A Novel Technique for the Reduction of Unsatisfactory Rate Using the ThinPrep® Methodology.
Shilpa Rungta, Jacqueline Nelson, Veena Parabdesai, Johnny Chackunkal, Kiju Manthuruthil, Sudha R Kini. Henry Ford Health System, Detroit, MI
Background: Since the implementation of SurePathTM liquid-based methodology for Pap smears in our laboratory in 2004, the unsatisfactory rate has remained constant below 0.4%. A second liquid-based methodology (ThinPrep®) was introduced in January, 2010 to accommodate the outreach customer needs. Subsequent monitoring revealed an increase in the unsatisfactory rate. Root cause analysis showed this increase to be primarily due to the introduction of ThinPrep® methodology, possibly due to clogging of the pores in the filter of the ThinPrep® device by fibrin clot and excessive blood. Recommendations for overcoming these problems included treatment of bloody samples with glacial acetic acid prior to processing, to lyse the red blood cells. This method is labor-intensive. Recent studies have also raised the possibility of some changes in the cytomorphology of the squamous cells post-glacial acetic acid treatment.
Design: Development of a less labor-intensive and safe technique to maintain the unsatisfactory rate at or below the threshold of 1%. Methods: Due to low specimen numbers of ThinPrep® for the first four months our study was initiated from May 2010 to August 2010. Of 874 cases processed with ThinPrep® methodology, 80 (9.2%) smears were identified as unsatisfactory by cytotechnologists. The residual unsatisfactory specimen was washed using Thin Prep® CytoLyt® solution and then reprocessed on the ThinPrep® instrument. CytoLyt® solution is a commercially available methanol based, buffered solution used as a preservative to support cells during transporting specimen vials and slide preparation.
Results: After utilizing the reprocessing intervention 52/80 (65%) cases were interpreted as satisfactory. The ThinPrep® unsatisfactory rate before intervention was 6.4% which dropped down to 3% after intervention.
The combined (SurePathTM and ThinPrep®) unsatisfactory rate pre-intervention ranged from 0.8-1.4% while post-intervention rate now falls in the range of 0.4-0.6%.
Conclusions: This reprocessing technique is one the most successful attempts to reduce the ThinPrep® unsatisfactory rate. This intervention will reduce patient recalls for repeat collection avoiding delay in interpretations and identification of abnormalities.
Tuesday, March 1, 2011 9:30 AM
Poster Session III # 97, Tuesday Morning