The use of extracorporeal membrane oxygenation for elective removal of a massive goitre causing a potentially difficult airway

A 50-year-old farmer presented to our service with a 20-year history of a multinodular goitre (MNG), and 12 months of worsening dysphagia, hoarseness and orthopnoea. Her medical history was significant for obstructive sleep apnoea, pulmonary hypertension, atrial fibrillation and a body mass index of 44. Examination revealed a large, mobile goitre (Fig. 1), slight stridor on deep inspiration, but no Pemberton's sign. At the time of surgery, she was biochemically euthyroid while on carbimazole (5 mg daily). Computerized tomography revealed a markedly enlarged thyroid, extending 15 cm craniocaudally from C1 to T2 (Fig. 2). The trachea was compressed to 7 mm at its narrowest, with displacement of the aerodigestive tract (Fig. 2a). While there was no retrosternal extension, there was significant upward growth to the base of the skull, displacing the oropharynx anteriorly and effacing the cervical lordosis. On airway assessment, the patient had reasonable mouth opening, good neck extension and a Mallampati score of 2. However, the vocal cords were unable to be visualized due to difficulty passing the nasendoscope beyond the nasopharynx. In anticipation of a difficult airway, total thyroidectomy proceeded after extensive multidisciplinary discussions involving endocrine surgeons, otolaryngologists, anaesthetists and intensivists. At the time of surgery, awake fibreoptic intubation (AFOI) was unsuccessful despite excellent topicalization with aerosolized local anaesthetic and patient cooperation. The fibreoptic scope was unable to negotiate the distorted oropharynx (Fig. 2b). Venovenous extracorporeal membrane oxygenation (VV-ECMO) was established before the induction of general anaesthesia, followed by intubation using a C-MAC videolaryngoscope with grade 1 laryngeal view. Total thyroidectomy proceeded without complications, and a large goitre weighing over 1 kg was excised (Fig. 3). Heparinization for the ECMO circuit did not have to be stopped for the thyroidectomy. There were no signs to indicate possible tracheomalacia at the end of the procedure or after extubation. Histopathology confirmed a benign MNG. Patient was decannulated and extubated day one post-operatively, and at the three-month review, the patient reported complete resolution of the obstructive symptoms (Fig. 1c). Large, non-retrosternal MNG are rarely seen in developed countries. Removal of massive MNG poses significant challenges for airway management, where the use of post-induction intubation is associated with a greater risk of morbidity and mortality.1-6 It is well accepted that a large subglottic retrosternal goitre without obvious malignancy rarely requires fibreoptic intubation6; whereas circulatory collapse post induction of general anaesthesia is more of a concern in these situations, especially if there is compression of the right atrium. In the case of large obstructing MNG with supraglottic extension, as in the case presented, the danger is not only of a potentially poor view on laryngoscopy post induction of anaesthesia due airway distortion, but the lack of front-of-neck airway access reduces options in the airway management algorithm.2, 5 As demonstrated, the size and configuration of the goitre precluded all front-of-neck airway access.1-4 While AFOI was a reasonable step, distortion of the oropharynx created an ‘S-bend’, which the fibreoptic scope was unable to negotiate. Without the possibility of a salvage surgical airway, ECMO was deemed the next safest option. Traditionally utilized in acute respiratory failure, VV-ECMO in lieu of ventilation or as a bridge to a definitive airway in elective surgery is a novelty.3, 6-10 The innovative use of ECMO allowed for safe induction of anaesthesia in a controlled environment, without the risk of losing control of the airway. We believe the safe provision of surgery for this patient was the culmination of effective interdisciplinary discussions perioperatively, the availability of sophisticated airway management and surgical techniques, whilst recognizing potential pitfalls and establishing alternative treatment algorithms. AS/CF/MB - data collection and manuscript draft. SH/JP/SG/JS - manuscript review and clinical input. JL - concept, data collection, manuscript review and clinical input. Open access publishing facilitated by Monash University, as part of the Wiley - Monash University agreement via the Council of Australian University Librarians.