Balloon Laryngoplasty: Contemporary Management of Pediatric Subglottic Stenosis / 대한이비인후과학회지

Balloon laryngoplasty is a noninvasive procedure for managing pediatric subglottic stenosis with promising outcomes of a lower rate of tracheostomy and a higher decannulation rate. It can be applied even in a severely narrowed airway stenosis such as Myer-Cotton grade III. It is gaining popularity because, unlike the traditional rigid dilation method, it is considered an option to avoid shearing mucosal damages. Endoscopic balloon laryngoplasty may be recommended as a primary treatment option in a symptomatic pediatric subglottic stenosis before performing an invasive laryngotracheal reconstruction surgery. Herein, we introduce our institute’s balloon laryngoplasty procedure step-by-step.

Microlaryngobronchoscopy Without Tracheostomy in Large Subglottic Cyst Obliterating Airway / 대한이비인후과학회지

Extended endotracheal intubation in infancy causes various complications. Upper airway disruption is very rare but reversible cause of respiratory insufficiency. Tracheostomy may not be avoidable in severe upper respiratory tract lesions especially in large subglottic cysts and severe subglottic stenosis; however, avoiding it is a priority when possible. A 7-month-old child who had a history of newborn respiratory distress syndrome and extended endotracheal intubation developed respiratory symptoms including stridor. A subglottic cyst was found by bronchoscopy and surginally removed with the tubeless anesthesia technique without tracheostomy. This method was successful even on infants. We report this case with a review of literature.

Risk Factors for Recurrence Free Survival in Patients With Parotid Gland Cancer: 10-Year Single Center Experience / 대한이비인후과학회지

Background and Objectives@#Parotid cancer is a rare malignancy tumor, constituting about 3% of head and neck cancers. Treatment of parotid carcinoma is challenging because of its rarity and unpredictable clinical course. Therefore, it is important to evaluate risk factors associated with prognosis and to predict adverse outcomes. In this article, we aimed to analyze risk factors associated with recurrence free survival in our 10-year single center retrospective study.Subjects and Method Retrospective medical chart review was performed for patients with parotid gland cancer who underwent parotidectomy with or without adjuvant treatment in our institute 2011 to 2020. Patient demographics, histopathologic results, operative method, treatment outcome were assessed. @*Results@#A total of 8 patients (15%) experienced recurrence. Old age and low body mass index was associated with recurrence. Univariate analysis also revealed that high clinical stage, tumor involvement in deep lobe and facial nerve, postoperative radiotherapy or concurrent chemo radiotherapy, positive resection margin, and high histologic grade were statistically significant with recurrence. Multivariate analysis concluded that facial nerve involvement with tumor was associated with higher incidence of recurrence. Deep lobe and facial nerve involvement, postoperative radiotherapy or concurrent chemo radiotherapy, positive resection margin, clinical stage, and histologic grade were statistically significant factors associated with recurrence free survival. @*Conclusion@#Our 10-year single institute study will be helpful for predicting adverse outcomes in parotid cancer patients.

A Case of Migrated Esophageal Foreign Body Removal Through Cervical Approach Under C-Arm Fluoroscopic Guidance / 대한이비인후과학회지

Foreign bodies in the upper airway and the esophagus are common and often removed in the outpatient setting using the rigid or flexible laryngoscope. Although most esophageal foreign bodies are removed from the digestive tract, in some cases, surgical intervention is required due to its difficult location. Esophageal foreign bodies often removed by esophagogastroduodenoscopy, but when they penetrate the esophagus and move to deep neck spaces, other approaches should be taken into consideration. We report a rare case of a 13-year-old patient whose esophageal foreign body moved to a deep neck compartment, which was embedded in the anterior vertebral muscle. We decided to perform neck exploration under C-arm guidance, successfully targeted and removed the foreign body.

Hyaluronic Acid Coating on Hydrophobic Tracheal Scaffold Enhances Mesenchymal Stem Cell Adhesion and Tracheal Regeneration

BACKGROUND@#Long segmental tracheal repair is challenging in regenerative medicine due to low adhesion of stem cells to tracheal scaffolds. Optimal transplantation of stem cells for tracheal defects has not been established. We evaluated the role of hyaluronic acid (HA) coating of tracheal scaffolds in mesenchymal stem cell (MSC) adhesion and tracheal regeneration in a rabbit model. @*METHODS@#A three-dimensionally printed tubular tracheal prosthesis was incubated with dopa-HA-fluorescein isothiocyanate in phosphate-buffered saline for 2 days. MSCs were incubated with an HA-coated scaffold, and their adhesion was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. HA coated scaffolds with or without MSC seeding were transplanted at the circumferential tracheal defect in rabbits, and survival, rigid bronchoscopy, radiologic findings, and histologic findings were compared between the two groups. @*RESULTS@#HA-coated scaffolds showed better MSC adhesion than non-coated scaffolds. The HA-coated scaffolds with MSC group showed a wider airway and greater mucosal regeneration compared to the HA-coated scaffolds without MSC group. @*CONCLUSION@#HA coating of scaffolds can promote MSC adhesion and tracheal regeneration.

Hyaluronic Acid Coating on Hydrophobic Tracheal Scaffold Enhances Mesenchymal Stem Cell Adhesion and Tracheal Regeneration

BACKGROUND@#Long segmental tracheal repair is challenging in regenerative medicine due to low adhesion of stem cells to tracheal scaffolds. Optimal transplantation of stem cells for tracheal defects has not been established. We evaluated the role of hyaluronic acid (HA) coating of tracheal scaffolds in mesenchymal stem cell (MSC) adhesion and tracheal regeneration in a rabbit model. @*METHODS@#A three-dimensionally printed tubular tracheal prosthesis was incubated with dopa-HA-fluorescein isothiocyanate in phosphate-buffered saline for 2 days. MSCs were incubated with an HA-coated scaffold, and their adhesion was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. HA coated scaffolds with or without MSC seeding were transplanted at the circumferential tracheal defect in rabbits, and survival, rigid bronchoscopy, radiologic findings, and histologic findings were compared between the two groups. @*RESULTS@#HA-coated scaffolds showed better MSC adhesion than non-coated scaffolds. The HA-coated scaffolds with MSC group showed a wider airway and greater mucosal regeneration compared to the HA-coated scaffolds without MSC group. @*CONCLUSION@#HA coating of scaffolds can promote MSC adhesion and tracheal regeneration.

Combination Therapy by Tissue-Specific Suicide Gene and Bevacizumab in Intramedullary Spinal Cord Tumor

Purpose@#Malignant gliomas are aggressive spinal cord tumors. In this study, we hypothesized that combination therapy using an anti-angiogenic agent, bevacizumab, and hypoxia-inducible glioblastoma-specific suicide gene could reduce tumor growth. @*Materials and Methods@#In the present study, we evaluated the effect of combination therapy using bevacizumab and pEpo-NI2-SV-TK in reducing the proliferation of C6 cells and tumor growth in the spinal cord. Spinal cord tumor was generated by the injection of C6 cells into the T5 level of the spinal cord. Complexes of branched polyethylenimine (bPEI)/pEpo-NI2-SV-TK were injected into the spinal cord tumor. Bevacizumab was then administered by an intraperitoneal injection at a dose of 7 mg/kg. The anti-cancer effects of combination therapy were analyzed by histological analyses and magnetic resonance imaging (MRI). The Basso, Beattie and Bresnahan scale scores for all of the treatment groups were recorded every other day for 15 days to assess the rat hindlimb strength. @*Results@#The complexes of bPEI/pEpo-NI2-SV-TK inhibited the viability of C6 cells in the hypoxia condition at 5 days after treatment with ganciclovir. Bevacizumab was decreased in the cell viability of human umbilical vein endothelial cells. Combination therapy reduced the tumor size by histological analyses and MRI. The combination therapy group showed improved hind-limb function compared to the other groups that were administered pEpo-NI2-SV-TK alone or bevacizumab alone. @*Conclusion@#This study suggests that combination therapy using bevacizumab with the pEpo-NI2-SV-TK therapeutic gene could be useful for increasing its therapeutic benefits for intramedullary spinal cord tumors.

Direct Reprogramming to Human Induced Neuronal Progenitors from Fibroblasts of Familial and Sporadic Parkinson’s Disease Patients

In Parkinson’s disease (PD) research, human neuroblastoma and immortalized neural cell lines have been widely used as in vitro models. The advancement in the field of reprogramming technology has provided tools for generating patient-specific induced pluripotent stem cells (hiPSCs) as well as human induced neuronal progenitor cells (hiNPCs). These cells have revolutionized the field of disease modeling, especially in neural diseases. Although the direct reprogramming to hiNPCs has several advantages over differentiation after hiPSC reprogramming, such as the time required and the simple procedure, relatively few studies have utilized hiNPCs. Here, we optimized the protocol for hiNPC reprogramming using pluripotency factors and Sendai virus. In addition, we generated hiNPCs of two healthy donors, a sporadic PD patient, and a familial patient with the LRRK2 G2019S mutation (L2GS). The four hiNPC cell lines are highly proliferative, expressed NPC markers, maintained the normal karyotype, and have the differentiation potential of dopaminergic neurons. Importantly, the patient hiNPCs show different apoptotic marker expression. Thus, these hiNPCs, in addition to hiPSCs, are a favorable option to study PD pathology.

Two Cases of Nuclear Protein in Testis Midline Carcinomas of Sinonasal Tract / 대한이비인후과학회지

Nuclear protein in testis (NUT) midline carcinoma (NMC) is a rare and aggressive tumor that is genetically characterized by chromosomal rearrangement of the NUT gene. NMC predominantly involves the midline structures of the body and the sinonasal tract is considered a preferential site. While the optimal management of NMC is unclear, more than 80% of patients will die within one year of their diagnosis despite intensive treatment. We report two cases of NMC of the sinonasal tract. Histopathologic results of the punch biopsy showed undifferentiated and poorly differentiated carcinoma. NUT immunohistochemical staining results were positive. Multimodal treatments including surgery, radiotherapy, and chemotherapy were performed. We also present a literature review to compare with the present cases. In our cases, we emphasize the importance of the early diagnosis and intensive treatment of NMC.

Three Cases of Hereditary Hemorrhagic Telangiectasia Treated with Bevacizumab / 대한이비인후과학회지

Hereditary hemorrhagic telangiectasia (HHT) is a hereditary, autosomal dominant, vascular dysplasia characterized by mucocutaneous telangiectasia, epistaxis, gastrointestinal bleeding, and iron deficiency anemia. Epistaxis in HHT is a recurrent and debilitating symptom, which is difficult to manage. Many methods have been tried with little success. Bevacizumab (Avastin®), a VEGF inhibitor, has been recently tried intranasally or systemically to control the recurrent epistaxis. We report three patients with HHT who were treated with intranasal bevacizumab application together with cauterization. In all three patients, recurrent epistaxis decreased considerably with improvement in quality of life. Here we describe the application methods, treatment results, and complications with literature review. We believe that this is the first report of treating epistaxis in HHT with intranasal application of bevacizumab in South Korea.

A Gene and Neural Stem Cell Therapy Platform Based on Neuronal Cell Type-Inducible Gene Overexpression

PURPOSE: Spinal cord injury (SCI) is associated with permanent neurological damage, and treatment thereof with a single modality often does not provide sufficient therapeutic outcomes. Therefore, a strategy that combines two or more techniques might show better therapeutic effects. MATERIALS AND METHODS: In this study, we designed a combined treatment strategy based on neural stem cells (NSCs) introduced via a neuronal cell type-inducible transgene expression system (NSE::) controlled by a neuron-specific enolase (NSE) promoter to maximize therapeutic efficiency and neuronal differentiation. The luciferase gene was chosen to confirm whether this combined system was working properly prior to using a therapeutic gene. The luciferase expression levels of NSCs introduced via the neuronal cell type-inducible luciferase expression system (NSE::Luci) or via a general luciferase expressing system (SV::Luci) were measured and compared in vitro and in vivo. RESULTS: NSCs introduced via the neuronal cell type-inducible luciferase expressing system (NSE::Luci-NSCs) showed a high level of luciferase expression, compared to NSCs introduced via a general luciferase expressing system (SV::Luci-NSCs). Interestingly, the luciferase expression level of NSE::Luci-NSCs increased greatly after differentiation into neurons. CONCLUSION: We demonstrated that a neuronal cell type-inducible gene expression system is suitable for introducing NSCs in combined treatment strategies. We suggest that the proposed strategy may be a promising tool for the treatment of neurodegenerative disorders, including SCI.