Characteristics of 43 multiple auricular deformity case families and auricle morphology in 463 microtia patients in South China

Subtractive thinking: A novel combined application of antihelix reconstruction and outer helix reconstruction to treat mild cases of type I to II conchal microtia

BACKGROUND

The management of mild cases of type Ⅰ to Ⅱ conchal microtia involves grafting cartilage to the affected ear to increase the cartilaginous area and transfer more skin to cover the larger cartilage. Herein, we performed a novel combined surgical procedure based on "subtractive thinking" that included antihelix reconstruction and outer helix reconstruction that was successful in patients with mild type I to II conchal microtia.

METHODS

From January 2018 to September 2022, 65 patients with mild, unilateral, type I to II conchal microtia were enrolled in this study. All patients were treated with a novel method at the Plastic Surgery Hospital of Peking Union Medical College. The perimeters, widths, and lengths of the healthy and affected ears were measured both preoperatively and postoperatively. Patients' levels of satisfaction were determined based on postoperative results.

RESULTS

The mean postoperative follow-up duration was 14.9 ± 2.65 months. All patients experienced no complications. Analysis revealed that our surgical method could effectively treat mild type I to II concha microtia irrespective of the auricular perimeter, width, and length (p < 0.0001). Furthermore, the patient satisfaction rate was 100%.

CONCLUSION

The combined surgical procedure, which includes antihelix and outer helix reconstructions, is a viable method of reconstructing type I to II auricular concha microtia.

Metabolomic characterization of congenital microtia: a possible analysis for early diagnosis

Background

Although metabolic abnormalities have been deemed one of the essential risk factors for growth and development, the relationship between metabolic abnormalities and microtia is still unclear. In this study, we aimed to establish a cell model of microtia and the changes of serum metabolites in patients with microtia.

Methods

After constructing a cell model of microtia with low expression of BMP5, we performed integrative metabolomics analysis. For the altered metabolites, the content of glycerophosphocholine (PC), triacylglycerol (TG), and choline in the serum of 28 patients (15 patients with microtia and 13 controls) with microtia was verified by enzyme-linked immunosorbent assay (ELISA).

Results

Detailed metabolomic evaluation showed distinct clusters of metabolites between BMP5-low expressing cells and normal control (NC) cells. The cell model of microtia had significantly higher levels of TG, PC, glycerophosphoethanolamine (PE), sphingomyelin, sulfatide, glycerophosphoglycerol, diacylglycerol, and glycosphingolipid. The main abnormal metabolites were mainly concentrated in the glycerophospholipid metabolism pathway, and PC and choline were closely related. In the serum of patients with microtia, the contents of PC, TG, and choline were significantly increased.

Conclusions

The individual serum samples confirmed the different metabolites between patients with microtia and controls. In particular, we showed that a newly developed metabolic biomarker panel has a high sensitivity and specificity for separating patients with microtia from controls.

Mitochondrial dysfunction resulting from the down-regulation of bone morphogenetic protein 5 may cause microtia

Background

Bone morphogenetic protein 5 (BMP5) has been identified as one of the important risk factors for microtia; however, the link between them has yet to be clarified. In this study, we aimed to demonstrate the relationship of BMP5 with mitochondrial function and investigate the specific role of mitochondria in regulating microtia development.

Methods

BMP5 expression was measured in auricular cartilage tissues from patients with and without microtia. The effects of BMP5 knockdown on cellular function and mitochondrial function were also analyzed in vitro. Changes in genome-wide expression profiles were measured in BMP5-knockdown cells. Finally, the specific impact of BMP5 down-regulation on mitochondrial fat oxidation was analyzed in vitro.

Results

BMP5 expression was down-regulated in the auricular cartilage tissues of microtia patients. BMP5 down-regulation inhibited various cellular functions in vitro, including cell proliferation, mobility, and cytoactivity. The functional integrity of mitochondria was also damaged, accompanied by a decrease in mitochondrial membrane potential, reactive oxygen species (ROS) neutralization, and reduced adenosine triphosphate (ATP) production. Carnitine O-palmitoyltransferase 2 and diacylglycerol acyltransferase 2, two of the key regulators of mitochondrial lipid oxidation, were also found to be decreased by BMP5 down-regulation.

Conclusions

Down-regulation of BMP5 affects glycerolipid metabolism and fatty acid degradation, leading to mitochondrial dysfunction, reduced ATP production, and changes in cell function, and ultimately resulting in microtia. This research provides supporting evidence for an important role of BMP5 down-regulation in affecting mitochondrial metabolism in cells, and sheds new light on the mechanisms underlying the pathogenesis of microtia.

Epidemiological Research of Microtia Combined With Congenital Heart Disease

Congenital heart disease (CHD) is one of the most common combined malformations of microtia. There is currently no specific study that investigates the relationship between microtia and CHD.

METHODS

This study collected microtia inpatients admitted from May 1, 2015 to July 31, 2016. The diagnosis of CHD was based on patient's symptoms, past history, and echocardiography. Pearson χ test was used to analyze the correlation between CHD and microtia.

RESULTS

A total of 30 cases (3.35%) were documented with CHD, including atrial septal defect (12/40.00%), ventricular septal defect (7/23.30%), patent ductus arteriosus (2/6.70%), complex congenital heart disease (3/10.00%), combined CHD (2/6.70%) and other malformations (4/13.30%). Analysis showed no statistically significant relation between CHD and the side of affected ear or gender.

CONCLUSIONS

The occurrence of CHD in microtia patients was higher than that in the general population. The relationship between them was explored mainly from the etiological perspective. Microtia and CHD were often combined in syndromes such as Goldenhar syndrome, 22q11 deletion syndrome, and CHARGE syndrome. Absence of genes or abnormal embryo development associated with these syndromes leads to the occurrence of both.