B0449 - Outcomes of Endoscopic Ultrasound-Guided Fine Needle Biopsy Using a Novel Hydrostatic Stylet Technique

Monday, October 24, 2022

10:00 AM – 12:00 PM ET

Location: Crown Ballroom

Has Audio

Presenting Author(s)

Patrick T. Magahis, BA

Joan & Sanford I. Weill Medical College of Cornell University
New York, NY

Patrick T. Magahis, BA¹, Donevan Westerveld, MD², Malorie Simons, MD², David L. Carr-Locke, MD², Kartik Sampath, MD², Reem Z. Sharaiha, MD, MSc², SriHari Mahadev, MD, MS²
¹Joan & Sanford I. Weill Medical College of Cornell University, New York, NY; ²New York-Presbyterian Hospital/Weill Cornell Medicine, New York, NY

Introduction: Endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is frequently used to obtain core samples for the diagnostic evaluation of solid lesions. The optimal technique for tissue acquisition using core biopsy needles remains uncertain. Here we report the outcomes of a novel hydrostatic stylet (HS) technique for core biopsy acquisition and evaluate its diagnostic yield, efficacy, and safety compared to conventional stylet slow-pull (SP).

Methods: The steps of the HS technique are detailed in Figure 1. We performed a retrospective analysis of patients who underwent EUS-FNB with core biopsy of solid lesions via HS or SP between January 2020 and April 2022. Exclusion criteria included cystic lesions, non-lesional liver biopsies, and specimens sent for cytological analysis only. Patient and lesion characteristics, the number of passes, sample adequacy, and adverse events were compared between HS and SP techniques.

Results: A total of 272 patients were included with 138 in the HS group and 134 in the SP group (Table 1). The anatomic distribution and size of lesions were similar in both groups with the head of the pancreas and lymph nodes being the two most common locations. The most utilized needle size was 22-gauge in both techniques. Compared to the SP approach, the HS technique demonstrated a significantly lower mean number of passes (1.2 vs 3.5, P< 0.001), higher sample adequacy (97.8% vs 83.6%, P< 0.001), and higher sensitivity (97.1% vs 89.7%). Rates and severity of adverse events in the HS group were comparable to the SP group (1.5% vs 2.2%, P=0.63) and existing literature.

Discussion: The novel HS technique demonstrated significantly improved biopsy sample adequacy and diagnostic yield while requiring fewer passes to obtain higher diagnostic success compared to a conventional EUS-FNB approach. Further prospective evaluation is needed to confirm these pilot findings and optimize EUS-FNB technique.

Figure: Figure 1. EUS-FNB Hydrostatic Stylet Technique Stepwise Progression

A. The stylet is removed from the core needle, and the channel is flushed with sterile water.
B. The stylet is partially reinserted, leaving 30 cm hanging out, in order to reduce friction within the articulating portion of the endoscope and to preserve a hydrostatic column of fluid between the stylet and needle tip.
C. The assistant braces their arm against a fixed object and holds the stylet motionless relative to the patient while the needle is advanced over it into the target tissue, letting go as the needle is withdrawn.
D. The sample is expressed directly into formalin by advancing the stylet and residual water column within the needle so producing a visible tissue core with minimal specimen fragmentation or blood contamination.

Characteristics	HS (n=138)	SP (n=134)	P-value
Male gender, n (%)	80 (58.0)	58 (48.3)	0.015
Age, mean ± SD, years	64.9 ± 13.5	66.2 ± 15.5	0.48
Lesion location, n (%)
Pancreas head	32 (23.2)	40 (29.9)
Lymph node	28 (20.3)	18 (13.4)
Liver mass	23 (16.7)	12 (8.9)
Stomach	11 (8.0)	18 (13.4)
Pancreas body	10 (7.3)	17 (12.7)
Pancreas tail	9 (6.5)	11 (8.2)
Biliary duct	7 (5.0)	4 (3.0)
Pancreas neck	7 (5.0)	4 (3.0)
Pancreas uncinate process	5 (3.6)	4 (3.0)
Duodenum	4 (2.9)	2 (1.5)
Left adrenal gland	2 (1.5)	2 (1.5)
Esophagus	0 (0)	2 (1.5)
Lesion size, mean ± SD, mm
Major diameter	22.5 ± 12.1	23.5 ± 10.9	0.55
Minor diameter	16.8 ± 8.9	19.4 ± 10.7	0.07
Number of passes, mean ± SD	1.2 ± 0.5	3.5 ± 1.4	< 0.001
Size of needle used, n (%)			0.03
19-gauge	17 (12.3)	6 (4.5)
22-gauge	116 (84.1)	126 (94.0)
25-gauge	5 (3.6)	2 (1.5)
FNB puncture site, n (%)			0.22
Gastric wall	63 (45.7)	73 (54.5)
Duodenal wall	73 (52.9)	58 (43.3)
Jejunal wall	1 (0.7)	0 (0)
Esophageal wall	1 (0.7)	0 (0)
Adverse events, n (%)	2 (1.5)	3 (2.2)	0.63
Sample diagnostic, n (%)	135 (97.8)	112 (83.6)	< 0.001
Sensitivity, % (95% CI)	97.1 (91.7-99.4)	89.7 (81.9-94.9)
Specificity, % (95% CI)	100 (89.1-100)	100 (78.2-100)

Table: Table 1. Demographic, Lesion, and Procedural Characteristics for 272 Patients Undergoing EUS-FNB via Hydrostatic Stylet (HS) or Stylet Slow-pull (SP) Techniques

Disclosures:

Patrick Magahis indicated no relevant financial relationships.

Donevan Westerveld indicated no relevant financial relationships.

Malorie Simons indicated no relevant financial relationships.

David Carr-Locke indicated no relevant financial relationships.

Kartik Sampath indicated no relevant financial relationships.

Reem Sharaiha indicated no relevant financial relationships.

SriHari Mahadev indicated no relevant financial relationships.

Patrick T. Magahis, BA¹, Donevan Westerveld, MD², Malorie Simons, MD², David L. Carr-Locke, MD², Kartik Sampath, MD², Reem Z. Sharaiha, MD, MSc², SriHari Mahadev, MD, MS². B0449 - Outcomes of Endoscopic Ultrasound-Guided Fine Needle Biopsy Using a Novel Hydrostatic Stylet Technique, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.