Dheeraj Kapoor, MD, FCCP, FACEE, FCCS*, Shikha Sachan, MD**, Manpreet Singh, MD, FCCP, FIMSA, FACEE, FCCS*, Jasveer Singh, MD*
*Assistant Professor, **Senior Resident
Govt. Medical College and Hospital, Chandigarh-160030, (India).
Correspondence: Dr. Dheeraj Kapoor, 1207, Sector 32 B, Chandigarh-160030, (India);
Phone: 911724622549, 919646121549; E-mail: email@example.com, firstname.lastname@example.org
There are certain concerns which need special attention in advance duchenne muscular dystrophy (DMD) such as anomalous airway anatomy, choking, risk of aspiration, nocturnal hypoventilation and frequent chest infections. Tracheostomy remains a choice in these patients, particularly those with impairment of bulbar-innervated musculature.  There may be a possibility of repeated endobronchial migration of tracheostomy tube (TT) due to the inherent airway abnormalities leading to airway trauma and refractory bronchospasm, which can delay the weaning process significantly.
A 19 year old boy with a diagnosis of DMD with severe thoracolumbar scoliosis (Cobb’s angle of 55°) was admitted in our ICU following severe respiratory failure. During his stay in ICU, he suffered repeated episodes of refractory bronchospasm leading to significant delay in weaning process. On investigating the cause, we found endobronchial malposition of the distal end of tracheostomy tube in right principle bronchus (Figure 1). We replaced the conventional tracheostomy tube with another tube of same size but with an adjustable fixation color (Vygon®). The flange was adjusted with tip of tracheostomy tube (distal end) at mid trachea and confirmed on chest X- ray (Figure 2) and fiberscope. Decline in peak airway pressures were immediately observed and patient was subsequently weaned off from the ventilator successfully.
DMD patients associated with severe scoliosis are well known to have distorted airway anatomy.  In literature, we could not find any data regarding the optimal choices in TT selection in patients with airway malformations. There are certain important factors such as the width, length, curvature, flexibility, and composition of the tube which need to be considered while choosing an ideal TT in these patients. Essentially, for allowing the linear trans-laryngeal flow of air, the outer diameter (OD) of a TT should not be more than the two-thirds to three-quarters of internal diameter of trachea and the distal curvature of the tube should be concentric and collinear with the tracheal shape. Also, the optimal length of TT should extend at least 2 cm beyond the stoma and 1-2 cm above the carinato possibly avert endobronchial migration and airway trauma.  In modern clinical practice, flexible fiberscope  and advance imaging such as computed tomography (CT) scan  and ultrasonography (USG)  is strongly suggested to fulfill the mentioned requirements by providing precise objective data for exact dimensions of TT in this subset of patients with anomalous airway. Further, we feel that a customized TT with adjustable fixation collar (Portex® Blue Line®, Bivona® Adult TTS™ Adjustable Neck Flange Hyperflex™, Vygon®) may be an optimum choice in these patients. These silicon tubes with adjustable fixation collar may possibly avert the potential complications such as endobronchial intubation or airway trauma in presence of the anomalous airway anatomy. 
Anomalous airway anatomy is one of the major concerns and can prove to be a detrimental factor during tracheostomy tube placement. Thoughtful selection of the customized tracheostomy tube clubbed with precise estimation of airway dimensions with newer imaging modalities is a crucial factor for better clinical outcome and should be enunciated by the intensivists in this subset of patients.
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Figure 1: Arrow showing right endobronchial position of tracheostomy tube
Figure 2: Arrow showing mid tracheal position of tracheostomy tube (with an adjustable fixation collar)