Session 4: New Pulse Biopsy Device Safe and Effective in Challenging Cases of Axillary Biopsies: Subgroup Analysis of Initial PULSE Data for Lymph Nodes of Small Size and Difficult Anatomic Location

Purpose: Core needle biopsy (CNB) and vacuum-assisted biopsy (VAB) used for image-guided minimally invasive tissue sampling have inherent design drawbacks regarding needle control, tissue yield and unnecessary tissue trauma due to dead space. This is especially relevant for anatomically complex procedures, such as biopsies of the axillary lymph nodes. Recently a novel 14G vacuum-assisted open-tip biopsy device, which incorporates pneumatic pulse technology to provide controlled needle insertion and accurate lesion targeting, has been developed (NeoNavia Biopsy System, NeoDynamics AB, Sweden). Purpose of the PULSE study (NCT03975855) was to document the performance of this novel device in the axillary lymph nodes.

Materials and Methods: Primary outcome of this ethically approved German prospective multi-center study was success rate (i.e., tissue sampled from the lymph node). A comprehensive set of risk parameters characterizing the anatomic complexity and procedural difficulty of the biopsy was defined and recorded. Initial results based on 115 patients has recently been reported. Post-hoc subgroup analysis presented herein includes patients who presented with at least one major risk parameter, i.e., lymph node size <10mm, distance of <5mm to blood vessel, muscle, or thoracic wall.

Results: In the initial PULSE data set, 50 patients presented with at least one major risk parameter. 62% (31/50), 32% (16/50) and 6% (3/50) patients presented with one, two and three risk parameters respectively. Mean age of patients was 58 years with a mean lymph node size of 15.5mm. Success rate for tissue sampling from the lymph node was 96% (48/50). Hematoma in the axilla occurred in 2% (1/50) of patients (mild). Pain in the axilla was reported in 4% (2/50) of patients (one mild, one moderate). Neither of these complications required treatment. An average of 3 samples were obtained per patient with a mean of 1.5 needle insertions. Pulses facilitated control during needle insertion in 94% (47/50) of cases and stabilization of the target lesion during needle insertion in 92% (46/50) of cases.

Conclusion: The biopsy device was safe and effective for percutaneous tissue sampling in axillary lymph nodes that presented parameters indicating high anatomic complexity and procedural difficulty. Pulses were perceived to stabilize the target lesion and provide needle control during insertion. It was possible to obtain multiple samples with a single insertion.

Clinical Relevance Statement: A new biopsy technology designed for controlled needle insertion, accurate lesion targeting, and high tissue yield is available with documented success in challenging cases of percutaneous axillary lymph node biopsies.