Comparative histological specimen adequacy and tolerability of endoscopic versus Baby Tischler forceps for anal canal biopsy during high-resolution anoscopy in people with HIV

Objectives Anal canal cancer is strongly associated with high-risk human papillomavirus infection and occurs at increased incidence in people living with HIV. High-resolution anoscopy (HRA) with directed biopsy is the reference standard for diagnosing histological high-grade squamous intraepithelial lesions (HSIL). Comparative data on diagnostic performance and tolerability of different biopsy forceps are limited. Methods We conducted an observational single-centre non-randomised study comparing endoscopic forceps (EF) and Baby Tischler forceps (BTF) for anal canal biopsy during HRA. Histological specimen adequacy was defined as the proportion of biopsies yielding adequate histopathological specimens. Tolerability was assessed using a visual analogue scale (VAS). Short-term adverse events were systematically recorded. Investigators also completed an exploratory structured poststudy assessment of procedural handling, bleeding control, feasibility of multiple biopsies and overall instrument preference. Results A total of 244 participants underwent 365 biopsies (208 with EF and 157 with BTF). Overall, 348/365 biopsies (95.3%) yielded adequate specimens, with no significant difference between EF and BTF (96.6% vs 93.6%; p=0.272). HSIL was detected more frequently in biopsies obtained with BTF than EF (50.3% vs 26.4%; p<0.001). Clinically relevant pain (VAS score ≥5) was similar between groups (8.17% vs 8.28%; p=1.00). Any postbiopsy adverse event occurred in 42.3% of EF and 41.1% of BTF procedures (p=0.958), and all events were mild and self-limited. Investigator-reported assessment favoured EF, particularly regarding handling and bleeding control. Conclusions EF and BTF demonstrated similarly high specimen adequacy and comparable short-term safety for anal canal biopsy during HRA. Clinically relevant pain did not differ between instruments. The higher HSIL detection rate observed with BTF should be interpreted cautiously given the non-randomised design and potential operator-related and procedural confounding. Further prospective studies are warranted.