Author Michael Armstrong1, Anupam Banerjee2, Shawn P.E. Nishi MD3 1Edward Via College of Osteopathic Medicine- Virginia Campus, Blacksburg, VA 2University of Texas Medical Branch, Galveston, TX 3Division of Pulmonary & Critical Care Medicine, University of Texas Medical Branch, Galveston, TX
Case
A 35-year-old male with a history of anxiety and depression presents
to the office with a gradual onset of worsening dyspnea on exertion and
decreased exercise tolerance. He has had trouble with this since his
teenage years, but has noted significant progression over the past 1-2
years, now associated with trouble with endurance. His symptoms are not
present at rest and he denies any cough, chest pain, or pleurisy.
Further history and physical exam led to obtaining CT imaging, which is
shown below:
Question
What is the diagnosis causing his shortness of breath?
A. Blunt trauma to the chest B. Pectus carinatum C. Pectus excavatum D. Flail chest
Answer
Answer: C. Pectus Excavatum - The CT shows a concave chest
wall deformity with cardiac displacement, most consistent with pectus
excavatum (PE).
Discussion
Pectus excavatum is a congenital abnormality of unclear etiology that
occurs in roughly 1 out of every 400 births. The typical progression
of pectus excavatum begins with minimal to no symptoms during childhood
with increasing symptoms as patients reach adolescence and become more
active in sports. Dyspnea with exercise, easy fatigability, and
decreased stamina and endurance are common complaints.1
Physical exam is usually notable for a male patient with a tall and
athletic body habitus and a slouching posture. There is a decreased
anteroposterior diameter of the chest with an anterior chest wall
concavity. Approximately half of these are asymmetric with the deeper
portion of the concavity on the right and the sternum rotated
posteriorly on the right. Tachycardia and diminished chest wall
excursion may be noted as well, secondary to the restrictive defect
caused by the thoracic abnormality.1
The evaluation of the pectus excavatum patient is done by
characterizing the severity of the deformity and assessing for any
secondary cardiopulmonary consequences. The severity is best shown by
full inspiration CT and can be defined using the Haller severity index
(also called pectus severity index – PSI), which is calculated by
dividing the inner width of the chest at its widest point by the
distance between the posterior surface of the sternum and the anterior
surface of the spine.1 Normal PSI is <=2.5. From the
measurements taken from the image below, this patient’s Haller index was
4.3. CT also has the advantage of showing the presence of cardiac
compression and displacement.
Cardiopulmonary evaluation involves using echocardiography to
evaluate for right atrial and ventricular compression, presence of
mitral valve prolapse, and stroke volume which can be compromised.
Cardiopulmonary exercise testing may also be useful and can demonstrate
decreased VO2 max due to reduced stroke volume. Pulmonary function
testing can show decreased expiratory airflow and lung volumes as a
result of compression of the thoracic cavity and poor expansion of the
chest wall.2
During the evaluation of pectus excavatum, it is also important to
consider any co-existing processes or conditions that may be present.
Two of note are primary ciliary dyskinesia (PCD) and pulmonary
non-tuberculosis mycobacterial (PNTM) disease as there is an increased
occurrence of pectus excavatum in both.3,4
Surgical management is indicated when 2 or more of the following apply:
Chest CT showing cardiac and/or pulmonary compression, and a CT index of ≥3.25.
Pulmonary function testing shows restrictive and/or obstructive lung disease.
Failure of a previous repair.2
Two popular surgical treatments are the highly modified “open”
Ravitch repair (HMRR) and the minimally invasive technique for repair of
PE (MIRPE) described by Nuss. With the HMRR, abnormal costochondral
cartilages are removed, and the sternum is fixated with a metal strut so
that the chest has a near-normal contour. The MIRPE forgoes any
cartilage resection and sternal osteotomy by placing a preformed convex
bar through bilateral incisions so that it lies under the sternum. This
bar is then turned over so that the concavity is facing posteriorly,
which raises the sternum and anterior chest wall to the desired
position. Both techniques lead to improvement in exercise tolerance,
stamina, endurance and quality of life.1 The long-term
success rate 1 year after bar removal in 903 patients who underwent
primary Nuss procedure (MIRPE) was excellent or good in 96.6% of cases.5
This patient was referred for the Nuss procedure with improvement of symptoms 1 year later.
References
Fonkalsrud EW. Current Management of Pectus Excavatum. World Journal of Surgery 2003; 27: 502-508.
Kelly RE. Pectus excavatum: historical background, clinical picture, preoperative evaluation and criteria for operation. Seminars in Pediatric Surgery 2008; 17: 181-193.
Knowles MR, Daniels LA, Davis SD, Zariwala MA, Leigh MW. Primary
Ciliary Dyskinesia: Recent Advances in Diagnostics, Genetics, and
Characterization of Clinical Disease. American Journal of Respiratory and Critical Care Medicine 2013; 188: 913-922.
Kim RD, Greenberg DE, Ehrmantraut ME, Guide SV, Ding L, Shea Y, Brown MR, Chernick M, Steagall WK, Glasgow CG, et al. Pulmonary Nontuberculous Mycobacterial Disease: Prospective Study of a Distinct Preexisting Syndrome. American Journal of Respiratory and Critical Care Medicine 2008; 178: 1066-1074.
Nuss D, Kelly RE. Indications and Technique of Nuss Procedure for Pectus Excavatum. Thoracic Surgery Clinics 2010; 20: 583-597.
