Primary versus modified secondary closure techniques for persistent tracheocutaneous fistula in pediatric patients.

PURPOSE: This study aimed at compating two closure techniques for tracheocutaneous fistulas (TCFs) in pediatric patients. METHODS: A total of 106 consecutive pediatric patients who underwent closure of a persistent TCF between April 2007 and February 2021 at a tertiary pediatric hospital were evaluated, and 103 pediatric patients aged between 12 months and 18 years were included. The clinical characteristics, perioperative outcomes, and postoperative outcomes were compared between TCF closure by primary closure (Group 1) and a modified secondary healing technique (Group 2). RESULTS: Of the 103 patients, 58 were classified into Group 1, and 45 into Group 2. The mean age at tracheostomy and TCF closure was significantly younger in Group 2, and the interval between decannulation to TCF closure was significantly shorter in Group 2. Procedural time and hospital stay were significantly shorter in Group 2 than Group 1. Group 2 had a significantly lower complication rate, need for revision surgery, and recannulation rate than Group 1. CONCLUSIONS: Modified secondary healing was more efficient in terms of procedural time and hospital stay, and safer (i.e., fewer complications). It is an effective surgical technique for closing a persistent TCF in younger patients more quickly after decannulation compared to primary closure.

Severe late dysphagia after multimodal treatment of stage III/IV laryngeal and hypopharyngeal cancer.

BACKGROUND: Long-term side effects after radiotherapy for organ preservation 'could deteriorate' the laryngeal function. This study intended to identify the incidence of severe late dysphagia following the multimodal treatment for stage III/IV laryngeal and hypopharyngeal cancer 'to evaluate the function of larynx'. METHODS: The medical records of patients successfully treated for laryngeal and hypopharyngeal cancer with a multimodal approach, including radiotherapy, were retrospectively analyzed. 'Functional larynx was defined as tolerable oral diet without severe late dysphagia or tracheostoma'. RESULTS: The study included 99 patients with a median follow-up period of 72 months. 'Tracheostomy during the follow-up period was required in only one patient due to aspiration pneumonia, and dysphagia is the main determinant for functional larynx'. The probability of maintaining functional larynx was 63% for 10 years, when the treatment was started with radiotherapy or concurrent chemoradiotherapy. In upfront surgery (operation first and adjuvant radiotherapy/concurrent chemoradiotherapy) group, 37% of patients required total laryngectomy as primary treatment and 43% of patients could maintain laryngeal function for 10 years. And severe late dysphagia in the latter group developed mainly after laryngeal preservation surgery. The patients aged ≥65 years showed significantly higher incidence of dysphagia. Severe late dysphagia was very rare in laryngeal cancer successfully cured with radiotherapy/concurrent chemoradiotherapy (1/25, 4%); however, it gradually increased over time in hypopharyngeal cancer patients showing a statistically significant difference from laryngeal cancer patients (P = 0.040). CONCLUSION: Severe late dysphagia occurred in 19.2% of patients treated for laryngeal and hypopharyngeal cancers, regardless of whether treatment started with radiotherapy/concurrent chemoradiotherapy or surgery.

In vivo engineering of bone tissues with hematopoietic functions and mixed chimerism.

Synthetic biomimetic matrices with osteoconductivity and osteoinductivity have been developed to regenerate bone tissues. However, whether such systems harbor donor marrow in vivo and support mixed chimerism remains unknown. We devised a strategy to engineer bone tissues with a functional bone marrow (BM) compartment in vivo by using a synthetic biomaterial with spatially differing cues. Specifically, we have developed a synthetic matrix recapitulating the dual-compartment structures by modular assembly of mineralized and nonmineralized macroporous structures. Our results show that these matrices incorporated with BM cells or BM flush transplanted into recipient mice matured into functional bone displaying the cardinal features of both skeletal and hematopoietic compartments similar to native bone tissue. The hematopoietic function of bone tissues was demonstrated by its support for a higher percentage of mixed chimerism compared with i.v. injection and donor hematopoietic cell mobilization in the circulation of nonirradiated recipients. Furthermore, hematopoietic cells sorted from the engineered bone tissues reconstituted the hematopoietic system when transplanted into lethally irradiated secondary recipients. Such engineered bone tissues could potentially be used as ectopic BM surrogates for treatment of nonmalignant BM diseases and as a tool to study hematopoiesis, donor-host cell dynamics, tumor tropism, and hematopoietic cell transplantation.

A Phase II Study of Genexol-PM and Cisplatin as Induction Chemotherapy in Locally Advanced Head and Neck Squamous Cell Carcinoma.

LESSONS LEARNED: Induction chemotherapy with Genexol-PM and cisplatin demonstrated modest tumor response in locally advanced head and neck squamous cell carcinoma.Considering favorable toxicity profiles and promising survival data, further studies on this regimen are warranted in patients with head and neck squamous cell carcinoma. BACKGROUND: Genexol-PM is a polymeric micellar formulation of paclitaxel without Cremophor EL. We investigated the efficacy and safety of Genexol-PM plus cisplatin as induction chemotherapy (IC) in patients with locally advanced head and neck squamous cell carcinoma (LA-HNSCC). METHODS: Patients received Genexol-PM (230 mg/m2) and cisplatin (60 mg/m2) every 3 weeks as IC. After three cycles of IC, definitive treatment of either concurrent chemoradiotherapy (CCRT) with weekly cisplatin (30 mg/m2) or surgery was performed. The primary endpoint was overall response rate (ORR) after IC. RESULTS: Of 52 patients enrolled, 47 completed three cycles of IC, and the ORR was 55.8% (95% confidence interval, 42.3-69.3). Although there was one treatment-related death, toxicity profiles to Genexol-PM and cisplatin were generally favorable, and the most common grade 3 or 4 toxicities were neutropenia (15.4%), anorexia (7.7%), and general weakness (7.7%). Fifty-one patients received definitive treatment (CCRT [n = 44] or radical surgery [n = 7]). The rate of complete response following CCRT was 81.8% (36/44). After a median follow-up of 39 months, estimates of progression-free survival (PFS) and overall survival (OS) at 3 years were 54.3% and 71.3%, respectively. CONCLUSION: IC with Genexol-PM and cisplatin demonstrated modest tumor response with well-tolerated toxicity profiles for patients with LA-HNSCC.

Hydrogel-laden paper scaffold system for origami-based tissue engineering.

In this study, we present a method for assembling biofunctionalized paper into a multiform structured scaffold system for reliable tissue regeneration using an origami-based approach. The surface of a paper was conformally modified with a poly(styrene-co-maleic anhydride) layer via initiated chemical vapor deposition followed by the immobilization of poly-l-lysine (PLL) and deposition of Ca(2+). This procedure ensures the formation of alginate hydrogel on the paper due to Ca(2+) diffusion. Furthermore, strong adhesion of the alginate hydrogel on the paper onto the paper substrate was achieved due to an electrostatic interaction between the alginate and PLL. The developed scaffold system was versatile and allowed area-selective cell seeding. Also, the hydrogel-laden paper could be folded freely into 3D tissue-like structures using a simple origami-based method. The cylindrically constructed paper scaffold system with chondrocytes was applied into a three-ring defect trachea in rabbits. The transplanted engineered tissues replaced the native trachea without stenosis after 4 wks. As for the custom-built scaffold system, the hydrogel-laden paper system will provide a robust and facile method for the formation of tissues mimicking native tissue constructs.

Treatment of chemically induced oral ulcer using adipose-derived mesenchymal stem cell sheet.

BACKGROUND: This study investigated the effects of mesenchymal stem cell (MSC) sheet transplantation on healing of chemically induced oral ulceration in a rabbit animal model. METHODS: Oral mucosal ulcers were induced by topical application of filter paper soaked with 70% acetic acid to the anterior gingiva and buccal mucosa of 12 New Zealand white rabbits. The animals were randomly assigned to two groups: with (treatment group, n = 6) or without (control group, n = 6) cell sheets applied to ulcers. Gross findings were sequentially evaluated, and histologic examination was performed on day 7. RESULTS: Based on gross inspection, ulceration resolved before day 5 in the treatment group; however, in the control group, healing was incomplete on day 7. In the treatment group, the total area of the ulcer decreased significantly from day 2 to day 5 (P < 0.001) and from day 5 to day 7 (P = 0.020), whereas the area decreased significantly from day 5 to day 7 in the control group (P < 0.001). Histologic and immunofluorescence examination revealed full-thickness mucosa healing and complete basal cell coverage in the treatment group; in contrast, only partial healing was observed on day 7 in the control group. CONCLUSIONS: Cell sheet technology using MSC can be an alternative treatment for oral ulcerations in that it can decrease healing time without invasive properties.

Predictive and prognostic value of PET/CT imaging post-chemoradiotherapy and clinical decision-making consequences in locally advanced head & neck squamous cell carcinoma: a retrospective study.

BACKGROUND: The accuracy of (18)F-fluorodeoxygluocose positron emission tomography/computed tomography (PET/CT) in predicting immediate failure after radical chemoradiotherapy (CRT) for HNSCC is poorly characterized at present. The purpose of this study was to examine PET/CT as a predictive and prognostic gauge of immediate failure after CRT and determine the impact of these studies on clinical decision making in terms of salvage surgery. METHODS: Medical records of 78 consecutive patients receiving radical CRT for locally advanced HNSCC were reviewed, analyzing PET/CTs done before and 3 months after CRT. Immediate failure was defined as residual disease or locoregional and/or systemic relapse within 6 months after CRT. RESULTS: Maximum standard uptake value (SUV) of post CRT PET/CT (postSUVmax) was found optimal for predicting immediate failure at a cutpoint of 4.4. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were 90.0%, 83.8%, 98.3%, and 45.0%, respectively. Of 78 patients studied, postSUVmax ≥ 4.4 prevailed in 20 (25.6%), with postSUVmax <4.4 in 58 (74.4%). At postSUVmax ≥ 4.4 (vs. postSUVmax <4.4) OS was poorer by comparison (3-year OS: 56.9 vs. 87.7%; P = 0.005), as was progression-free survival (3-year PFS: 42.9 vs. 81.1%; P < 0.001). At postSUVmax ≥ 4.4, OS with and without immediate salvage surgery did not differ significantly (3-year OS: 60.0 vs. 55.6%; Log-rank P = 0.913). CONCLUSION: Post CRT PET/CT imaging has prognostic value in terms of OS and PFS and is useful in predicting immediate therapeutic failure, given its high NPV. However, OS was not significantly altered by early salvage surgery done on the basis of post CRT PET/CT findings.

Characterization and preparation of bio-tubular scaffolds for fabricating artificial vascular grafts by combining electrospinning and a 3D printing system.

The last decade has seen artificial blood vessels composed of natural polymer nanofibers grafted into human bodies to facilitate the recovery of damaged blood vessels. However, electrospun nanofibers (ENs) of biocompatible materials such as chitosan (CTS) suffer from poor mechanical properties. This study describes the design and fabrication of artificial blood vessels composed of a blend of CTS and PCL ENs and coated with PCL strands using rapid prototyping technology. The resulting tubular vessels exhibited excellent mechanical properties and showed that this process may be useful for vascular reconstruction.

Healthcare service use and medical outcomes of tracheostomy-dependent children: a nationwide study.

BACKGROUND: Despite the rising trend of tracheostomies in children, there is a lack of comprehensive resources for families to navigate the challenges of living with a tracheostomy, emphasising the need for evidence-based support in understanding postoperative care and long-term adjustments. This study aimed to examine the pattern of using healthcare services and nationwide medical outcomes in children who underwent a tracheotomy before the age of 2 years. METHODS: This retrospective study used the National Health Insurance System database from 2008 to 2016 and included all children codified with tracheotomy procedure codes before their second birthday. Healthcare utilisation, such as medical costs, number of hospital visits, home healthcare nursing and medical diagnoses on readmission, in the first 2 years after tracheotomy was evaluated. Multivariable logistic regression analysis was used to determine the factors affecting mortality. RESULTS: In total, 813 patients were included in this study. Their use of healthcare services and the accompanying expenses were higher than the national medians for similar age groups; however, both metrics decreased in the second year. The major causes of admission within 2 years of surgery were respiratory and neurological diseases. The mortality rate within 2 years was 37.8%. Higher risks of mortality were associated with having two or more complex chronic conditions. Use of home healthcare nursing services was associated with a lower mortality risk. CONCLUSION: Paediatric patients with more complex chronic conditions tended to have higher mortality rates within 2 years after surgery. However, receiving home healthcare nursing was significantly associated with a reduced risk of death. Many causes of hospitalisation may be preventable with education and supportive care. Therefore, further research for establishing an integrated care system for these patients and their caregivers is required.

The Clinical Features and Risk Factors of Subglottic Cysts in Children: A Clinical Experience Using the Spontaneous Respiration Technique.

OBJECTIVES: Subglottic cysts (SGCs) are a rare cause of respiratory distress resulting from upper airway obstruction in infants and young children. Risk factors other than prematurity with a history of endotracheal intubation have not yet been well elucidated. Therefore, we aimed to describe the clinical features and analyze the risk factors of SGCs. METHODS: We conducted a retrospective review of medical records of pediatric patients who underwent marsupialization for SGCs between January 2017 and March 2022. These records were then compared with those of controls with a history of neonatal intubation, with a case-to-control ratio of 1:3. RESULTS: Eleven patients (eight boys and three girls) diagnosed with SGCs and 33 control patients (26 boys and seven girls) were included. All patients had a history of premature birth and neonatal intubation. Symptoms of SGCs appeared at a mean age of 8.2 months (range, 1-14 months) after extubation. The mean duration of intubation was 21.5 days (range, 2-90 days), and the intubation period was longer in patients with SGCs than in controls (21.5±24.8 days vs. 5.3±7.1 days; P<0.001). Furthermore, gestational age (28.3±4.2 weeks vs. 33.8±4.4 weeks; P=0.001) and birth weight (1,134.1±515.1 g vs. 2,178.2±910.1 g; P=0.001) were significantly lower in patients with SGCs than in controls. Multivariable analysis identified the intubation period as an independent risk factor. CONCLUSION: This study showed that gestational age, birth weight, and the intubation period were significantly associated with the development of SGCs. Pediatric patients presenting with progressive dyspnea who have the corresponding risk factors should undergo early laryngoscopy for the differential diagnosis of SGC.

Tongue Reduction Surgery Improves Mandibular Prognathism in Beckwith-Wiedemann Syndrome Without Compromising Tongue Function.

OBJECTIVES: This study evaluated the surgical outcomes of patients with Beckwith-Wiedemann syndrome who underwent tongue-reduction surgery and analyzed whether the malocclusion and mandibular prognathism caused by macroglossia could be improved. METHODS: A retrospective medical record review was performed for 11 patients with Beckwith-Wiedemann syndrome whose macroglossia was surgically treated. Demographic data, symptoms and signs, and intraoperative and postoperative surgical outcomes were evaluated. Surgery was performed by a single surgeon using the "keyhole" technique, involving midline elliptical excision and anterior wedge resection. Preoperative and postoperative plain skull lateral X-rays were evaluated to assess prognathism improvement. RESULTS: The median age at the time of surgery was 35.09 months, and the ratio of males to females was 4:7. The median surgical time was 98±31.45 minutes, and the median duration of the postoperative intensive care unit stay was 3.81±2.4 days. There were no airway complications. Two patients (18.2%) had postoperative wound dehiscence; however, there was no nerve damage, recurrence, or other complications. Among the five patients who underwent postoperative speech evaluation, all showed normal speech development, except one patient who had brain dysfunction and developmental delay. Measurements of the A point-nasion-B point (ANB) angles and sella-nasion-B point (SNB) angles (point A is the most concave point of the anterior maxilla; point B is the most concave point on the mandibular symphysis) on plain X-rays showed a significant decrease in the postoperative SNB angle (P <0.001) and a significant increase in the ANB angle (P <0.011). CONCLUSION: Tongue-reduction surgery is an effective and safe technique for severe forms of macroglossia associated with Beckwith-Wiedemann syndrome. In addition, it improves mandibular prognathism in young Beckwith-Wiedemann syndrome patients with macroglossia.

Predictors of Early and Late Response to Esomezol and Lifestyle Modification in Adults With Laryngopharyngeal Reflux Disease: A Prospective, Multicenter, Open-Label Cohort Study.

OBJECTIVES: This study aimed to assess predictors of the response to varying durations of proton pump inhibitor (PPI) use and lifestyle modification treatment for laryngopharyngeal reflux disease (LPRD). METHODS: Between October 2014 and June 2016, a prospective, multicenter, open-label, single-cohort, intention-to-treat, observational study was conducted at eight referral hospitals across the Republic of Korea to examine predictors of early and late response to treatment in adult patients (age ≥19 years) with LPRD. Participants underwent standard treatment (PPI [Esomezol] and lifestyle modification) for 3 months. Response to treatment was defined as greater than 50% improvement in reflux symptom index score. The primary outcome was potential predictors of treatment response at 1 and 3 months. The secondary outcome was potential predictors distinguishing early from late responders. RESULTS: In total, 394 patients were enrolled. Improved sleep habits was a positive predictor (odds ratio [OR], 1.785; 95% confidence interval [CI], 1.06-3.007; P=0.029), while initial alcohol consumption (OR, 0.587; 95% CI, 0.355-0.969; P=0.037) and past medication history (OR, 0.438; 95% CI, 0.215-0.891; P=0.005) were negative predictors of response after 1 month of treatment. High pre-reflux finding score was a positive predictor (OR, 1.187; 95% CI, 1.049- 1.344; P=0.007), while male sex (OR, 0.516; 95% CI, 0.269-0.987; P=0.046), higher depression score (OR, 0.867; 95% CI, 0.784-0.958; P=0.005), and past thyroid hormone medication history (OR, 0.161; 95% CI, 0.033-0.788; P=0.024) were negative predictors of response after 3 months of treatment. Past medication history (OR, 0.438; 95% CI, 0.215-0.891; P=0.023) was the only negative predictor for early responders compared to late responders. CONCLUSION: Adult patients with LPRD and a history of prior medication use may require longer treatment durations to achieve a therapeutic response. Future research should explore the incorporation of diverse treatment approaches to improve treatment outcomes for patients exhibiting negative prognostic indicators.

Assessment of Esophageal Reconstruction via Bioreactor Cultivation of a Synthetic Scaffold in a Canine Model.

OBJECTIVES: Using tissue-engineered materials for esophageal reconstruction is a technically challenging task in animals that requires bioreactor training to enhance cellular reactivity. There have been many attempts at esophageal tissue engineering, but the success rate has been limited due to difficulty in initial epithelialization in the special environment of peristalsis. The purpose of this study was to evaluate the potential of an artificial esophagus that can enhance the regeneration of esophageal mucosa and muscle through the optimal combination of a double-layered polymeric scaffold and a custom-designed mesenchymal stem cell-based bioreactor system in a canine model. METHODS: We fabricated a novel double-layered scaffold as a tissue-engineered esophagus using an electrospinning technique. Prior to transplantation, human-derived mesenchymal stem cells were seeded into the lumen of the scaffold, and bioreactor cultivation was performed to enhance cellular reactivity. After 3 days of cultivation using the bioreactor system, tissue-engineered artificial esophagus was transplanted into a partial esophageal defect (5×3 cm-long resection) in a canine model. RESULTS: Scanning electron microscopy (SEM) showed that the electrospun fibers in a tubular scaffold were randomly and circumferentially located toward the inner and outer surfaces. Complete recovery of the esophageal mucosa was confirmed by endoscopic analysis and SEM. Esophagogastroduodenoscopy and computed tomography also showed that there were no signs of leakage or stricture and that there was a normal lumen with complete epithelialization. Significant regeneration of the mucosal layer was observed by keratin-5 immunostaining. Alpha-smooth muscle actin immunostaining showed significantly greater esophageal muscle regeneration at 12 months than at 6 months. CONCLUSION: Custom-designed bioreactor cultured electrospun polyurethane scaffolds can be a promising approach for esophageal tissue engineering.

Gene expression profile of early in vitro biofilms of Streptococcus pneumoniae.

In this study, the gene expression profile of early in vitro Streptococcus pneumoniae biofilm with respect to planktonic cells in cDNA microarray analysis is reported. Microarray analysis with respect to planktonic cells was performed on total RNA extracted from biofilms grown in 24-well microtiter plates. To validate the microarray results, real-time RT-PCR was performed on 13 differentially expressed genes and one constitutively expressed gene. The cDNA-microarray analyses identified 89 genes that were significantly differentially expressed in biofilm and planktonic cells. Genes involved in isoprenoid biosynthesis, cell wall biosynthesis, translation and purine and pyrimidine nucleotide metabolic pathways were exclusively expressed in the biofilms, whereas transcription regulator genes were exclusively expressed in planktonic cells. The real-time RT-PCR results of 13 differentially regulated genes were completely in agreement with the microarray data. The exclusive up regulation in biofilms of genes involved in the mevalonate pathway, cell wall biosynthesis, translation and purine and pyrimidine nucleotide metabolic pathways suggests that expression of these genes may be required for initial biofilm formation, and growth and survival of bacteria in biofilms. The up regulation of related genes suggests that cells in biofilms may be under stress conditions and possibly actively involved in the protein synthesis required to adapt to a new environment.

Case of impacted subglottic metallic foreign body removal without tracheostomy through an endotracheal tube.

A foreign body in the upper airway can cause serious morbidity and mortality, especially in pediatric patients. This case report describes an innovative way to remove an impacted foreign body distal to the vocal folds through an endotracheal tube without tracheostomy.

Prevention of Tracheo-Innominate Artery Fistula Formation as a Complication of Tracheostomy: Two Case Reports.

Tracheo-innominate artery fistula (TIF) is a rare complication of tracheostomy and refers to the formation of a fistula between the trachea and innominate artery. Because TIF is fatal, prevention rather than treatment is very important. Here we report the cases of two high-risk patients who underwent tracheostomy, and in whose cases attempts were made to lower the risk of TIF. In the first patient who developed a chest deformity with Duchenne muscular dystrophy, a tracheostomy was performed with a high-level (cricothyroid level) approach compared with the standard tracheostomy. In the second patient, the thoracic cage was relatively small due to a giant omphalocele, and the risk of a fistula forming was decreased by wrapping the innominate artery with an opened polytetrafluoroethylene vascular graft after resolving crowding of the intrathoracic cavity by total thymectomy. There was no TIF occurrence at the outpatient follow-up in either case. We expect that our approaches may be effective intervention measures for preventing TIF.

Hypofractionated radiotherapy for early stage glottic cancer: efficacy of 3.5 Gy per fraction.

PURPOSE: The purpose of this study was to evaluate the treatment outcomes and toxicity profile of patients with early glottic cancer who underwent hypofractionated radiation therapy (RT) with 3.5 Gy per fraction. MATERIALS AND METHODS: A retrospective review was performed of the medical records of 35 patients with early stage (T1-2N0M0) glottic cancer who underwent definitive RT. The dose fractionation scheme was 59.5 Gy in 17 fractions. Posterior commissure was excluded from the clinical target volume (CTV) for 26 patients (74.3%) without glottic lesions close to this region. RESULTS: With a median follow-up of 16.23 months (range, 6.82 to 67.15 months), no local, regional, or distant recurrence was reported. Acute hoarseness (65.7%), mucositis (68.6%), radiation dermatitis (60.0%) was frequent. One patient (2.9%) reported grade 3 acute toxicity (mucositis) and there was no grade 4-5 acute toxicity. There was no grade ≥3 late toxicities; however, grade 1 late intermittent hoarseness was frequent (45.7%). The receiver operative characteristic analysis revealed that mean hypopharyngeal dose was predictive for acute grade ≥2 mucositis (area under the curve=0.9314; 95% confidence interval, 0.8524-1). The optimal threshold of mean hypopharyngeal dose for occurrence of acute grade ≥2 mucositis was 26.31 Gy, with a specificity and sensitivity of 83.3% and 88.2%, respectively. CONCLUSION: Hypofractionated RT with fraction size of 3.5 Gy for early glottic cancer is effective. The hypopharyngeal mean dose could predict the occurrence of grade ≥2 acute mucositis. The posterior commissure can be safely excluded from the CTV.

Injection laryngoplasty of human adipose-derived stem cell spheroids with hyaluronic acid-based hydrogel improves the morphological and functional characteristics of geriatric larynx.

AIM: As the geriatric population increased, the need of treatment for laryngeal atrophy and dysfunction increased. This study was performed to evaluate the effects of injection of human adipose-derived stem cell (hASC) spheroid-loaded catechol-conjugated hyaluronic acid (HA-CA) hydrogel on therapeutic rejuvenation of the geriatric larynx. METHODS: Stem cell spheroids with hyaluronic acid-based hydrogel were injected into the laryngeal muscles of 18-month-old Sprague-Dawley rats. The effects of hASC spheroids were examined in the following four groups: SHAM, injected with PBS; GEL, injected with HA-CA hydrogel; MONO, injected with single hASCs in HA-CA hydrogel; and SP, injected with hASCs spheroids in HA-CA hydrogel. The rejuvenation efficacy in geriatric laryngeal muscle tissues at 12 weeks postinjection was evaluated and compared by histology, immunofluorescence staining, and functionality analysis. RESULTS: Total myofiber cross-sectional area and myofiber number/density, evaluated by detection of myosin heavy chain with antibodies against laminin and fast myosin heavy chain, were significantly higher in the SP group than in the other groups. The lamina propria of the larynx was evaluated by alcian blue staining, which showed that the HA was increased significantly in the SP group compared to the other groups. In functional analysis, the glottal gap area was significantly reduced in the SP group compared to the other groups. The phase difference in the vocal fold during vibration was also smaller in the SP group than in the other groups, but the difference did not reach statistical significance. CONCLUSION: Injection of hASC spheroids with hyaluronic acid-based hydrogel improves the morphological and functional characteristics of geriatric larynx.

Application and Efficiency of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange in Laryngeal Microsurgery.

OBJECTIVES/HYPOTHESIS: This study aimed to analyze the feasibility of transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) during laryngeal microsurgery (LMS) and investigated its efficiency and application according to the location of the lesion. STUDY DESIGN: Retrospective chart review. METHODS: Patients over 20 years of age who underwent LMS without underlying cardiac, pulmonary, or cerebrovascular disease were retrospectively reviewed. Overall, 54 patients with endotracheal intubation (ETI) and 44 patients with THRIVE were included. The operation and anesthesia time, induction and emergence time, oxygen saturation (SpO2 ), and transcutaneous carbon dioxide (TcCO2 ) levels were analyzed and compared between the two ventilation methods according to disease subsite. RESULTS: Compared with ETI, patients with THRIVE presented reduced operation time (16.3 ± 9.69 min vs. 21.9 ± 12.0 min), anesthesia time (33.6 ± 11.4 min vs. 45.4 ± 13.9 min), emergence time (6.73 ± 2.49 min vs. 8.52 ± 3.17 min), without significant decreases in SpO2 but with increased TcCO2 (10.9 ± 6.12% vs. 7.33 ± 3.86%). Comparing THRIVE to ETI for lesions at the glottis yielded similar findings, which were particularly more significant. However, lesions above the glottis presented no significant difference for any parameters between THRIVE and ETI groups. Lesions involving multiple subsites and prolonged operation time were risk factors for the intraoperative conversion of ventilation method. CONCLUSION: THRIVE is reliable for maintaining oxygenation during LMS and is efficient in reducing the operation and emergence times, leading to shorter anesthesia time, especially for lesions at the glottis. However, caution is required administering THRIVE, when lesion involves multiple subsites, and when operation time is prolonged. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:1061-1068, 2022.

Use of high-flow nasal oxygen in spontaneously breathing pediatric patients undergoing tubeless airway surgery: A prospective observational study.

The use of high-flow nasal oxygen is gaining popularity in apneic and spontaneously breathing adult patients during anesthesia. This prospective observational study evaluated the effect of high-flow nasal oxygen in maintaining adequate oxygenation and ventilation in spontaneously breathing pediatric patients with dynamic airway obstruction, undergoing tubeless airway surgery. Oxygenation was provided via an age-appropriate, high-flow nasal cannula at a flow rate of 2 L kg-1 min-1. Propofol and remifentanil were used to maintain anesthesia while preserving spontaneous respiration. We sought to determine the incidence and risk factors of rescue ventilation. Rescue ventilation with a face mask was performed when the pulse oximetry oxygen saturation was <90% or transcutaneous carbon dioxide was >80 mm Hg. In total, 27 patients were included in the final analysis. Median (interquartile range) of pulse oximetry and transcutaneous carbon dioxide were 100% (99%-100%) and 58.4 mm Hg (51.4-70.3 mm Hg), respectively. Altogether, 9 (33.3%) patients needed rescue ventilation during anesthesia. Of these, 7 patients (25.9%) developed oxygen desaturation (<90%) and 2 patients (7.4%) developed hypercarbia. Patients who required rescue ventilation were significantly younger (8.2 vs 28.8 months, P = .02) and required a longer anesthesia time (55.7 vs 41.0 minutes, P = .04) than those who did not. In conclusion, High-flow nasal oxygen is an alternative technique to maintain oxygenation in children undergoing airway surgeries. However, younger age and longer anesthesia time are significant risk factors leading to the requirement of rescue ventilation in these patients. Further studies with large sample size are required for clinical application of these techniques.