Incidence, prevalence, and pattern of medical service utilization of children's rare lung diseases in South Korea.

INTRODUCTION: Children's rare lung diseases are a heterogeneous group of rare lung diseases with significant morbidity and mortality. There is very limited information on the incidence and prevalence of children's rare lung diseases in Asia. We investigated the nationwide incidence, prevalence, and pattern of medical service utilization of children's rare lung diseases in Korea. METHODS: We studied patients who were diagnosed with rare lung diseases coded per International Statistical Classification of Diseases and Related Health Problems, 10th Edition and registered in the national rare diseases database of confirmed patients. Data was extracted from the Korean National Health Insurance Service Claims database over 2019-2021. RESULTS: Average incidence rate was 12.9 new cases per million children per year, and average prevalence rate was 60.2 cases per million children during the study period of 2019-2021. We found that more than 65% of new cases were diagnosed before 2 years of age. ChILD, primary ciliary dyskinesia, and cystic fibrosis were usually diagnosed after 6 years of age. Congenital airway and lung anomalies were often diagnosed before 2 years of age. Busan and Gyeongsangnam-do residents tended to visit hospitals near their place of residence, while residents of other areas tended to visit hospitals in Seoul regardless of their area of residence. CONCLUSIONS: We examined the epidemiology of rare lung diseases in children in South Korea. Our estimation of the incidence and prevalence could be used for sustainable health care and equitable distribution of health care resources.

Evidence-based management guidelines for noncystic fibrosis bronchiectasis in children and adolescents.

Noncystic fibrosis bronchiectasis is a chronic respiratory disease that carries high socioeconomic and medical burdens and is caused by diverse respiratory illnesses. To improve clinical outcomes, early recognition, active treatment of exacerbations, and prevention of further exacerbations are essential. However, evidence for the treatment and prevention of acute exacerbation of noncystic fibrosis bronchiectasis, especially in children, is lacking. Therefore, the evidence- and consensus-based guidelines for medical and nonmedical treatment strategies for noncystic fibrosis bronchiectasis in children and adolescents were developed by the Korean Academy of Pediatric Allergy and Respiratory Disease using the methods recommended by the Grading of Recommendations Assessment, Development, and Evaluation working group with evidence published through July 2, 2020. This guideline encompasses evidence-based treatment recommendations as well as expert opinions, addressing crucial aspects of the treatment and management of non-cystic fibrosis bronchiectasis in children. This includes considerations for antibiotics and airway clearance strategies, particularly in areas where evidence may be limited. Large, well-designed, and controlled studies are required to accumulate further evidence of management strategies for noncystic fibrosis bronchiectasis in children and adolescents.

Long-term macrolide treatment for non-cystic fibrosis bronchiectasis in children: a meta-analysis.

Recurrent bacterial infection causes frequent bronchiectasis (BE) exacerbations. The effectiveness and safety of long-term administration of macrolides in BE remain controversial, especially in children who require minimal treatment to prevent exacerbation. We conducted this meta-analysis to determine the usefulness of long-term macrolide use in pediatric BE. We searched PubMed, Cochrane Library databases, Embase, KoreaMed, Igaku Chuo Zasshi, and Chinese National Knowledge Infrastructure databases. We identified randomized controlled trials (RCTs) which elucidated long-term macrolide treatment (≥ 4 weeks) in non-cystic fibrosis BE in children aged < 18 years. The primary outcome was frequency of acute exacerbation; secondary outcomes included changes in pulmonary function, sputum scores, and adverse events including bacterial resistance. We included four RCTs. Long-term macrolide treatment showed a significant decrease in the frequency of exacerbation (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.10-0.87), mean number of exacerbations per patient (mean difference, - 1.40; 95% CI, - 2.26 to - 0.54), and sputum purulence score (mean difference, - 0.78; 95% CI, - 1.32 to - 0.24). However, long-term macrolide treatment was accompanied by an increased carriage of azithromycin-resistant bacteria (OR, 7.13). Long-term macrolide administration prevents exacerbation of BE in children; however, there are risks of increasing antibiotic resistance. Benefits and risks should be weighed and determined on a patient-by-patient basis.

Associated Factors for Asthma Severity in Korean Children: A Korean Childhood Asthma Study.

PURPOSE: Childhood asthma has a considerable social impact and economic burden, especially in severe asthma. This study aimed to identify the proportion of childhood asthma severity and to evaluate associated factors for greater asthma severity. METHODS: This study was performed on 667 children aged 5-15 years with asthma from the nationwide 19 hospitals in the Korean childhood Asthma Study (KAS). Asthma was classified as mild intermittent, mild persistent, and moderate/severe persistent groups according to the National Asthma Education and Prevention Program recommendations. Multinomial logistic regression models were used to identify the associated factors for greater asthma severity. RESULTS: Mild persistent asthma was most prevalent (39.0%), followed by mild intermittent (37.6%), moderate persistent (22.8%), and severe persistent asthma (0.6%). Onset later than 6 years of age (adjusted odds ratio [aOR], 1.69 for mild persistent asthma; aOR, 1.92 for moderate/severe persistent asthma) tended to increase asthma severity. Exposure to environmental tobacco smoke (aOR, 1.53 for mild persistent asthma; aOR, 1.85 for moderate/severe persistent asthma), and current dog ownership with sensitization to dog dander (aOR, 5.86 for mild persistent asthma; aOR, 6.90 for moderate/severe persistent asthma) showed increasing trends with greater asthma severity. Lower maternal education levels (aOR, 2.32) and no usage of an air purifier in exposure to high levels of outdoor air pollution (aOR, 1.76) were associated with moderate/severe persistent asthma. CONCLUSIONS: Modification of identified environmental factors associated with greater asthma severity might help better control childhood asthma, thereby reducing the disease burden due to childhood asthma.

Effect of multi-ethnicity and ancestry on prevalence of allergic disease.

BACKGROUND/PURPOSE: Differences exist among racial and ethnic groups in the prevalence and severity of allergic diseases. However, influence of population admixing on allergic disease has not been studied. We examined the effect of population admixing on the occurrence of allergic disease. METHODS: We reviewed the data of 68,043 adolescents who participated in the 11th Korea Youth Risk Behavior Web-based Survey, which provides a sample that is representative of the entire Korean middle school and high school student population. Multi-ethnic status was determined by using parental country of birth and prevalence of asthma, allergic rhinitis (AR), and atopic dermatitis (AD) was determined by questionnaire. RESULTS: Multi-ethnic adolescents accounted for approximately 0.9% of the total adolescents. Prevalence of asthma was significantly higher in multi-ethnic group than non multi-ethnic group while that of AR and AD was significantly higher in non multi-ethnic group than multi-ethnic group. Parental region of country at birth showed a significant difference in prevalence of allergic disease. Univariate analysis found that urbanity, perceived economic status (PES), parental region of country at birth, and environmental tobacco smoke (ETS) showed a significant odds ratio (OR) in asthma, AR, and AD. Body mass index (BMI) showed a significant OR in asthma and AD. After adjusting for urbanity, PES, BMI and ETS, multiethnicity showed significantly lower OR in AR and AD. CONCLUSION: Population admixing appears to have significant effect on the prevalence of allergic disease. Further study will be needed to clarify the effect of population admixing on prevalence of allergic disease.

Clinical characteristics and etiologies of bronchiectasis in Korean children: A multicenter retrospective study.

BACKGROUND: Bronchiectasis is a chronic pulmonary disease characterized by progressive and irreversible bronchial dilatation. The aim of the present study was to investigate the etiologies and clinical features of bronchiectasis in Korean children. METHODS: We performed a retrospective review of the medical records for children diagnosed with bronchiectasis between 2000 and 2017 at 28 secondary or tertiary hospitals in South Korea. RESULTS: A total of 387 cases were enrolled. The mean age at diagnosis was 9.2 ±â€¯5.1 years and 53.5% of the patients were boys. The most common underlying cause of bronchiectasis was preexisting respiratory infection (55.3%), post-infectious bronchiolitis obliterans (14.3%), pulmonary tuberculosis (12.3%), and heart diseases (5.6%). Common initial presenting symptoms included chronic cough (68.0%), recurrent pneumonia (36.4%), fever (31.1%), and dyspnea (19.7%). The most predominantly involved lesions were left lower lobe (53.9%), right lower lobe (47.1%) and right middle lobe (40.2%). No significant difference was observed in the distribution of these involved lesions by etiology. The forced expiratory volume in 1 s (FEV1) levels were lowest in cases with interstitial lung disease-associated bronchiectasis, followed by those with recurrent aspiration and primary immunodeficiency. CONCLUSIONS: Bronchiectasis should be strongly considered in children with chronic cough and recurrent pneumonia. Long-term follow-up studies on pediatric bronchiectasis are needed to further clarify the prognosis and reduce the disease burden in these patients.

A papilloma in a large cyst of the breast: A case report.

INTRODUCTION: Intracystic lesions of the breast prove to be benign more often than malignancy, most intracystic lesions are benign papillomas. Generally sizes of cysts that contain papilloma are small. Relatively cysts that contain papillary carcinoma are large. A papilloma in a large cyst of the Breast is rare. PRESENTATION OF CASE: We report a rare case of a papilloma in a large cyst of the breast that presented a painless palpable mass. A 53-yr-old woman noticed palpable mass in her right breast. Ultrasonography indicated a 7 × 7 cm sized large cyst. There is a 2 × 2.5 cm sized hyper-echoic, polypoid mass in the cyst. On fine-needle aspiration was not obtained malignant cells. Excisional biopsy was done. Pathologic finding was papilloma. DISCUSSION: Tumors in a large cyst of the breast is difficult in distinguish benign from malignancy by preoperative imaging, cytological and histological study. CONCLUSION: Excisional biopsy should be performed before cancer surgery such as mastectomy to manage the cysts with intracystic growths.

Extent of central lymph node dissection for papillary thyroid carcinoma in the isthmus.

PURPOSE: The incidence of papillary thyroid carcinoma (PTC) arising from the isthmus is low; however, these tumors have aggressive clinical and pathological features. Moreover, the existing guidelines regarding the extent of surgery for this type of tumor are unclear. METHODS: This study enrolled 282 patients who underwent total thyroidectomy with bilateral central lymph node dissection. The patients were divided into 2 groups based on the location of the median line of the PTC. Group I included patients in whom the median line was located between the lateral margins of the trachea; group II included all others. We compared the 2 groups and conducted a multivariate analysis to assess risk factors for contralateral node metastasis from a PTC arising from the isthmus. RESULTS: Patients in group I had significantly higher frequencies of extrathyroidal extension and central lymph node metastasis. Group I also had a higher frequency of contralateral node metastasis, and a tumor size >1.0 cm was identified as an independent risk factor for contralateral node metastasis among patients in this group. CONCLUSION: Bilateral central lymph node dissection could be considered for patients with isthmic PTCs >1.0 cm in size who have clinically suspicious node metastasis.

Comparison of skin-sparing mastectomy using LigaSure™ Small Jaw and electrocautery.

BACKGROUND: Skin-sparing mastectomy (SSM) is increasingly used in patients with breast cancer. We compared the differences between use of electrocautery and LigaSure™ Small Jaw in patients with breast cancer who underwent SSM. METHODS: Between January 2012 and December 2015, 81 patients with breast cancer who underwent SSM were selected and were divided into the electrocautery group and the LigaSure™ Small Jaw group based on the devices that were used. Clinicopathological characteristics, body mass index, operative time, and weight of removed breast were obtained from medical records. Total amount and days of drain use, until removal, and postoperative skin necrosis, requiring debridement, were also analyzed. RESULTS: The study population consisted of 50 patients in the electrocautery group and 31 in the LigaSure™ Small Jaw group. The latter group has significantly shorter operative time (117.5 ± 16.9 vs. 104.0 ± 23.6 min, P = 0.004). The mean total volume of drainage was less (805 ± 278 vs. 694 ± 131 mL, P = 0.017) and mean duration of drainage was also significantly shorter in the LigaSure™ Small Jaw group (11.3 ± 2.5 vs. 10.1 ± 2.0 days, P = 0.029). CONCLUSIONS: The use of LigaSure™ Small Jaw during skin-sparing mastectomy shortened the operative time and duration of drainage and reduced the total volume of drainage.

Delayed Epidural Mucin Collection after Surgery for Spinal Metastatic Pancreatic Adenocarcinoma.

A rare case of delayed large epidural mucin collection causing neurologic deficit after surgery for metastatic pancreatic cancer is reported. A 65-year-old man presented with intractable upper-thoracic back pain radiating to the chest and gait disturbance. He had a history of subtotal pancreatectomy due to intraductal papillary mucinous neoplasm (IPMN) of the pancreas and concurrent chemotherapy. Eight months after pancreatectomy, multiple thoracic spinal metastasis was diagnosed with routine up positron emission tomography-computed tomography. Radiotherapy for spinal metastasis and subsequent chemotherapy was carried out. Sixteen months after pancreatectomy, gait disturbance occurred and follow-up thoracic magnetic resonance imaging (MRI) showed aggravation of metastasis at T2 and T4 compressing the spinal cord. We performed a decompressive laminectomy with subtotal resection of the tumor masses and pedicle screw fixation at C7-T6. Neurologic status improved after the operation. Histopathologic examinations revealed the tumor as metastatic mucin producing adenocarcinoma. Three months after surgery, motor weakness and pain was reappeared. MRI showed large amount of epidural fluid collection. We performed wound revision and there was large amount of gelatinous fluid at the epidural space. We suggest that postoperative mucin collection and wound problems should be considered after surgery for mucin producing metastatic pancreatic tumor.

Significance of micrometastases in the calculation of the lymph node ratio for papillary thyroid cancer.

PURPOSE: The lymph node ratio (LNR) is an important prognostic factor in papillary thyroid carcinoma (PTC), but micrometastases in cervical lymph nodes (LNs) are not of great clinical importance. In this study, we analyzed the accuracy of prediction of the prognosis depending on whether micrometastases were included in the number of metastatic LNs when calculating LNR. METHODS: The study included 353 PTC patients who underwent total thyroidectomy with neck LN dissection, and calculated LNR by 2 methods according to whether micrometastases were included in the number of metastatic LNs: Method 1 did not and method 2 did include. To compare the predictive values of LNR by the 2 methods, correlation coefficients and receiver operating characteristic (ROC) curves were analyzed. RESULTS: Positive correlations were found between LNR and preablation stimulated thyroglobulin (sTg) levels in both methods, but the correlation between method 1 LNR and preablation sTg level was significantly stronger than that for method 2 (Fisher z = 1.7, P = 0.045). The areas under these 2 independent ROC curves were analyzed; the prognostic efficacy of method 1 LNR was more accurate than that of method 2 LNR, and the difference was statistically significant (P = 0.0001). CONCLUSION: Regional recurrence of PTC can be predicted more accurately by not including micrometastases in the number of metastatic LNs when calculating LNR.

Fulminant course in a case of malignant phyllodes tumor.

We present the case of a 31-year-old woman with an inflammatory and ulcerative malignant phyllodes tumor in her right breast. A right modified radical mastectomy and transverse rectus abdominis myocutaneous (TRAM) flap were performed. A month after the initial operation, several masses recurred at the superior margin and deep margin of the TRAM flap. Wide excision was performed, but masses recurred at the inferior margin and in both lung fields 2 weeks after the second operation. Six weeks after the second operation, the patient died due to progression of dyspnea and respiratory failure.

Roles of Bcl-2 and caspase-9 and -3 in CD30-induced human eosinophil apoptosis.

BACKGROUND/PURPOSE: Activation of cell surface CD30 by immobilized anti-CD30 monoclonal antibodies (mAb) induces strong apoptosis in human eosinophils. This anti-CD30 mAb-induced eosinophil apoptosis is inhibited by the addition of inhibitors of p38, ERK1/2 mitogen-activated protein kinases, and phosphatidylinositol 3-kinase. However, there is little data investigating the role of Bcl-2 and caspases in eosinophil apoptosis induced by anti-CD30 mAb. We sought to determine whether anti-CD30 mAb induces human eosinophil apoptosis via Bcl-2 and caspase pathways. METHODS: Peripheral blood was drawn from 37 healthy volunteers. The CD30 expression on eosinophils was measured at various time points. Eosinophils were then cultured in plates precoated with anti-CD30 mAb (clone Ber-H8), isotype control immunoglobulin G1, interleukin (IL)-5, or dexamethasone. Western blot analysis was performed to determine the expression of Bcl-2, procaspase-8, -9, and -3, and caspase-8, -9, and -3 after cross-linking of CD30. Human eosinophils were also cultured in plates precoated with anti-CD30 mAb (clone Ber-H8) in the presence or absence of caspase-9 or -3 inhibitors. Eosinophil apoptosis was assessed using flow cytometry. RESULTS: The addition of anti-CD30 mAb significantly increased eosinophil apoptosis compared with controls. In western blot analysis, the addition of anti-CD30 mAb significantly decreased the expression of Bcl-2 and procaspase-9 and -3 and increased the expression of caspase-9 and -3. The addition of caspase-9 or -3 inhibitors decreased anti-CD30 mAb-induced human eosinophil apoptosis. Procaspase-8 or caspase-8 expression was not changed in response to various stimuli. CONCLUSION: Anti-CD30 mAb-induced human eosinophil apoptosis is likely to be mediated through Bcl-2 and caspase-9 and -3.

The Applicability of Intraoperative Neuromonitoring in Patients with Preoperative Motor Weakness during Spine Surgery.

OBJECTIVE: The purpose of our study is to evaluate the success rate and feasibility of intraoperative neuromonitoring (IONM) focusing on transcranial motor evoked potential (TcMEP) monitoring for patients with preoperative motor weakness in spine surgery. METHODS: Between November 2011 and December 2013, TcMEP and somatosensory evoked potential (SSEP) monitoring were attempted in 130 consecutive patients undergoing spine surgeries for cervical or thoracic cord lesions. Patients ranged in age from 14 to 81 years (mean±standard deviation, 56.7±14.8 years), and 84 patients were male. The success rates of both SSEP and MEPs monitoring were assessed according to the preoperative Medical Research Council (MRC) and Nurick grades. RESULTS: TcMEP was recorded successfully in 0%, 28.6%, 72.3%, and 100% of patients with MRC grades 1, 2, 3, 4, and 5, respectively. SSEP was obtained from 0%, 37.5%, 21.5%, 61.4%, and 85.4% of patients with MRC grades 1, 2, 3, 4, and 5, respectively. TcMEP was recorded successfully in 84% of patients with Nurick grades 1-3 and 26% of patients with Nurick grades 4-5. SSEPs were recorded successfully in 76.3% of patients with Nurick grades 1-3 and 24% of patients with grades 4-5. CONCLUSION: IONM during spine surgery may be useless in patients with MRC grades 1-2, applicable MRC grade 3, and useful MRC grades 4-5. MRC grade 3 is a critical point of indication for application of MEPs. In unmonitorable cases with MRC grade 3, increasing stimulus intensity or facilitation techniques may be considered to improve the usefulness of TcMEP.

Pre-ablation stimulated thyroglobulin is a better predictor of recurrence in pathological N1a papillary thyroid carcinoma than the lymph node ratio.

BACKGROUND: Papillary thyroid carcinomas (PTC) with lymph node metastases have a high recurrence rate. We analyzed the potential of lymph node ratio (LNR) and the level of pre-ablation stimulated thyroglobulin (sTg) as risk factors predicting recurrence in patients with pathological N1a PTC. MATERIALS AND METHODS: This study involved 192 patients with pathologically confirmed PTC and central neck lymph node metastases who underwent total thyroidectomy with central lymph node dissection (CLND). The clinico-pathological characteristics, the pre-ablation sTg level and post-treatment recurrences were examined. Univariate and multivariate analyses were performed to identify factors associated with recurrence in these patients. RESULTS: During a median follow-up of 63 months, 17 patients had loco-regional recurrences. Receiver operating characteristic curve analysis showed that the appropriate cut-off values for LNR and the pre-ablation sTg level was 0.48 and 9.3 ng/mL, respectively. Patients with LNR values of ≥0.48 had a significantly worse disease-free survival (DFS) than those with LNR values of <0.48 (P = 0.015), and patients with pre-ablation sTg level values of ≥9.3 ng/mL had significantly worse DFS than those with pre-ablation sTg level values <9.3 ng/mL (P < 0.001). Relative to patients with LNR values of <0.48, those with LNR values of ≥0.48 had higher median pre-ablation sTg level values (0.55 vs. 4.20; P < 0.001). The correlation covariant between the LNR value and the pre-ablation sTg level value was r = 0.454 (P < 0.001). Multivariate analysis showed that a LNR value of ≥0.48 (P = 0.386) was not an independent risk factor for recurrence. To the contrary, a pre-ablation sTg level value of ≥9.3 ng/mL (P < 0.001) was an independent risk factor for recurrence. CONCLUSION: A high pre-ablation sTg level is a better predictor of recurrence in pathological N1a PTC than a high LNR value. Careful follow-up of patients with this risk factor is recommended.

Pentraxin 3 as a clinical marker in children with lower respiratory tract infection.

BACKGROUND: Pentraxin 3 (PTX-3) is an acute-phase protein that increases in the plasma during inflammation. OBJECTIVE: We aimed to evaluate the usefulness of PTX-3 as a clinical marker in children with lower respiratory tract infection (LRTI) and examine the correlation of PTX-3 with other biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT). METHODS: We enrolled 117 consecutive patients admitted to Seoul St. Mary's Hospital with LRTI using the WHO criteria. We recorded data on fever duration and peak temperature before admission, duration of fever after admission, respiratory rate, heart rate, oxygen saturation upon admission, duration of oxygen supplementation, and duration of hospital stay. Upon admission, white blood cell (WBC) count, erythrocyte sedimentation rate, CRP level were measured. Multiplex respiratory virus polymerase chain reaction was performed using nasal swabs. PTX-3, PCT, and various cytokines were measured after the study had been completed. RESULTS: We found that there was no significant difference in the level of PTX-3 according to the type of viral infection. PTX-3 levels showed a significant correlation with PCT levels, but not with levels of CRP. The level of PTX-3 showed a significant correlation with peak temperature and duration of fever before admission as well as interleukin (IL)-6 levels. PCT levels showed a significant correlation with IL-6 and granulocyte-colony stimulating factor levels, peak temperature, and duration of fever before admission, and duration of hospital stay. CRP levels showed a significant correlation with duration of fever before admission, total WBC count, and neutrophil count. PCT levels significantly predicted a hospital stay of 7 days or more. PTX-3, PCT, and CRP levels showed no correlation with any other clinical features. CONCLUSION: PTX-3 reflected disease severity but failed to predict length of hospital stay. Further studies evaluating the use of PTX-3 as a biomarker in mild LRTI would be useful.

Should central lymph node dissection be considered for all papillary thyroid microcarcinoma?

BACKGROUND: Central lymph node dissection (CLND) in patients with papillary thyroid microcarcinoma (PTMC) is still controversial. The aim of this study was to examine the risk factors and the incidence of central lymph node metastases (CLNMs) in patients with PTMC who underwent thyroidectomy and CLND. PATIENTS AND METHODS: Between 2002 and 2013, 613 patients were enrolled who underwent thyroidectomy with routine CLND for PTMC at the Korea University Medical Center, Ansan Hospital and risk factors and the incidence of CLNM were analyzed. In addition, we also evaluated the complications after thyroidectomy with CLND. RESULTS: Out of 613 patients, 239 (39.0%) were found to have CLNM. Male sex (p = 0.012), tumor size ≥ 0.5 cm (p = 0.001), capsular invasion or extrathyroidal extension (p = 0.029), and multifocality (p = 0.004) were independent risk factors for CLNM. Among the 69 patients who had PTMC without these risk factors, CLNM was identified in 12 (17.4%). In this study group, two (0.3%) had permanent recurrent laryngeal nerve injury, two (0.3%) had persistent hypocalcemia, and two (0.3%) developed postoperative hemorrhage. CONCLUSION: CLNM in PTMC is highly prevalent in male sex, tumor size ≥ 0.5 cm, extrathyroidal extension, and multifocality. Even in PTMC patients without these risk factors, the incidence of CLNM is rather higher than expected, and the complication rate of thyroidectomy with CLND is acceptable. Thus, CLND should be considered in all patients with PTMC.

Cadaveric Analysis of Posterior Pharyngoesophageal Wall Thickness: Implications for Anterior Cervical Spine Surgery.

STUDY DESIGN: A cadaveric study. OBJECTIVE: To investigate possible variations of posterior pharyngoesophageal (PE) wall thickness in the horizontal plane and their implications for anterior spine surgery. SUMMARY OF BACKGROUND DATA: Lower cervical levels (C5-7) are most commonly involved in cases of PE injury, and PE wall thickness could be one of the proposed reasons for the high incidence of PE injuries at these levels. The purpose of this study was to document thickness variations of the posterior PE wall at different cervical spine levels, because the study could provide valuable anatomical information that could reduce iatrogenic injuries caused by retractors or instrumentation. METHODS: Thirteen formaldehyde-fixed cadaveric specimens were included in current study. PE specimens were harvested from epiglottis to suprasternal notch within 2 months of formaldehyde fixation and sectioned axially. Four slices corresponding to the superior and inferior borders of thyroid cartilage, cricoid cartilage, and 2  cm below cricoid cartilage were sectioned. Posterior PE wall thickness was measured at three zones as follows: median, lateral, and paramedian. Posterior PE wall thicknesses were measured by a pathologist. RESULTS: Based on one-way ANOVA, posterior PE wall thickness showed several significantly different variations depending on cervical level and horizontal plane. PE walls were thinnest at the level of cricoid cartilage (P < 0.05). This difference was more pronounced in the median zone, because of thickness variations in the muscular layer (P < 0.001). CONCLUSION: The posterior PE wall was thinnest in the median zone at the cricoid cartilage level. Variations in muscle layer thickness caused PE wall thickness differences. The smaller wall thickness at the level of the cricoids cartilage and in the midline zone may place it at higher risk of injury, and special care should be taken during dissection, retraction, and instrument placement. LEVEL OF EVIDENCE: 3.

Effect of breastfeeding on lung function in asthmatic children.

Effect of breastfeeding on the protective effect on asthma has been studied extensively but remains controversial. Studies regarding the effect of breastfeeding on lung function have also been conflicting. The aim of this study was to determine the influence of breastfeeding on lung function in asthmatic children. We included 555 patients who visited Severance Children's Hospital Allergy Clinic with asthma. Pulmonary function, its bronchodilator response (BDR), fractional nitric oxide, and sputum eosinophils were measured. Parents completed questionnaires with information on feeding practices, family history of allergic disease, exposure to tobacco smoke, and presence of pets. Breastfeeding duration was categorized as not breastfed, breastfed <6 months, and breastfed ≥6 months. Within the asthma group, we stratified by atopic sensitization. We also investigated whether exclusivity of breastfeeding had any modifying effect on lung function. In the asthma group, ratio of forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) significantly increased according to breastfeeding duration: 86.6 ± 8.7 for not breastfed group, 87.2 ± 8.6 for <6 months group, and 88.8 ± 7.7 for ≥6 months group. Within asthma group, only the nonatopic subjects showed a significant increase of FEV1/FVC, maximal midexpiratory flow, and decrease of maximal response to BD according to breastfeeding duration. Increase in FEV1/FVC was seen in the exclusive breastfeeding for ≥6 months group compared with those partially breastfed but FVC was significantly lower in those exclusively breastfed <6 months group compared with those partially breastfed. BDR decreased with breastfeeding duration in the nonatopic asthma group. In conclusion, longer duration of breastfeeding appears to have a favorable effect on lung function in asthmatic children, especially in nonatopic subjects.