Acquired Restrictive Thoracic Dystrophy

Induced Cor Pulmonale

Hsu-Ping Wu,1 Tien-Yu Wu,1 Charles Jia-Yin Hou,1,2 Cheng-Ho Tsai1,2 and Yih-Jer Wu1,2,3

Acquired restrictive thoracic dystrophy (ARTD), a rare iatrogenic disease, is characterized by an underdeveloped

thoracic cage resulting from an inappropriate surgical correction of pectus excavatum, the most common type of

chest wall deformity. We describe a 29-year-old young man with ARTD, stemming from pectus excavatum

correction surgery in his toddler age, who developed cor pulmonale with chronic respiratory acidosis, hypoxemia,

and moderate pulmonary hypertension. His symptoms were partially ameliorated after medical treatment. Surgical

correction of the chest wall was suggested, but declined because of high mortality and morbidity rates incurred by

the operation.

Key Words: Acquired restrictive thoracic dystrophy � Cor pulmonale � Heart failure � Pectus excavatum

INTRODUCTION

Chest wall deformities may cause variable cardio-

pulmonary dysfunction, either symptomatic or asymp-

tomatic.1 Pectus excavatum is the most common chest

wall deformity, for which a variety of correction proce-

dures have been developed. However, inappropriate pro-

cedures of surgical correction for pectus excavatum may

lead to acquired restrictive thoracic dystrophy (ARTD),

which is charactized by an underdeveloped chest wall

and hypoplastic lungs.2 We describe a 29-year-old young

man who had severe chronic cor pulmonale. Through a

careful review of the medical history, physical examina-

tion, as well as the image and hemodynamic studies, we

diagnosed this rare iatrogenic disease. To our know-

ledge, this is the first case report showing severe chronic

cor pulmonale induced by ARTD at this late age.

CASE REPORT

A 29-year-old young man, a non-smoking barber,

came to our hospital with complaint of progressive short-

ness of breath, severe dyspnea on exertion (~50 m by

walking) and leg edema for at least 3 months. In addition,

he also had progressive orthopnea, paroxysmal nocturnal

dyspnea, and cough with blood-tinged sputum. Tracing

back his history, we found that mild dyspnea on exertion

off and on had been noticed for more than 10 years.

On admission, the patient had a body temperature of

37.5 �C, a pulse rate of 100 beats/min, a respiratory rate

of 20/minute, and a blood pressure of 129/87 mmHg.

His heart sound yielded grade 3 holo-systolic murmur at

the left lower sternal border. Both jugular veins were

found engorged, with obvious pitting edema on both

lower legs. On his lower chest, there was a surgical scar

caused by the surgery for correcting pectus excavatum

when he was a toddler. Additionally, his chest cage

seemed obviously small and underdeveloped (Figure 1A).

Acta Cardiol Sin 2010;26:132�5 132

ARTD Induced Cor PulmonaleCase Report Acta Cardiol Sin 2010;26:132�5

Received: November 9, 2009 Accepted: February 9, 20101Cardiovascular Medicine, Department of Internal Medicine, Mackay

Memorial Hospital; 2Department of Medicine, Mackay Medical

College, and Mackay Medicine, Nursing and Management College,

and Taipei Medical University; 3Institute of Traditional Medicine,

National Yang-Ming University, Taipei, Taiwan.

Address correspondence and reprint requests to: Dr. Yih-Jer Wu,

Cardiovascular Medicine, Department of Internal Medicine, Mackay

Memorial Hospital, No. 92, Sec. 2, Chung-Shan North Road, Taipei

10449, Taiwan. Tel: 886-2-2543-3535 ext. 2456; Fax: 886-2-2543-

3535 ext. 3238; E-mail: jacobyjwu@ms1.mmh.org.tw

Chest film (Figure 1B) revealed cardiomegaly and

pulmonary congestion. The twelve-lead ECG (Figure

1C) showed normal sinus rhythm with right ventricular

(RV) hypertrophy and a right-deviated cardiac axis.

Echocardiography demonstrated RV enlargement and

moderate pulmonary hypertension (68-75 mmHg) with

paradoxical interventricular septal wall motion. How-

ever, the ventilation-perfusion scan excluded the pre-

sence of unmatched defect.

To elucidate the cause of right heart failure and pul-

monary hypertension, cardiac catheterization was ar-

ranged. Left ventriculography exhibited normal left ven-

tricular (LV) systolic function (LV ejection fraction:

79%) with a normal LV end-diastolic pressure (14

mmHg). LV and aortic blood O2 saturation (SaO2) was

only 78%, and the patient’s arterial blood gas in room air

showed severe hypoxemia (PaO2 39 mmHg), and hyper-

capnia (PaCO2 59 mmHg) with metabolic compensation

(HCO3 34 mmol/l). His hemoglobin level was up to 17

g/dL, implying that the hypoxemia was a chronic pro-

cess. Data of right-side cardiac catheterization demon-

strated a significantly elevated main pulmonary arterial

pressure [60/38, 45 mmHg (systolic/diastolic, mean

pressure)] with a prominent reduction of oxygen satura-

tion (48.5%). All other data were consistent with fea-

tures of cor pulmonale, and no obvious intra-cardiac or

extra-cardiac shunt was noticed. There was also a de-

crease of cardiac index (1.63 L/min/m2) with promi-

nently elevated pulmonary vascular resistance (12.8

Wood units). No evidence of proximal pulmonary embo-

lism, pulmonary artery stenosis, pulmonary vein stricture

or stensosis could be found by pulmonary angiography.

Suspecting cor pulmonale from cardiac catheter-

ization, we further looked into whether there was lung

parenchymal disease. High-resolution chest computed

tomography demonstrated a small and flattened thoracic

cage with dilated RV and pulmonary trunks. There was

neither lung fibrosis nor other lung parenchymal dis-

eases (Figure 2A). Also, the heart was significantly com-

pressed by the narrowed chest wall, with a Haller sever-

ity index ratio (= transverse thoracic distance/sterno-

vertebral distance) up to 3.97 (normal value: < 2.5) (Fig-

ure 2B). Pulmonary function test revealed a striking re-

duction of functional vital capacity (FVC) (0.71 L, 17%

133 Acta Cardiol Sin 2010;26:132�5

ARTD Induced Cor Pulmonale

Figure 1. (A) The appearance of this 29-year-old young man’s chest wall deformity and his surgical scar; (B) Chest radiography shows marked

cardiomegaly; (C) Twelve-lead ECG shows right-axis deviation, precordial leads poor R wave progression.

A

B

C

predicted), forced expiratory volume in the first second

(FEV1) (0.41 L, 12% predicted), FEV1/FVC (58%),

forced expiratory flow, mid-expiratory phase (FEF

25-75%) (0.17 L/S, 4% predicted), total lung capacity

(1.88 L, 33% predicted and functional residual capacity

(1.31 L, 39%). This data indicated a significant reduc-

tion of lung volume with combined severe obstructive

and restrictive lung disease. Taken together, all evidence

pointed to the diagnosis of acquired restrictive thoracic

dystrophy (ARTD) with severe chronic cor pulmonale.

The patient was treated with water and salt restric-

tion, diuretics and bronchodilators during admission. Clini-

cal condition was partially improved afterwards. Al-

though surgical correction was one option for the further

treatment, there was no strong evidence supporting that the

surgery would be the treatment of choice. On the contrary,

there was report showing rapid deterioration of cardio-

pulmonary function after surgery for pectus excavatum.3

and surgery per se also has high mortality and morbidity

rates because of the poor cardiopulmonary functions.

Our patient declined any surgical intervention. He was

discharged after his clinical condition was stabilized,

and was regularly followed up in our outpatient clinic.

DISCUSSION

Pectus excavatum results in variable cardiopulmonary

function limitation.4 It is one of the most common con-

genital chest wall anomalies, occurring in approximately

1 in every 700 births.4 The laboratory and clinical fea-

tures of our case demonstrated similar findings. However,

this patient had a unique feature: that the chest wall

deformity resulted from previous correction surgery for

pectus excavatum in his early age. On chest film, this

chest wall deformity has been described as “like the

rib-cage of a dog”5 (see Figure 1B). This acquired chest

wall deformity, which was previously named “acquired

Jeune’s syndrome” or “restrictive lung disease”,3 is some-

times not easily discernible from other congenital chest

wall deformities. Recent studies described the disease us-

ing a more comprehensive term “acquired restrictive tho-

racic dystrophy”, or “ARTD” for short.2

ARTD is a rare iatrogenic disease resulting from

faulty surgical correction techniques that removes the

growth plates from the rib cartilage, and thus, freezes the

subsequent chest wall development.5 Although some au-

thors had also pointed out that the age of surgery was

crucial for the development of ARTD,3 a more recent re-

port suggests that the cause of ARTD is not that the op-

eration is performed at an early age, but that inappro-

priate surgical technique was performed.5

The Ravitch technique or its modifications for

pectus deformities correction had been generally per-

formed by different surgeons for decades. One of the

major concepts of Ravitch technique is deformed carti-

lages resection. However, too-large segment of cartilage

resection often damages perichondrial sheaths and even

interfere with rib growth plates, which further causes ei-

Acta Cardiol Sin 2010;26:132�5 134

Hsu-Ping Wu et al.

Figure 2. (A) Chest CT shows neither lung fibrosis nor other lung

parenchymal disease, but markedly dilated pulmonary trunk. (B)

reduction of sternovertebral distance, RV compressed by sternum.

Calculated sternovertebral distance is 4.59 cm internal transverse

thoracic distance is 18.22 cm. Haller severity index ratio is 3.97.

A

B

ther unstable chest or depressed chest wall development

(such as ARTD).6 Recently developed minimally inva-

sive repair for pectus excavatum, the Nuss technique,

has become more widely accepted and provides excel-

lent outcomes. There is no need to resect rib cartilage or

perform sternal osteotomy in the Nuss technique, theo-

retically minimizing the occurrence of ARTD.7 To pre-

vent occurrence of ARTD, any surgical procedures

should avoid radical subperichondrial resection of the

cartilage, extirpation of growth centers, and suturing to-

gether of the perichondrial strips retrosternally, as de-

scribed by Robicsek et al.5

Some ARTD patients may also have recurrence of

the pectus excavatum.5 In this case report, a prominently

increased Haller index (= internal transverse thoracic

distance/sternovertebral distance) (Figure 2B), which

reached the range (= 3.97; normal value: < 2.5) for the

diagnosis of pectus excavatum,3 was also found, in addi-

tion to an underdeveloped chest cage.

Serial studies were needed to figure out the final

diagnosis in our case. Firstly, marked cardiomegaly and

desaturated arterial blood with a widened alveolar-arterial

oxygen gradient (A-a DO2 = 29.85 mmHg) may suggest

the existence of congestive heart failure. A normal LV sys-

tolic function with a relatively clear lung field excluded the

possibility of LV failure related dyspnea. Secondly, an en-

larged RV with moderate pulmonary hypertension and

paradoxical movement of interventricular septum, raised

the possibility of lung parenchyma, pulmonary artery, or

shunting disorder related RV failure. Pulmonary embo-

lism and shunting were excluded by ventilation-perfusion

scan of lung and cardiac catheterization, respectively. Other

studies for collagen disease related pulmonary hyperten-

sion, such as antinuclear antibody, rheumatoid factor and

anti-neutrophil cytoplasmic antibody, all turned out to be

normal. High resolution chest CT also showed absence

of lung parenchymal abnormality. Lastly, the bizarrely

small chest cage from the appearance and the chest CT,

the unique scar suggestive of a previous extensive resec-

tion of rib cartilage, together with an evidence of severe

restrictive lung disease from the pulmonary function

test, lead us to the final diagnosis of ARTD.

Although ARTD or pectus excavatum basically re-

sults in a restrictive lung disease, it may be sometimes

complicated with an obstructive lung disease, perhaps

caused by repeated lower airway infections or inflamma-

tion.7 Our case was also reported to have an obstructive

lung disease, in addition to prominent features of restric-

tive lung disease. This was the reason why bronchodila-

tors seemed helpful in the treatment of our patient.

Although chest wall deformity is not uncommon, se-

vere cor pulmonale is still a very rare consequence.8

Symptomatic treatments may include water/salt restric-

tion and diuretics. Whether surgical treatment at this late

stage would result in a better clinical outcome is still an

issue of debate from currently available evidence.4,9,10

In summary, we have reported a rare iatrogenic dis-

ease, ARTD, which induced severe chronic cor pul-

monale and hypoxemia. Even though patient’s symp-

toms were temporarily ameliorated after treatment, the

long-term prognosis was still very poor. This case report

alerts us that a more prudential and careful evaluation

before the surgical correction for pectus excavatum is

essential to avoid this iatrogenic disaster.

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135 Acta Cardiol Sin 2010;26:132�5

ARTD Induced Cor Pulmonale