A novel rat model for tracheal mucosal damage assessment of following long term intubation.

OBJECTIVE: Tracheal mucosal damage is a well-known complication of endo-tracheal intubation and animal models are essential for studying the underlying cellular injury cascade. The novel rat model described here is based on retrograde intubation via tracheotomy and suture fixation of the tube. It aims to simulate the common clinical scenario of tube-related airway damage due to long term intubation. STUDY DESIGN: Prospective randomized control pilot study. METHODS: Male Sprague-Dawley were randomly assigned into two groups: control (no intubation, n = 10), one week of intubation (n = 13). The animals were then euthanized and the trachea was sent for histological analysis. Epithelial damage, mucosal thickness, mucosal gland hypertrophy and fibrosis were reviewed. RESULTS: Intubation procedure survival rate was 84.6% (11/13) and 100% in the control (10/10). The damaged ciliary mechanism was a common finding in the intubated group compared to the preserved normal ciliary architecture in almost all control rats. Average tracheal mucosal thickness was 119.0 ±â€¯21.8 µm for the control group and 254.6 ±â€¯22.8 µm for the intubated group, (p < 0.001). The ciliary damage score was 1.00 ±â€¯0.02 in the intubated group, and 0 ±â€¯0.02 in the control group. (p < 0.001). The (objective) average total tracheal mucosal gland area was 19,530 ±â€¯24,606 in the intubated group and 10,031 ±â€¯23,461 in the control group (p < 0,05). Collagen deposition seems higher in the intubated trachea compared to the control. CONCLUSIONS: We describe a novel rat-based animal model for simulating tracheal mucosal damage following long term intubation. This animal model is easy to carry out, reproducible and involves containable animal mortality rates. LEVEL OF EVIDENCE: I.

Retrosternal goiter presenting as deep vein thrombosis of the arm.

INTRODUCTION: Deep vein thrombosis of the upper-extremity (ueDVT) is often caused by trauma to the subclavian vein, central venous line and hypercoagulation disorders. CASE REPORT: We present a case of a ueDVT due to retrosternal goiter compressing the right brachiocephalic vein. Low molecular weight heparin was initiated subcutaneously and fluid was aspirated from the thyroid cyst causing an immediate improvement. Cytology detected no malignancy. At eight-month follow-up, the patient showed complete resolution of her symptoms. DISCUSSION: In general, the optimal treatment should include removal of the compressing thyroid. In co-morbid patients and a dominant thyroidal cyst, thyroid aspiration may be sufficient.

A novel rat model for assessment of laryngotracheal injury following transoral intubation.

OBJECTIVE: Laryngotracheal damage is a well-described complication of endotracheal intubation and animal models are essential for studying the underlying cellular injury cascade. This novel rat model is based on transoral intubation and aims to simulate the common clinical scenario of tube-related airway damage. METHODS: Prospective randomized control pilot study. 28 male Sprague-Dawley were randomly assigned into three groups: control, 3-h' intubation and 6-h' intubation. The animals were then euthanized and their laryngotracheal complexes sent for histological analysis. Epithelial damage, mucosal thickness and mucosal gland hypertrophy were reviewed. RESULTS: Total of 13 control animals and 15 intubated animals. 10 intubated animals survived the study protocol. Loss of epithelial surface architecture including damage to the microscopic ciliary mechanism was a common feature amongst all intubated animals. Average mucosal thickness of the larynx (including vocal cords and subglottic area) was 143 ±â€¯88 µm for control rats, 315 ±â€¯101 µm for rats intubated 3 h and 574 ±â€¯174 µm for rats intubated 6 h .This was a statistically significant difference. Average mucosal gland hypertrophy in the laryngeal subsite was 0.41 ±â€¯0.5 in control rats, 1.4 ±â€¯0.5 in rats intubated 3 h and 2.0 ±â€¯0.0 for rats intubated 6 h (statistically significant difference). There was a clear difference between three and 6 h of intubation with poorer mucosal injury parameters for longer intubation. CONCLUSIONS: We describe a novel rat-based animal model for simulating airway mucosal damage following transoral intubation. This animal model is easy to carry out, reproducible and involves containable animal mortality rates.