Role of newer imaging modalities for airway assessment in dynamic tracheal compression
A 45 year old female, with body mass index (BMI) 24 Kg/cm2, presented to our hospital with shortness of breath on lying supine for the past 3 months, more so when lying on right side, hence she preferred to sleep on the left side. She had two episodes of hemoptysis. She had been able to perform her daily activities without any distress.\nShe was treated elsewhere as bronchial asthma and referred to our center for evaluation of hemoptysis. On examination, she was found to have a swelling in the left lobe of the thyroid, compressing and pushing the trachea to the right. Auscultation of her chest revealed bilateral inspiratory and expiratory wheeze. CT of the neck and thorax revealed an enlarged left lobe of thyroid measuring 3.4 × 3.3 × 3.4 cm with dense nodular calcification, causing short segment external compression and tracheal luminal narrowing. The stenosis extended from upper margins of C7 to T2 vertebrae, with a length of 3.1 cm and minimal diameter of 0.31 cm []. Fine needle aspiration cytology (FNAC) of the swelling revealed colloid goiter and she was posted for a left hemithyroidectomy.\nRoom air arterial blood gas analysis showed Partial pressure of arterial oxygen (PaO2) of 80.5 mmHg, PaCO2 of 41 mmHg, pH of 7.41. Pulmonary function tests could not be performed because of hemoptysis.\nPreoperative fiberoptic bronchoscopy with a 4.8 mm bronchoscope revealed tracheal compression by extraluminal mass with a smooth margin 1.5 cm below the glottis. Tracheal lumen was narrowed by 80% []. The bronchoscope could not be passed beyond the narrowed segment.\nWhen the patient was explained about the risks and options, she was not willing for any major resection or procedure. After written informed consent, patient was nebulized with 5 ml of 4% lignocaine and pre oxygenated with 100% O2 for 10 min through a nasopharyngeal airway. She was placed supine with a slight left tilt. Intravenously (IV), Glycopyrrolate 0.2 mg, incremental doses of midazolam (2 mg) and fentanyl (100 μg) were given. A 4.5 mm fiberoptic bronchoscope (FOB) threaded through a 5 mm internal diameter (ID) microlaryngeal tracheal tube (MLT) was passed nasally. The FOB was introduced close to the mass, and gently pushed past the obstruction. Lower part of trachea and carina were visualized. There was no bleeding or tumor debris visualized. The MLT was advanced over the FOB. A little resistance was noted but the tube could be passed below the mass without undue force. The FOB was withdrawn and trachea ventilated with a tidal volume of 450 ml, 8 breaths /min, and I: E = 1:3. The left lobe of the thyroid being stony hard and densely adherent to trachea could not be completely resected. As the patient was not willing for tracheal resection and reconstruction, an isthumectomy and release of fibrotic tissue around the trachea was done. Before closure, the 5.0 mm (ID) MLT was replaced with a 6.0 mm ID MLT over an Aintree Intubating Catheter. As this could be passed without any resistance, it was followed by the passage of a 7.0 mm ID endotracheal tube with little resistance. Postoperatively, patient was electively ventilated, anticipating airway edema. Under steroid cover, 24 h later, the patient was extubated over a tube exchanger, with standby tracheostomy. She had no respiratory distress and was discharged on the 6th postoperative day. Histopathology report revealed papillary carcinoma. As the patient did not want any major definitive surgery; she was referred to a regional cancer institute for further management.