Stefano Manodoro

Graft-related complications and biaxial tensiometry following experimental vaginal implantation of flat mesh of variable dimensions

To compare the occurrence of graft‐related complications (GRCs) and biomechanical properties of meshes implanted vaginally and abdominally.

Acute In Vivo Response to an Alternative Implant for Urogynecology

Purpose. To investigate in vivo the acute host response to an alternative implant designed for the treatment of stress urinary incontinence (SUI) and pelvic organ prolapse (POP). Methods. A biodegradable scaffold was produced from poly-L-lactic acid (PLA) using the electrospinning technique. Human and rat adipose-derived stem cells (ADSCs) were isolated and characterized by fluorescence-activated cell sorting and differentiation assays. PLA scaffolds were seeded and cultured for 2 weeks with human or rat ADSCs. Scaffolds with and without human or rat ADSCs were implanted subcutaneously on the abdominal wall of rats. After 3 and 7 days, 6 animals from each group were sacrificed. Sections from each sample were analyzed by Haematoxylin and Eosin staining, Sirius red staining, and immunohistochemistry for CD68, PECAM-1, and collagen I and III. Results. Animals responded to the scaffolds with an acute macrophage response. After 7 days of implantation, there was extensive host cell penetration, new blood vessel formation, and new collagen deposition throughout the full thickness of the samples without obvious differences between cell-containing and cell-free scaffolds. Conclusions. The acute in vivo response to an alternative implant (both with and without cells) for the treatment of SUI and POP showed good acute integration into the host tissues.

Mesh contraction: in vivo documentation of changes in apparent surface area utilizing meshes visible on magnetic resonance imaging in the rabbit abdominal wall model.

Introduction and hypothesisOur aim was to analyze the apparent contraction of meshes in vivo after abdominal wall reconstruction and evaluate histological and biomechanical properties after explantation.MethodsNine New Zealand female rabbits underwent repair of two full-thickness 25xa0×xa030-mm midline defects in the upper and lower parts of the abdomen. These were primarily overlaid by 35xa0×xa040-mm implants of a polyvinylidene fluoride (PVDF) DynaMesh (nu2009=u20096) or polypropylene meshes Ultrapro (nu2009=u20096) and Marlex (nu2009=u20096). Edges of the meshes were secured with iron(II,III) oxide (Fe3O4)-loaded PVDF sutures. Magnetic resonance images (MRIs) were taken at days 2, 30 and 90 after implantation. The perimeter of the mesh was traced using a 3D spline curve. The apparent surface area or the area within the PVDF sutures was compared with the initial size using the one-sample t test. A two-way repeat analysis of variance (ANOVA) was used to compare the apparent surface area over time and between groups.ResultsPVDF meshes and sutures with Fe3O4 could be well visualized on MRI. DynaMesh and Marlex each had a 17xa0% decrease in apparent surface area by day 2 (pu2009<u20090.001 and pu2009=u20090.001), respectively, which persisted after day 90. Whereas there was a decrease in apparent surface area in Ultrapro, it did not reach significance until day 90 (pu2009=u20090.01). Overall, the apparent surface area decreased 21xa0% in all meshes by day 90. No differences in histological or biomechanical properties were observed at day 90.ConclusionsThere was a reduction in the apparent surface area between implantation and day 2, indicating that most mesh deformation occurs prior to tissue in-growth.

Diaphragm Repair with a Novel Cross-Linked Collagen Biomaterial in a Growing Rabbit Model.

Background Neonates with congenital diaphragmatic hernia and large defects often require patch closure. Acellular collagen matrices (ACM) have been suggested as an alternative to synthetic durable patches as they are remodeled by the host or could also be used for tissue engineering purposes. Materials and Methods 2.0x1.0 cm diaphragmatic defects were created in 6-weeks old New-Zealand white rabbits. We compared reconstruction with a purpose-designed cross-linked ACM (Matricel) to 4-layer non-cross-linked small intestinal submucosa (SIS) and a 1-layer synthetic Dual Mesh (Gore-Tex). Unoperated animals or animals undergoing primary closure (4/0 polyglecaprone) served as age-matched controls. 60 (n = 25) resp. 90 (n = 17) days later, animals underwent chest x-ray and obduction for gross examination of explants, scoring of adhesion and inflammatory response. Also, uniaxial tensiometry was done, comparing explants to contralateral native diaphragmatic tissue. Results Overall weight nearly doubled from 1,554±242 g at surgery to 2,837±265 g at obduction (+84%). X-rays did show rare elevation of the left diaphragm (SIS = 1, Gore-Tex = 1, unoperated control = 1), but no herniation of abdominal organs. 56% of SIS and 10% of Matricel patches degraded with visceral bulging in four (SIS = 3, Matricel = 1). Adhesion scores were limited: 0.5 (Matricel) to 1 (SIS, Gore-Tex) to the left lung (p = 0.008) and 2.5 (Gore-Tex), 3 (SIS) and 4 (Matricel) to the liver (p<0.0001). Tensiometry revealed a reduced bursting strength but normal compliance for SIS. Compliance was reduced in Matricel and Gore-Tex (p<0.01). Inflammatory response was characterized by a more polymorphonuclear cell (SIS) resp. macrophage (Matricel) type of infiltrate (p<0.05). Fibrosis was similar for all groups, except there was less mature collagen deposited to Gore-Tex implants (p<0.05). Conclusions Matricel induced a macrophage-dominated inflammatory response, more adhesions, had appropriate strength but a lesser compliance compared to native tissue. The herein investigated ACM is not a viable option for CDH repair.

In vitro sealing of iatrogenic fetal membrane defects by a collagen plug imbued with fibrinogen and plasma

We aimed to demonstrate local thrombin generation by fetal membranes, as well as its ability to generate fibrin from fibrinogen concentrate. Furthermore, we aimed to investigate the efficacy of collagen plugs, soaked with plasma and fibrinogen, to seal iatrogenic fetal membrane defects.