A Reproducible Bibliometric Analysis of Perianal Fistula in Crohn's Disease Research (1992-2025): Retrieval Sensitivity and Knowledge Structure.

Perianal Fistula in Crohn's Disease (PFCD) spans gastroenterology, colorectal surgery, imaging, and regenerative medicine, making bibliometric findings sensitive to retrieval and normalization choices. A reproducible Web of Science Core Collection (WoSCC) analysis was conducted on PFCD publications from 1992 through 2025. The prespecified Primary title, abstract, and Author Keyword search retrieved 1,694 records; after document-type and topical screening, 769 eligible publication records formed the Primary corpus. Two alternative retrieval strategies were evaluated as sensitivity analyses. Author Keywords were normalized using a documented terminology dictionary, deduplicated within records, and analyzed separately from Keywords Plus. R was used for descriptive bibliometrics, citation-age indicators, retrieval sensitivity analyses, and the full-window reference co-citation workflow; VOSviewer 1.6.21 was used for Author Keyword co-occurrence and country-, institution-, and author-level co-authorship networks. Publication output reached 80 papers in 2025. The United States contributed the most publications (n = 225), while Imperial College London (n = 53) and Ailsa L. Hart (n = 43) led institution- and author-level output, respectively. The most frequent cleaned Author Keywords were "Crohn's disease" (n = 462), "perianal fistula" (n = 246), and "fistula" (n = 102). At a minimum occurrence threshold of five, the VOSviewer Author Keyword network contained 63 items, 561 links, six clusters, and a total link strength of 2,235. The reference co-citation network contained 913 cited references, 88,364 edges, and 12 Leiden communities (Q = 0.319199; mean standard silhouette = 0.068155), indicating modest modularity with substantial thematic overlap. Sensitivity analyses showed high concordance in annual trends and leading entities, supporting a stable core PFCD knowledge structure while underscoring the importance of transparent retrieval, normalization, counting, and citation procedures.