PULMONARY
FUNCTION
IN PECTUS
EXCAVATUM
George Polgar, M.D., and C. Everett Koop, M.D., Sc.D. (Med.)
Department of Physiology, Graduate School of Medicine, University of Pennsylvania, and the
Research Department and Surgical Clinic of The Children’s Hospital of Philadelphia
(Submitted November 9; accepted for publication December 4, 1962.)
This investigation was supported in part by a Public Health Service Research Career Development
Award (Number: HE-K3-9471) from the National Heart Institute, Public Health Service (Dr. Polgar).
PRESENT ADDRESS: (G.P.) The Children’s Hospital of Philadelphia, 1740 Bainbridge Street,
Phila-delphia 46, Pennsylvania.
PEDIATRICS, August 1963
I
N 1956 we expressed concern over thenumerous surgical corrections for
pee-tus excavatum in children with
physio-logical evidence or clinical symptoms of
disability.’ Nevertheless, present experience
indicates that many surgeons still advise early operations for prevention of assumed
but unproven future handicaps.
Many surgeons believe the cosmetic im-provement with its psychological benefits
justifies the surgical risk. If so, the
indica-tions as vell as the dangers should be
ac-curately stated rather than presenting
parents who must make the decision con-cerning surgery with loose predictions of
future physiological impairment.
Only 50 patients have been operated
upon in this clinic for the correction of
pectus excavatum in the past 13 years, most of whom had their operations before 1956.
The decision to operate was always based upon subjective evidence whether the mdi-cations seemed to be exercise intolerance,
severe deformity, or a progressing narrow-ing of the anterior-posterior diameter of
the thorax at the level of the xiphoid while the diameter at the manubrium remained
stationary or increased.
Cosmetic improvement was never our
sole indication for surgery, because we be-lieve the postoperative configuration of the
chest and the scar did not justify the high potential risk.
Edeiken and Wolferth’ as early as 1932 showed that in spite of displacement of the heart in pectus excavatum, electrocardio-grams exhibited no consistent electrical axis deviation. Their opinion was that no clearly
defined effect on functional capacity of the
heart existed in uncomplicated funnel
chests. Rydell and Jennings,’ working with adults with funnel chest, believed they
had seen none with serious enough
pul-monary or cardiac difficulty to justify op-eration. Evans4 concluded that patients with funnel chest and suspected heart dis-ease were usually invalids because of
mcdi-cal advice rather than true impairment of cardiac function.
Our experience has made us cautious
about relating apparent improvement in cx-ercise tolerance to corrective surgery for funnel chest. One patient with severe fun-nd chest and respiratory difficulties had
asthma, and his respiratory abnormality
seemed more related to the latter problem than to his deformity. Another child who took part in sports and strenuous exercise
after surgery was one whose preoperative difficulties were due to psychiatric with-drawal in a family where his mother de-serted an alcoholic father rather than to his thoracic defect. A dramatic change in
cx-ercise tolerance post-operatively coincided with his father’s giving up alcohol and his
remarriage to a woman who became an adequate mother to the child.
These experiences and our inability to reconcile the number of children for whom operation is recommended with the number
of adults with asymptomatic pectus
excava-tum continue to dictate a conservative operative policy for the asymptomatic pa-tient with funnel chest.
Asymptomatic patients with pectus
se-5.0 TOTAL
LUNG
CAPACITY L 8.0
3.0
2.0
4.0
80 CM
lected at random for studies of pulmonary
function. The tests of pulmonary
physi-ology reported here require patient
co-operation, and further study is
contem-plated in younger children, not old enough
to take part in the tests outlined.
SUBJECTS
Among the 12 children studied, 9 were
males and 3 were females; their average
age was 75//i 2 years, with an approximate range of 5 to 15 years. Close relatives of
four of them had similar, but usually
smaller, deformities. The time when the parents generally first noticed the abnor-mality was early in infancy or at birth.
None of the patients had a history of
exer-cisc intolerance or of respiratory or cardiac
diseases. Eight patients had been followed
clinically for periods from 2 to 8 years prior
to the lung function test. In two children
the comparison of the anterior-posterior
di-ameter of the thorax in the depth of the
funnel and at the manubrium, indicated an
increasing severity. In two cases there was
a relative improvement by the same corn-parison; in four there was no change. The grade of the deformity was assessed
clini-cally as severe, moderate, and mild,
accord-ing to the depth and angulationof the de-formity. At the time of the pulmonary
func-tion tests, it was severe in four, moderate in
seven, and mild in one case.
METHODS
Lung volumes, resting minute ventila-tion, maximal mid-expiratory flow rate, and
maximal breathing capacity were measured on a 9-liter spirometer with a two-speed
chart drive (the fast speed: 13
inch/see-ond). In combination with this a helium catharometer was used for the closed
cir-cuit equilibration method of measuring
functional residual capacity.5 The patients
breathed 10% helium in room air, with an
extra 2.5% oxygen. Oxygen was continuously supplied to the system to compensate for
oxygen consumption during the test.
Usually a single test was performed. Lung
compliance during quiet breathing was
cal-culated from simultaneous recordings of
esophageal pressure changes, transmitted from a balloon 10 cm long placed 5-10 cm above the cardia containing 1 ml of air, and of the rate of flow of air measured with a
pneumotachograph at the mouth and then
graphically integrated into volume.0 All
measurements were made with the patients in sitting position.
The results were plotted against standing height, body surface area, or actual lung
volume; they were compared with normal values by Helliesen et al., Cook et al.,8
Caro and DuBois,’ and Ferris et al.’ ‘
These authors have given the normal range for the different measurements by one or two standard errors of estimate (SEE) on
either side of the regression line for the average values; some of them defined this same range in terms of standard deviation.
$40 160
HEIGHT
Fic. 1. Relation between total lung capacity and
height in 12 children with pectus excavatum. For the meaning of arrows see text. The lines
rep-resent two standard errors of estimate above and
below the regression line for normal subjects (
100
% 50
40 #{149}
50
20
‘I
S
I .0
0.5
I00 180CM
ARTICLES
RESU LTS
The total lung capacity (Fig. 1) of only one patient was less than the lower limit
of normal, and another one was
border-line (see arrows); all the others were within
the predicted range. In those with the
small total lung capacity the residual vol-ume (Fig. 2) was also small (see arrows)
but it was normal in all the others. As a
re-sult those with smaller lungs had a normal
ratio of residual volume to total lung ca-pacity (Fig. 3, see arrows); in only one pa-tient was this ratio above normal, in
an-other one it was close to the upper limit, in all others it was normal. The measured
values for vital capacity (Fig. 4) and for
functional residual capacity (Fig. 5) were
fairly evenly distributed within the normal range.
140 160
HE 1GW?’
Fic. 2. Relation between residual volume and
height in 12 children with pectus excavatum. For
the meaning of arrows see text. The lines
repre-sent two standard errors of estimate above and
below the regression line for normal subjects (Helliesen et al.’).
I0
w-.-S
S
S S
;
$00 120 0 160 ISOGM
HEIGHT
Fic. 3. Residual volume/total lung capacity ratio versus height in 12 children with pectus
cxcava-turn. For the meaning of arrows see text. The
lines represent two standard errors of estimate
above and below the regression line for normal
sul)jeCts (Cook et a!.’).
Values for resting minute ventilation,
respiratory rate, and tidal volume were poorly reproducible, as they usually are in
this age group, and were, therefore,
cx-eluded from the evaluation of this study.
1aximal breathing capacity (Fig. 6) was normal in all patients. One boy, who was also the oldest, had a very low-normal maximal breathing capacity. The same pa-tient produced a lower than normal max-imal mid-expiratory flow rate (Fig. 7, see
arrow), while the others, except one, were within normal limits. Lung compliance,
measured in seven patients (Fig. 8), was normal in six, but in one of the patients with the relatively small lungs it was below normal (see arrow). Blood gas studies were
omitted in each case because of the nor-mal or near normal results of the other
tests.
Three patients were tested more than
once. In one, the functional residual
capac-ity was increased by about 50% but was
still within normal range following our operative procedure for correction of funnel
chest. For the next 7 months variations occurred in test results giving no clear
evaluation of the response to surgery. The
other two patients showed no change in
pulmonary function after one year, but in
one of them the total lung capacity
S
VITAL
CAPACITY
L 5.0
4.0
3.0
2.0
l.0
0.5
100 120 140
NEIGH T
FUNCTIONAL
RESIDUAL
CAPACIT L 4.0
3.0
2.0
I.0
100 120 140 160 180 CM
HEIGHT
Fic. 5. Relation between functional residual capac-ity and height in 12 children with pectus excava-turn. The lines represent two standard errors of
estimate above and below the regression line for
normal subjects (Helliesen et al.’).
S
.
I
PECTUS EXCAVATUM
plotted against body surface area and
com-pared with the results obtained by Caro
and DuBois9 on 18 normal children. The
limits in these data are given by ±1 SEE. Most of these values fall below the level
of - 1 SEE of the normal values of the
same authors when correlated with the
functional residual capacity rather than
with body surface area. There is still an
obvious correlation between flow rates
and lung volumes (Fig. 9). Considering that the measured values for functional residual capacity were within the normal
range (Fig. 5) and also that heights and
weights were in normal relationship to
each other, the explanation of the
dis-crepancy could be either that the normal values for functional residual capacity by
various authors are different or that an
in-creased turbulence in the distorted upper
airways with forced expiration and/or some
limitation of the maximal performance of the expiratory muscles caused a slight
re-,.0 ‘ I0 CM duction of maximal flow rates in these
pa-Fic. 4. Relation between vital capacity and height in 12 children with pectus excavatum. The lines
represent bvo standard errors of estimate above and below the regression line for normal subjects
(Ilelliesen et al.7).
COMMENT
The results obtained in these studies re-vealed that most of the 12 patients with pectus excavatum had no abnormalities of pulmonary function. Two children had
rel-atively small lung volumes; in one there
was evidence of some stiffening of the
lungs. The boy who had a low maximal
breathing capacity and maximal mid-expira-tory flow rate was 15 years old and, there-fore, was not likely to be less co-operative
than the rest of the group. This patient had a minimal degree of scoliosis, a rarity in
connection with pectus excavatum, but a
deformity which is likely to produce
ab-normalities of pulmonary 912,13
The results of the maximal
mid-expira-tory flow rate test deserve some comments.
MAXIMAL. Mt-EXPIRAT0RV
FL RATE
L/MII 300
200
I00
/
L UNG
COMPL lANCE
ML /CM H20 a
MAXIMAL
BREAThING
CAFC1TV L/MIN
x -#{149}- FEMALE
.- MALE
I
160
140
120
l00 eo
60 -
-40
__0 120 140 160 180
HEIGHT CM
30
I00 tients. Insufficient cooperation of the
rel-atively young patients should probably not
be excluded. The significance of the slight deviation from normal values is question-able.
The small and inconsistent abnormalities found in the 12 patients gave no objective
basis for correlating these with the degree of the deformity. Among the four children
with the most severe deformity was the
one with the scoliosis; one had slightly
de-creased lung volumes; another had a some-what increased residual volume to total lung capacity ratio. This ratio was also
high in the case with the mildest deformity. Very few data on pulmonary function in pectus excavatum have been published. Some authors report a moderate percentage
of “decreased ventilatory reserve” and “pulmonary insufficiency,”ll but others
be-lieve that “objective evidence for
cardio-respiratory involvement is usually lack-ing,”1’ or that “as a rule the cardiopulmo-nary function is generally normal or only
slightly reduced.”16
One cause for these different opinions
may be found in the report of Fink, Rivin,
and Murray,1 who suggest that some
pa-FIG. 6. Relation between maximal breathing capac-ity and height in 12 children with pectus excava-turn. For the meaning of the arrow see text. The lines represent two standard errors of estimate
above and below the regression line for males and
females respectively (Ferris et al.’#{176}h1)
, ,
“0 05 1.0 I5 2:0 N1
BSA
FIG. 7. Relation between maximal mid-expiratcry flow rate and body surface area in 12 children with pectus excavatum. For the meaning of the arrow see text. The broken lines represent one standard error of estimate above and below the regression line for normal subjects (Caro et al.’).
tients among the 27 they studied may have
an underlying lung disease which would
be the primary cause for abnormal
pul-monary functions.
120 I40 160 180CM
I HEIGHT
f
FIG. 8. Relation between lung compliance and height in seven patients with pectus excavatum. For the meaning of arrow see text. The lines rep-resent two standard errors of estimate above and below the regression line for normal subjects
/
/
/
, 200
I00
214
MAXiMAL
MIDEXPIR4TORy
FLOW RATE
L/MIN 300
I’
1.0 20 FUNCTIONAL RESIDUAL
CAPACITY
FIG. 9. Relation between maximal mid-expiratory
flow rate and functional residual capacity in 12 children with pectus excavatum. Broken lines rep-resent one standard error of estimate above and below the regression line for normal subjects
(Caro et a!.’).
In 22 patients who had no associated lung disease, their studies revealed only
slight deviations from normal data. This same factor must be taken into
considera-tio:t in the present study.
The physiologic data presented here
along with the clinical evaluations would
suggest that the asymptomatic child
prob-ably never requires surgical correction of a pectus excavatum in order to improve his respiratory function. However, the lack of
a significant malfunction of the lungs in these children at the present time should not diminish our concern about predicting how well such children with a funnel chest might fare in adult life if confronted with
acute or chronic pulmonary diseases. It is certainly true that children with a history
of repeated bouts of pneumonia may not
continue with pulmonary infection after re-pair of a pectus excavatum.
Another unpredictable factor is the effect of the gradual stiffening of the thorax with advancing age on respiratory function of
these patients. In kyphoscoliosis the chest cage rigidity which develops with older age is a late complication of the deformity.
With these reservations, the function of
thoracic organs apparently remains suf-ficiently normal to require no supposed
benefits from corrective surgery. The pos-sibility of pulmonary complications in adult life from uncorrected funnel chest in child-hood will require observation over a much
longer time.
SUMMARY
Pulmonary function studies were
essen-tially normal in 12 children with pectus excavatum. The deviations from the
pre-.-.---. dicted values were slight, inconsistent, and
3.0 L had no correlation with the degree of the deformity. These findings present no basis
for a physiological indication for corrective surgery of funnel chest. Predictions
can-not be made concerning the ability of the patient with pectus excavatum to withstand
acute or chronic pulmonary disease in later life. Prolonged follow-up studies on a group of patients such as this, as well as on a
post-operative group, would seem to be in-dicated.
REFERENCES
1. Koop, C. E. : The management of pectus excavatum. Surg. Clin. N. Amer., 36:1627, 1956.
2. Edeiken, J., and Wolferth, C. C. : The heart
in funnel chest. Amer. J. Med. Sci., 184: 445, 1932.
3. Rydell, J. R., and Jennings, W. K. : The
surgi-cal treatment of funnel chest deformity. Amer. J. Surg., 88:69, 1954.
4. Evans, W. : Heart in sternal depression. Brit.
Heart J., 8:162, 1946.
5. Meneely, G. R., and Kaltreider, N. L. : Use
of helium for determination of pulmonary
capacity. Proc. Soc. Exp. Biol. Med., 46:
266, 1941.
6. Mead, J., and Whittenberger, J. L. : Physical
properties of human lungs measured during
spontaneous respiration. J. Appl. Physiol., 5: 779, 1953.
7. Helliesen, P. J., et a!.: Studies of respiratory
physiology in children : I. Mechanics of res-piration and lung volumes in 85 normal
children 5 to 17 years of age. PIAmICs, 22:80, 1958.
8. Cook, C. D., et al.: Studies of respiratory physiology in children : 11. Lung volumes
and mechanics of respiration in M patients
with cystic fibrosis of the pancreas.
9. Caro, C. G., and DuBois, A. B. : Pulmonary
function in kyphoscoliosis. Thorax, 16:282,
1961.
10. Ferris, B. G., Jr., Whittenberger, J. L., and
Gallagher, J. R. : Maximum breathing ca-pacity and vital capacity of male children and adolescents. PEDIATRIcs, 9:659, 1952. 11. Ferris, B. C., Jr., and Smith, C. W. : Maxi-mum breathing capacity and vital capacity
in female children and adolescents.
PEDI-ATRICS, 12:341, 1953.
12. Fishman, A. P., Turino, G. M., and
Bergof-sky, E. H. : Disorders of the respiration and
circulation in subjects with deformities of
the thorax. Mod. Cone. Cardiov. Dis., 27: 449, 1958.
13. Cook, C. D., et a!.: Pulmonary physiology in children : III. Lung volumes, mechanics of
respiration and respiratory muscle strength
in scoliosis. PEDIATRICS, 25:766, 1960.
14. Welch, K. J.: Satisfactory surgical correction
of pectus excavatum deformity in child-hood.
J.
Thor. Surg., 36:697, 1958.15. Hansen, J. L., and Jacoby, 0. : The respiratory function before and following surgery in cases of funnel chest. Acta Chir. Scand., 3:226, 1956.
16. Backer, 0. G., Br#{252}nner, S., and Larsen, V.:
The surgical treatment of funnel chest: initial and follow-up results. Acta Chir. Scand., 121:253, 1961.
17. Fink, A., Rivin, A., and Murray, J. F. : Pectus excavatum : an analysis of twenty-seven cases. Arch.
mt.
Med., 108:427, 1961.Acknowledgment
The writers are indebted to Robert W. Toft,
MS., for his technical assistance.
PEDIAi-mc SURGERY, Ed. 2; Orvar Swenson, Appleton-Century-Crofts, 1962, XIV, 779 pp. $20.00.
As Dr. Swenson says in his preface, the
major change carried out in this second edition Of his textbook consists of an expanded section on heart surgery. There is a considerable dis-sertation on complete transposition of the great vessels, remarkably well illustrated, and a
con-cisc resume of malformations of the heart
which may be corrected by surgical proce-dures. Although it is undoubtedly true that this expanded section contributes something to the second edition, it is not an exhaustive coverage
of the field of cardiovascular surgery in chil-dren.
In other regards, the second edition is very much like the first, which was a highly personal
experience with pediatric surgery. It covers a broad field from instruction in knot-tying to technical details for the completion of
opera-tions on complex congenital anomalies. Any personal account such as this is understandably dogmatic, but the dogma would have been a little more palatable if the reader was informed
that there are many more ways than one to
skin a cat.
However, Swenson has presented a scope of pediatric surgery as it is encountered by one who deals exclusively in this specialty. Fur-thermore, he has added technical hints,
phi-losophies, and personal prejudices which in the
final analysis tell the reader what to do, how
to do it, and when. If this is the goal of a textbook, it has been well achieved.
The sections on megacolon and urinary tract problems are outstanding. Statistics in reference to results in general are minimal. Those who own the first edition have one of the best texts available and need not feel it must be replaced by the second, except for a broader view of cardiovascular surgery.
