Comparative study of four different types of intraperitoneal mesh prostheses in rats

Abstract Purpose: To compare four types of mesh regarding visceral adhesions, inflammatory response and incorporation. Methods: Sixty Wistar rats were divided into four groups, with different meshes implanted intraperitoneally: polytetrafluoroethylene (ePTFE group); polypropylene with polydioxanone and oxidized cellulose (PCD); polypropylene (PM) and polypropylene with silicone (PMS). The variables analyzed were: area covered by adhesions, incorporation of the mesh and inflammatory reaction (evaluated histologically and by COX2 immunochemistry). Results: The PMS group had the lowest adhesion area (63.1%) and grade 1 adhesions. The ePTFE and PM groups presented almost the total area of their surface covered by adherences (99.8% and 97.7% respectively) The group ePTFE had the highest percentage of area without incorporation (42%; p <0.001) with no difference between the other meshes. The PMS group had the best incorporation rate. And the histological analysis revealed that the inflammation scores were significantly different. Conclusions: The PM mesh had higher density of adherences, larger area of adherences, adherences to organs and percentage of incorporation. ePTFE had the higher area of adherences and lower incorporation. The PMS mesh performed best in the inflammation score, had a higher incorporation and lower area of adherences, and it was considered the best type of mesh.

Evaluation of systemic inflammatory responses in cholecystectomy by means of access. Single-port umbilical incision, transvaginal NOTES, laparoscopy and laparotomy

PURPOSE: To evaluate and compare clinical and inflammatory responses to the surgical trauma caused by cholecystectomy via several access approaches: single-port umbilical incision (SILS), transvaginal natural orifice transluminal endoscopic surgery (NOTES), laparoscopy, and Laparotomy.METHODS: Twenty-eight female pigs were equally divided into four groups and submitted to cholecystectomy by single-port umbilical incision, transvaginal NOTES, laparoscopy, or Laparotomy. An additional five animals served as controls (sham group). Animals were monitored perioperatively regarding anesthesia and surgical procedure times, as well as for the presence of complications. Postoperatively, they were evaluated regarding time to ambulation and feeding, and the presence of clinical events. Procalcitonin, C-reactive protein (CRP), and AQUI feron-gamma (IFN-γ) measurements were performed before surgery and immediately, two days, and seven days after surgery. Animals were sacrificed and necropsied at seven days after surgery.RESULTS: All procedures were successfully performed as proposed in each group. Only minor complications, such as gallbladder perforation and bleeding from the liver bed, were observed during surgery in all groups. The vaginal NOTES group showed higher anesthesia and surgical procedure times compared to the other groups (p<0.001). No other between-group differences in perioperative or postoperative times, clinical evolution, or serum inflammatory markers were observed. Only adhesions were found on necropsy, with no differences between groups.CONCLUSION: The single-port umbilical and transvaginal NOTES access approaches were feasible and safe compared to laparoscopic and laparotomy for cholecystectomy.