Secondary Thoracic Insufficiency Syndrome in None Ambulatory Myelodisplastic Children

Authors

Norman Ramirez MD Pablo Valentin BS Frances M. Rodriguez BS/ RT Francisco Jaume MD Axel Velez MD Ivan Iriarte MD John Flynn MD ( Deceased)

Introduction None ambulatory children with myelodysplasia develop

progressive neuromuscular scoliosis at an early age.

This early onset scoliosis affect lung growth and normal respiration.

They develop Secondary Thoracic Insufficiency Syndrome due the diaphragms is forced cephalad by the collapsing spinal deformity and short trunk.

The natural history of Secondary TIS has never been described

Purpose

To evaluate the spine and chest anatomy of early onset scoliosis in myelodysplastic none ambulatory patients.

Determine how the chest wall mechanics and lung function are affected

Describe the natural history of Secondary TIS

Methods and Material 31 Myelodisplastic None Ambulatory patients were

evaluated

Demographic History and physical examination Radiographs CT scans Pulmonary function test Arterial blood gases Echocardiogram

Results 15 male/ 16 female Two patients currently deceased due to respiratory

failures Average age : 14.6 years ( range : 5 – 27 years) Body Mass Index : 18 ( range : 8 to 33 ) Respiratory problems: Snoring :

17 pts

Mouth breathing: 21 pts

Cessant Breathing: 9 pts

Insomnia : 7 pts

Somnolence: 7 pts

Radiographs

Scoliosis Level : Mostly T8 to Pelvis

Cobb Angle: AP

Supine: 30°

Sitting : 40°

Sitting push up: 29°

Lateral : Kyphosis Lordosis

Sitting : 35° 75°

Radiographs

Space available for the Lung (SAL) : 85%

Thoracic Spine Height : Sitting 18 cm

Sitting Push up 19 cm

Supine traction 20 cm

Lumbar Spine Height: Sitting 9 cm

Sitting Push up 12 cm

Supine traction 10 cm

Ct Scan

Thoracic Spine Height: 19 cm Expected: 28 cm Lumbar Spine Height: 11 cm Expected: 18 cm

Lung Volume 1376 cm3

Expected Lung Volume ( Age/Gender) 3195 cm3

Lung Volume/ Expected Lung Volume: 43 %

Pulmonary Function Test

Forced Vital Capacity %: 56

Forced Expiratory Volume 1 %: 55

FEV1/ FVC Ratio: 112

Blood gases/ Echocardiogram

Blood Gases : PO2 : 99

PCO2: 35

HCO3: 25

Echocardiogram: No evidence of pulmonary hypertension

Conclusions This the first study to validate the entity named

Secondary TIS

In none ambulatory myelodysplastic patients the progressive spine deformity causes Secondary TIS

At early age the respiratory dysfunction can be difficult to detect clinically

The most important factor was the sagittal spine deformity.