Annals of Pediatric Surgery actually says they aren't accepting further submissions as of October 2023.
If there isn't a faculty member who thinks that this case is reportable, then it likely is not worth your time. I do agree that submitting to a conference is more likely to be successful, and your school may have some funding to send you if you're presenting. Even if they don't have money to send you, the cost of flying in and out just for the poster session could be cheaper than some journals' publication fees and it definitely requires a lot less work.