Airway management in cervical spine ankylosing spondylitis: Between a rock and a hard place
A 69-year-old gentleman presented with 3 year history of progressive dysphagia. His past medical history was significant for AS with previous anaesthetics notable for failed direct laryngoscopy and considerably difficulty with fibreoptic orotracheal intubation.\nThe patient's presenting dysphagia was first evaluated by the ear nose and throat (ENT) surgeon whose awake flexible fiberoptic nasoendoscopy revealed a significant bulging of the posterior pharyngeal wall into the airway at the level of the epiglottis. A plain X-ray and computed tomography scan of the spine demonstrated significant anterior cervical osteophytes from C3 to C5 with the largest osteophyte of size equivalent to the diameter of the vertebral body at level C3 and C4 [Figure and ]. Patient was referred to the Spine Surgery Unit and he was scheduled to undergo removal of the exuberant anterior cervical osteophytes for symptomatic relief of his dysphagia. The surgeons requested that an elective pre-operative tracheostomy be avoided, if possible as this would interfere with the planned surgical approach through an incision through the anterior triangle of the neck. In the Pre-anaesthetic Clinic, after careful evaluation and discussion with the patient, an awake fibreoptic intubation was planned.\nAfter an appropriate period of fasting, patient was brought to the OR with both the ENT and Spine Surgery teams in attendance. After standard monitoring was instituted, in the semi-sitting position; airway topicalization with 2% lidocaine spray was attempted. A right superior laryngeal nerve block and trans-tracheal injection were performed with 2 ml each of 2% lidocaine. Patient was placed supine, but as his head did not touch the mattress (phantom pillow sign); a stack of flannel in the configuration of a ramp was placed under his head, neck, and torso.\nA modified nasal trumpet (MNT) was prepared by inserting a 15 mm universal connector from a 7.0 mm ID tracheal tube into the flanged end of a 30Fr nasal airway [simulated in ]. This was lubricated and inserted into the left nares. Oxygen (3 l/min) was delivered through this airway using the anaesthetic breathing circuit and capnography confirmed a patent airway and adequate spontaneous breathing. Into the other nares, the split nasopharyngeal airway (SNPA) was inserted. The SNPA is a 32Fr nasal airway, which had previously been cut spirally [simulated in ]. A standard adult fibreoptic bronchoscope (5.5 mm) was loaded with a size 7.0 mm ID reinforced tracheal tube (LMA Fastrach tube, Vitaid, Toronto, Canada). The bronchoscope was introduced through the SNPA and the large posterior pharyngeal wall bulge was evident. Advancing and rotating the SNPA caudad and posterior to the bony bulge was required to facilitate visualisation of the vocal cords,caudad and posterior to the bony bulge. The vocal cords were sprayed with 2cc of 2% lidocaine and the bronchoscope passed into the trachea without resistance. The SNPA was withdrawn out of the nares and peeled off the bronchoscope. The lubricated tracheal tube was then threaded off the bronchoscope into the trachea. Patient tolerated the procedure well and after confirmation of the appropriate position of the tracheal tube, anaesthesia was induced intravenously and then maintained with sevoflurane in an air-oxygen mixture using controlled ventilation.\nThe surgeons performed a left-sided anterior neck approach to the cervical spine and then proceeded to dissect the pharynx off of the osteophytes. The dissection was carried down to the pre-vertebral fascia covering the osteophytes. They removed the anterior osteophytes from C3 to 5. After removal of the bony elements, the pharynx was once again evaluated to make sure there was no soft-tissue pathology. The neck was closed in layers. Throughout the surgery, all monitored parameters remained stable.\nAt the end of surgery, the need for a definitive postoperative airway was discussed. The possibility of pharyngeal oedema and anticipated difficult airway due to the AS were considered and though leaving the trachea intubated was considered, it was decided that the patient would be best served by an elective tracheostomy. After the oxygen delivery was reduced to FiO2 of 0.3, a tracheostomy was performed and the tracheal tube was removed. He woke up breathing comfortably and was monitored in the Post-Anaesthetic Care Unit overnight. The tracheostomy was decannulated on the 3rd post-operative day and he was discharged on the 5th post-operative day. When followed-up 6 weeks later, he continued to be doing well - his dysphagia partially resolved and he was able to swallow semi-solid food.