The Content of Pre-habilitative Interventions for Patients Undergoing Repair of Abdominal Aortic Aneurysms and Their Effect on Post-Operative Outcomes: A Systematic Review

Abstract

Patients requiring abdominal aortic aneurysm (AAA) repair are at risk of post-operative complications due to poor pre-operative state. Pre-habilitation describes the enhancement of functional capacity and tolerance to an upcoming physiological stressor, intended to reduce those complications. The ability to provide such an intervention (physical, pharmacological, nutritional, or psychosocial) between diagnosis and surgery is a growing interest, but its role in AAA repair is unclear. This paper aimed to systematically review existing literature to better describe the effect of pre-habilitative interventions on post-operative outcomes of patients undergoing AAA repair. EMBASE and Medline were searched from inception to October 2020. Retrieved papers, systematic reviews, and trial registries were citation tracked. Randomised controlled trials (RCTs) comparing post-operative outcomes for adult patients undergoing a period of pre-habilitation prior to AAA repair (open or endovascular) were eligible for inclusion. Two authors screened titles for inclusion, assessed risk of bias, and extracted data. Primary outcomes were post-operative 30 day mortality, composite endpoint of 30 day post-operative complications, hospital length of stay (LOS), and health related quality of life (HRQL) outcomes. The content of interventions was extracted and a narrative analysis of results undertaken. Seven RCTs with 901 patients were included (three exercise based, two pharmacological based, and two nutritional based). Risk of bias was mostly unclear or high and the clinical heterogeneity between the trials precluded data pooling for meta-analyses. The quality of intervention descriptions was highly variable. One exercise based RCT reported significantly reduced hospital LOS and another improved HRQL outcomes. Neither pharmacological nor nutritional based RCTs reported significant differences in primary outcomes. There is limited evidence to draw clinically robust conclusions about the effect of pre-habilitation on post-operative outcomes following AAA repair. Well designed RCTs, adhering to reporting standards for intervention content and trial methods, are urgently needed to establish the clinical and cost effectiveness of pre-habilitation interventions.