This is a prospective, non-randomized, single center, data collection study of patients treated with open surgical repair (OR) for complex aortic aneurysms (CAAs).

Patients in need of OR for CAAs will be placed in this prospective, non-randomized, single center, data collection study. Choice of the prosthetic graft and configuration will be based on surgeon's preference and extent of the disease. OR will be performed by vascular surgeons at Mayo Clinic, Rochester, assuming no difference in surgical techniques.

Demographics, clinical presentation, preoperative clinical and imaging assessment, intraoperative information, length of ICU stay and hospitalization, early and late mortality, major adverse events (MAEs), reintervention, rupture and QoL at different postoperative time points (4 months, 1 year, 3 years and 5 years) will be recorded according to well-designed case report forms (CRFs) and SF-36 form. Follow-up information will be obtained from office visits or mailing questionnaires (SF-36 form and CAA-specific questionnaire).

Patients will be asked to fill out the SF-36 forms preoperatively, and along with the CAA-specific questionnaire at 4 months, 1 year, 3 years and 5 years post-operatively. Physician assistants or study coordinators will interview all patients prior to treatment (during office evaluation). The follow-up assessments will be conducted by questionnaires (SF-36 and CAA-specific questionnaire) and office visits as well. If no response in 6 weeks after sending out questionnaires at each time point, telephone interview will be followed.

Inclusion Criteria:

Patients undergoing elective, emergent or urgent OR for CAAs, including:

1. Abdominal aortic aneurysms (AAA) not eligible for endovascular aneurysm repair (EVAR), including 1) Infrarenal AAA with complex aneurysm morphology 2) Short neck infrarenal AAA 3) Juxtarenal AAA 4) Suprarenal AAA
2. Thoracoabdominal aortic aneurysms (TAAA) (Type I - IV)
3. Chronic aortic dissections

Exclusion Criteria:

1. Patients who refuse to participate the study
2. Patients age < 18 years
3. Pregnant breastfeeding patients

Patients undergoing open repair (OR) for complex aortic aneurysms (CAAs) at Mayo Clinic, Rochester, Minnesota will be enrolled.