How Is Pulmonary Function and Exercise Tolerance Affected in Patients With AIS Who Have Undergone Spinal Fusion?

What Are the Effects of Posterior Corrective Surgery, With or Without Thoracoplasty, on Pulmonary Function in Adolescent Idiopathic Scoliosis? A Systematic Review and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

This study's objective is to provide a critical review of the current literature regarding the changes in pulmonary function (PF) in Adolescent idiopathic scoliosis (AIS) patients who have undergone posterior spinal fusion and instrumentation (PSF), with and without thoracoplasty (TP).

METHODS

A comprehensive search was performed using the following databases: EMBASE, PubMed, EBSCOhost (CINAHL and Medline) and OpenGrey. Our focus was on studies that compared pre-and postoperative percent-predicted values of forced vital capacity (%FVC) or forced expiratory volume in 1 second (%FEV1) in AIS patients who had undergone PSF, with and without TP, with a minimum 2-year follow-up. The risk of bias for included studies was assessed using the ROBINS-I ("Risk Of Bias In Non-randomised Studies - of Interventions") tool. Mean change scores were depicted using forest plots.

RESULTS

Fifteen studies met our inclusion criteria. The results of our analysis suggest that PSF with TP caused a significant deterioration of %FVC in individuals with moderate AIS, with no significant effect on %FEV1. It also showed a minor improvement of FEV1% in individuals with moderate AIS after PSF only, but no significant change in %FVC.

CONCLUSIONS

PSF with TP caused a significant deterioration of % FVC while PSF alone caused a minor improvement of FEV1% in individuals with moderate AIS with a minimum 2-year follow-up.

Defining "successful" treatment outcomes in adolescent idiopathic scoliosis: a scoping review

PURPOSE

Adolescent idiopathic scoliosis (AIS) is the most common type of scoliosis that affects children aged 10-18 years old, manifesting in a three-dimensional spinal deformity. This study aimed to explore outcome measures used in defining AIS treatment success. Particularly, analyzing the extent of qualitative and quantitative (radiographic and quality of life domains) measures to evaluate AIS and whether AIS treatment approaches (surgical, bracing and physiotherapy) influences outcomes used as proxies of treatment success.

METHODS

EMBASE and MEDLINE databases were used to conduct a systematic scoping review with 654 search queries. 158 papers met the inclusion criteria and were screened for data extraction. Extractable variables included: study characteristics, study participant characteristics, type of study, type of intervention approach and outcome measures.

RESULTS

All 158 studies measured quantitative outcomes. 61.38% of papers used radiographic outcomes whilst 38.62% of papers used quantitative quality of life outcomes to evaluate treatment success. Irrespective of treatment intervention utilized, the type of quantitative outcome measure recorded were similar in proportion. Moreover, of the radiographic outcome measures, the subcategory Cobb angle was predominantly used across all intervention approaches. For quantitative quality of life measures, questionnaires investigating multiple domains such as SRS were primarily used as proxies of AIS treatment success across all intervention approaches.

CONCLUSION

This study identified that no articles employed qualitative measures of describing the psychosocial implications of AIS in defining treatment success. Although quantitative measures have merit in clinical diagnoses and management, there is increasing value in using qualitative methods such as thematic analysis in guiding clinicians to develop a biopsychosocial approach for patient care.

Pulmonary function in children and adolescents with untreated idiopathic scoliosis: a systematic review with meta-regression analysis

BACKGROUND CONTEXT

One of the controversies in untreated idiopathic scoliosis is the influence of curve size on respiratory function. Whereas scoliosis patients with curves over 90 to 100 degrees are agreed to be at risk for cardiorespiratory failure in later life, the impairment of curves below 90 degrees is generally considered mild. Although various studies showed that pulmonary function is affected in patients with scoliosis, quantification of the relation between curve size and pulmonary function is lacking.

PURPOSE

This systematic review with meta-regression analysis aims to characterize the relation between pulmonary function tests and scoliosis severity in children and adolescents with idiopathic scoliosis.

STUDY DESIGN

Systematic review with meta-regression analysis.

METHODS

Pubmed, Embase, Cochrane, and CINAHL were systematically searched until November 3, 2020, for original articles that reported (1) severity of scoliosis quantified in Cobb angle, and (2) pulmonary function tests in children and adolescents with untreated idiopathic scoliosis. Exclusion criteria were other types of scoliosis, non-original data, post-treatment data, and case reports. All study designs were included, and relevant study details and patient characteristics were extracted. The primary outcome was the effect of Cobb angle on pulmonary function as expressed by the slope coefficient of a linear meta-regression analysis.

RESULTS

A total of 126 studies, including 8,723 patients, were retrieved. Meta-regression analysis revealed a statistically significant inverse relation between thoracic Cobb angle and absolute and predicted forced vital capacity in 1 second, forced vital capacity, vital capacity, and total lung capacity. For these outcomes, the slope coefficients showed a decrease of 1% of the predicted pulmonary function per 2.6 to 4.5 degrees of scoliosis. A multivariable meta-regression analysis of potential confounders (age, year of publication, and kyphosis) hardly affected the majority of the outcomes.

CONCLUSION

This meta-regression analysis of summary data (means) from 126 studies showed an inverse relationship between the thoracic Cobb angle and pulmonary function. In contrast to previous conclusions, the decline in pulmonary function appears to be gradual over the full range of Cobb angles between <20 and >120 degrees. These findings strengthen the relevance of minimizing curve progression in children with idiopathic scoliosis.

CARDIORESPIRATORY FUNCTION OF PATIENTS WITH ADOLESCENT IDIOPATHIC SCOLIOSIS

ABSTRACT Objective: Adolescent idiopathic scoliosis (AIS) is a spinal deformity that can cause cardiorespiratory dysfunction, contributing to decreases in tolerance for aerobic exercise (TAE) and in functionality. The objective is to assess the TAE and lung capacity of patients who underwent corrective AIS surgery in the pre- (PRE) and postoperative (POST) periods. Methods: Sixty individuals, PRE (n=30, age: 18.5±2.4 years) and POST (n=30, age: 24.5±4.5 years), participated in the study. The forced vital capacity (FVC), the forced expiratory volume in the first second (FEV1) and the FEV1/FVC ratio, as well as the maximum inspiratory and expiratory pressure were verified. The TAE was assessed by the distance travelled in the 6-minute walk test (6MWT), together with blood pressure, heart rate, respiratory rate and peripheral oxygen saturation measured at the beginning and at the end of the test. Results: A mild restrictive pattern in lung function and reduced expiratory muscle strength were observed in both groups, but with no difference between the PRE and POST groups. No difference was found between the PRE (534±67.1 m) and POST (541± 69.5 m) groups for the distance travelled in the 6MWT, though both were below the predicted percentage (82.8±10.0% and 84.8±10.9%, respectively). Hemodynamic and respiratory changes caused by the 6MWT were observed, except for the peripheral oxygen saturation. Conclusion: The results suggest that even after surgical correction, patients with AIS continue to have low TAE. Level of evidence III; Therapeutics Study - Investigation of Treatment Results / Case-control study.

Pulmonary Implications of Pediatric Spinal Deformities

"Pediatric spinal deformities may be associated with pulmonary complications in a patient's lifetime. A review of the diagnosis of spinal abnormalities includes classifications of scoliosis and kyphosis, correlating physical examination findings and radiographic interpretation. The natural history of untreated spine deformities is reviewed along with the associated altered pulmonary compromise. Treatment options for children affected by spinal deformities are discussed, including the relative indications, the efficacy, pros and cons of different treatment options, along with the evidence to support these. This overview of spine deformities includes research outcomes to support the care of these pediatric patients."

Does thoracoplasty adversely affect lung function in complex pediatric spine deformity? A 2-year follow-up review

STUDY DESIGN

Retrospective review of prospective multi-center cohort.

OBJECTIVE

To investigate the impact of thoracoplasty on pulmonary function at 2-year follow-up among complex pediatric spine deformity patients. Complex pediatric spine deformities may be associated with significant rib prominence causing body image concerns. Surgical correction of spine deformity may include thoracoplasty to correct the rotational prominence. Some surgeons refrain from performing thoracoplasty due to its purported negative effect on pulmonary function. There is paucity of literature on the effect of thoracoplasty on pulmonary function at 2-year follow-up in pediatric patients with complex spine deformity.

METHODS

We reviewed data of 312 patients (> 100°, with or without vertebral column resection (VCR)) or (< 100° with VCR)) from an international multicenter database. Data of 106 patients with complete radiographic and pulmonary function test (PFT) assessment with a minimum of 2-year follow-up was analyzed. Paired t test was performed to compare pre-op and 2-year PFT results. PFT comparison was stratified based on thoracoplasty status (thoracoplasty: Group 1 vs. no thoracoplasty: Group 2).

RESULTS

106 patients (61 patients Group 1 vs. 45 in Group 2). The average age and gender ratio were similar in both groups (p  >  0.05). Group 1 had significantly lower body mass index (BMI) compared to Group 2 (18.4 kg m^-2 ± 2.8 vs. 19.9 kg m^-2  ±  4.8, p  =  0.0351). The average baseline coronal and sagittal Cobbs were larger for Group 1 relative to Group 2 (p  < 0.05). The distribution of deformity etiology and curve types, and apices were similar between the two groups (p  >  0.05). The rate of pre-op utilization of halo gravity traction (HGT) was 52.5% vs. 26.7% (p  =  0.008), at an average duration of 103 days vs. 47 days, p  =  0.0001. The rate of surgical osteotomies was similar in both groups. Estimated blood volume (EBV) loss was greater in Group 1 (63.1% vs. 43.1%, p  =  0.0012). Post-op coronal and sagittal Cobb correction was similar in both groups. The incidence of post-op pulmonary complication was similar in both groups (8.2% vs. 8.9%, p  =  0.899). Baseline and 2-year follow-up PFT did not differ significantly between and within the groups. Vertebral column resection (VCR) did not negatively affect PFT in both groups.

CONCLUSION

Despite higher curve magnitudes in patients undergoing surgical correction and thoracoplasty for complex pediatric spine deformity, our findings revealed that thoracoplasty does not negatively affect pulmonary function at 2-year follow-up.

Growing-rod Graduates With Idiopathic Early-onset Scoliosis Have Comparable Exercise Tolerance to Patients With Surgically Treated Adolescent Idiopathic Scoliosis

BACKGROUND

Growing-rod (GR) treatment is the current standard for progressive idiopathic early-onset scoliosis (I-EOS) in young children. Despite good radiographic outcomes, the impact of scoliosis treatment on pulmonary functions is not well-defined in this patient population. The aim of this study was to evaluate pulmonary functions and exercise tolerance in I-EOS patients graduated from GR treatment and to compare them with age-matched, surgically treated adolescent idiopathic scoliosis (AIS) patients and healthy controls.

METHODS

Eight GR graduates with I-EOS with pulmonary function tests and complete radiographic results were compared with a group of 9 thoracic AIS patients at least 2 years out from posterior fusion. Both groups were also compared with a set of 10 healthy individuals. All subjects underwent cardiopulmonary exercise testing and spirometry to evaluate pulmonary function.

RESULTS

Age, sex, height, arm span, weight, residual deformity, and level of instrumentation in GR and AIS patients were similar. In the GR group, forced vital capacity % and forced expiratory volume in 1 second % values were reduced compared with the healthy controls and AIS group (P<0.001, <0.001 and 0.036, 0.046, respectively). Breathing reserve index at lactate threshold (BRILT) was higher in GR and AIS patients (P=0.001 and 0.002, respectively), and was similar between GR and AIS patients (P=0.916). Heart rate at lactate threshold was higher in GR and AIS groups compared with controls (P<0.001 and 0.001, respectively).

CONCLUSIONS

AIS and GR patients demonstrated reduced pulmonary reserve and exercise tolerance compared with their peers with no spinal deformity. However, exercise tolerance of I-EOS patients treated with the GR method was similar to that of operated AIS patients. These results suggest a positive impact of GR treatment in children with I-EOS.

LEVEL OF EVIDENCE

Level III-cross-sectional comparative study.

Computed tomography-based bronchial tree three-dimensional reconstruction and airway resistance evaluation in adolescent idiopathic scoliosis

PURPOSE

To investigate airway development and airway resistance by computed tomographic three-dimensional (3D) reconstruction of the bronchial tree in patients with adolescent idiopathic scoliosis (AIS). We evaluated factors predicting postoperative respiratory complications to provide timely treatment, prevent complications, and improve operative and anesthetic safety.

METHODS

From August 2015 to August 2017, 53 AIS patients with a mean age of 15.4 years (range 10-20 years) were included in this study. Scoliotic parameters on radiographs were analyzed. Airway resistance was obtained by pulmonary function testing. All patients' pulmonary bronchial trees were 3D-reconstructed via chest thin layer computed tomography to explore the correlation between the spinal-thoracic deformity parameters and airway resistance.

RESULTS

Correlations between scoliotic parameters and airway development parameters were not statistically significant (P > 0.05). The scoliotic parameters such as Cobb angle, apical vertebral translation, rotation angle to sagittal plane, rotation angle to middle line, and apical vertebral body-rib ratio (AVB-R) were positively correlated with tracheal bifurcation angle (R²: 0.429, 0.374, 0.430, 0.504, and 0.414, respectively; P < 0.05). Cobb angle, rib hump, and apical vertebral body-rib ratio (AVB-R) were positively correlated with left principal bronchus length to right principal bronchus length (PBL-R) (R²: 0.373, 0.503, and 0.377, respectively; P < 0.05). Superficial area of bronchial tree (SABT) and narrow cross section of trachea (NCT) were negatively correlated with plethysmography Pre-Ref resistance ratio (Pre/Ref) (R²: - 0.365 and - 0.452, respectively; P < 0.05). SABT and NCT were negatively correlated with respiratory impedance (Zrs) (R²: - 0.327 and - 0.436, respectively; P < 0.05).

CONCLUSIONS

Pulmonary bronchial development in patients with AIS is affected by spinal-thoracic deformity. Comprehensive assessment of preoperative pulmonary function, especially airway resistance, is necessary in patients with AIS whether the thoracic scoliosis is severe or mild-to-moderate. These slides can be retrieved under Electronic Supplementary Material.