Pre-emptive veno-venous ECMO in advanced tracheal malignancy prior to tracheal stenting

Abstract

Extracorporeal membrane oxygenation (ECMO) is helpful in providing ventilatory support when other conventional methods of ventilation fail. We report a case of successful management of advanced tracheal malignancy with impeding airway obstruction where veno-venous ECMO (VV-ECMO) was instituted prior to performing critical endotracheal procedure. After securing the VV-ECMO through right jugular vein and left femoral vein under local anaesthesia, the tracheal stent placement was conducted under flexible bronchoscope and fluoroscope control. Oxygenation and carbon dioxide levels were maintained by the ECMO. VV-ECMO is a useful adjunct in the management of subglottic difficult airway obstruction due to complex tracheal pathology where conventional ventilation may not be possible or adequate.

Background

Extracorporeal life support is used in the management of patients with intractable cardiac and/or respiratory failure where conventional methods of treatment have failed. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is life-saving in providing severely hypoxic and/or hypercapnic patients with ventilatory support. It has also shown usefulness in the management of patients for non-traditional indications, such as severe upper central airway obstruction.¹

We report a case of successful management of advanced tracheal malignancy where preemptive VV-ECMO was instituted because of impending airway obstruction prior to performing critical endotracheal procedures.

Case presentation

A 62-year-old woman was admitted to the cardiothoracic surgery unit in the university hospital. She was a known case of T2N0M0 squamous cell carcinoma of the left vocal cord 5 years ago that was treated with external beam radiation only. Three months prior to the presentation, she started reporting progressive shortness of breath, stridor and blood-stained sputum.

At the time of presentation, she was tachypnoeic and had stridor at rest. She was tachycardic at 130 beats/min and was gasping for air. The physical examination was notable for inspiratory stridor, otherwise the breath sounds in the chest were clear.

Investigations

She underwent CT scan of neck and chest, which showed evidence of a circumferential enhancing soft tissue lesion measuring approximately 1.7×2.4×3 cm at the distal trachea about 3 cm above the carina. (figure 1A). The lesion was filling >90% of the tracheal lumen with significant luminal narrowing (figure 1B). There were no associated mediastinal lymphadenopathy or lung abnormalities. The site of the previous tumour showed no evidence of recurrence. Since the tracheal lesion was highly suspicious of malignancy, a full-body Positron Emission Tomography (PET) scan was ordered. The PET showed a highly fluorodeoxyglucose (FDG) avid superior mediastinal tracheal mass with a standard uptake (SUV) value of 11.2. There was no uptake in the regional lymph nodes or distant locations.

Figure 1.

CT neck and chest showing a circumferential soft tissue enhancing lesion (A) coronal plane, and (B) transverse plane.

Features were all highly suspicious for endotracheal tumour, probably recurrence of the squamous cell carcinoma. It was located below the vocal cords and extended up to the carina. The length was more than 3 cm and the narrowing of the trachea was very significant, with almost total occlusion of the trachea.

Differential diagnosis

The patient’s case was discussed urgently in oncology multidisciplinary team meeting. Features were highly suspicious of a locally advanced endotracheal tumour. In a patient with previous airway malignancy in almost the same location, a recurrence of the previous tumour type was most likely. It could also be a new tumour type, but is very unlikely to be a benign process.

The length of the tumour was beyond safe surgical tracheal resection and anastomosis. Since the patient would need non-surgical management for the tumour in the form of radiotherapy and/or chemotherapy, a biopsy will be needed to confirm diagnosis and tailor the appropriate therapy. However, the patient was very symptomatic with impending airway obstruction and it would be difficult to safely take a biopsy via a bronchoscope.

Thoracic intensivist/anaesthetists present in the meeting felt that conventional airway management techniques would be risky during the endotracheal procedure as the stenosis was low in the trachea and very tight. In addition, until non-surgical therapies are effective and shrink the tumour, the airway stenosis needs to be relieved and patient made to feel comfortable.

Treatment

The patient was very symptomatic and was severely short of breath with stridor. She was put on non-invasive ventilation and was given steroids to reduce tissue oedema. However, the stridor and shortness of breath did not show any significant improvement.

In view of this clinical picture, we needed to take a biopsy of the tumour to confirm the diagnosis and start therapy. Thus, patient will need placement of a tracheal stent to relieve the airway obstruction, to be followed by medical treatment of the tumour.

Unfortunately, the required stent size was not available inhouse and had to be flown in from the manufacturer, which would take few days. Thus, it was decided to put the patient on VV-ECMO and secure ventilation. This will allow to stabilise the patient until the stent arrives. Once the stent arrives, VV-ECMO will allow safe biopsy of the tumour followed by tracheal stenting without risking the patient’s ventilation with such a critical stenosis.

The patient was in distress with an increased stridor, and she could not lie flat. She was lying at 45 degrees and cannulation was done in a head-up position under local anaesthesia. Respiration was supported with a face mask and high-flow oxygen only. Pre-ECMO insertion arterial blood gas showed pH of 7.22, PO₂ of 98, PCO₂ of 75 and lactate of 4.2.

Awake VV-ECMO was established using a 21 French venous inflow cannula in the right internal jugular vein and a 25 French outflow cannula in the right femoral vein (RMI, Edwards Lifesciences LLC, Irvine, California) percutaneously using the Seldinger technique with the help of ultrasound guidance. Heparin 5000 IU was given at the time of cannulation. Cardiohelp ECMO system (Getinge, Göteborg) was used for ECMO institution. The ECMO settings were stable at flows of 1.8 l/min/m², Revolutions Per Minute (RPM) 1650/min, venous pressure −32 mm Hg and SvO₂ 56%. A target Activated Clotting Time (ACT) of around 160–180 s was achieved with heparin infusion according to protocol. Post ECMO insertion, pH was 7.43, PCO₂ was 33, PO₂ was 226 and lactate was 2.1

The procedure was uneventful, and her stridor improved immediately after instituting the ECMO because of decreased respiratory drive as a result of improvement of oxygenation. She remained on minimal oxygen via nasal prong for 3 days, until the stent arrived.

During the stent placement procedure, the patient’s oxygenation was maintained completely with the VV-ECMO. Anaesthesia was instituted only for patient comfort during airway manipulation. The VV-ECMO allowed continuous and stable oxygenation of the patient so we could perform the tracheal procedure. General anaesthesia was induced with propofol and fentanyl and was maintained with propofol and remifentanil infusion.

We were prepared for bleeding during the biopsy. Minor bleeding can be controlled by packing with topical vasoconstrictive agent like epinephrine or use of antifibrinolytic agent tranaxemic acid. Local coagulation therapy like laser or argon plasma coagulation was available in case the simple procedure to control bleeding did not suffice. Finally, deployment of the covered tracheal stent would have taken care of any remaining bleeding as it would have caused sufficient tamponade of the bleeding spot.

An endotracheal biopsy of the mass was taken. After securing haemostasis, a tracheal stent was placed under fluoroscopic guidance (figure 2A, B). A 22×6 cm Ultraflex uncovered tracheobronchial stent system, distal release, was used (Boston Scientific, Malborough, Massachusetts, USA). The stent was released distally just proximal to the carina and covering the whole tumour length. The post stent deployment bronchoscopy showed a widely open trachea. Biopsy and stent implantation was performed successfully within 60 min without episodes of desaturation.

Figure 2.

(A) Fluoroscopic image of tracheal stent. (B) Post stent placement X-ray.

Outcome and follow-up

The patient was haemodynamically stable and off oxygen post procedure, so the VV-ECMO was rapidly weaned and removed on the same day. Two days later, the patient was discharged, and she remained symptom-free on follow-up 2 weeks later.

Biopsy results revealed invasive, moderately differentiated squamous cell carcinoma. She was offered chemoradiotherapy and tolerated this very well with acceptable minimal side effects.

Two years later, the patient presented with haemoptysis. Repeat bronchoscopy revealed granulation tissue proximal to the stent. The granulation tissue was resected and cleared with a flexible bronchoscope and argon beam coagulation. The fragments were analysed and showed hyperplastic squamous mucosa with acute inflammation and no evidence of malignancy.

The patient remains asymptomatic. She is on regular follow-up and has shown no evidence of tumour recurrence after 3 years.

Discussion

The present case has shown that VV-ECMO has saved the life of a patient, with critical airway obstruction from a tumour, by establishing and stabilising ventilation of the patient. VV-ECMO gave enough time and support to the patient while a critical airway procedure was being planned and executed. The ECMO insertion was pre-emptively done before clinical worsening of the patient, both ventilatory and haemodynamically. It was also done preemptively for expected ventilation difficulties during stent placement.

Few case reports describe the use of ECMO in patients with central airway obstruction. Willms et al have reported the use of emergency ECMO to resuscitate the patient with acute airway obstruction. They also described 12 previously reported cases where ECMO was used in a similar situation. All the patients survived to hospital discharge.²

In 1986, Hicks reported the first use of pre-emptive ECMO in patients with impossible airway.³ As the number of patients with lung cancer and tracheal malignancies is increasing, the likelihood of incidence and chances of central airway obstruction will also increase, especially in elderly patients. Thus, the potential indication for preventive use of ECMO in such a situation will also increase.⁴

Hong et al used pre-emptive VV-ECMO in 18 cases to support ventilation in severe airway obstruction.⁵ Kim et al in their study recommended elective initiation of ECMO in cases where observed tracheal stenosis was less than 5 mm using bronchoscopic or chest CT measurement.⁶ It is increasingly being used in cases requiring complicated tracheal surgery like carinal resection and reconstruction, or long-segment tracheal tumour resection.⁷ The use of ECMO gives better visualisation of the surgical site compared with with the use of conventional ventilation techniques like maintenance of spontaneous ventilation, intermittent positive pressure ventilation via the side port of rigid bronchoscope, and low-frequency or high-frequency jet ventilation.⁸

ECMO not only prevents perioperative death during induction of complex airway, but also increases intraoperative stability and safety. However, it does not come without inherent complications. The most common complication is bleeding associated with the use of anticoagulation and coagulopathy resulting from prolonged exposure of the blood to the foreign external circuit. Heparin-coated cannulas and circuit has improved the safety of the procedure by minimising the use of heparin boluses and even infusions. It has also allowed prolonged safe circuit use of up to 30 days.⁹

Other adverse events include vascular injury caused by cannulation, thromboembolism, ischaemia to distal limb and end-organ ischaemia. These are more common with the use of veno-arterial ECMO compared with patient on VV-ECMO, such as in this case.⁹

Spontaneous ventilation or intermittent positive pressure ventilation was not possible in this case because of severe tracheal stenosis and increasing stridor; any attempt to pass the guiding catheter could have caused catastrophic complete airway obstruction. Distal tracheal intubation via tracheostomy was not an option because of the tumour location in the thorax.

Jet ventilation could have been one of the airway therapeutic options available at the time of tracheal intervention. However, since the patient was demonstrating increasing respiratory distress and stridor, and there was no available suitable tracheal stent at that time, it was important to urgently secure the ventilation and put the patient on elective VV-ECMO for patient safety. Jet ventilation was not considered an option as we were worried about progression to complete tracheal obstruction before stent arrival.

The major consideration in these patients with severely compromised airways is the timing of initiation of ECMO support. A multidisciplinary team approach is paramount in arriving at the correct management strategy.

Thus, VV-ECMO is an important adjunct in the management of patients with critical central airway obstruction. It is not only life-saving, but also allows a relaxed atmosphere to plan and execute the best treatment option available for the patient.

Learning points.

• Veno-venous extracorporeal membrane oxygenation (ECMO) is a novel concept in the management of patients with complex and critical airway disease to provide optimal ventilatory support when the conventional methods are not feasible.

• It should be a multidisciplinary team approach with detailed information about the aetiology and availability of various management options.

• It provides a safe environment during complex airway intervention. ECMO has acceptable complication rates.

• We advocate preventive preoperative ECMO initiation in a subset of patients who are at high risk of catastrophic airway obstruction during airway intervention that can lead to complete airway obstruction in high-grade tracheal stenosis.

Ethics statements

Patient consent for publication

Obtained.