A 15-year old boy is in your clinic for evaluation of pectus excavatum. The patient confesses that the deformity bothers him from a cosmetic and social viewpoint. However, he and his parents are mostly concerned that he feels shortness of breath with moderate exercise and are focused on how correction will affect his cardiopulmonary status. You tell them that the evidence suggests that they should expect

 

a improved pulmonary function testing early with regression after bar removal.

 

b improved pulmonary function testing but decreased cardiac function in the first year after operation.

 

c the most improvement in cardiopulmonary function is with an open Ravitch approach.

 

d improvement in cardiac output and exercise tolerance due to improvement in LV function.

 

e resolution of paradoxical motion of abdominal wall muscles during deep respiration.

e

E

D

D

d

correct answer

e resolution of paradoxical motion of abdominal wall muscles during deep respiration.

 

Literature has continued to focus on the cardiopulmonary effects of minimally invasive repair of pectus excavatum (MIRPE) otherwise known as the Nuss procedure. Children are typically not symptomatic until they reach adolescence. Symptoms include exercise intolerance, difficulty with endurance and shortness of breath with exercise. Improvement in exercise intolerance can be seen immediately, even with the bar in place. Improvement in pulmonary function occurs due to changes in respiratory mechanics. Using motion analysis, it has been shown that preoperatively there is paradoxical increased motion of the abdominal wall musculature during deep breathing in patients with pectus excavatum. There is also diminished movement of the upper and lower sternum. It is hypothesized that the increased abdominal wall motion is a compensatory reaction to the decreased sternal motion. These paradoxical motions were noted to resolve 6 months postoperatively and have been postulated to be the reason for improved pulmonary function testing and improved exercise tolerance.

 

Evaluation of resting pulmonary function testing has shown initial decline in the FVC and FEV1 shortly after repair with MIRPE but improvement above baseline following bar removal. Additionally, changes in pulmonary function testing has been shown to be less favorable following an open Ravitch type repair when compared to MIRPE which is felt to be due to the disruption of the costochondral cartilage with subsequent recalcification and fixation of the chest. Cardiac function has been shown to improve as soon as two weeks postoperatively in some studies using cardiovascular magnetic resonance (CMR) imaging. MIRPE improves compression of the right ventricle due to its anterior location in the chest. For those patients who have low right ventricular ejection fraction preoperatively, this relief of compression can lead to improved right ventricular function at rest. Due to the posterior location of the left ventricle, this effect is not seen in the left ventricle and studies have not shown any conclusive improvement in cardiac output or cardiac index with MIRPE.

A 15-year old boy is in your clinic for evaluation of pectus excavatum. The patient confesses that the deformity bothers him from a cosmetic and social viewpoint. However, he and his parents are mostly concerned that he feels shortness of breath with moderate exercise and are focused on how correction will affect his cardiopulmonary status. You tell them that the evidence suggests that they should expect

 

a improved pulmonary function testing early with regression after bar removal.

 

b improved pulmonary function testing but decreased cardiac function in the first year after operation.

 

c the most improvement in cardiopulmonary function is with an open Ravitch approach.

 

d improvement in cardiac output and exercise tolerance due to improvement in LV function.

 

e resolution of paradoxical motion of abdominal wall muscles during deep respiration.

E