Download PDF
CC BY-NC-ND 4.0 · Endosc Int Open 2019; 07(04): E594-E599
DOI: 10.1055/a-0842-6332
Original article
Owner and Copyright © Georg Thieme Verlag KG 2019

When high viscosity of pancreatic cysts precludes effective EUS-FNA: a benchtop comparison of negative pressure devices

Leonard T. Walsh
1   Penn State Health Milton S. Hershey Medical Center, Internal Medicine, Hershey, Pennsylvania, United States
,
Lindsay Mitchell
2   Penn State, Department of Mechanical and Nuclear Engineering, University Park, Pennsylvania, United States
,
Ansh Johri
3   Penn State College of Medicine, Department of Medicine, Hershey, Pennsylvania, United States
,
Nicholas Matone
4   Burns and McDonnell, Electrical Engineering, Wallingford, Connecticut, United States
,
Mary Frecker
2   Penn State, Department of Mechanical and Nuclear Engineering, University Park, Pennsylvania, United States
,
Matthew Moyer
5   Penn State Health Milton S. Hershey Medical Center, Division of Gastroenterology and Hepatology, Hershey, Pennsylvania, United States
› Author Affiliations
Further Information

Publication History

submitted 25 August 2018

accepted after revision 13 December 2018

Publication Date:
12 April 2019 (online)

Also available at
   Permissions and Reprints

Abstract

Background and study aims Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of pancreatic cystic lesions (PCLs) is an important diagnostic tool; however, it is often unsuccessful due to high viscosity of cystic fluid. In an effort to improve FNA, we objectively compared eight vacuum device configurations to determine the most effective method for aspirating viscous fluid collections. We also tested a high-frequency oscillation (HFO) technique that could be employed in FNA.

Materials and methods Maximum gauge pressures of four vacuum devices were measured: two standard EUS-FNA syringes, a 50-cc Alliance II device, and a nonmedical hand vacuum pump. To aspirate a viscous stock solution, 19-gauge and 22-gauge needles were used and flow rates were calculated. HFO was also applied to the needle during aspiration to determine effect on aspiration rate.

Results Aspiration devices generated maximum gauge pressures ranging from –21.5 to –27.5 inHg. The 19-gauge FNA needle aspirated viscous fluid 11.3 × faster on average than a 22-gauge needle. HFO increased average flow rates by 29.7 % in 19G and 124.6 % in 22G configurations.

Conclusion EUS-FNA of viscous fluid can be optimized by using the lowest possible gauge needle and connecting a vacuum device capable of generating and sustaining near perfect vacuum. This can be accomplished by maximizing syringe volume. In addition, connector-tubing length between the syringe and needle should be minimized, and tubing wall should be sufficiently strong to resist collapse under vacuum. Other novel techniques to increase fluid yield include a hand vacuum pump and application of HFO to FNA.

 

  • References

  • 1 Pusateri AJ, Krishna SG. Pancreatic cystic lesions: pathogenesis and malignant potential. Diseases 2018; 6: 1-12
    PubMedGoogle Scholar
  • 2 Brugge W. Diagnosis and management of cystic lesions of the pancreas. J Gastrointest Oncol 2015; 6: 375-388
    PubMedGoogle Scholar
  • 3 Muthusamy VR, Chandrasekhara V, Acosta RD. et al. The role of endoscopy in the diagnosis and treatment of cystic pancreatic neoplasms. Gastrointest Endosc 2016; 84: 1-9
    CrossrefPubMedGoogle Scholar
  • 4 Oh HC, Kim MH, Hwang CY. et al. Cystic lesions of the pancreas: challenging issues in clinical practice. Am J Gastroenterol 2008; 103: 229-239
    CrossrefPubMedGoogle Scholar
  • 5 Hong SK, Loren D, Rogart J. et al. Targeted cyst wall puncture and aspiration during EUS FNA increases the diagnostic yield of premalignant and malignant pancreatic cysts. Gastrointest Endosc 2012; 75: 775-782
    CrossrefPubMedGoogle Scholar
  • 6 Cengel YA, Cimbala JM. Internal Flow. Fluid Mech Fundament Appl 2014; 3: 347-418
    PubMedGoogle Scholar