing:
ASSOCIATED DISORDERS pleural effusion (p. 791), diaphragmatic Nutrition/Diet
• Cardiomegaly paralysis, upper airway obstruction An adequate plan of nutrition may improve
• Brachycephalic airway syndrome (e.g., • Other causes of respiratory distress (p. 879) surgical candidacy and overall outcome.
hypoplastic trachea)
• Swimmer’s syndrome: commonly presenting Initial Database Possible Complications
between 4 weeks and 3 months of age Thoracic radiographs: • Nonsurgical complications: persistent sternal
• Mucopolysaccharidosis (single case report) • Dorsal sternal deviation ± malpositioning of defects (with associated clinical signs), hair
• Recurrent respiratory infections (e.g., the cardiac silhouette and decreased thoracic loss and abrasions from external splinting
pneumonia) volume • Surgical complications: hemorrhage (damage
• Heart murmurs (usually systolic) • Cardiomegaly: may be real or artifactual to intrathoracic vessels), wound dehiscence,
• Other congenital defects secondary to malpositioning of the cardiac infection, re-expansion pulmonary edema,
silhouette pneumothorax, anesthetic complications
Clinical Presentation • Opacity in right lung field (may be mistaken
Clinical sings vary. Severity of anatomic for infiltrative process) Recommended Monitoring
abnormalities and severity of clinical signs are • Postoperative monitoring for hemorrhage,
not well correlated. Advanced or Confirmatory Testing pulmonary edema, pneumothorax
• Echocardiography: required to identify ○ Packed cell volume (PCV) and total
HISTORY, CHIEF COMPLAINT concurrent cardiac disease solids (TS), respiratory rate and effort,
• Pectus excavatum is often an incidental • Thoracic computerized tomography (CT): auscultation closely monitored in hospital
finding with no associated clinical signs. surgical planning, Haller index
• Exercise intolerance, cough, vomiting, • Pulmonary function testing (rarely PROGNOSIS & OUTCOME
poor appetite, weight loss, hyperpnoea, performed)
and recurrent respiratory infections have • Prognosis varies with severity of clinical
all been reported. TREATMENT signs and presence of comorbid conditions.
Asymptomatic or mildly affected without
PHYSICAL EXAM FINDINGS Treatment Overview other congenital defects or comorbid condi-
• Defect of the caudal sternum with dorsal Surgery is the treatment of choice for severely tions have a good to excellent prognosis.
concavity (by definition) affected animals. For asymptomatic patients, • Patients with clinical signs but without
• Tachypnea with inspiratory or paradoxical treatment is not necessary. For mildly affected other defects have a good prognosis with
effort may be appreciated. animals, symptomatic and supportive care may early surgery.

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