Name: Video: Inducing Controlled Arterial and Venous Malperfusion in Rodent Models for Ischemia Studies
Uploaded: 2024-07-05T14:50:00
Duration: 3 min 56 s
Description: 67 Views. Inducing Controlled Arterial and Venous Malperfusion in Rodent Models for Ischemia Studies

inducing controlled arterial and venous malperfusion in rodent models for ischemia studies

Rat Model for Visceral Organ Malperfusion Studies

While the implications of tissue perfusion deprivation in the form of local or systemic tissue malperfusion conditions have long been recognized, they persist as one of the primary causes of morbidity and mortality in both the United States and Europe1. These malperfusion conditions are the third leading cause of tissue degradation, following malignancy and septic inflammation, but have a far wider spectrum of origins compared to the latter two2.
This spectrum ranges from local mechanisms such as atrial fibrillation with thromboembolic occlusion, vasoconstriction, and iatrogenic or traumatic dissection, to systemic mechanisms such as cardiac insufficiency or shock, sepsis, hypovolemia, and steal phenomena. These diverse mechanisms underlie a variety of medical and surgical conditions. The significant morbidity and mortality associated with these conditions have directed medical attention toward procedures for reinstating blood flow to malperfused tissues in order to forestall necrosis and restore organ function over the decades3.
This research effort has resulted in a variety of pharmaceutical, medical, and surgical solutions to restore physiological organ perfusion, including advances in bypass surgery4, endovascular procedures5, extracorporeal membrane oxygenation6,7, organ machine perfusion during transplantation8, and artificial blood substitutes9.
Yet, despite these significant developments, malperfusion, especially of visceral organs, remains a pressing issue in patient care, and the demand for further research on biomedical processes and rescue strategies is high. Valid biological models are of utmost importance in enabling this kind of research. Due to the multifactorial aspects of tissue perfusion research, which include not only cell biology but also vascular microanatomy and rheology, an appropriate model requires a degree of biological complexity that only a complete model organism can provide, making rodents the obvious model of choice.
Tissue malperfusion can be differentiated into three distinct conditions: isolated arterial ischemia, isolated venous congestion, and combined malperfusion10. Clinically relevant scenarios for these conditions include (1) Arterial ischemia: Atrial fibrillation with thromboembolic occlusion, septic emboli, vasoconstriction, iatrogenic or traumatic vascular dissection or clamping, cardiac insufficiency or shock, aortic dissection, sepsis and hypovolemia, extreme arterial obstruction due to external constriction, pulmonary artery embolism, chronic arterial vascular occlusive diseases, or steal phenomena; (2) Venous congestion: Iatrogenic or traumatic vascular dissection or clamping, heart failure, liver fibrosis or cirrhosis, venous obstruction due to external constriction, venous thrombosis, venous insufficiency, and Budd-Chiari syndrome; (3) Combined malperfusion: Combinations of the above conditions and advanced stages of the aforementioned conditions, such as secondary venous congestion due to ischemia-induced fibrosis or secondary arterial ischemia due to congestion-induced retention, as well as specific organ conditions like ischemic inflammation (e.g., ischemic colitis)11,12.
This article, therefore, aims to provide a step-by-step model to induce controlled, reversible visceral arterial ischemia, venous congestion, and combined malperfusion via midline laparotomy in rats for both survival and non-survival applications, as depicted in Figure 1. The experimental model offers a controlled environment for studying the multifaceted dynamics of arterial ischemia, venous congestion, and their combined sequelae, emulating clinically relevant scenarios encountered in various conditions.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/67171/67171fig01.jpg" /> 
Figure 1: Overview of the protocol. Schematic depiction of vascular rat anatomy and depiction of the clamping site (gray arrow). (A) Physiological perfusion. (B) Arterial ischemia. (C) venous congestion. (D) Combined malperfusion. <a href="https://www.jove.com/files/ftp_upload/67171/67171fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Author Spotlight: Advancing Spectral Characterization of Physiological and Malperfused Tissues

Controlled Reversible Visceral Arterial Ischemia, Venous Congestion and Combined Malperfusion via Midline Laparotomy in Rats

Inducing Controlled Arterial and Venous Malperfusion in Rodent Models for Ischemia Studies

inducing-controlled-arterial-venous-malperfusion-rodent-models-for

Research

JoVE Journal

Medicine

67 Views. Inducing Controlled Arterial and Venous Malperfusion in Rodent Models for Ischemia Studies

Video: Inducing Controlled Arterial and Venous Malperfusion in Rodent Models for Ischemia Studies

Besides sepsis and malignancy, malperfusion is the third leading cause of tissue degradation and a major pathomechanism for various medical and surgical conditions. Despite significant developments such as bypass surgery, endovascular procedures, extracorporeal membrane oxygenation, and artificial blood substitutes, tissue malperfusion, especially of visceral organs, remains a pressing issue in patient care. The demand for further research on biomedical processes and possible interventions is high. Valid biological models are of utmost importance in enabling this kind of research. Due to the multifactorial aspects of tissue perfusion research, which include not only cell biology but also vascular microanatomy and rheology, an appropriate model requires a degree of biological complexity that only an animal model can provide, rendering rodents the obvious model of choice. Tissue malperfusion can be differentiated into three distinct conditions: (1) isolated arterial ischemia, (2) isolated venous congestion, and (3) combined malperfusion. This article presents a detailed step-by-step protocol for the controlled and reversible induction of these three types of visceral malperfusion via midline laparotomy and clamping of the abdominal aorta and caval vein in rats, underscoring the significance of precise surgical methodology to guarantee uniform and dependable results. Prime examples of possible applications of this model include the development and validation of innovative intraoperative imaging modalities, such as Hyperspectral Imaging (HSI), to objectively visualize and differentiate malperfusion of gastrointestinal, gynecological, and urological organs.

This article introduces a standardized procedure for controlled, reversible malperfusion of visceral organs in rat models. The aim is to induce these malperfusion states with a high degree of methodological certainty and control while maintaining technical simplicity and error resilience.

Besides sepsis and malignancy, malperfusion is the third leading cause of tissue degradation and a major pathomechanism for various medical and surgical ...