SPYBITE BIOPSY SYSTEM DURING CHOLANGIOSCOPY – LEARNING CURVE AND EXPERIENCES FROM A SINGLE CENTRE, TERTIARY HOSPITAL IN THE UNITED KINGDOM

Aims Previous small studies have suggested that SpyBite may be superior to cytology brushings and standard forceps biopsies. However, the utility for establishing a biliary diagnosis and the learning process required for this procedure is still unclear. The objective of this study was to investigate the learning process for SpyBite biopsies in a tertiary centre cholangioscopy service.

Methods This was a single-centre observational study performed by retrospective examination of medical records and endoscopic data. All cases performed between October 2018 to February 2019 were reviewed, following introduction of the SpyBite biopsy system. Clinical data was independently recorded by two medically trained data collectors and then compared. Any discrepancies were resolved by discussion and re-checking medical notes. Given the low numbers of patients included in this sampling frame, descriptive rather than analytical statistics were used.

Results 15 cholangioscopy procedures were performed with SpyBite biopsies taken (14 patients, with 1 repeat case). The key performance indicator of establishing diagnosis vs non-definitive diagnosis from biopsies was assessed. An increased likelihood of diagnosis was observed after 6 procedures had been performed. Despite the small sample population, both groups were well matched for gender, age, co-morbidities and haematological/biochemical results prior to the procedure. There was a greater likelihood of having a final diagnosis of inflammatory biliary disease from initial non-diagnostic or non-biopsied procedures (71.4%), compared to higher yield of dysplasia or cancer in the biopsy-diagnostic group (75%).

Conclusions Increased diagnostic accuracy using endobiliary SpyBite biopsies appears to be achieved with additional caseload and biopsy numbers. This may suggest increased diagnosis with procedural performance, however the individual case mix of patients may also play a large role in determining the extent of this learning curve. We conclude that following initiation of the SpyBite biopsy system, there is a short but recognisable learning period even for experienced biliary endoscopists.