Nonintubated anesthesia is feasible and might be associated with shorter surgery time and shorter hospitalization for tracheal/carinal resection and reconstruction. Only case reports and a few small retrospective series study were conducted to evaluate nonintubated anesthesia for tracheal/carinal resection and reconstruction; no randomized control trials exist. Further exploration should focus on selection of optimal candidates and prospective validation.
Key points
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Nonintubated anesthesia is feasible and might be associated with shorter surgery time and shorter hospitalization for tracheal/carinal resection and reconstruction.
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Only case reports and a few small retrospective series study were conducted to evaluate nonintubated anesthesia for tracheal/carinal resection and reconstruction; no randomized control trials exist.
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Further exploration should focus on selection of optimal candidates and prospective validation.
Background
Tracheal resection with end-to-end anastomosis is a very frequent intervention for tracheal tumor or stenosis in general. Tracheal tumor is a rare tumor of the upper respiratory system, consisting of only 2% upper respiratory neoplasms. It usually presents with airway obstruction and irritating symptoms, including cough, sore throat, dyspnea, and shortness of breath. The diagnosis of such disease is confirmed by fibrobronchoscopy or computed tomography. Tracheal stenosis may be caused by prolonged mechanical ventilation, intraluminal and extraluminal neoplasms, or trauma. The resection of stenotic airway segments may significantly improve the patient’s quality of life. However, anesthetic management for both tracheal neoplasms and stenosis procedures is challenging.
Mechanically induced ventilation with intubated anesthesia is considered standard care during tracheal resection and anastomosis, including upper, intrathoracic, and carinal tumor, which requires careful coordination between the surgical and anesthesia teams during airway excision and anastomosis. Once the trachea is transected, a second tube is inserted into the distal airway to assure ventilation. However, mechanically induced ventilation is widely associated with pulmonary damage, and endotracheal intubation also increases the risk of airway edema and stenosis. In some special cases, the intubation could be challenging because of a narrowed airway; then, endoscopic dilation should be arranged, which may be less effective.
Spontaneous ventilation-induced nonintubated surgery has been intensively investigated recently and reported to reduce the perioperative adverse effects of tracheal intubation and general anesthesia in many thoracic diseases. In addition, in order to maintain spontaneous ventilation, the nonintubated procedure is performed without or with very little muscle relaxant, which might be another factor contributing to more rapid recovery after surgery. Furthermore, without the influence of the tracheal tube, end-to-end anastomosis of tracheal has become not only easier and faster but also tidier.
Currently, the evidence on application of nonintubated anesthesia is mainly from case reports, and only 2 case series studies. In 2010, Macchiarini and colleagues first reported a case series of 21 upper tracheal resections for benign stenosis in nonintubated awake patients. Cervical epidural anesthesia and awake sedation were used to maintain spontaneous breathing during surgery. No intraoperative intubation or jet ventilation was required. Twenty consecutive patients with subglottic or upper trachea stenosis were enrolled. Permissive hypercapnia was well tolerated perioperatively. There was no conversion to intubation during surgery or early complications. They experienced only 1 case that required a nasotracheal tube for 36 hours after the surgical procedure. Patients had excellent or good functional outcomes, with no early relapse of stenosis. The investigators suggested that awake and tubeless upper airway surgery is feasible and safe and has a high level of patient satisfaction.
Jiang and colleagues in their surgical center then published the first propensity matching cohorts in 2018, demonstrating that spontaneous ventilation is a feasible procedure in airway surgery in highly selected patients. A total of 18 patients were collected in their study; patients with tracheal/carinal tumor were treated with traditional or spontaneous ventilation video-assisted thoracic surgery (VATS) resection and reconstruction. Both median operative time, carinal reconstruction, and tracheal end-to-end anastomosis times were significantly shorter in the spontaneous ventilation group compared with the intubated group. The lowest oxygen saturation during the procedure was similar in 2 cohorts. No conversion to tracheal intubation was needed in the spontaneous ventilation group. No difference was observed regarding postoperative complications in the 2 groups. Their study suggested that spontaneous ventilation surgery could be a valid alternative to conventional intubated VATS for airway surgery. They emphasized that nonintubated airway surgery not only avoids general anesthesia with tracheal intubation and mechanical ventilation but also provides an ideal surgical field without any intraoperative tubing systems. However, they also proposed 2 major shortages: the first was the small sample size with limited its repeatability in other cohorts, and the second was that strict restriction for body mass index (BMI) of less than 25 would affect its use in a larger population, for example, western countries.
Except for the above 2 case series studies, several case reports describe the use of nonintubated anesthesia in other tracheal surgeries. Shao and colleagues reported a case of complete endoscopic bronchial sleeve resection of right lower lung cancer under nonintubated epidural anesthesia. Peng and colleagues described the technique of nonintubated complete thoracoscopic surgery for carinal reconstruction in a patient with adenocarcinoma of the trachea. Guo and colleagues introduced a case of uniportal video-assisted thoracoscopic surgery in tracheal tumor under spontaneous ventilation anesthesia. Caronia and colleagues reported a cervical tracheal resection and reconstruction under spontaneous ventilation anesthesia. Because of the failure of the repeated endoscopic dilatations and severe stenosis, in their case, nonintubated surgery was the only strategy for a definitive management of tracheal stenosis.
Since the first attempt on nonintubated anesthesia for tracheal resection and reconstruction in 2014, the authors’ center has completed more than 50 such cases. In this study, the authors review this topic and provide some of their experiences on nonintubated anesthesia for tracheal/carinal resection and the reconstruction technique in their center.
Anesthesia management
Preparation Before Anesthesia
Electrocardiogram, heart rate, percutaneous oxygen saturation (Sp o 2 ), end-tidal carbon dioxide partial pressure, and noninvasive blood pressure were routinely monitored after the patient entered the operating room; midazolam and atropine were administered 30 minutes before anesthesia induction.
Anesthesia Induction and Maintenance
Tracheal reconstruction under spontaneous ventilation anesthesia was performed using intravenous anesthesia combined with regional nerve block according to the location and operation of the tracheal tumor, including bilateral superficial cervical plexus block, thoracic paravertebral nerve block, vagus nerve block, and phrenic nerve block.
A laryngeal mask airway (LMA) (Double-laryngeal mask [FORNIA, Disposable Laryngeal Mask]) was used as a supraglottic device for tracheal reconstruction under spontaneous ventilation anesthesia. The laryngeal mask can be easily placed without using a muscle relaxant. Without a muscle relaxant, the airway obstruction caused by the relaxation of the throat muscle is avoided. The LMA is suitable for patients with tracheal tumor or upper trachea stenosis, avoiding difficult tracheal intubation. Single-lumen tracheal tube or a blocked tube could go through the laryngeal mask during surgery for some special needs. The sealing pressure of the LMA can reach 40 cm H 2 O, which meets the requirements of high ventilation resistance. Maintaining an unobstructed airway is the key to tracheal reconstruction under spontaneous ventilation anesthesia. Timely airway suction and distal tracheal suspension are beneficial for obtaining stable oxygenation after the airway is opened.
Cervical Tracheal Reconstruction
Cervical tracheal reconstruction is commonly used in patients with upper airway tumors or postintubation tracheal stenosis. Intravenous sedation and bilateral superficial cervical plexus block can provide adequate analgesia and maintain spontaneous breathing during the operation, and intratracheal anesthesia can avoid intraoperative cough reflexes. Cervical epidural anesthesia, which was selected for upper airway surgery in the previous studies, had been proven to possibly lead to fatal complications, including spinal block, epidural hematoma, bilateral nerve phrenic paralysis, and systemic hypotension. Therefore, the authors prefer bilateral cervical superficial plexus block. According to their experience, after the trachea was opened, the oxygenation and hypercapnia would improve because of the removal of the airway obstruction. When the airway was divided, patients breathed air through the distal tracheal, maintaining Sp o 2 greater than 90%. Mild hypercapnia was noted in some patients, caused by a decrease of minute volume during sedation.
Tracheal and Carinal Reconstruction
VATS tracheal and carinal resection and reconstruction under spontaneous ventilation anesthesia is stricter and more difficult than cervical tracheal reconstruction. Intravenous sedation combined with thoracic paravertebral nerve block is also recommended. An oxygen tube would be placed in the distal trachea or the contralateral main bronchus via the incision after opening the airway. The contralateral lung retains spontaneous breathing to maintain oxygenation. Thoracoscopic vagal nerve block can be simply operated and effectively prevents intraoperative cough. If diaphragmatic movement is obvious during the operation, phrenic nerve block can be performed.
Hypercapnia is common during VATS tracheal and carinal resection and reconstruction. In the authors’ experience, P a co 2 may increase to 80 mm Hg, but it never causes hemodynamics unstable and anesthesia conversion, which is also reported by Jiang and colleagues.
Conversion to Intubation
Conversion to intubation at any time during surgery is feasible. According to the authors’ experience, a decrease in Sp o 2 occurs during the opening of the airway, and a high-frequency snorkel can be connected to the hollow main tube or the main bronchus. When using high-frequency ventilation, it should be confirmed that the airway is open to prevent air pressure or pneumothorax. If improvement of Sp o 2 is not obvious, conversion to tracheal intubation should be performed.
Surgery process
Upper Trachea Resection and Reconstruction
The authors have described the technique of upper trachea resection and reconstruction and reported a case in 2016. The patient was placed in the standard supine position with dorsal flexion of the neck. Sedation was started; also, 40% to 50% oxygen was delivered using a laryngeal mask, and cardiorespiratory vital parameters were constantly monitored as mentioned before. To ensure surgical safety, devices for tracheal intubation and mechanical ventilation were readily available in case of life-threatening airway obstruction or other complications. An additional dose of 2% lidocaine was injected into the surgical site during the operation to achieve an adequate level of anesthesia. At the time of skin incision, lidocaine was infiltrated in the cervical incision area ( Fig. 1 ). Dissection was carried out in a standard way, and, after identification of the upper airway, the trachea was infiltrated with additional lidocaine to avoid cough reflex. A circumferential dissection of the stenotic tract or tumor was performed to preserve the recurrent nerves and tracheal vascularization ( Fig. 2 ). Then, the stenosis or tumor was posteriorly dissected from the esophagus.
