BRIEF REPORT Technique for Creation of Artificial Pneumothorax for Pain Relief during Radiofrequency Ablation of Peripheral Lung Tumors: Report of Seven Cases Takao Hiraki, MD, Hideo Gobara, MD, Kentaro Shibamoto, MD, Hidefumi Mimura, MD, Yuko Soda, MD, Mayu Uka, MD, Yoshihisa Masaoka, MD, Shinichi Toyooka, MD, and Susumu Kanazawa, MD ABSTRACT This report describes seven cases in which a pneumothorax was artificially created for relief from severe pain that occurred during radiofrequency (RF) ablation of peripheral lung tumors. In this procedure, the multitined probe surrounding the lesion was advanced into the chest, displacing the tines and the peripheral tumor away from the parietal pleura and the chest wall and resulting in pain relief in one patient; in the remaining patients, an intravenous catheter was also introduced, followed by the administration of carbon dioxide (CO 2 ) into the space between the tumor and the parietal pleura. The pain decreased considerably immediately after this procedure. No complication related to the creation of the artificial pneumothorax was observed. Creation of an artificial pneumothorax is a safe and effective method for pain relief. ABBREVIATION CO 2 = carbon dioxide Pain experienced by patients during radiofrequency (RF) ablation of lung cancer is an important concern. Severe intraprocedural pain may oblige operators to alter the ab- lation algorithm (eg, decrease RF power and ablation time) to reduce pain. Such altered algorithms may affect the ablation zone and, ultimately, local efficacy. Intraproce- dural pain may be more prominent when treating tumors located close to the pleura (1). The parietal pleura and chest wall are sensitive to pain because abundant sensory nerve branches originate from the intercostal nerve, contrary to the case in the visceral pleura and lung parenchyma (2). An artificial pneumothorax was assumed to be effective for pain relief. We discuss seven cases in which an artificial pneumothorax was created for pain relief during RF abla- tion of peripheral lung tumors. CASE REPORT We obtained approval from the institutional review board for performing percutaneous computed tomography (CT) fluoroscopy– guided RF ablation for lung tumors and to report the relevant data regarding these procedures in this retrospective study. Informed consent was obtained from the patients before performing this procedure. We created an artificial pneumothorax in an attempt to relieve pain during RF ablation of lung cancer in November 2005. From November 2005 to January 2010, we have used this method in 33 patients (40 tumor cases). This number includes 27 patients (33 tumor cases) in whom the artificial pneumothorax was created as a prophylaxis against the anticipated pain. These 27 patients were excluded because the mechanism of action of artificial pneumothorax against pain relief cannot be elucidated in this group owing to the absence of a control group. This report is confined to the six patients (seven tumor cases) in whom the artificial pneu- mothorax was created after the patients complained of severe pain. From the Departments of Radiology (T.H., H.G., K.S., H.M., Y.S., M.U., Y.M., S.K.) and Cancer and Thoracic Surgery (S.T.), Okayama University Medical School, 2-5-1 Shikatacho, Okayama 700-8558, Japan. Received August 12, 2010; final revision received November 15, 2010; accepted December 15, 2010. Address correspondence to T.H.; E-mail: takaoh@tc4.so-net.ne.jp None of the authors have identified a conflict of interest. © SIR, 2011 J Vasc Interv Radiol 2011; 22:503–506 DOI: 10.1016/j.jvir.2010.12.018