Pull vs. wet: rendimiento diagnóstico y calidad de las muestras de las PAAF guiadas por USE en las masas sólidas del páncreas

Differential diagnosis of pancreatic masses is challenging. The endoscopic ultrasound-guided fine-needle aspiration method with the highest diagnostic yield has not been established. It was realized a prospective, randomized, double-blind study of the endoscopic ultrasound-guided fine-needle aspiration in solid lesions of the pancreas to compare and evaluate diagnostic yield and aspirate quality between wet and pull technique. Forty-one patients were enrolled. The wet technique presented a sensitivity, a specificity, a positive and negative predictive value, and a diagnostic accuracy of 58.3%, 100%, 100%, 25% and 63.4%, respectively. In the capillary technique they were: 75%, 100%, 100%, 35.7% and 78.1%, respectively. Comparing the diagnostic yield between both techniques, there was no statistically significant difference (McNemar’s test p = 0.388). Regarding the cellularity of the specimen, both in cytology and the cell block samples, no significant difference was observed between the techniques (p = 0.84 and 0.61, respectively). With respect to contaminating blood in the specimen, there was no difference in cytology samples (p = 0.89) and no difference in cell block samples (p = 0.08). The suitability of cytology samples for diagnosis was similar in both techniques (wet = 57.5% and capillary = 56.7%, p = 0.94) and there was no difference in cell block samples (wet = 75% and capillary = 66.1%, p = 0.38). In this study we did not observe differences in diagnostic yield or sample quality. Since both techniques are effective, we suggest the simultaneous and alternate use of both methods.