Consistency and pathophysiological characterization of a rat polymicrobial sepsis model via the improved cecal ligation and puncture surgery

- Inconsistency is the major problem for CLP in pharmacological study of sepsis.
- Syringe needle based puncture methods mainly affect consistency in CLP modeling.
- The CLP surgery is improved by using new developed three edged puncture needles.
- Three edged puncture needles enable consistency and severity control in CLP model.

Sepsis is the leading cause of death for critical ill patients and an essential focus in immunopharmacological research. The cecal ligation and puncture (CLP) model is regarded as a golden standard model for sepsis study. However, this animal model is easily affected by variability problems and dramatically affects pharmacological evaluation of anti-sepsis therapies, which requires standardized procedures and stable outcomes. Herein, the traditional syringe needle based puncture method was used as the major unstable factor for CLP models. Syringe needles created varied mortality in parallel experimental groups of CLP rats; they were inconsistent for severity control as mortality in CLP rats was not correlated with change in punctures, ligation lengths, or needle sizes. Moreover, the use of drainage tubes or strips, which was supposed to strengthen drainage stability, also failed to improve consistency of traditional syringe needles. To solve the consistency problem, an improved design of CLP surgery by puncture with newly-developed three-edged needles was described herein. In contrast to traditional syringe needles, these three-edged needles ensured more stable outcomes in repetitive groups. Furthermore, increased severity was found to be consistent with the enlarged needle size, as shown by the elevated mortality, increased proinflammatory cytokines, abnormal coagulation, worsen acidosis and more severe acute lung injury. In conclusion, application of the newly-developed three-edged needles provides a simple and feasible method to improve stability when conducting CLP surgery, which is significant for pharmacological studies on sepsis.