Prospective evaluation of new 22 gauge endoscopic ultrasound core needle using capillary sampling with stylet slow-pull technique for intra-abdominal solid masses.

GOALS: The aim of this study was to evaluate the adequacy and diagnostic yield of the histologic core obtained with a 22 G endoscopic ultrasound histology needle using capillary sampling with stylet slow-pull technique without on-site cytopathologist.
BACKGROUND: No standard technique for new EUS histology needle has been established. STUDY: A total of 125 consecutive patients with intra-abdominal solid masses were enrolled prospectively between October 2011 and March 2013. EUS-guided fine needle biopsy (EUS-FNB) with a 22 G histology needle using capillary sampling with stylet slow-pull technique was performed.
RESULTS: A total of 133 EUS-FNB procedures targeting the pancreas, lymph node, retroperitoneal mass, ampulla of Vater, gallbladder, common bile duct, duodenum, and liver were performed in 125 patients. EUS-FNB was technically feasible in all cases, and a visible core was obtained in 128 cases (96%). Histologic core specimens suitable for pathologic assessment were reported in 111 cases (83%). There were no procedure-related adverse events. According to the determinants of malignancy with EUS-FNB, the sensitivity, specificity, positive and negative predictive values, and accuracy were 85%, 98%, 99%, 77%, and 89%, respectively. In addition, histologic architecture with or without immunohistochemical staining of the core biopsy specimens was useful for pathologic confirmation in 101 cases (76%).
CONCLUSIONS: A 22 G EUS-FNB using capillary sampling with stylet slow-pull technique showed a high diagnostic yield and histologic core acquisition for the histologic diagnosis of various intra-abdominal masses without an on-site cytopathologist. Furthermore, a histologic core with or without immunohistochemical staining was helpful for clinical decision making in 76% of the intra-abdominal solid masses.