Capillary and wet techniques. A pilot study comparing two tissue sampling methods guided by endoscopic ultrasound

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Endoscopic ultrasound (EUS)-guided fine-needle tissue acquisition is crucial for accurate cytopathological analysis.
• Optimizing tissue sample quality is essential for reliable diagnosis of various tumors.

Purpose of the Study:

• To compare the efficacy of two EUS-guided tissue sampling techniques: capillary and wet.
• To determine which technique provides superior sample quality for cytopathological analysis of pancreatic, bile duct, liver, and lymph node tumors.

Main Methods:

• A pilot prospective study involving 26 patients with tumors or metastases.
• Each patient underwent both capillary and wet EUS-guided tissue sampling during the same procedure.
• Samples were evaluated blindly by two pathologists for diagnostic quality.

Main Results:

• The capillary technique enabled diagnosis in 96.15% of cases (Pathologist A) and 96.15% (Pathologist B).
• The wet technique enabled diagnosis in 88.46% of cases (Pathologist A) and 92.30% (Pathologist B).
• Inter-observer agreement for histopathological diagnosis was excellent (kappa=1 for capillary, 0.948 for wet).

Conclusions:

• The capillary technique demonstrated superior performance over the wet technique for EUS-guided tissue sampling.
• Higher sample quality and cellularity were achieved with the capillary method, leading to better diagnostic yield.