The PREHAAAB Trial: Multimodal Prehabilitation for Patients Awaiting Open Abdominal Aortic Aneurysm Repair

An abdominal aortic aneurysm is a condition where the major artery in the abdomen becomes larger than usual. Over time, as it continues to grow, the wall of the artery weakens and there is a risk that the artery can burst causing internal bleeding and death. Aortic aneurysms are fixed when they reach a certain size to prevent that outcome. The surgery to fix them is a major, high-risk surgery that is associated with a lot of complications and a slow recovery back to normal. The time between diagnosis and surgery is called the pre-operative period and is a key time to optimize a patient's health in order to ensure the best possible outcomes following surgery. This study will look at whether a multidisciplinary pre-operative program that involves exercise training, nutritional advice and supplementation, and psychosocial support will reduce complications following surgery. This program should decrease complications and speed up a patient's recovery back to normal after surgery. It is also a way for patients to take ownership of their disease and play an active role in their health care journey. The benefits from this program will go beyond the pre-operative time frame, as the habits and knowledge gained will improve their health over their lifetime. This study will also assess the economic impact and cost of a program like this.

Abdominal aortic aneurysms (AAA) are asymptomatic until they rupture, which carries an 80- 90% mortality. Therefore, AAA are surgically repaired when they reach 5.0 cm in women and 5.5cm in men. Despite advances to surgical technique and peri-operative care, open surgical repair still carries a high incidence of post-operative complications of 30-40%, and a long recovery period. This is largely because the surgery itself is major abdominal surgery, and these patients often have significant comorbidities and low functional status. Multimodal prehabilitation (MP) is a concept that uses the preoperative timeframe (between diagnosis and surgery) to optimize physical, nutritional, and emotional wellbeing to improve a patient's functional status and ability to withstand the stress of surgery. To date, there is no study evaluating the effect of MP on post-operative complications following open AAA repair.

The primary objective of this trial is to determine if MP will decrease complications as measured by the comprehensive complication index following open AAA repair compared to standard of care. This trial will also assess the effect of MP on functional capacity, hospital length of stay, 30-day mortality and health related quality of life, as well as to assess cost effectiveness, adherence, and fidelity to the intervention.

Eligibility Criteria:
Inclusion Criteria:

* Participants older than 50 years of age awaiting elective open AAA repair with AAA diameter ≤6.9cm. Participants should have the ability to give informed consent.

Exclusion Criteria:

* Participants undergoing thoracic, thoracoabdominal and/or perivisceral AAA repair.
* Participants with ruptured or symptomatic AAA.
* Participants with AAA maximal diameter ≥7cm.
* Physical inability to exercise: severe osteoarthritis, musculoskeletal or neurological impairment that precludes exercise.
* Contraindication to exercise: rest systolic blood pressure ≥ 180 mmHg and/or diastolic ≥ 100 mmHg, uncontrolled atrial or ventricular arrythmias or proven exercise induced arrhythmias, unstable angina, unstable or acute heart failure, severe symptomatic valvular stenosis, dynamic left ventricular outflow tract obstruction or other comorbidities that imply clinical instability.
* Cognitive impairment that would impede understanding of study procedures, informed consent or study questionnaires or the inability to effectively communicate in English/French/Spanish/Catalan.