Eligibility criteria and study selection
Original studies that assess effectiveness and safety of HIFU in management of PAS were considered eligible. Review articles, conference papers, animal studies, and case reports were excluded. Neither sample size nor language were used for exclusion.
To assess eligibility, titles of retrieved articles were first screened for relevance. Thereafter, abstracts of filtered articles were reviewed for eligibility. Following the second screen, full texts of indeterminate articles were retrieved, and were assessed by 2 researchers, independently. Conflicting decisions were resolved by consensus in collaboration with the principle investigator.