OBJECTIVE. This study retrospectively evaluates complications after lung radiofrequency ablation (RFA). MATERIALS AND METHODS. Complications were assessed for each RFA session in 420 consecutive patients with 1403 lung tumors who underwent 1000 RFA sessions with a cool-tip RFA system. A major complication was defined as a grade 3 or 4 adverse event. Risk factors affecting frequent major complications that occurred with an incidence of 1% or more were detected using multivariate analysis. RESULTS. Four deaths (0.4% [4/1000]) related to RFA procedures occurred. Three patients died of interstitial pneumonia. The other patient died of hemothorax. The major complication rate was 9.8% (98/1000). Frequent major complications were aseptic pleuritis (2.3% [23/1000]), pneumonia (1.8% [18/1000]), lung abscess (1.6% [16/1000]), bleeding requiring blood transfusion (1.6% [16/1000]), pneumothorax requiring pleural sclerosis (1.6% [16/1000]), followed by bronchopleural fistula (0.4% [4/1000]), brachial nerve injury (0.3...

Iatrogenic injury to the healthy ureter during ureteroscope-guided ablation of malignant or nonmalignant disease can result in ureteral stricture. Transforming growth factor (TGF)-β₁-mediated scar formation is considered to underlie ureteral stricture, but the cellular sources of this cytokine and the sequelae preceding iatrogenic stricture formation are unknown. Using a swine model of ureteral injury with irreversible electroporation (IRE), we evaluated the cellular sources of TGF-β₁ and scar formation at the site of injury and examined in vitro whether the effects of TGF-β₁ could be attenuated by pirfenidone. We observed that proliferation and α-smooth muscle actin expression by fibroblasts were restricted to injured tissue and coincided with proliferation of macrophages. Collagen deposition and scarring of the ureter were associated with increased TGF-β₁ expression in both fibroblasts and macrophages. Using in vitro experiments, we demonstrated that macrophages stimulated by cells that were killed with IRE, but not LPS, secreted TGF-β₁, consistent with a wound healing phenotype. Furthermore, using 3T3 fibroblasts, we demonstrated that stimulation with paracrine TGF-β₁ is necessary and sufficient to promote differentiation of fibroblasts and increase collagen secretion. In vitro, we also showed that treatment with pirfenidone, which modulates TGF-β₁ activity, limits proliferation and TGF-β₁ secretion in macrophages and scar formation-related activity by fibroblasts. In conclusion, we identified wound healing-related macrophages to be an important source of TGF-β₁ in the injured ureter, which may be a paracrine source of TGF-β₁ driving scar formation by fibroblasts, resulting in stricture formation.

Radiofrequency ablation of the lung provides a favorable 3-year overall survival rate of 84% for patients with otherwise surgically resectable colorectal lung metastases measuring 3 cm or smaller. Background Although radiofrequency ablation (RFA) is widely performed for the treatment of colorectal cancer (CRC) lung metastases, its efficacy for candidates with surgically resectable disease is...