Airway management for right thoracoscopic tracheal tumour resection after left pneumonectomy assisted by cardiopulmonary bypass: a case report

Abstract

Background

The incidence of secondary tracheal tumours following lung cancer surgery is notably low. Patients with tracheal tumours typically present with symptoms such as coughing, sputum production, haemoptysis, wheezing, stridor, and dyspnoea. In cases of peripheral structure invasion, symptoms may further extend to hoarseness and dysphagia. Initial symptoms may be notably non-distinct. However, the development of pronounced airway symptoms often signifies a critical condition.

Case presentation

A 70-year-old male with severe chest tightness and asthma was transferred to our hospital for emergency treatment. He had undergone left pneumonectomy for non-small cell carcinoma of the left upper lobe of the lung 3 years prior. The examination confirmed that a secondary tumour originated from the left main bronchus and extended to the carina, occupying 90% of the diameter of the tracheal lumen. To relieve the patient’s emergency airway, we chose right thoracoscopic resection of the tracheal tumour assisted by cardiopulmonary bypass (CPB), which provides extracorporeal lung support and a good surgical field.

Conclusion

In patients with secondary tracheal tumours after left pneumonectomy for lung cancer, perioperative airway management is challenging for anaesthesiologists, and patients’ oxygenation should receive close attention. This article describes the airway management process of this patient for reference.

Background

Tracheal tumours originate from the epithelium, salivary glands and mesenchymal structures. They are rare among respiratory tumours, and malignant tracheal tumours are more common than benign tumours. Squamous cell carcinoma and adenoid cystic carcinoma are the two most common pathological types of tracheal tumours [1]. Secondary intratracheal metastasis of primary lung cancer is extremely rare, with a total incidence rate of only 0.44% (6/1372) [2]. This patient was diagnosed with non-small cell carcinoma in the left upper lobe of the lung three years prior and underwent left pneumonectomy. The postoperative pathology of the tracheal tumour revealed moderate differentiation of squamous cell carcinoma, which was a secondary tracheal tumour from the left main bronchus. Conventional tracheal tumour treatment was not suitable for this patient. In consideration of many factors, cardiopulmonary bypass (CPB)-assisted right thoracoscopic resection of the tracheal tumour was selected.

Case Presentation

Clinical presentation

A 70-year-old male experienced dry cough, chest tightness, and asthma, leading to admission to a local hospital. A chest computed tomography (CT) scan was performed (Figs. 1 and 2), revealing an abnormal density shadow with enhancement at the left bronchial opening and a shrunken left thoracic cavity after left pneumonectomy. Consequently, the patient was transferred to our hospital for emergency treatment.

Fig. 1

Preoperative horizontal CT of the patient

Fig. 2

Preoperative coronal CT of the patient

Three years prior, the patient had been admitted to our hospital’s cardiothoracic surgery department with an obstruction in the upper lobe of the left lung found by CT. He was diagnosed with non-small cell lung cancer of the left upper lung via fiberoptic bronchoscopy. The patient underwent left pneumonectomy and regional lymph node dissection under general anaesthesia with single-operation hole thoracoscopy. Postoperative pathology revealed the following: (1) The presence of medium-to-low differentiated squamous cell carcinoma in the left main bronchus, surrounded by high-grade squamous intraepithelial neoplasia. The lesion measured 3 cm×2.5 cm, extended along the main bronchial wall, and invaded the upper and lower lobes of the proximal bronchus, with significant deep intrusion into the lamina propria. Cancer recidivism was observed in the subepithelial mesenchyme above the main bronchial margin, with high-grade squamous intraepithelial neoplasia on the surface. (2) The presence of medium-to-low differentiated squamous cell carcinoma in the left upper lobe, measuring 3.5 cm×3 cm×2.5 cm, and the visceral pleura showed no signs of cancer recurrence. The surgeon suggested expanding the scope of resection to include carinal resection and reconstruction at that time, which was riskier than expected. Consequently, further resection was not performed after communicating with the family. The surgeon suggested postoperative radiotherapy and chemotherapy, but the patient did not follow medical advice. He came to the hospital for re-examination six months after this operation, and the CT image (Fig. 3) showed there was no recurrent tracheal tumour following the left pneumonectomy.

Fig. 3

CT re-examination after left pneumonectomy

The patient had a history of hypertension but no history of other diseases. At admission, the patient’s diagnosis included a secondary tracheal tumour originating from the left main bronchus and extending to the carina, main airway stenosis, postoperative non-small cell carcinoma of the left upper lobe, pulmonary infection, and Grade II hypertension.

The patient was admitted to the hospital requiring supplementary oxygen through a dual nasal system, achieving a pulse oximeter oxygen saturation (SpO₂) of 90% with an oxygen flow rate of 5 L/min. The presenting symptoms included dyspnoea, laryngeal stridor, and signs of irritability. Upon transfer to the intensive care unit (ICU) on the same day, the patient displayed a heart rate (HR) of approximately 110 beats/min and a blood pressure of 188/99 mmHg. Treatment involved the initial infusion of dexmedetomidine at a 1 µg/kg/h dosage for the first 10 min, followed by a reduced rate of 0.6 µg/kg/h for sedation purposes. Additionally, respiratory support was provided through high-flow nasal cannula oxygen therapy (HFNC) with a flow rate of 50 L/min, a fraction of inspiration O2 (FIO₂) of 50%, a SpO₂ of 100% and a respiratory rate (RR) of 20 beats/min. Blood pressure monitoring and blood gas analysis were facilitated through left radial artery catheterization. The blood gas analysis revealed the following: FIO₂: 41.00%, potential of hydrogen (pH): 7.21, partial pressure of carbon dioxide (PCO₂): 77.40 mmHg, partial pressure of oxygen (PO₂): 213.20 mmHg, lactic acid: 3.40 mmol/L, and HCO³⁻: 30.90 mmol/L. There were no detected abnormalities in coagulation function.

Fiberoptic bronchoscopy was performed under electrocardiogram (ECG) monitoring, full sedation, and bedside monitoring by an intensive care physician. The results (Fig. 4) revealed that new organisms were present in the lower trachea; there was protrusion from the lumen, an abundant blood supply on the surface, and the tumour originated from the left bronchial stump; and no bleeding was detected. After multidisciplinary consultation, right-sided thoracoscopic resection of the tracheal tumour under the support of CPB was planned on the second day.

Fig. 4

Tracheal tumour under fiberoptic bronchoscopy

Surgical procedures

When the patient entered the operating room, he was short of breath and unable to lie flat, so he was positioned on his right side. HFNC was administered, and his vital signs were recorded as follows: arterial blood pressure (ABP): 196/93 mmHg, HR: 82 beats/min, RR: 28 beats/min, SpO₂: 100%. The arterial blood gas analysis revealed the following: FIO₂: 41.00%, pH: 7.27, PCO₂: 78.66 mmHg, PO₂: 497.96 mmHg, lactic acid: 1.01 mmol/L, and HCO³⁻: 35.50 mmol/L. Nicardipine was administered at 3 mg/h for continuous pumping, and the ABP gradually decreased to 149/76 mmHg. We allowed the patient to gargle 10 mL of 1% dyclonine mucilage hydrochloride and inhaled sevoflurane, and we gradually increased the concentration of sevoflurane from 1 to 2.5%. After the patient regained consciousness, 10 mL of 2% lidocaine was sprayed for airway surface anaesthesia. Transoral fiberoptic bronchoscopy revealed a new hard mass in the trachea above the carina, and the 5.2 mm fiberoptic bronchoscope barely passed. The ID7.0 mm tracheal tube was placed above the new organism in the airway at a depth of 21 cm under the guidance of a fiberoptic bronchoscope.

We allowed the patient to breathe 2.5% sevoflurane, preserving spontaneous respiration, and changed the patient to a flat position. We administered 400 U/kg heparin intravenously, and then the right femoral artery and vein were cut and placed with a catheter, which was connected to the CPB machine for later use. With the patient in the left lateral position, the activated clotting time of whole blood (ACT) was measured at 490 s, and then CPB was initiated at a flow rate of 4.0 L/min. General anaesthesia induction was performed with 0.5 mg/kg midazolam, 1 mg/kg propofol, 0.5 µg/kg sufentanil, and 0.2 mg/kg mivacurium. Intraoperative anaesthesia was maintained with 200 mg/h propofol, 1 mg/h remifentanil, and 18 mg/h mivacurium, and the BIS value was maintained at 40–60. At the same time, we monitored the SpO₂ of both upper limbs of patient.

The surgeon explored the right side of the chest under a thoracoscope, and the singular venous arch was severed after clamping with the Endo-GIA. Later, we stopped respiration and made a 2 cm longitudinal incision in the tracheal membrane to the right of the carina, but the SpO₂ of right upper limb suddenly decreased to 78%. We immediately placed a sterile suction tube connected to oxygen in the distal right main bronchus for ventilation, and then, the SpO₂ gradually increased to 96%. The tumour grew out of the left bronchial stump, protruded out of the main airway, and basically blocked the airway. The diameter of the tumour was approximately 1.5 cm, and the pedicle was located at the root of the left main bronchial stump.

The tumour was completely resected via an electrocoagulation hook and ultrasonic knife, and the specimen was sent for pathology. Considering that the distal end of the left main bronchial stump and the left pulmonary trunk stump were adhered together and could not be separated, and that the duration of CPB should not be too long, only tumour resection was performed, after which the sputum suction tube was removed and the tracheal incision was sutured. Later, we restored the anaesthesia machine to control ventilation, stopped cardiopulmonary bypass, and provided protamine to antagonize heparin. The surgeon used warm water to rinse the chest and then inflated the right lung, which expanded well with no air leakage in the trachea or lung lobes. Postoperative pathology revealed the following: (1) Endotracheal neoplasia showing squamous cell carcinoma with moderate differentiation; (2) Trachea: ALK (-) C-met (-).

Follow up

The patient was admitted to the ICU for monitoring and treatment after surgery and was successfully extubated that night. He was transferred to the general ward the next day and was discharged from the hospital with a cough suppressant after a good recovery.

He returned to the hospital for a follow-up consultation one month later. The CT image (Fig. 5) and fiberoptic bronchoscopy result (Fig. 6) revealed that there was no clear indication of tumour recurrence or metastasis.

Fig. 5

Postoperative chest CT of the patient

Fig. 6

Postoperative fiberoptic bronchoscopy of the patient

Discussion and conclusions

In this case, the patient experienced a noticeable obstruction in the left main bronchus stump after left pneumonectomy, which extended to the carina of the main bronchus. This led to the obstruction covering approximately 90% of the trachea’s diameter and resulted in severe dyspnoea. Typical treatment approaches for tracheal tumours include endoscopic treatment, radiotherapy, chemotherapy, and surgical resection. However, owing to the substantial size of the tumour and its abundant surface blood supply, endoscopic treatment was considered high risk. As such, surgical resection was selected after multiple medical disciplines were consulted. Compared with traditional thoracotomy, thoracoscopic surgery has several benefits, including less trauma, less bleeding, less impact on lung function and faster postoperative recovery. However, the patient posed a few surgical challenges. These included left thoracic adhesion following left pneumonectomy and the deep location of the tumour near the carina, which was obscured by the aortic arch, making it troublesome to expose. Additionally, the azygos vein crosses the root of the right main bronchus. This posed an increased risk of accidental injury to the vein, which could lead to excessive bleeding and difficulty in haemostasis, thus increasing the overall operational risk [3]. Considering all the factors, right thoracoscopic resection was ultimately chosen.

Thoracoscopic surgery provides ample space for the procedure, and given the patient’s history of left pneumonectomy, one-lung ventilation on the left was not an option. Thus, the procedure can only be conducted with the support of extracorporeal membrane lung oxygenation (ECMO) or CPB. While there has been a case of ECMO-assisted carina resection and reconstruction after left pneumonectomy [4], the patient’s financial situation drove us to opt for CPB in this case. CPB replaces the patient’s lung function, avoids the adverse consequences caused by complete airway obstruction, and facilitates airway management [5]. Additionally, there is no need to cross the tracheal tube during the operation, which reduces the interference of the pipeline and provides a good visual range for the surgery. Owing to the large amount of heparin used during surgery, patients are at high risk of coagulation dysfunction and bleeding. However, heparin coating in the ECMO circuit can reduce the use of heparin, thus reducing the risk of bleeding and the side effects caused by the use of various blood products [6]. After establishing an effective airway, we immediately used protamine to antagonize heparin, thereby restoring mechanical ventilation, shortening the duration of CPB and reducing the risk of bleeding. Primary tracheal tumours were first resected under CPB in 1961 [7], and then other extracorporeal life support techniques were applied to tracheal surgery [8].

The patient was brought into the operating room in a right lateral position, which presented challenges in establishing femoral arteriovenous cannulation. In addition, anaesthesia induction could have led to muscle relaxation and potential collapse of the bronchial tube wall due to the sizable tumour, which could have caused total obstruction of the tracheal cavity and failure to sustain oxygenation. As a result, establishing catheterization for CPB before anaesthesia induction was crucial.

Under sedation and surface anaesthesia of the airway accomplished through the inhalation of 2.5% sevoflurane, spontaneous breathing could be maintained, which made tracheal intubation successful, and the patient was placed in a supine position for catheterization. The administration of sevoflurane to patients with challenging airways offers several benefits; it not only sedates patients, reduces agitation and oxygen consumption but also allows them to maintain spontaneous breathing. This prevents the fiberoptic bronchoscope from initiating a tracheal spasm, reducing the risk of respiratory obstruction and ensuring effective oxygenation [9,10,11].

Given the patient’s inability to be intubated smoothly and the possible damage to organs due to hypoxia, we decided to utilize CPB. Following successful catheterization, systemic heparinization was initiated for CPB. When the trachea was cut and mechanical ventilation was stopped, the patient’s SpO₂ was only 78%. The patient may have developed Harlequin Syndrome, a common complication of femoral arteriovenous cannulation for CPB parallel to spontaneous circulation. Its main mechanism is that a portion of the upper body’s blood flow is powered by the heart, but the blood could not be oxygenated due to nonventilation of the lung, resulting in lowered peripheral oxygen saturation. The main solutions are as follows: (1) Use vacuum-assisted venous drainage (VAVD) to drain blood from the right heart under negative pressure so that more saturated blood infused from the femoral artery would be supplied to the whole body. (2) Improve lung function to increase the oxygen content of blood ejected from the heart. (3) Increase pump perfusion volume to ensure oxygen supply. So a sputum suction tube was guided to the distal right main bronchus. This enabled oxygen to diffuse into the right lung, maintaining an adequate ventilation/perfusion ratio of the right lung and ensuring oxygenation. As a result of these manoeuvres, the patient’s SPO₂ gradually increased to 96%. However, caution is needed, as a larger pump perfusion volume, although helpful in maintaining upper body blood perfusion, might also increase left ventricular end-diastolic pressure, leading to the development of pulmonary oedema. Appropriate hypothermia is also an effective intervention to decrease the potential organ damage arising from hypoperfusion. In addition, for early detection we should continuously monitor the SpO₂ on both sides of the patient and measured blood gas on both sides every 15 min.

This case presented unique challenges for airway management due to left pneumonectomy and airway tumour resection through a right thoracoscope. These constraints require ensuring the patient’s oxygenation while simultaneously collapsing the right lung to provide enough surgical space. Therefore, the optimal strategy for airway management hinges on the use of either CPB or ECMO. During CPB, anaesthesiologists must closely monitor the patient’s oxygenation to counteract any potential hypoxia arising from low blood flow perfusion or blood hedging. Furthermore, rigorous respiratory management should be implemented during CPB. This scenario inevitably demands that anaesthesiologists possess not only rich knowledge and experience in airway management but also a high degree of proficiency in the perioperative management of CPB.