Modified Montgomery Thyroplasty Procedure

Modified Montgomery thyroplasty was performed under general anesthesia with laryngeal mask insertion and muscle relaxation. The monitoring used was 5-lead ECG, non-invasive blood pressure, pulse oximetry (SpO₂), capnography (EtCO2), depth of anesthesia using Physiometrix SEDLine^®, and neuromuscular relaxation using TOF-WATCH SX^®.
Midazolam intravenous (0.03 mg kg⁻¹) was administered to reduce the patient’s anxiety as premedication. At the time of anesthetic induction, it was administered intravenously fentanyl (0.7 mcg kg⁻¹), propofol (2–2.5 mg kg⁻¹), and rocuronium (0.6 mg kg⁻¹). After 2 min in an optimal neuromuscular relaxation state (TOF ratio 0/0), Auragain laryngeal mask airway was introduced (see Figure 3A). A T-tube connector (Double Swivel Connector-Mallinchrodt™) was applied to the laryngeal mask (see Figure 3B) for subsequent insertion of the flexible fiberscope through it without compromising the anesthetized patient’s airway, ensuring adequate ventilation of the patient (Figure 3 and Figure 4). Repeated doses of rocuronium were administered (0.2 mg kg⁻¹) during the surgery when the TOF ratio was above 2/4 to ensure the relaxation and lateralization of the healthy vocal cord, keeping the glottic lumen open and thus allowing different medialization measurements of the paralyzed vocal cord without putting the airway at risk.
Anesthetic maintenance throughout the sedative was performed with continuous infusions of IV propofol (6 mg kg h⁻¹) and IV remifentanil (0.05–0.15 mcg kg min⁻¹) according to patient needs. For laryngeal mask ventilation, 6–7 mL kg⁻¹ tidal volume was delivered, with a respiratory rate adjusted to achieve an EtCO2 of 25–35 mmHg and a FiO² of 21–50% (reducing to 21% when the electric scalpel was used to minimize the risk of ignition). Likewise, the peak pressure in the airways was evaluated at the time of the tests with the meters mentioned above. This pressure must not exceed 40 cmH₂O, and it was necessary to check that the tidal volume was not reduced by more than 20% compared to the initial volume with the introduction of the definitive prosthesis meter. Therefore, monitoring the peak airway pressure at the time of prosthesis measurement influenced the decision on the definitive size of the final prosthesis.
After surgery, the patient was awakened: the intravenous infusions of propofol and remifentanil were stopped, and sugammadex (2–4 mg kg⁻¹, according to the relaxation grade) was administered IV to reverse the effects of muscle relaxation and speed recovery [23 (link)]. Prior to the removal of the laryngeal mask, the recovery of reflexes and response to basic verbal commands was expected, as well as spontaneous ventilation by the patient with TOF ratio > 0.9.
Other medications administered were: a prophylactic dose of antibiotic, such as 1 g/100 mg of amoxicillin-clavulanate (1 g/100 mg) or ciprofloxacine (200 mg) IV 30 min before the surgery, metilprednisolone (1 mg kg⁻¹) after the anesthesia induction, and paracetamol, ketoprofen and ondansetron iv 20 min before the surgery end.