A Prospective Experimental Study to Investigate the Peritoneal Adhesion Formation of Argon Plasma Coagulation (APC) Versus a Novel Aerosol Plasma in a Rat Model.

BACKGROUND: This is a prospective, randomized, controlled, single-blinded study to investigate peritoneal adhesion formation of standard argon plasma coagulation (APC) versus aerosol plasma coagulation in a rat model. METHODS: Bilateral lesions were created on the abdominal wall of 16 female Wistar rats with standard and aerosol plasma coagulation APC energy in a standard fashion. After 10 days, the rats were killed humanely to evaluate the peritoneal trauma sites. Adhesion incidence, quantity, and quality were scored 10 days postoperatively and studied histopathologically. RESULTS: Average energy intake was 97.7 ± 3.1 J for APC and 93.8 ± 4.2 J for aerosol plasma coagulation. Incidence of adhesion formation was 74.2% for standard APC and 16.1% for aerosol plasma coagulation (P < .0001). Standard APC mainly results in dense adhesions. Histological evaluation revealed no significant difference with regard to the average depth of lesions created by APC and aerosol plasma coagulation (P = 0.21) at day 10; both groups showed an identical morphology of necrosis and granulation tissue formation. CONCLUSIONS: This study compares adhesion formation of standard APC versus aerosol plasma coagulation in a rat model. Standard APC produced significantly more adhesions. Aerosol plasma coagulation creates fewer adhesions, which are of lower grade, which seems to be achieved mainly by improved peritoneal conditioning in this animal model.

Animal model for local pharmacotherapy in adhesion prophylaxis--a proof of concept.

BACKGROUND: On the one hand, barrier materials remain the only licensed adjuncts for postoperative adhesion reduction in the United States. On the other hand, pharmacotherapy for adhesion reduction has been a focus of intensive research. Therefore, the next step in the evolution of adhesion prophylaxis will consist of pharmacological functionalization of barrier materials to locally elute drugs. However, conventionally available animal models for postoperative adhesions are not optimized to screen candidate pharmaceutical agents for their local adhesion suppressing properties. Therefore, we have developed an animal model specifically for this purpose. METHODS: Ischemic peritoneal lesions are created by ligating buttons of transversus abdominis muscle with sutures. These ischemic lesions are then directly injected with the candidate pharmaceutical agent. Injection of ischemic tissue ensures that the tested agent can only exert a local effect. Lesions injected with normal saline serve as internal controls. RESULTS: In a pilot experiment n = 40 lesions were created in 10 Wistar rats and injected with normal saline. When analyzed by interval laparotomy on postoperative day 10, 58% (n = 23/40) of these lesions were affected by adhesions (95% confidence interval 42-71%). None of the adhesions were avascular. Ten adhesions were filmy and vascular. Twelve adhesions were dense and vascular. One adhesion involved organ inclusion with the liver attached to the experimental lesions. CONCLUSION: The described model is suitable for screening pharmaceutical agents for their local adhesion suppressing properties. It will help with the development of novel adhesion barriers that simultaneously function as drug-eluting vehicles.

A prospective, randomized, experimental study to investigate the peritoneal adhesion formation of noncontact argon plasma coagulation in a rat model.

OBJECTIVE: To investigate the peritoneal adhesion formation of two pulsed noncontact argon plasma coagulation (APC) modes in a rat model. DESIGN: Prospective, randomized, controlled, and blinded study. SETTING: Laboratory facilities of a university department of obstetrics and gynecology. ANIMAL(S): Ten female Wistar rats. INTERVENTION(S): Bilateral lesions were created on the abdominal wall with low and high APC energy in a standard fashion. After 10 days the rats were killed to evaluate the peritoneal trauma sites. MAIN OUTCOME MEASURE(S): Adhesion incidence, quantity, and quality were scored 10 days after surgery and studied by histopathologic analysis. RESULT(S): The area of coagulation was 30 ± 8.4 mm(2) in the case of high APC energy and 12 ± 5.6 mm(2) (low APC energy). Macroscopic thermal damage of the peritoneum is significantly higher when applying high APC energy. Adhesions due to APC with high energy occurred in 64% and with low energy in 6% of cases. High energy results mainly in dense adhesions. The lesions in the high-energy group showed intense granulation tissue formation with centrally located myocyte necrosis with intense neutrophilic inflammation. CONCLUSION(S): This study describes for the first time that different noncontact APC energy settings induce peritoneal adhesions in a reproducible rat model. Higher energy produced significantly deeper tissue defects and adhesions of higher grade. A plasma coagulation system that develops fewer adhesions can be achieved by lower temperature and a more homogeneous application and if the application area desiccates more slowly.