Spontaneous ventilation with double-lumen tube intubation for video-assisted thoracic surgery thymectomy: a pilot study

Background: Spontaneous ventilation is considered the most physiological anaesthesia method in thoracic surgery; however, this procedure is controversial because of the potential risk of an unsafe airway. We conducted a retrospective, monocentric, interventional cohort study, which was a pilot evaluation of Spontaneous Ventilation using a double-lumen tube Intubation (SVI) technique for video-assisted thoracic surgery (VATS) thymectomy. Methods: Fifteen patients underwent SVI VATS thymectomy in two groups: myasthenia gravis (MG) group ( n=11) and non-MG group (n=4), with a mean age of 34.6 and 41.1 years, respectively. The mean body mass index (BMI) was 24.6 (range, 15.9-33.7) kg/m(2). SVI VATS thymectomy was performed with a short relaxation period for intubation, local anaesthesia for the right incision, and vagal and intercostal nerve blockade. After the relaxant effect, the patient breathed spontaneously, and a thymectomy was performed. Sufficient oxygenation was achieved with positive end-expiratory pressure (PEEP) and pressure support ventilation (PSV). Results: SVI VATS thymectomy was performed without conversion to sternotomy, thoracotomy, or mechanical ventilation. The patients breathed spontaneously for 77.56% of the operative time. The median minimal arterial oxygen tension, median maximal arterial carbon dioxide tension, and median operative time were 82.4 ( range, 56.1-247.2) mmHg, 59.2 (range, 44.8-67.8) mmHg, and 75 (range, 60- 120) min, respectively. The median chest tube duration and length of postoperative hospital stay were 1 and 4 days, respectively. In one patient with MG, reintroduction of a chest tube was necessary because of pneumothorax. In two patients with MG, myasthenic symptoms progressed postoperatively and required neurological admittance, although no myasthenic crisis occurred. Histological analysis in the MG group revealed persistent thymus in seven cases, persistent thymus and follicular hyperplasia in three cases, and fatty tissue with lymphoid infiltration in one case. In the non-MG group, a persistent thymus was observed in two cases, while follicular hyperplasia and micronodular thymoma were reported in one case. Conclusions: The SVI VATS approach is safe and feasible for thymectomy. However, further studies are required to verify the advantages of spontaneous ventilation during thymectomy for MG.