SESSION TITLE: Novel Bronchoscopic Treatments
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Tuesday, October 29, 2013 at 04:30 PM - 05:30 PM
PURPOSE: Ablative therapies for lung tumors, such as radiofrequency and cryotherapy, have demonstrated local control, but with significant drawbacks such as fistula formation, and small and irregularly shaped ablation zones. Microwave (MW) energy is ideally suited for ablation in the lung because of its operative characteristics in air and tissue. However, percutaneous approaches have significant morbidity due to puncturing the chest wall. To address these problems, we developed a flexible system capable of delivering MW energy to distal lung during bronchoscopy, and tested this system in in vivo swine lung.
METHODS: Flexible 17 gauge MW antennas were developed for use with a microwave generator (Neuwave, Madison, WI). Each antenna is an enclosed, gas-cooled design. Prototypes were tested in anesthetized pigs. After anesthesia, antennas were bronchoscopically guided through an extended working channel to distal lung under fluoroscopy. Four ablations at different power and time settings were performed in each of three pigs. The pigs were euthanized, the lungs removed, and the ablation zones dissected from the surrounding tissue. Ablation zones were measured, photographed, fixed and examined under H&E staining.
RESULTS: Twelve ablations were performed. Pneumothoracies developed on three occasions, two from inadvertent distal placement of the antenna, and one from an antenna that had gas coolant leak. Each pneumothorax was treated with a chest tube and ablations continued. Ablations measured 1.2 cm to 3.7 cm (short axis) roughly corresponding to the power used, and were approximately oval. Ablations showed central necrosis, surrounded by a zone of edema, a transition zone, and then viable tissue.
CONCLUSIONS: This study suggests that flexible, endobronchial MW ablation in the lung is feasible, avoiding percutaneous approaches and possible complications. Additionally, the ablation zone size and shape appear to be dependent on the power delivered.
CLINICAL IMPLICATIONS: MW is ideally suited for use in the lung, and endobronchial approaches may limit morbidity. Further development may provide for additional lung cancer treatment that is safe and effective.
DISCLOSURE: Rick Schefelker: Employee: Neuwave Medical Matthew Thiel: Employee: Neuwave Medical Mark Thom: Employee: Neuwave Medical Jeff Bissing: Employee: Neuwave Medical Christopher Brace: Grant monies (from industry related sources): Neuwave Medical Fred Lee: Shareholder: Neuwave Medical The following authors have nothing to disclose: John Ferguson, Katarine Egressy
This abstract reports the results of a research study. At this time, the specific technology to be discussed has not been approved for use in humans