The Endoscopic Technique
Two pulmonologists and one respiratory therapist were present at the time of cryoextraction. Two bronchoscopes (Olympus BF-P180, Olympus, Tokyo, Japan) were utilized and each controlled by a separate pulmonologist. A single Olympus endoscope video cart was used. An Erbe (Tubingen, Germany) 1.9-mm multi-use cryoprobe was inserted through the 2.0 mm working channel of 1 bronchoscope and advanced into the center of the thrombus. Freeze times of 5 - 15 seconds were utilized to adhere to the proximal end of the thrombus, being mindful to avoid contact with the ETT or tracheobronchial wall. The bronchoscope and cryoprobe (with attached thrombus) were withdrawn en bloc. Immediately following bronchoscope removal, the assisting respiratory therapist disconnected the bronchoscope-cryoprobe from the video cart and connected the second bronchoscope, already in the hands of the other pulmonologist. This second bronchoscope, with a clean lens and patent suction channel, was inserted into the ETT to assess the airway and control bleeding. Once bleeding was controlled, any fresh blood obfuscating the remaining thrombus was cleared in preparation for repeat cryoextraction. The bronchoscopes were then disconnected-reconnected in the same fashion until the entire thrombus extending from the distal trachea to the left subsegmental bronchi was removed [Figures 1B and 1D]. Due to increasing degrees of active bleeding at the proximal portion of the right main bronchus, dilute epinephrine was instilled near the carina. The procedure was then terminated with plans for cryoextraction of the right side at a later date. The second procedure was performed 7 days later in the same manner, and the entire tracheobronchial tree was subsequently cleared of obstruction [Figure 2]. Roughly 1 week following cryotherapy, the patient was taken off of ECMO and ultimately extubated to non-invasive positive pressure ventilation.