human 66 postoperative complication Humans 60 Postoperative Complications 49 female 47 male 47 adult 40 Female 39 Male 37 Article 34 retrospective study 29 Adult 25 Retrospective Studies 25 middle aged 23 procedures 23 Middle Aged 20 treatment outcome 20 aged 19 major clinical study 19 Treatment Outcome 17 Aged 16 clinical article 16 controlled study 16 follow up 16 risk factor 14 Adolescent 13 adolescent 13 adverse event 13 incidence 12 Risk Factors 11