Time-of-day effect and the yield of endoscopic ultrasound fine needle aspiration

The timing of the endoscopic procedures has been recently proposed to be a factor in the quality of colonoscopic polyp detection. We aimed to investigate whether the time-of-day has an effect on the diagnostic yield and specimen adequacy of endoscopic ultrasound fine needle aspiration (EUS-FNA).

The retrospective study was set in a safety net community hospital. The 212 EUS-FNAs performed at our institution between July 2011 and January 2014 were retrospectively analyzed. Pancreatic masses, pancreatic cysts, and lymphadenopathy were most common indications for EUS-FNAs. Data were collected with regard to the timing of the procedure, presence of on-site cytopathologic evaluation, the number of needle passes, diagnosis, and specimen adequacy for cytopathologic evaluation. Statistical analysis was performed using unpaired two-tailed Student's t-test.

There was no difference in the diagnostic yield for malignancy across all indications between the AM and PM groups. In the morning group 31/87 (36%) procedures and in the afternoon group 50/125 (40%) procedures were diagnostic for malignancy (P = 0.522). There was no difference in the specimen adequacy for cytopathologic evaluation across all indications between the AM and PM groups. In the morning group, 58/87 (67%) procedures and in the afternoon group 90/125 (72%) procedures were adequate for cytopathologic evaluation (P = 0.408). On-site cytopathologist was more available for AM than PM procedures; however, the lack of AM vs. PM difference in the yield and specimen adequacy persisted regardless of on-site cytopathologist presence.

Time-of-day of the procedure (morning vs. afternoon) does not affect EUS-FNA diagnostic yield for malignancy or specimen adequacy for cytopathologic evaluation.