High-Frequency Jet Ventilation Versus Spontaneous Respiration for Percutaneous Cryoablation of Lung Tumors: Comparison of Adverse Events and Procedural Efficiency

BACKGROUND. High-frequency jet ventilation (HFJV) facilitates accurate probe placement in percutaneous ablation of lung tumors but may increase risk for adverse events, including systemic air embolism. OBJECTIVE. The purpose of this study was to compare major adverse events and procedural efficiency of percutaneous lung ablation with HFJV under general anesthesia to spontaneous respiration (SR) under moderate sedation. METHODS. This retrospective study included consecutive adults who underwent CT-guided percutaneous cryoablation of one or more lung tumors with HFJV or SR between January 1, 2017, and May 31, 2023. We compared major adverse events (Common Terminology Criteria for Adverse Events grade ≥ 3) within 30 days postprocedure and hospital length of stay (HLOS) of 2 days or more using logistic regression analysis. We compared procedure time, room time, CT guidance acquisition time, CT guidance radiation dose, total radiation dose, and pneumothorax using generalized estimating equations. RESULTS. Overall, 139 patients (85 women, 54 men; median age, 68 years) with 310 lung tumors (82% metastases) underwent 208 cryoablations (HFJV, n = 129; SR, n = 79). HFJV showed greater rates than SR for the treatment of multiple tumors per session (43% vs 19%, respectively; p = .02) and tumors in a nonperipheral location (48% vs 24%, p < .001). Major adverse event rate was 8% for HFJV and 5% for SR (p = .46). No systemic air embolism occurred. HLOS was 2 days or more in 17% of sessions and did not differ significantly between HFJV and SR (p = .64), including after adjusting for probe number per session, chronic obstructive pulmonary disease, and operator experience (p = .53). Ventilation modalities showed no significant difference in procedure time, CT guidance acquisition time, CT guidance radiation dose, or total radiation dose (all p > .05). Room time was longer for HFJV than SR (median, 154 vs 127 minutes, p < .001). For HFJV, the median anesthesia time was 136 minutes. Ventilation modalities did not differ in the frequencies of pneumothorax or pneumothorax requiring chest tube placement (both p > .05). CONCLUSION. HFJV appears to be as safe as SR but had longer room times. HFJV can be used in complex cases without significantly impacting HLOS of 2 days or more, procedure time, or radiation exposure. CLINICAL IMPACT. Selection of the ventilation modality during percutaneous lung ablation should be based on patient characteristics and anticipated procedural requirements as well as operator preference.

Systemic Air Embolism Following Diagnostic Bronchoscopy

A 51-year-old man was admitted to have a nodule evaluated using chest computed tomography (CT). Shortly after curetting and transbronchial biopsies via bronchoscopy, hypotension, bradycardia, unconsciousness, and left hemiplegia appeared and resolved within one hour. Head CT showed cerebral air embolism. The following day, lower left quadrant pain developed. Pneumatosis intestinalis on abdominal CT and elevation of creatine kinase and troponin T levels indicated air embolism in the mesenteric and coronary arteries. Some reports have documented cerebral air embolism alone after bronchoscopy; however, we should consider systemic air embolism, even when encountering a patient without specific symptoms related to any organ.