Experiences of Tracheal Procedure Assisted by Extracorporeal Membrane Oxygenator
A 43-year-old woman was transferred from another hospital complaining of aggravated dyspnea on exertion. She was diagnosed with squamous cell carcinoma of the trachea with liver and bone metastasis (clinical stage IV, T4N3M1b) one month prior. The trachea mass was located 3 cm below the vocal cord and was worsening the dyspnea (). For symptom relief, mass excision using rigid bronchoscopic cryotherapy was planned. During the procedure, extracorporeal lung assist was also planned to prevent complications such as respiratory arrest due to airway obstruction and a prolonged procedure.\nThe extracorporeal membrane oxygenator (ECMO) insertion and cryotherapy were performed at the intensive care unit (ICU) without intubation. The patient was 159 cm in height and weighed 64.5 kg (body surface area 1.69 m2). Midazolam (2 mg) and ketamine (100 mg) were used for sedation induction, and remifentanil (0.1 µg/kg/min) was continuously infused for sedation during the procedure. Before ECMO cannula insertion, heparin 4,000 IU was administered for anticoagulation. An inflow cannula (18 Fr) was inserted into the right femoral vein, and an outflow cannula (22 Fr) into the left femoral vein according to Seldinger's technique. The peak flow of the ECMO perfusion was 4.0 L/min, and nafamostat mesilate (7.5 mg/hr) was continuously administered via the outflow cannula for anticoagulation. Rigid bronchoscopic cryotherapy was performed for 20 minutes without any complications (). After the procedure, the patient was stabilized without bleeding and cautiously weaned off the ECMO. The total ECMO time was 478 minutes. No problems occurred during or after ECMO perfusion. The patient was transferred to the general ward on same day of the operation and was discharged from the hospital on postoperative day 3. The follow-up bronchoscopy on postoperative day 13, revealed an intact airway with a regressed tumor size ().\nThe representative case was introduced above. A total of planned extracorporeal lung assist in five patients were performed from December 2009 to March 2011 (). The patients' mean age was 64.4 years. The underlying diseases that lead to tracheal stenosis were malignancies in four cases and tracheal stent malfunctions in two cases. A venovenous type ECMO (Capiox Emergency Bypass System; Terumo Inc., Tokyo, Japan) was applied at the ICU in all the cases. Among the six tracheal procedures, three tracheal stent insertions were performed in the fluoroscopy room, and the other procedures at the ICU. The mean ECMO duration was 775.2 minutes. Nafamostat mesilate or heparin was used for anticoagulation. In the stent removal and cryotherapy cases, nafamostat mesilate (mean dosage 0.13 mg/kg/hr) was infused via the outflow cannula to reduce bleeding complications. In the cases using heparin, the activated clotting time was maintained at 160 to 180 seconds.\nExcept in one case, there was no emergency situation or complications during ECMO perfusion. One early death caused by bleeding occurred. A 74-year-old man who had undergone tracheal stent insertion 2 months previously, underwent tracheal stent removal due to a tracheal stent fracture. ECMO insertion and tracheal stent removal were performed without any problems. However, five hours after the procedure, bleeding of an unknown origin occurred despite the use of a low dose of nafamostat mesilate.