Influence of sling material on inflammation and collagen deposit in an animal model

Abstract

Aim:Compare inflammation and collagen production induced by four sling materials in female rats. Methods: Adult female rats (n=144) were submitted to a urinary incontinence model and neutering. After four weeks they were randomized in 5 groups: Sham; autologous sling; Marlex; swine intestinal submucosa (SIS), and polypropylene mesh (TVT). Animals were killed at 7, 30 and 90 days. The inflammatory infiltrated area was rated from 0 to 3 (0=area smaller than 25%, 1=between 25% and 50%, 2 between 50% and 75%, and 3 for areas greater than 75%). The presence of granuloma and necrosis was noted. Penetration in the vesical wall was evaluated employing a system of scores from 0 to 3. The amount of collagen I and III, and the total was assessed using the Picro-Sirius staining technique. Results: The Sham group presented lower inflammatory parameters at 7 days. On the 30th day, the autologous fascia presented inflammatory reactions similar to the Sham group, and lower than the remaining groups. The synthetic materials demonstrated greater inflammatory reactions at 60 days. No differences between groups were observed other than those concerning collagen production, except at 60 days, when TVT and SIS differed from Fascia and Sham in the production of collagen III. Conclusion: Autologous fascia produced less inflammatory reaction and collagen. TVT and Marlex caused more intense and longer-lasting inflammatory reaction with greater visceral penetration. When TVT was used , this process resulted in a higher quantity of collagen III. The presence of SIS, although presenting a less intense inflammatory reaction than the synthetics, also caused greater collagen III production at 60 days.

Histopathology of excised midurethral sling mesh

“…Additionally, our findings could be a result of tissue remodeling/fibrosis that may occur following placement of a midurethral sling [17][18][19]. One could hypothesize that in the presence of an inflammatory state, the sling may retract and/or shrink therefore applying undue tension along its path, which in turn may lead to increased levels of voiding dysfunction.…”

Polypropylene mesh and the host response

“…Using an animal model, de Almeida et al noted that at day 60, both Prolene® (1,500-μm pores) and Marlex® (PP, 600-μm pores) induced a similar inflammatory response. However, Prolene® produced a greater amount of collagen type III, whereas Marlex® had no difference in collagen production compared with sham [12]. Junge et al used the rat abdomen to study the influence of various mesh materials on collagen deposition [13].…”

Comparative study of polypropylene and aponeurotic slings in the treatment of female urinary incontinence

“…In a doctoral thesis, de Almeida et al (18) described an experiment in rats using slings composed of autologous fascia, pig intestine submucosa, tension-free vaginal tape (TVT) and Marlex®. These authors concluded that the material that caused the least inflammatory reaction and produced the least collagen was the autologous fascia.…”