Is levator trauma an independent risk factor for anal incontinence?

AIM: To determine the role of levator ani trauma in anal incontinence (AI), whilst controlling for anal sphincter injury. METHODS: The records of 1273 patients who had attended a tertiary urogynaecology unit between 1st of January to 31st December 2016 were reviewed. AI was assessed using St Mark's score and visual analogue scale (VAS). Levator muscle and anal sphincter trauma were examined by translabial ultrasound using tomographic imaging, with archived data sets investigated blinded against all clinical data. A complete avulsion was diagnosed if at least three central tomographic slices showed an abnormal muscle insertion, rated separately for each side. A significant anal sphincter defect was diagnosed if at least four out of six slices showed a defect of ≥ 30°. RESULTS: Avulsion was associated with St Mark's score (P = 0.005) and VAS bother of AI (P = 0.022) both on univariate analysis and when controlling for external anal sphincter (EAS) trauma on translabial imaging, forceps, body mass index (BMI) and age (P = 0.011 and P = 0.04, respectively). AI expressed as a binary variable was significantly associated with avulsion on univariate analysis (P = 0.011), although the association became nonsignificant after controlling for anal sphincter trauma, age, BMI and forceps delivery (P = 0.084). CONCLUSION: In this retrospective observational study, we found a weak association between levator ani avulsion and measures of AI, which largely remained significant when controlling for anal sphincter trauma. However, given the large data set, any clinical effect of levator trauma on AI is likely to be minor.

Composite mesh design for delivery of autologous mesenchymal stem cells influences mesh integration, exposure and biocompatibility in an ovine model of pelvic organ prolapse.

The widespread use of synthetic transvaginal polypropylene mesh for treating Pelvic Organ Prolapse (POP) has been curtailed due to serious adverse effects highlighted in 2008 and 2011 FDA warnings and subsequent legal action. We are developing new synthetic mesh to deliver endometrial mesenchymal stem cells (eMSC) to improve mesh biocompatibility and restore strength to prolapsed vaginal tissue. Here we evaluated knitted polyamide (PA) mesh in an ovine multiparous model using transvaginal implantation and matched for the degree of POP. Polyamide mesh dip-coated in gelatin and stabilised with 0.5% glutaraldehyde (PA/G) were used either alone or seeded with autologous ovine eMSC (eMSC/PA/G), which resulted in substantial mesh folding, poor tissue integration and 42% mesh exposure in the ovine model. In contrast, a two-step insertion protocol, whereby the uncoated PA mesh was inserted transvaginally followed by application of autologous eMSC in a gelatin hydrogel onto the mesh and crosslinked with blue light (PA + eMSC/G), integrated well with little folding and no mesh exposure. The autologous ovine eMSC survived 30 days in vivo but had no effect on mesh integration. The stiff PA/G constructs provoked greater myofibroblast and inflammatory responses in the vaginal wall, disrupted the muscularis layer and reduced elastin fibres compared to PA + eMSC/G constructs. This study identified the superiority of a two-step protocol for implanting synthetic mesh in cellular compatible composite constructs and simpler surgical application, providing additional translational value.