Orally Inhaled Drug Particle Transport in Computerized Models of Laryngotracheal Stenosis

2020 ◽  
pp. 019459982095967
Author(s):  
Dennis Onyeka Frank-Ito ◽  
Seth Morris Cohen
Keyword(s):  
Tracheal Stenosis ◽  
Particle Transport ◽  
Particle Deposition ◽  
Inhaled Corticosteroids ◽  
Academic Medical Center ◽  
Subglottic Stenosis ◽  
Laryngotracheal Stenosis ◽  
Drug Particle ◽  
Computed Tomography Images ◽  
Stenotic Segment

Objective Adjuvant management for laryngotracheal stenosis (LTS) may involve inhaled corticosteroids, but metered dose inhalers are designed for pulmonary drug delivery. Comprehensive analyses of drug particle deposition efficiency for orally inhaled corticosteroids in the stenosis of LTS subjects are lacking. Study Design Descriptive research. Setting Academic medical center. Methods Anatomically realistic 3-dimensional reconstructions of the upper airway were created from computed tomography images of 4 LTS subjects—2 subglottic stenosis and 2 tracheal stenosis subjects. Computational fluid dynamics modeling was used to simulate airflow and drug particle transport in each airway. Three inhalation pressures were simulated, 10 Pa, 25 Pa, and 40 Pa. Drug particle transport was simulated for 100 to 950 nanoparticles and 1 to 50 micron-particles. Particles were released into the airway to mimic varying inhaler conditions with and without a spacer chamber. Results Based on smallest to largest cross-sectional area ratio, the laryngotracheal stenotic segment shrunk by 57% and 47%, respectively, for subglottic stenosis models and by 53% for both tracheal stenosis models. Airflow resistance at the stenotic segment was lower in subglottic stenosis models than in tracheal stenosis models: 0.001 to 0.011 Pa.s/mL vs 0.024 to 0.082 Pa.s/mL. Drug depositions for micron-particles and nanoparticles at stenosis were 0.06% to 2.48% and 0.10% to 2.60% for subglottic stenosis and tracheal stenosis models, respectively. Particle sizes with highest stenotic deposition were 6 to 20 µm for subglottic stenosis models and 1 to 10 µm for tracheal stenosis models. Conclusion This study suggests that at most, 2.60% of inhaled drug particles deposit at the stenosis. Particle size ranges with highest stenotic deposition may not represent typical sizes emitted by inhalers.

Endoscopic technique to mark the site of tracheal stenosis for resection

2007 ◽  
Vol 121 (8) ◽  
pp. 790-793 ◽  
Author(s):  
G Lichtenberger ◽  
C Sittel ◽  
A L Merati ◽  
Á Reményi
Keyword(s):  
Tracheal Stenosis ◽  
Tracheal Resection ◽  
Open Approach ◽  
Laryngotracheal Stenosis ◽  
Reconstructive Procedure ◽  
Additional Time ◽  
Reliable Technique ◽  
Diseased Segment ◽  
Inside Out ◽  
Stenotic Segment

AbstractBackground:It is difficult to precisely localise the extent of the diseased segment on the external aspect of a stenotic trachea. A technique has been developed of marking the upper margin of stenosis, in order to open the airway at the appropriate level during segmental resection.Materials and methods:Prior to the open reconstructive procedure, the stenosis is visualised using microlaryngoscopy. An endo-extraluminal technique is used to drive a suture from inside out through the skin; this then serves to mark the exact top margin of the stenotic segment. This suture serves as a guide for the surgeon during the open approach to tracheal resection.Results:This technique was performed in 16 cases, and allowed precise localisation of the stenosis in each case.Conclusion:Transcutaneous localisation of laryngotracheal stenosis, using the Lichtenberger device, is an easy and reliable technique requiring a minimum of additional time.

scholarly journals Advanced Laryngotracheal Stenosis in a Tertiary Provincial Government Hospital: A Prospective Case Series

2019 ◽  
Vol 34 (1) ◽  
pp. 30-33
Author(s):  
Jules Verne M. Villanueva ◽  
Ronaldo G. Soriano
Keyword(s):  
Tracheal Stenosis ◽  
Case Series ◽  
Provincial Government ◽  
Subglottic Stenosis ◽  
Laryngotracheal Stenosis ◽  
Government Hospital ◽  
Prolonged Intubation ◽  
Laryngotracheal Reconstruction ◽  
Prospective Case Series ◽  
Grade Iii

Objective: To describe the clinical profiles, interventions, and surgical outcomes of patients with advanced (grade III and IV) laryngotracheal stenosis prospectively seen over a 2-year period.   Methods:             Design:           Prospective Case Series             Setting:           Tertiary Provincial Government Hospital             Participants:  Five (5) patients with advanced laryngotracheal stenosis       confirmed by laryngoscopy and/or tracheoscopy. Results: Five (5) patients (4 males, 1 female), aged 23 to 31years (mean 27-years-old) diagnosed with advanced laryngotracheal stenosis between June 2016 to June 2018 were included in this series. Four resulted from prolonged intubation (14 - 60 days) while one had a prolonged tracheotomy (13 years). Presentations of stenosis included dyspnea on extubation attempt (n=3), failure to extubate (n=1) and failure to decannulate tracheotomy (n=1). Stenosis length was 3 cm in two, and 1.5 cm in three. Of the five (5) patients, three had grade IV stenosis while two had grade III stenosis based on the Cotton-Myer Classification System. Two of those with grade IV stenosis and both patients with grade III stenosis had undergone prolonged intubation. The stenosis involved the subglottis in three, and combined subglottic and tracheal stenosis in two. Prolonged intubation was present in all three with subglottic stenosis, and in one of the two with combined subglottic and tracheal stenosis. Two patients underwent open surgical approaches while three underwent endoscopic dilatation procedures. Four patients were successfully decannulated while one is still on tracheostomy. None of them had post-operative complications. Conclusion:  Advanced laryngotracheal stenosis is a challenging entity that results from heterogenous causes. Categorizing stenosis and measuring stenosis length may help in treatment planning and predicting surgical outcome.  Keywords: laryngotracheal stenosis; laryngotracheal reconstruction; tracheal resection anastomosis; subglottic stenosis; tracheal stenosis

Tracheal Stenosis: A CFD Approach for Evaluation of Drug Delivery

2015 ◽  
Author(s):  
Shahab Taherian ◽  
Hamid Rahai ◽  
Bernardo Z. Gomez ◽  
Thomas Waddington ◽  
Jeremy R. Bonifacio
Keyword(s):  
Pressure Drop ◽  
Tracheal Stenosis ◽  
Particle Transport ◽  
Particle Deposition ◽  
Transport Model ◽  
Ct Images ◽  
Patient Specific ◽  
Oxygen Intake ◽  
Cfd Simulations ◽  
The Impact

The existence of obstructions such as tracheal stenosis has major impacts on respiratory functions. Therapeutic effectiveness of inhaled medications is influenced by tracheal stenosis, and particle transport and deposition pattern are modified. The majority of studies have focused on obstructions in branches of the airways, where the flow is diverted to the other branches to meet the needed oxygen intake. In this study we have investigated the effects of trachea with and without stenosis/obstruction on particle depositions and air flow in a human respiratory system. Patient specific CFD simulations were conducted; CT-scans of a patient with tracheal stenosis were used to create 3D models of bronchial tree up to 8 generations. The section of the stenosis was manually modified to create a healthy trachea. Comparisons between CFD simulations before and after intervention demonstrate the impact of the stenosis on flow characteristics and particles distribution. The numerical investigations were performed using the implicit Unsteady Reynolds-Averaged Navier-Stokes equation (U-RANS), using the commercially available software (STAR-CCM+) from CD-Adapco, along with K-ω; shear stress transport model. Two sets of CT-images of inhalation and exhalation were used for assigning Patient-specific boundary conditions at the outlets. Lagrangian Phase model was used to simulate particle transport and depositions of 10, 5 and 2.5 micron diameter particles. Results of the particle depositions for 10 micron particles highlight the difference in depositions and ultimately inhaled medications in patients with and without tracheal stenosis. Particle deposition for normal Tidal volume increased due to stenosis from 47% to 51% for 10 Micron particles and not a significant change for the 2.5 Micron particles (from 4.5% to 4.7%). Comparisons of pressure drop in each generation between patient with tracheal stenosis and the healthy lung showed significant increase in pressure drop after the stenosis, which were experienced in all generations downstream. Experimental validation of the CFD results were made with a model of healthy trachea up to 3rd generation, manufactured using Additive Layer Manufacturing (ALM) from CT-images and pressure results were compared with the corresponding CFD results. Good agreements were found.

scholarly journals Our results in surgical treatment of laryngotracheal stenosis, ten years experience

2006 ◽  
Vol 59 (7-8) ◽  
pp. 309-316 ◽  
Author(s):  
Rajko Jovic ◽  
Borislav Baros ◽  
Dejan Djuric ◽  
Milorad Bjelovic ◽  
Karol Canji ◽  
...  
Keyword(s):  
Vocal Cord ◽  
Tracheal Stenosis ◽  
Costal Cartilage ◽  
Segmental Resection ◽  
Laryngotracheal Stenosis ◽  
Cartilage Graft ◽  
T Tube ◽  
Costal Cartilage Graft ◽  
Anterior Posterior ◽  
Stenotic Segment

Introduction. There are numerous techniques for the treatment of laryngotracheal stenosis. The aim of this paper was to present surgical techniques and results of treatment of laryngeal and laryngotracheal stenosis in a ten-year period by retrospective analysis. Material and methods. Medical records of 34 patients (17 male and 17 female) surgically treated for laryngeal or laryngotracheal stenosis between 1995 and 2004 were analyzed. 19 (55.9%) patients had previous surgical procedures, whereas fifteen patients (44.1 %) were diagnosed and treated for the first time. Results. 5 patients had a glottic-subglottic stenosis, 11 patients had a subglottic stenosis, 16 patients had subglottic-tracheal stenosis and 2 patients had a glottic-subglottic-tracheal stenosis. 21 patients had normal vocal cord motion, 8 patients showed unilateral vocal cord fixation, and 5 had bilateral vocal cord fixation. Laryngotracheoplasty with anterior-posterior costal cartilage graft was performed in 24 patients, while single stage segmental laryngotracheal resection of the stenotic part was performed in 8 patients. One patient was operated in direct laryngomicroscopy and one with dilatation of the stenotic segment with T tube insertion. The most common complication was the development of granulation due to use of the Montgomery T-tube which was removed in direct laryngomicroscopy. Except for one patient, 33(97%) patients were decannulated. There was no perioperative mortality. Conclusion. Although laiyngotracheoplasty with anterior-posterior costal cartilage graft placement cannot be used in all cases of laryngotracheal stenosis, it was the method of choice in previously operated patients with segmental resection of the stenotic segment. This method requires use of Montgomery T-tube or anesthesiological tube, which is very hard to keep clean. Better recovery, short hospitalization and excellent results were obtained with the cricotracheal segmental resection. .

scholarly journals Hybrid Knife, a Novel Drug Delivery Tool for Treatment of Tracheal Stenosis: A Case Report

2020 ◽  
pp. 014556132094664
Author(s):  
Yan Yin ◽  
Wen-hui Ma ◽  
Wei Li ◽  
Hai-feng Ma ◽  
Jian Kang ◽  
...  
Keyword(s):  
Tracheal Stenosis ◽  
Balloon Dilatation ◽  
High Efficiency ◽  
Treatment Method ◽  
Subglottic Stenosis ◽  
Submucosal Layer ◽  
Topical Medication ◽  
Pressure Water ◽  
Technological Limitations ◽  
Novel Drug

The treatment of subglottic stenosis remains a challenge due to anatomic and technological limitations, and there is no consensus regarding treatment. Restenosis and granulation formation are the most common complications. Balloon dilatation combined with cryotherapy and adjuvant topical medication is one treatment method. However, the efficacy of adjuvant topical medication is controversial, and the lack of efficacy may be related to the effective dose of the drug delivered to the submucosal layer of the lesion. Therefore, a tool with high efficiency for delivering medications to the submucosal layer via injection may play an important role in treatment. A hybrid knife (HK) with a pressure water jet traditionally used in endoscopy submucosal dissection to inject saline into the submucosa was employed here to inject medications for subglottic stenosis, followed by electrical excision. Here, we report the case of a man with complex subglottic stenosis who underwent balloon dilatation combined with cryotherapy and an adjuvant submucosal triamcinolone injection performed with an HK. The drug was delivered more efficiently into the submucosal layer, and the lumen of the trachea was patent. Performing a submucosal injection with an HK may be a new approach to deliver medications to the submucosal layer for the treatment of tracheal stenosis.

scholarly journals Multimodality Surgical Approach in Management of Laryngotracheal Stenosis

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Ashfaque Ansari ◽  
Annju Thomas
Keyword(s):  
Primary Anastomosis ◽  
Delayed Diagnosis ◽  
Subglottic Stenosis ◽  
Long Term Results ◽  
Laryngotracheal Stenosis ◽  
Surgical Anastomosis ◽  
Suture Tension ◽  
Multiple Treatments ◽  
Almost All

Introduction. Postintubation laryngotracheal stenosis requires a precise diagnosis and an experienced operator in both endoscopic and surgical treatment. This report presents surgically treated cases of laryngotracheal stenosis secondary to long-term intubation/tracheostomy with review of the literature. Materials and Methods. In this retrospective study, we present 5 cases (a 23-year-old male, 13-year-old male, 22-year-old male, 19-year-old male, and 33-year-old female) of postintubation/tracheostomy laryngotracheal (glottic/subglottic) stenosis in the years 2016 and 2017. Each patient was managed differently. Intubation characteristics, localization of stenosis, surgical technique and material, postoperative complications, and survival of patients were recorded. Results. The site of stenosis was in the subglottis in 4 patients and glottis in 1 patient. The mean length of the stenosis was greater in the postintubation group. Postintubation stenosis had a mean duration of intubation of 6.8 days, compared to 206.25 days of cannulation following tracheostomies. Each patient underwent an average of 2 procedures during their treatment course. One patient underwent open surgical anastomosis because of recurrent subglottic stenosis after multiple treatments. Phonation improved immediately in almost all except in the patient who underwent only endoscopic dilatation. Discussion. The reasons for laryngeal stenosis and its delayed diagnosis have been reviewed from the literature. Suture tension should be appropriate, and placement of the suture knot outside the trachea minimizes formation of granulation tissue. The published reports suggest that resection by endoscopy with laser and open technique resection and primary anastomosis are the best treatment modality so far as the long-term results are concerned. Conclusion. Resection of stenotic segment by open surgical anastomosis and laser-assisted resection is a safe option for the treatment of subglottic stenosis following intubation without the need for repeated dilation. Endoscopic dilation can be reserved for unfit patients.

scholarly journals Resection of the stenotic segment with individually tailored anastomosis for symptomatic congenital tracheal stenosis in infants

2014 ◽  
Vol 45 (6) ◽  
pp. e215-e219 ◽  
Author(s):  
P. L. Aaltonen ◽  
J. T. Puntila ◽  
P. K. Suominen ◽  
I. P. Mattila ◽  
H. I. Sairanen ◽  
...  
Keyword(s):  
Tracheal Stenosis ◽  
Congenital Tracheal Stenosis ◽  
Stenotic Segment

Emergency Management of Tracheal Stenosis

1980 ◽  
Vol 89 (1) ◽  
pp. 46-48
Author(s):  
Isaac Eliachar ◽  
Kurt Simon ◽  
Jesmond H. Birkhan ◽  
Henry Z. Joachims
Keyword(s):  
Emergency Management ◽  
Endotracheal Tube ◽  
Tracheal Stenosis ◽  
Airway Patency ◽  
Cuffed Endotracheal Tube ◽  
Temporary Relief ◽  
Small Gauge ◽  
A New Technique ◽  
Definitive Surgery ◽  
Stenotic Segment

A new technique for immediate though temporary relief of airway obstruction due to tracheal stenosis is described. Introduction of a small gauge cuffed endotracheal tube past the stenotic segment, followed by repeated withdrawal with the cuff inflated, allows for effective and safe retrograde bougienage. Airway patency is maintained throughout. Following this procedure introduction of an endotracheal tube or tracheostomy cannula is facilitated and definitive surgery can be planned.

Lathyrogenic Agents as Therapy for Subglottic Stenosis—A Pilot Study

1987 ◽  
Vol 97 (5) ◽  
pp. 446-451 ◽  
Author(s):  
Gary L. Livingston ◽  
Joyce A. Schild
Keyword(s):  
Pilot Study ◽  
Surgical Repair ◽  
Canine Model ◽  
Subglottic Stenosis ◽  
Laryngotracheal Stenosis ◽  
Human Beings ◽  
Scar Contracture ◽  
The Past ◽  
Human Use ◽  
Collagen Cross Linking

The surgical repair of subglottic stenosis (SGS) is often unsuccessful because of recurrence of the scar contracture. Over the past few years, two lathyrogenic agents (compounds that inhibit collagen cross-linking) have been shown effective in prevention of stenosis in animal models that have deep caustic esophageal burns. Since the principles of induced lathyrism have not been applied to the treatment of laryngotracheal stenosis, a pilot study using a canine model was conducted to test the efficacy of penicillamine and N-acetyl-L-cysteine in reduction of the rate of reformation of SGS. In all six animals used, a complete, 10 to 15 mm thick, mature SGS was induced experimentally, then opened with a Co2 laser. The dogs that were treated with lathyrogenic agents exhibited a lower rate of re-stenosis (one maintained patency throughout the 5 weeks of treatment) when compared to the two control dogs. Histologic sections of the subglottis in each dog revealed severe cricoid collapse, necrosis, and scarring, and thus demonstrated similarities to SGS in human beings. The two lathyrogenic agents used in this study are already approved for human use and may represent a valuable form of adjunctive therapy in the surgical management of SGS.

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