Ingrid Hein

November 06, 2017

TORONTO — The diagnostic yield of bronchoscopy, with or without radial endobronchial ultrasound (R-EBUS), is significantly lower than what has been understood, new research shows.

"We thought we were pretty good at this," said Nichole Tanner, MD, from the Medical University of South Carolina in Charleston. A previous meta-analysis showed a 70% yield for pulmonary nodules (Chest. 2012;142:385-393), she reported.

However, more recently, the American College of Chest Physicians (ACCP) Quality Improvement Registry, Evaluation, and Education (AQuIRE) registry "showed a lower yield for guided bronchoscopy with and without R-EBUS, ranging from 38% to 57%," (Am J Respir Crit Care Med. 2016;193:68-77), she pointed out.

"Perhaps the yield is not as good as the meta-analysis suggests," Dr Tanner explained here at CHEST 2017.

The inability to reach a diagnosis after bronchoscopy in patients with pulmonary lesions, which leads to more invasive testing that involves surgery, is leaving researchers looking for the most effective approach and instruments to do the job.

"We wanted to know the standard yield in the community," she said.

We're just not as good at bronchoscopy as we thought we were.

In their study, Dr Tanner and her colleagues found that ultrathin bronchoscopy with R-EBUS was significantly better than standard bronchoscopy, but yield rates were not up to the 70% commonly thought to be the standard (49.1% vs 37.7%; P = .011).

"What this tells me is that the meta-analysis is not right," she explained. Her team found results closer to those from the AQuIRE registry than from the meta-analysis. "We're just not as good at bronchoscopy as we thought we were; diagnostic yield is, in fact, closer to 50%."

Dr Tanner's team assessed 221 patients who underwent transbronchial lung biopsy with standard fluoroscopy-guided bronchoscopy or bronchoscopy with an ultrathin bronchoscope and R-EBUS with fluoroscopy at one of five centers. Twenty-four patients were excluded from the analysis because of protocol deviations.

Mean age was 67 years in the study cohort, and 51% of the patients were male. Mean lesion size was 30.4 mm in the standard group and 31.8 mm in the in the R-EBUS group.

Table. Location of Lesions Detected

Location of Lesion Standard Bronchoscopy, % (n = 85) Ultrathin bronchoscope plus R-EBUS, % (n = 112)
Left lower lobe 10.6 10.7
Left upper lobe 28.2 31.3
Right lower lobe 20.0 8.9
Right middle lobe 11.8 9.8
Right upper lobe 29.4 39.3


Initially, the diagnostic yield was significantly lower in the standard group than in the R-EBUS group (26.8% vs 48.7%; P = .002).

The 46 patients who did not receive a diagnosis in the standard group were then crossed over to the R-EBUS group, which resulted in the diagnosis of another seven patients, Dr Tanner explained.

The average size of the lesions detected as 31.1 mm (range, 13.0 - 58.7 mm).

The procedure was performed using forceps. "The limitation of this study is that we did not do any fine-needle diagnoses," Dr Tanner said. Previous studies have shown that the use of a needle increases yield.

In fact, she pointed out, a multicenter Japanese study of 305 patients showed a yield of 81% with ultrathin bronchoscope, navigational technology, and endobronchial ultrasound (Am J Respir Crit Care Med. 2015;192:468-476).

But "we don't have that technology available to us," Dr Tanner said.

However, CT-guided biopsy has a yield of about 94% for pulmonary legions. "If I'm concerned enough for a patient, I might consider going straight for that," she said.

Ultimately, bronchoscopy is performed to investigate more than one thing. "You might be suspicious about lung cancer, for example, and this allows you to sample lungs, then the primary lesion. Often, you're trying to get multiple answers," she explained.

"This study says we're bad at this and don't have great yield. My experience is the same," said pulmonologist Yasin Khan, MD, from the University of Toronto.

Any Good at Threading a Needle?

Dr Khan compared the procedure to threading a needle. "If you're holding the edge of the needle really close, you can get it, but if you hold it an inch back, it'll be more difficult to maneuver into eye of needle," he explained.

Skill is also a factor. "These instruments require a certain level of skill or expertise that not every pulmonologist has. If you put an instrument in the hands of someone used to doing standard, but not used to doing thin with R-EBUS, it will be more difficult to get same yield," Dr Khan told Medscape Medical News.

"The closer a lesion is to the opening of an airway, the easier it is to move your bronchoscope," he pointed out. As airways branch more and more, you have less control over where your bronchoscope will go. "For some areas of the chest, the procedure is limited."

"But I do think that this technology has a place," Dr Khan said. If diagnosis is unsuccessful with one of these methods, the next step is the surgical procedure of open biopsy. "A that point, we have to go in and take out a small segment of the lungs to get the lesion out for diagnostic purposes."

Choice of procedure should be personalized to patient preference. It depends on the lesion a patient has, the treatment facility, and the patient's comfort level. "All these things come into the decision-making process," he said.

Although the current instruments are adequate for seeing the lesion, they might not be adequate for performing this procedure, he added.

Dr Tanner and Dr Khan have disclosed no relevant financial relationships.

CHEST 2017: American College of Chest Physicians Annual Meeting : Abstract 1123A. Presented October 31, 2017.

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