Delayed laryngeal implant infection and laryngocutaneous fistula after medialization laryngoplasty.

BACKGROUND: Medialization laryngoplasty is a common procedure for voice rehabilitation in patients with unilateral vocal fold paralysis. Complications are uncommon and delayed infections involving implants are rare. We report a delayed infectious complication following an animal scratch resulting in a laryngocutaneous fistula. METHODS: Case report. RESULTS: A 73-year-old female underwent a successful and uneventful medialization laryngoplasty for idiopathic unilateral vocal fold paralysis using a silastic implant. More than one year after surgery, she presented with an anterior neck infection following an animal scratch with CT neck findings of a left strap muscle abscess. After incision and drainage, cultures grew methicillin-resistant Staphylococcus aureus. Despite culture-directed antibiotic therapy, the neck continued to drain persistently. Laryngoscopy with stroboscopy revealed a medialized vocal fold with no obvious granulation tissue and normal mucosal pliability. The patient underwent neck exploration revealing a laryngocutaneous fistula. Thus, both the fistulous tract and implant were removed. The wound was closed with a strap muscle advancement into the laryngoplasty window. One month after surgery and antibiotics, the patient had no signs of recurrent neck infection, with a well-healing wound and stroboscopic findings of complete glottic closure, symmetric vocal fold oscillation and acceptable phonation with mild supraglottic compression. CONCLUSIONS: Delayed complications of medialization laryngoplasty are rarely reported. This case demonstrates a delayed infection of a laryngeal implant after an animal scratch requiring implant removal, local tissue reconstruction, and culture-directed antibiotic therapy.

Pyogenic granuloma of the larynx: A rare cause of hemoptysis.

Pyogenic granuloma (PG) may involve gingival mucosa (granuloma gravidarum) in pregnancy but rarely involves the airway. This case report is perhaps the only reported presentation of PG in the larynx causing hemoptysis at a late stage of pregnancy. On laryngoscopic exam, a vascular, right false vocal fold neoplasm was identified with pathological characteristics consistent with PG. Conclusions: Pyogenic granuloma is a relatively common tumor of pregnancy but rarely involves the larynx. In the case of airway involvement during pregnancy, it is best managed in coordination with the high-risk obstetrical team and can be removed safely via standard microsurgical techniques.

Combination Cancer Therapy Using Chimeric Antigen Receptor-Engineered Natural Killer Cells as Drug Carriers.

The therapeutic limitations of conventional chemotherapeutic drugs include chemo-resistance, tumor recurrence, and metastasis. Numerous nanoparticle-based active targeting approaches have emerged to enhance the intracellular concentration of drugs in tumor cells; however, efficient delivery of these systems to the tumor site while sparing healthy tissue remains elusive. Recently, much attention has been given to human immune-cell-directed nanoparticle drug delivery, because immune cells can traffic to the tumor and inflammatory sites. Natural killer cells are a subset of cytotoxic lymphocytes that play critical roles in cancer immunosurveillance. Engineering of the human natural killer cell line, NK92, to express chimeric antigen receptors to redirect their antitumor specificity has shown significant promise. We demonstrate that the efficacy of chemotherapy can be enhanced in vitro and in vivo while reducing off-target toxicity by using chimeric antigen receptor-engineered NK92 cells as carriers to direct drug-loaded nanoparticles to the target site.

Cadaveric Study on the Safety of High-Flow Nasal Oxygen in Laser Microlaryngeal Surgery.

INTRODUCTION: High-flow nasal oxygen (HFNO), or transnasal humidified rapid-insufflation ventilatory exchange (THRIVE), is a technique providing apneic oxygenation and a degree of ventilation during microlaryngeal surgery. Its use with laser has been questioned due to concern for airway fire. For fire to occur, a triad of ignition source, oxidizer, and fuel source must be present. By using HFNO and eliminating an endotracheal tube (fuel source), it is hypothesized that airway fire risk is minimal. We tested this theory with human cadavers using HFNO with increasing levels of FiO2 while performing microlaryngeal laser surgery. METHODS: HFNO was placed on two cadavers, and oxygen was administered at incrementally increasing fraction of inspired oxygen (FiO2) concentrations (30%-100%). Laryngeal microsurgery was conducted with CO2 and KTP lasers applied for 30 s. Oxygen readings were taken at several anatomic locations along the body assessing oxygen concentrations in correlation with increasing FiO2 administration. RESULTS: The use of CO2 and KTP laser on cadaveric vocal folds produced char but no spark or airway fire at any of the tested oxygen concentrations. Apart from the mouth, there was minimal increase in oxygen levels at the surrounding anatomic sites despite elevating FiO2 levels. CONCLUSION: HFNO may be safe to use during microlaryngeal laser surgery. By eliminating the endotracheal tube as a fuel source, risk of airway fire may be negligible. Our study safely applied CO2 and KTP lasers for an uninterrupted 30 s with HFNO at 70 L/min and 100% FiO2 producing no spark or fire. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Cancer Risk Associated with Continuous Positive Airway Pressure: A National Study.

OBJECTIVE: In 2021 the U.S. FDA issued a Class 1 safety recall notice for specific devices due to a risk of carcinogen exposure. The objective of this study was to evaluate reports of cancer linked to CPAP devices to understand implications for the field of sleep medicine. METHODS: Cases of cancer involving CPAP devices were retrieved from the MAUDE database from 2014 to 2021 and analyzed with descriptive statistics. RESULTS: A total of 2571 patient injuries were associated with CPAP. Reports of cancer (n = 209; 4.62%) were the second most commonly documented patient problem associated with CPAP, although 1950 (43.13%) patients had a device problem without an associated injury. Of the 209 cancer cases associated with CPAP, 200 (95.7%) of the adverse event reports were received by the FDA in 2021. There were 174 (9.15%) descriptions of the CPAP polyurethane sound abatement foam degrading in association with a cancer diagnosis, but degradation was more commonly not associated with malignancy (n = 1728; 90.85%). Other frequently documented CPAP device problems included broken devices (n = 279; 6.92%), fire (n = 182; 4.51%), and patient-device incompatibility (n = 144; 3.57%). CONCLUSION: Malignancy associated with CPAP devices has been reported; however, future studies are required to establish causation. Given 95.7% of those documented cases were reported in 2021, otolaryngologists should be prepared to discuss the risks of carcinogenesis associated with CPAP. The otolaryngology community should also be aware of the potential bandwagon effect and the implications for CPAP compliance. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:2270-2274, 2022.

Custom implants for medialization laryngoplasty: a model that considers tissue compression.

OBJECTIVE: Unilateral vocal fold paralysis can be treated with surgical medialization with a carved silastic implant. One challenge to this approach is anticipating the dimensions of the implant for adequate medialization. The purpose of this study was to develop a predictive model for implant design based on a patient's unique laryngeal anatomy and considering compression of the vocal fold. STUDY DESIGN: Retrospective chart review, prospective cadaver study, and prospective patient study. METHODS: A retrospective chart review was performed on patients who received silastic medialization laryngoplasty with favorable outcome and who had preoperative computed tomography. Data including Voice Handicap Index, maximum phonation time, and implant dimensions were collected from medical records, and laryngeal measurements were taken from preoperative imaging. Measurements were taken from computed tomography scans of three cadavers who underwent laryngoplasty for this study. Tissue compression (TC) was calculated and analyzed. A model to predict successful implant dimensions was developed and applied prospectively in 16 patients. RESULTS: Eleven patients from the chart review and three cadavers were included. Of all laryngeal metrics, width of the vocal fold at maximal medialization was most strongly correlated to TC (r = 0.728). Linear regression was performed (y = 0.50x - 1.2, R(2) = 0.53, P = 0.005, F = 12.39). Of the prospective patients, 15 of 16 demonstrated complete glottis closure with the premeasured silastic implant. CONCLUSIONS: Vocal fold compression by silastic implants is linearly correlated with vocal fold-width at maximal medialization. A predictive formula was generated to anticipate TC and was successful in designing custom implants for patients.

Type I gore-tex laryngoplasty for glottic incompetence in mobile vocal folds.

OBJECTIVE: To determine the effectiveness of gore-tex medialization thyroplasty for the management of glottic incompetence (GI) in patients with mobile vocal folds. METHODS: Twenty patients with glottic incompetence (GI) and mobile vocal folds were retrospectively analyzed after gore-tex medialization laryngoplasty. Pre- and postoperative outcome measures including grade, roughness, breathiness, asthenia, strain of the voice (GRBAS), glottal function index (GFI), and voice-related quality of life (VRQOL) were compared to detect surgical effectiveness. Two anesthetic subgroups were identified and compared: general anesthesia, via laryngeal mask airway (LMA) anesthetic, and local anesthesia. RESULTS: Statistically significant differences were identified between pre- and postoperative VRQOL (P<0.0001), GFI (P<0.01), and composite GRBAS (P<0.0001) after a mean follow-up time of 7.8 months. Both the LMA and the local anesthetic subgroups demonstrated similar significance across these measures. GFI and VRQOL scores demonstrate a moderate correlation (ρ=0.71). Perceptual voice quality (GRBAS) correlates slightly better with VRQOL scores (ρ=-0.6; P<0.01) than qualitative measures of glottal function (GFI) (ρ=0.43). CONCLUSION: Gore-tex thyroplasty provides reliable medium-term improvement in both perceptual and subjective voice parameters in the setting of GI with mobile vocal folds.

Identification of a class of HCV inhibitors directed against the nonstructural protein NS4B.

New classes of drugs are needed to combat hepatitis C virus (HCV), an important worldwide cause of liver disease. We describe an activity of a key domain, an amphipathic helix we termed 4BAH2, within a specific HCV nonstructural protein, NS4B. In addition to its proposed role in viral replication, we validate 4BAH2 as essential for HCV genome replication and identify first-generation small-molecule inhibitors of 4BAH2 that specifically prevent HCV replication within cells. Mechanistic studies reveal that the inhibitors target 4BAH2 function by preventing either 4BAH2 oligomerization or 4BAH2 membrane association. 4BAH2 inhibitors represent an additional class of compounds with potential to effectively treat HCV.