Enhanced vascular biocompatibility of decellularized xeno-/allogeneic matrices in a rodent model.

Glutaraldehyde preservation is the gold standard for cardiovascular biological prosthesis. However, secondary calcifications and the absence of tissue growth remain major limitations. Our study assessed in vitro and in vivo the biocompatibility of human (fascia lata, pericardium) and porcine tissues (pericardium, peritoneum) treated with a physicochemical procedure for decellularization and non-conventional pathogens inactivation. Biopsies were performed before and after treatment to assess decellularization (HE/Dapi staining/DNA quantification/MHC I/alpha gal immunostaining) and mechanical integrity. Forty-five rats received an abdominal aortic patch of native cryopreserved tissues (n = 20), treated tissues (n = 20) or glutaraldehyde-preserved bovine pericardium (GBP, control, n = 5). Grafts were explanted at 4 weeks and processed for HE/von Kossa staining and immunohistochemistries for lymphocytes (CD3)/macrophages (CD68) histomorphometry. 95% of decellularization was obtained for all tissues except for fascia lata (75%). Mechanical properties were slightly altered. In the in vivo model, a significant increase of CD3 and CD68 infiltrations was found in native and control implants in comparison with decellularized tissues (p < 0.05). Calcifications were found in 3 controls. Decellularized tissues were recolonized. GBP showed the most inflammatory response. This physicochemical treatment improves the biocompatibility of selected xeno/allogeneic tissues in comparison with their respective native cryopreserved tissues and with GBP. Incomplete decellularization is associated with a significantly higher inflammatory response. Our treatment is a promising tool in the field of tissue decellularization and tissue banking.

Improvement of mesh recolonization in abdominal wall reconstruction with adipose vs. bone marrow mesenchymal stem cells in a rodent model.

BACKGROUND: Reconstruction of muscle defects remains a challenge. Our work assessed the potential of an engineered construct made of a human acellular collagen matrix (HACM) seeded with porcine mesenchymal stem cells (MSCs) to reconstruct abdominal wall muscle defects in a rodent model. METHODS: This study compared 2 sources of MSCs (bone-marrow, BMSCs, and adipose, ASCs) in vitro and in vivo for parietal defect reconstruction. Cellular viability and growth factor release (VEGF, FGF-Beta, HGF, IGF-1, TGF-Beta) were investigated under normoxic/hypoxic culture conditions. Processed and recellularized HACMs were mechanically assessed. The construct was tested in vivo in full thickness abdominal wall defect treated with HACM alone vs. HACM+ASCs or BMSCs (n=14). Tissue remodeling was studied at day 30 for neo-angiogenesis and muscular reconstruction. RESULTS: A significantly lower secretion of IGF was observed with ASCs vs. BMSCs under hypoxic conditions (-97.6%, p<0.005) whereas significantly higher VEGF/FGF secretions were found with ASCs (+92%, p<0.001 and +72%, p<0.05, respectively). Processing and recellularization did not impair the mechanical properties of the HACM. In vivo, angiogenesis and muscle healing were significantly improved by the HACM+ASCs in comparison to BMSCs (p<0.05) at day 30. CONCLUSION: A composite graft made of an HACM seeded with ASCs can improve muscle repair by specific growth factor release in hypoxic conditions and by in vivo remodeling (neo-angiogenesis/graft integration) while maintaining mechanical properties.

Laparoscopic repair of primary ventral hernias: a series of 118 consecutive patients.

BACKGROUND: The aim of that study is to assess the surgical outcomes after laparoscopic repair of primary ventral hernias (PVH). METHODS: The series consisted of 118 consecutive patients presenting with PVH (13 epigastric and 105 umbilical hernias) operated between 2001 and 2010 by laparoscopy. Surgical repair consisted in intraperitoneal placement of a Parietex composite mesh centred on the defect with a minimum overlapping of 3 cm. The mesh was secured to the abdominal wall with a double crown of helical tacks alone or by an association of transfascial sutures and tacks. Patients' data were recorded prospectively. All patients were checked during office visit one month and one year after surgery and thereafter periodically evaluated by phone call. RESULTS: There were 32 women and 86 men with a mean age of 53 +/- 12 years and a body mass index (BMI) of 32 +/- 5. The median width of the defect was 2 cm (range : 1-6 cm). There was no conversion to open surgery. The mean operative time was 44 +/- 18 min. and the hospital stay 2 +/- 1 days. We noted 7 (6%) postoperative complications: 6 seromas and 1 hypodermitis. One month after surgery, no umbilical skin necrosis was observed and 102 patients (84%) considered the cosmetic result as excellent. With a mean follow-up of 66 +/- 37 months, no complication related to the use of the mesh was recorded and the recurrence rate was 3% (4/118). Predictive factors of recurrence were: BMI > or = 35 (14% (4/29), p < 0.001), mesh overlapping < 5 cm (20% (3/15), p < 0.002) and mesh fixation by tacks alone (8% (4/48), p < 0.05). CONCLUSION: Laparoscopic PVH repair is associated with very low morbidity, excellent cosmetic result and a recurrence rate of 3%. Improvement in surgical repair technique with systematic use of transfascial sutures and mesh overlapping > or = 5 cm should decrease the recurrence rate especially in obese patients.