The goal of this retrospective observational study is to evaluate whether prophylactic mesh reinforcement during abdominal wall closure can prevent incisional hernias (IH) in patients undergoing open abdominal aortic aneurysm (AAA) repair. The main questions it aims to answer are:

• Does mesh reinforcement reduce the incidence of incisional hernias?
• What is the frequency of associated postoperative complications? Researchers will compare the outcomes of patients who underwent mesh-reinforced closures to literature-reported outcomes for non-mesh cases to assess differences in IH incidence and complications.

Participants will:

• Undergo clinical follow-ups and abdominal ultrasounds to detect IH.
• Complete quality-of-life questionnaires (EQ-5D and PROMIS).

Inclusion Criteria:

• Adult patients (≥18 years old) who underwent open abdominal aortic aneurysm (AAA) repair with prophylactic retromuscular mesh reinforcement between January 2019 and January 2024
• Availability of complete medical records, including preoperative history, surgical details, and postoperative follow-up data
• Attendance at a clinical follow-up examination at least one year after the procedure
• General informed consent signed for the use of medical data for research purposes

Exclusion Criteria:

• Patients with incomplete or missing medical records, including preoperative, intraoperative, or follow-up data
• Patients who required a re-laparotomy involving incision or suture of the prophylactic mesh and subsequently developed an incisional hernia.
• Patients who did not attend the required clinical follow-up examination at least one year postoperatively.

The study population consists of adult patients who underwent open abdominal aortic aneurysm (AAA) repair with prophylactic retromuscular mesh reinforcement at the Fribourg Cantonal Hospital between 2019 and 2024.