This study is a single-center, prospective, randomized, double-blinded, placebo-controlled phase II clinical trial to evaluate the efficacy of "NAD+ supplementation" with Basis™ (Nicotinamide Riboside and Pterostilbene) in preventing acute kidney injury (AKI) in patients undergoing complex aortic aneurysm repair and open aortic arch reconstruction.

Inclusion Criteria:

• A patient may be included in the study if the following conditions are present:

  1. Male or female;

  2. Age > 18 years old;

  3. Patients who match the criteria for indication of elective open aortic arch replacement or repair:

     1. Total arch;
     2. Non-total arch;

  4. Patients who match the criteria for indication of elective complex aortic aneurysm repair has to respect the following conditions:

     a. Patients undergoing complex aortic aneurysm open reconstruction with a suprarenal clamp; i. thoracoabdominal aortic aneurysms Crawford extent I to IV ; ii. abdominal aortic aneurysms of juxtarenal, pararenal, or paravisceral type; b. For endovascular approach: i. patients with pararenal or thoracoabdominal aortic aneurysms Crawford extent I to IV and known stage III or IV of chronic kidney disease (CKD); ii. patients with pararenal or thoracoabdominal aortic aneurysms Crawford extent I to IV and solitary or single functioning kidney and known stage III or IV CKD;

  5. Patients will be allowed to participate in concomitant endovascular aortic stent-graft trials and prospective cohort studies as long as these do not involve another investigational study drug.

Exclusion Criteria:

• Patients must be excluded from the study if any of the following conditions are true:

5.2.1 General Exclusion Criteria

1. Unwilling to comply with the follow-up schedule;
2. Inability or refusal to give informed consent by the patient or a legally authorized representative;
3. Pregnant or breastfeeding;
4. Subject who takes multivitamins containing vitamin B3 derivatives in a dose > 200 mg/day; 5.2.2 Clinical / Laboratory Exclusion Criteria
5. Renal failure defined as eGFR< 15 mL/min/1.73m2
6. Patients in permanent Renal Replacement Therapy;
7. Patients with chronic liver disease: Child-Pugh score class B and C; 5.2.3 Medication Exclusion Criteria
8. Patients in chemotherapy scheme;
9. Patients taking any immunosuppressant, except for corticosteroids;
10. Patients taking any of these well-known P-glycoprotein substrates: digoxin, fexofenadine, indinavir, sirolimus.