"Multimodality diagnosis with the joint use of EBUS with ENB has pushed the diagnostic yield of flexible bronchoscopic procedures closer to the sensitivity obtainable through either transthoracic CT-guided or surgical biopsies", noted Armin Ernst, M.D., of Harvard Medical School, who wrote the article with colleagues at the University of Heidelberg, Germany. "The ultimate goal of reliable and minimally invasive biopsy of peripheral lung lesions now appears feasible."
The results of the prospective, randomized and multicentre trial were reported in the first issue for July 2007 of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
The study recruited 120 patients with evidence of peripheral lung lesions or solitary pulmonary lesions on prior CT scans who were randomly assigned to undergo bronchoscopic diagnosis by one of three techniques: EBUS alone, ENB alone, or ENB and EBUS in combination. The diagnostic yield - the percentage of correct diagnoses - of each was then analysed. If these minimally invasive techniques proved inconclusive, a surgical biopsy, the "gold-standard" for diagnosis, was performed.
"The design of the study deserves comment and compliment", wrote Gerard Silvestri, M.D., M.S., in an accompanying editorial. "Rarely do we see a prospective, multicentre trial in the field of interventional pulmonology. Rarer still are subjects randomized to different treatment strategies."
EBUS and ENB represent newer technologies that are growing in use. EBUS allows for direct visualization of lesions, but lacks a navigation system and requires the operator to manoeuver based on prior radiological investigations, such as CT scans. ENB, on the other hand, has a highly specialized real-time navigation system, but lacks a means of directly visualizing the lesion.
The researchers found that the EBUS procedure by itself had a diagnostic yield of 69 percent. ENB alone had a diagnostic yield of 59 percent. But the combination of the two increased the diagnostic yield to 88 percent, independent of lesion size - a highly significant improvement. In addition, the researchers noted a trend toward improved sensitivity in detecting benign diseases, though it was not statistically significant.
The safety of the combined procedures was assessed by tracking of complications. One of the primary negative outcomes in bronchoscopy is pneumothorax. In this study, the rate of pneumothorax using either ENB or EBUS alone was 5 percent, and in the combined procedures it was 8 percent - a statistically insignificant difference. Another concern was that the extended sedation or anaesthesia required in the combined procedure may increase adverse effects due to prolonged sedation or anaesthesia, but none was documented.
In his editorial, Dr. Silvestri notes that this study would most likely benefit patients who were too sick to undergo a surgical biopsy but would benefit from chemotherapy if cancer was confirmed through this combined, minimally invasive technique.