Endobronchial ultrasound–guided biopsies made after an electrocautery incision to the lymph node improved biopsy yields from 39% to 71% in 38 nodes, according to a small study presented at the annual meeting of the American College of Chest Physicians meeting.
"Because it is not always possible to pass biopsy forceps through defects in the lymph node – the literature indicates a failure rate of between 10% and 29% – we developed a novel technique," said presenter Dr. Kyle Bramley of Yale University, New Haven, Conn.
The technique employs EBUS, and involves passing an electrocautery knife activated at 40 W through the working channel of the scope in order to make an incision in the bronchial wall and enlarge the defect in the lymph node. This facilitates passage of the forceps into the node so that a larger biopsy sample can be obtained.
To test their technique, Dr. Bramley and his colleagues designed a prospective observational cohort study at a single tertiary academic medical center. Twenty patients (mean age, 68 years), including 11 women, who were undergoing EBUS were enrolled. An associated lung mass was present in 14 (70%) of the participants; 6 (30%) had isolated lymphadenopathy. One patient had prior lymphoma, and two others had prior lung cancer.
The researchers evaluated 68 nodes in all; 19 patients had nodes greater than 9 mm. Cautery was only used when initial attempts failed to biopsy nodes 9 mm or larger using EBUS-guided miniforceps of 1.2 mm.
The average node size biopsied using EBUS-transbronchial needle aspiration (EBUS-TBNA) was 5.7 mm. The average forceps-biopsied node was 15.8 mm.
In all, 23 nodes were biopsied successfully on the first pass using EBUS-TBNA only. The biopsies yielded diagnostic material such as lymphocytes, malignancy, or granulomas in 15 of these nodes.
Of the 15 nodes that required cautery, 12 yielded diagnostic material, and 3 had no diagnostic material.
The overall yield increased from 39% (15 out of 38) without cautery to 71% (27 out of 38) when cautery was used.
Notably, four patients had clinically relevant discrepancies between their cytologies and histopathologies. "In all four, TBNA provided a definitive diagnosis," said Dr. Bramley. "The forceps provided fibroconnective tissue or necrotic debris."
These results did not negate the efficacy of the cautery technique, according to Dr. Bramley. "We think we had a forceps issue ... the 1.2 mm are flexible, but they were unable to push all the way through a tough lymph node capsule."
Dr. Bramley also said that other factors, including the operator learning curve, the smaller size of the nodes the investigators attempted to biopsy, and the "nonideal" population they were studying, contributed to these results.
He and his colleagues have since adjusted the procedure to make cauterization routine and to include a 1.9-mm transbronchial biopsy forceps needle, "which, incidentally, is a lot less expensive than the larger forceps we’d been using," he said.
Although more study is needed, Dr. Bramley said he and his team believed that this technique would be appropriate for future use in isolated mediastinal lymphadenopathy, especially with a low suspicion of non–small cell lung carcinoma; evaluation of lymphoma; and clinical trials requiring core biopsy.
Dr. Bramley had no relevant disclosures.