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Characterising recovery following abdominal aortic aneurysm repair using cardiopulmonary exercise testing and patient reported outcome measures.

PURPOSE
Surgery is associated with a post-operative stress response, changes in cardiopulmonary reserve, and metabolic demand. Here recovery after abdominal aortic aneurysm repair is investigated using cardiopulmonary exercise testing and patient-reported questionnaires.


MATERIALS AND METHODS
Patients undergoing open (n = 21) or endovascular (n = 21) repair undertook cardiopulmonary exercise tests, activity, and health score questionnaires pre-operatively and, 8 and 16 weeks, post-operatively. Oxygen uptake and ventilatory parameters were measured, and routine blood tests were undertaken.


RESULTS
Recovery was characterised by falls in anaerobic threshold, peak oxygen uptake, and oxygen pulse at 8 weeks which appeared to be associated with operative severity; the fall in peak oxygen uptake was greater following open vs. endovascular repair (3.5 vs. 1.6 ml.kg-1.min-1) and anaerobic threshold showed a similar tendency (3.1 vs. 1.7 ml.kg-1.min-1). In the smaller number of patients re-tested these changes resolved by 16 weeks. Reported health and activity did not change.


CONCLUSIONS
Aortic repair is associated with falls in the anaerobic threshold, peak oxygen uptake, and oxygen pulse of a magnitude that reflects operative severity and appears to resolve by 16 weeks. Thus, post-operatively patients may be at higher risk of further metabolic insult e.g. infection. This further characterises physiological recovery from aortic surgery and may assist in defining post-operative shielding time.IMPLICATIONS FOR REHABILITATIONAbdominal aortic aneurysm repair is a life-saving operation, the outcome from which is influenced by pre-operative cardiopulmonary reserve; individuals with poor reserve being at greater risk of peri-operative complications and death. However, for this operation, the physiological impact of surgery has not been studied.In a relatively small sample, this study suggests that AAA repair is associated with a significant decline in cardiopulmonary reserve when measured 8 weeks post-operatively and appears to recover by 16 weeks. Moreover, the impact may be greater in endovascular vs. open repair.