# Animal model of a bovine pericardial patch for thoracoabdominal aortic aneurysms: step by step

## TL;DR

This study developed a reliable animal model for thoracoabdominal aortic aneurysms using a bovine pericardial patch and sequential clamping, which can help test new treatments.

## Contribution

The study introduces a stable and low-mortality animal model for TAA using a bovine pericardial patch and sequential clamping.

## Key findings

- The bovine pericardial patch model showed no differences in operative or clamping time compared to other methods.
- Sequential clamping significantly reduced mortality compared to single clamping after 4 weeks.
- The model remained stable and patent for up to 4 weeks, making it suitable for testing endovascular therapies.

## Abstract

The treatment of thoracoabdominal aortic aneurysms (TAA) has advanced. Understanding the pathophysiology and surgical approaches to this disease is essential for best therapeutic performance.

We aimed to improve previously described methods for creating thoracoabdominal aortic aneurysms in a porcine animal model, reducing surgical procedure time and specimen mortality.

A total of 18 swine underwent a surgical procedure to create a TAA. An autologous peritoneal patch was used to create the aneurysm in 2 animals, and a bovine pericardial patch was used in the other 16. The animals were followed up postoperatively, and the aneurysm sac was reexamined after 4 weeks. The animals that did not die in the post-operative period were euthanized according to institutional recommendations.

All of the animals underwent laparotomy with retroperitoneal access. Two received an autologous peritoneal patch and 16 received a bovine pericardial patch. Three animals underwent single suprarenal clamping, while 15 underwent sequential clamping. There were no differences in operative time (p=0.207) or total clamping time (p=0.276) between groups. There was a higher mortality rate after 4 weeks in animals that received single clamping (100%) than sequential clamping (26.7%) (p=0.0017).

The experimental model of TAA using a bovine pericardial patch and a sequential clamping technique provided a stable and reliable platform that remains stable and patent for up to 4 weeks. This model can be extremely valuable for assessing new endovascular therapy options in living organisms.