Pulmonary Function Testing in Children

Management of Thoracic Insufficiency Syndrome in Patients With Jeune Syndrome Using the 70 mm Radius Vertical Expandable Prosthetic Titanium Rib

BACKGROUND

Jeune syndrome (JS) often results in lethal thoracic insufficiency syndrome. Since 1991, vertical expandable prosthetic titanium rib Dynamic PosteroLateral Expansion Thoracoplasty was used at our institution for treatment of JS. This study assesses the safety and efficacy of this procedure.

METHODS

Twenty-four JS patients were treated, 2 lost to follow-up, 17 with a minimum of 2-year follow-up retrospectively reviewed for clinical course: Assisted Ventilation Rate, respiratory rate, capillary blood gases, pulmonary function testings, and complications. Upright anteroposterior/lateral radiographs were measured for Cobb angle, kyphosis, lordosis, thoracic width, and thoracic/lumbar spinal height. Computed tomography scan lung volumes were obtained in 12 patients.

RESULTS

Mean age at initial implant was 23 months (7 to 62 mo) with an average 8.4 years (2.3 to 15.6 y) of follow-up. Average chest width increased from 121 to 168 mm at follow-up (P<0.001). Preoperatively, 7/17 (41%) patients had scoliosis. The remainder developed scoliosis during treatment, 8 requiring additional implants. Thoracic and lumbar spinal height was normal preoperatively and stayed normal during treatment. Thoracic kyphosis/lumbar lordosis was stable. Average computed tomography scan total lung volumes increased 484 to 740 mm3 (P<0.001), and Assisted Ventilation Rate status tended to improve (P=0.07). Average forced vital capacity was 34% predicted at first test and 27% predicted at last follow-up. Early demise after surgery was common with multisystem disease. Mean respiratory rate decreased from 35 to 24 bpm at last follow-up (P<0.05). Survival rate of the 22 patients was 68%. Migration of the rib cradles/titanium slings occurred in 12 patients, superficial infections in 5 patients, deep infections in 4 patients, and wound dehiscence in 5 patients. Infection rate was 4.6% per procedure.

CONCLUSIONS

The survival rate in JS with surgery was nearly 70% (compared with 70% to 80% mortality without treatment) with less ventilator dependence. Both C1 stenosis and scoliosis are common in JS. Spinal height in JS is normal. Complications are frequent, but tolerable in view of the clinical gains and increase in survival.

Anatomy and assessment of the pediatric airway

Airway and respiratory complications are the most common causes of morbidity during general anesthesia in children. The airway changes in size, shape and position throughout its development from the neonate to the adult (1). Knowledge of the functional anatomy of the airway in children forms the basis of understanding the pathological conditions that may occur. This in turn allows a comprehensive assessment of the pediatric airway to take place, including a detailed medical history, clinical examination and specific investigative procedures.

[Selective dorsal T1-T6 fusion of the thoracic spine and effects on thorax growth: experimental study in prepuberal New Zealand White rabbits]

PURPOSE OF THE STUDY

The purpose of this study is to assess the consequences brought by selective dorsal arthrodesis of thoracic spine (T1-T6) to the growth of spine and thoracic volume in operated and sham-operated New Zealand White rabbits, between prepubertal age and the end of somatic growth, through the study of computerised tomography (CT) scans periodically carried out on them after arthrodesis surgery.

MATERIAL AND METHODS

Nine female rabbits were subjected to surgery for selective dorsal arthrodesis of the upper thoracic spine and three were sham-operated. Surgery was performed at age nine weeks, before the onset of puberty. Two "C"-shaped titanium bars were placed beside the spinous processes of the thoracic vertebrae to obtain a selective posterior arthrodesis of the first six thoracic vertebrae. Under general anesthesia, three CT scans were performed, 10 (t1), 55 (t2) and 139 (t3) days after surgery. Measures were obtained by Myrian Pro software for three different groups: group 1 with complete fusion, group 2 with incomplete fusion, group 3 sham-operated.

RESULTS

The total dorsal and ventral lengths of thoracic vertebral bodies in the spinal segment T1-T6 was smaller in group 1 and group 2 than in group 3, whereas no differences were observed between the three groups in the T7-T12 segment. The average of the dorsoventral/laterolateral thoracic diameter ratio at fused levels was less than 1 in group 1 as well as in group 2; on the contrary, in group 3 it was greater than 1. The sternum and lung volume grow less.

CONCLUSIONS

Vertebral arthrodesis in the treatment of progressive idiopathic scoliosis in prepubertal patients is not ideal, but is still a choice in treating major deformities of the spine. Postoperative assessment of spinal deformity is essential, feasible and recordable through CT scans. Dorsal arthrodesis in prepubertal rabbits changes thoracic growth patterns. In operated rabbits, the dorsoventral thoracic diameter grows more slowly than the laterolateral thoracic diameter. The sternum, the total lengths of thoracic vertebral bodies in the spinal segment T1-T6 and lungs grow less. The Crankshaft phenomenon is evident at the fused vertebral levels where there is a reduction of thoracic kyphosis.

Dorsal arthrodesis of thoracic spine and effects on thorax growth in prepubertal New Zealand white rabbits

STUDY DESIGN

Dorsal arthrodesis of thoracic spine in a prepubertal New Zealand White rabbit model.

OBJECTIVE

Evaluating the consequences of dorsal arthrodesis on the growth of the spine, sternum, and thorax in prepubertal rabbits, through the study of CT scans.

SUMMARY OF BACKGROUND DATA

Vertebral arthrodesis in the treatment of progressive idiopathic scoliosis in prepubertal patients is not ideal, but is still a choice in treating major deformities of the spine. Postoperative assessment of spinal deformity is essential, feasible, and recordable through CT scans.

METHODS

Twelve female rabbits, 9 weeks old, were subjected to surgery for dorsal arthrodesis of the upper thoracic spine. Surgery involved the implant of 2 "C"-shaped titanium bars, which were placed beside the spinous processes of the thoracic vertebrae. Three CT scans were performed, 10 (T1), 55 (T2), and 139 (T3) days after surgery. Measures were obtained by Myrian Pro software for 3 different groups: G1 with complete fusion, G2 with incomplete fusion, and G3 sham-operated.

RESULTS

The average of the dorsoventral/laterolateral thoracic diameter ratio at fused levels is lower than 1 in G1 as well as in G2; on the contrary, in G3 is higher than 1. The average growth of the sternum length between T1 and T2 and between T2 and T3 is minor in G1 than in G2 and G3. The dorsal and ventral lengths of thoracic vertebral bodies in the spinal segment D1-D6 is smaller in G1 and G2 than in G3, whereas no differences were observed between the 3 groups in the D7-D12 segment without arthrodesis.

CONCLUSION

Dorsal arthrodesis in prepubertal rabbits changes thoracic growth patterns. In operated rabbits, the dorsoventral thoracic diameter grows more slowly than the laterolateral thoracic diameter. The sternum as well as the lengths of thoracic vertebral bodies in the spinal segment D1-D6 grow less. The crankshaft phenomenon is evident at the fused vertebral levels where there is a reduction of thoracic kyphosis.

The volume of lung parenchyma as a function of age: a review of 1050 normal CT scans of the chest with three-dimensional volumetric reconstruction of the pulmonary system

STUDY DESIGN

An Institutional Review Board-approved retrospective review of 3400 sequential CT scans of the thorax obtained at a single institution over a 3-year period from 2000 to 2003 was performed.

OBJECTIVES

We determined values for the volume of the right lung, left lung, and total lung volume and plot these data as a function of age and sex.

SUMMARY OF BACKGROUND DATA

To our knowledge, no normative data on CT determined lung volume as a function of age have been published.

METHODS

All examinations with a report of a normal CT scan of the chest (1050 examinations) were identified. The volume of lung parenchyma in each normal examination was determined by performing a three-dimensional reconstruction of the pulmonary system.

RESULTS

Predicted increases in pulmonary volume with age for the third to 97th percentiles of male and female children were calculated.

CONCLUSIONS

Normal values for the volume of lung parenchyma as a function of age and sex increase the clinical utility of a standard CT scan of the thorax in evaluating children with complex spinal deformities. They are a useful adjunct to pulmonary function testing. These data can be used in the pre- and postoperative evaluation of patients who are at risk of thoracic insufficiency syndrome, particularly in patients younger than 5 years of age, when standard pulmonary function testing cannot be accomplished. The effects of nonoperative treatment, early spinal fusion, and new techniques for the fusionless management of spinal deformity on lung volume can be quantified and compared to normal values.

Pulmonary function for pectus excavatum at long-term follow-up

PURPOSE

The aim of this article was to assess whether and to what extent pulmonary function recovered to normal degree postoperatively and to investigate the changes in pulmonary function after surgical correction and the value of surgical correction.

METHODS

A total of 27 patients who could be questioned and examined in person at the outpatient department of our hospital were included in this study. Of these patents, 24 were boys and 3 were girls. Their ages ranged from 3 to 16 years (mean, 8.67) at follow-up. The mean age at surgery was 4 years, and mean years of follow-up was 6.8. Pulmonary functional measurements included in vital capacity (VC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV-TLC ratio, maximal voluntary ventilation (MVV), force ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal midexpiratory flow curve (MMEF), maximal expiratory flow in 75% vital capacity (V75), maximal expiratory flow in 50% vital capacity (V50), maximal expiratory flow in 25% vital capacity (V25), and breathing reserve ratio (BR).

RESULTS

TLC, FRC, MVV, MMEF, V75, and V50 values were not different from the normal values. IVC, FVC, FEV1, and V25 values were decreased significantly compared with the normal values. The RV and RV-TLC were high in 87.5% cases.

CONCLUSIONS

Preoperative symptoms obviously improved after operation. There was little airway obstruction in the patients postoperatively. The patients with pectus excavatum should be operated on as soon as possible.

Pulmonary function and respiratory morbidity in school-age children born prematurely and ventilated for neonatal respiratory insufficiency

We examined 72 children aged 6-9 years to assess the effects of prematurity and ventilator treatment on subsequent lung function and respiratory morbidity. The preterm study group (n = 42) was divided into children with a history of bronchopulmonary dysplasia (BPD) (n = 10), children who had had neonatal respiratory treatment but no BPD (n = 19), and children without severe neonatal respiratory problems (n = 13). The BPD children as a group had markedly lower specific airway conductance and larger residual volume than did the full-term control group, but there were no significant differences in spirometric measurements. The BPD group also had higher respiratory morbidity requiring hospitalizations, particularly during the first 2 years of life, than did the children in the other study groups. Therefore, BPD may improve but does not disappear as age increases. Non-BPD children who had had ventilator treatment as neonates recovered well and suffered no severe respiratory problems after infancy. Pulmonary function parameters in prematurely born children without neonatal ventilator treatment did not differ from those in the full-term control group. Thus, neonatal lung disease seems to be a more important determinant of abnormal pulmonary function at a later age than is prematurity alone.