Effect of stem cells and fibrin concentration on the vascularization of the Medpor orbital implant.

BACKGROUND: To determine the effect of adipose-derived adult stem cells (ADASCs) and optimal concentration of fibrin on fibrovascular ingrowth into porous polyethylene orbital implants (Medpor). METHODS: Medpor sheet treated with O.25% fibrin only and ADASCs in mixtures containing fibrin (0.25%, 0.5% or 1.25%) were applied to a Medpor sheet and implanted in the back of each of 20 athymic nude mice. After 10 days, implants were removed and observed for fibrovascularization and stability. Haemoglobin, collagen and cellular DNA content were determined in quantitative assays. RESULTS: Haemoglobin, collagen and cellular DNA levels were significantly higher in ADASC group than in the cell-free implant (0.25% fibrin only) group (P < 0.01). The level of haemoglobin and collagen content was significantly higher in the ADASC + 0.5% fibrin group among the ADASC and fibrin mixtures (P < 0.01). CONCLUSION: ADASCs significantly improved fibrovascularization on Medpor compared with implants alone. Fibrin, used together with ADASCs to potentiate fibrovascularization, was most effective at concentrations of 0.5%.

Clinicopathologic findings after nasolacrimal polyurethane stent implantations.

PURPOSE: To evaluate the results of nasolacrimal polyurethane stent implantations for the treatment of primary acquired nasolacrimal duct obstruction, and to determine the effects of various surgical procedures, including stent removal, in subsequent nasolacrimal duct obstruction. METHODS: This study included 15 patients who had nasolacrimal polyurethane implantations for the treatment of primary acquired nasolacrimal duct obstruction. Occluded stents were removed either by nasal endoscopy or during dacryocystorhinostomy (DCR). Cultures and biopsies were performed on the removed stents, and the results of the secondary DCR were analyzed for a 6-month follow-up period. RESULTS: During stent removal surgery, various degrees of chronic inflammatory reaction and fibrous tissue formation were detected in the lacrimal sac and nasolacrimal duct. Formations of granuloma and fibrous tissue were found in 15 eyes, and culture-positive reaction were found in nine of the 15 eyes. Conventional dacryocystorhinostomy surgery was performed in nine of the 15 eyes and a silicone tube was located at the canaliculi. Subjective and objective outcome were favorable in 13 of the 15 eyes. CONCLUSIONS: The success rate of nasolacrimal polyurethane stent implantation for the treatment of primary acquired nasolacrimal duct obstruction is low. This may result from a chronic inflammatory reaction. Despite the low success rate of nasolacrimal polyurethane stent implantation, the success rate of endonasal DCR as a subsequent surgery is favorable.

Surgical outcomes of orbital trapdoor fracture in children and adolescents.

PURPOSE: Orbital trapdoor fractures are uncommon but more frequent in children and adolescents. Orbital trapdoor fractures have been discussed in many previous reports, early treatment has been advocated but there is controversy over treatment policy and surgical outcomes. Our retrospective study analyzed the surgical outcomes of orbital trapdoor fracture in children and adolescents to investigate the appropriate timing of treatment and the relationship between severity of extraocular muscle movement (EOM) limitation before the operation and the period of recovery after operation. METHODS: A total of 44 children and adolescents with orbital wall fractures were operated on from 2009 to 2013. This study included 25 patients who underwent surgery for orbital trapdoor fractures; age range 9-18 years (mean age 14.0). We investigated the interval from trauma to surgery, the period of full EOM recovery after operation and the correlation between these factors, retrospectively. RESULTS: The mean follow-up duration was 90.2 days. At follow-up, nine out of ten patients who underwent surgery within 24 h (Group 1) had full EOM recovery, with a mean recovery time of 25.1 days; five out of six patients who underwent surgery within 24-72 h (Group 2) had full EOM recovery with a mean recovery time of 60.2 days; and seven out of nine patients who underwent surgery after 72 h (Group 3) had full EOM recovery with a mean recovery time of 67.6 days. There was no statistical difference in the operation success rates between the groups. Also, the four patients that not completely recovered EOM had a mild EOM limitation below grade -1. CONCLUSION: In our study, we found that patients with orbital trapdoor fractures can recover full EOM regardless of the interval from trauma to surgery. Therefore, we suggest that appropriate surgical technique is important in the treatment of patients with orbital trapdoor fractures, in addition to the urgent surgery recommended for these fractures in a pediatric population. Furthermore, we expect a good prognosis following the treatment of orbital trapdoor fractures if appropriate surgical techniques are used, even if a relatively long time has passed after the trauma.

Inhibition of blood vessel formation by a chondrocyte-derived extracellular matrix.

In this study, the chondrocyte-derived extracellular matrix (CECM) was evaluated for its activity to inhibit vessel invasion in vitro and in vivo. Human umbilical vein endothelial cells (HUVECs) and rabbit chondrocytes were plated on a bio-membrane made of CECM or human amniotic membrane (HAM). The adhesion, proliferation, and tube formation activity of HUVECs and chondrocytes were examined. The CECM and HAM powders were then mixed individually in Matrigel and injected subcutaneously into nude mice to examine vessel invasion in vivo after 1 week. Finally, a rabbit model of corneal neovascularization (NV) was induced by 3-point sutures in the upper cornea, and CECM and HAM membranes were implanted onto the corneal surface at day 5 after suture injury. The rabbits were sacrificed at 7 days after transplantation and the histopathological analysis was performed. The adhesion and proliferation of HUVECs were more efficient on the HAM than on the CECM membrane. However, chondrocytes on each membrane showed an opposite result being more efficient on the CECM membrane. The vessel invasion in vivo also occurred more deeply and intensively in Matrigel containing HAM than in the one containing CECM. In the rabbit NV model, CECM efficiently inhibited the neovessels formation and histological remodeling in the injured cornea. In summary, our findings suggest that CECM, an integral cartilage ECM composite, shows an inhibitory effect on vessel invasion both in vitro and in vivo, and could be a useful tool in a variety of biological and therapeutic applications including the prevention of neovascularization after cornea injury.