Colon Ascendens Stent Peritonitis (CASP) - a Standardized Model for Polymicrobial Abdominal Sepsis

Abstract

Sepsis remains a persistent problem on intensive care units all over the world. Understanding the complex mechanisms of sepsis is the precondition for establishing new therapeutic approaches in this field. Therefore, animal models are required that are able to closely mimic the human disease and also sufficiently deal with scientific questions. The Colon Ascendens Stent Peritonitis (CASP) is a highly standardized model for polymicrobial abdominal sepsis in rodents. In this model, a small stent is surgically inserted into the ascending colon of mice or rats leading to a continuous leakage of intestinal bacteria into the peritoneal cavity. The procedure results in peritonitis, systemic bacteraemia, organ infection by gut bacteria, and systemic but also local release of several pro-and anti-inflammatory cytokines. The lethality of CASP can be controlled by the diameter of the inserted stent. A variant of this model, the so-called CASP with intervention (CASPI), raises opportunity to remove the septic focus by a second operation according to common procedures in clinical practice. CASP is an easily learnable and highly reproducible model that closely mimics the clinical course of abdominal sepsis. It leads way to study on questions in several scientific fields e.g. immunology, infectiology, or surgery. Video LinkThe video component of this article can be found at http://www.jove.com/video/2299/ Protocol 1. Preparation of the Mouse 1. Anesthetize the mouse by intraperitoneal injection of the narcotic fluid (see table of reagents) and place it in supine position. 2. The feet of the mouse need to be fixed with tape on the plate to ensure a stable position of the animal during the operation. Operation

Anti-inflammatory and anti-bacterial effects of iron chelation in experimental sepsis

“…We have observed increased levels of TNF-a, IL-1b, IL-6, and IFN-g in CASP-induced sepsis. Similar results were reported by other groups using the CASP model [30,31]. Maier et al [31] observed that serum cytokines (TNF-a, IL-1b, and IL-10) steadily increased during the period of 6 to 18 h after CASP surgery.…”

Is there value in plasma cytokine measurements in patients with severe trauma and sepsis?

“…A clear signal that we were on the wrong track was that plasma TNFα and IL-1β concentrations were often several logs higher in these models than they were in human sepsis or trauma (Table 1). More recent models that have been employed over the last decade include the commonly used models of polymicrobial abdominal sepsis, including the cecal ligation and puncture (CLP) model [20] and the colon ascendence stent peritonitis model (CASP) [21]. Early on, these models were thought to incite not only the early proinflammatory SIRS component of sepsis, but also, the later anti-inflammatory response, representing the early SIRS-CARS model proposed by Bone and colleagues [22].…”

Development of animal experimental model for bacterial peritonitis

“…Este resuelve uno de los problemas que pueden ocurrir con CLP, que es la formación de un absceso intraabdominal en lugar de un shock séptico por peritonitis. El CASP es un modelo relativamente nuevo y poco común de peritonitis difusa polimicrobiana que reproduce la clínica de una peritonitis aguda [10], además de alterar el flujo sanguíneo cecal con necrosis secundaria de la pared intestinal. La principal desventaja de CASP en comparación con CLP es su mayor complejidad.…”