Sternal Repair with Bone Grafts Engineered from Amniotic Mesenchymal Stem Cells

Background We aimed at determining whether osseous grafts engineered from amniotic mesenchymal stem cells (aMSCs) could be employed in postnatal sternal repair. Methods Leporine aMSCs were isolated, identified, transfected with green fluorescent protein (GFP), expanded, and seeded onto biodegradable electrospun nanofibrous scaffolds (n=6). Constructs were dynamically maintained in an osteogenic medium and equally divided into two groups with respect to time in vitro, namely 14.6 or 33.9 weeks. They were then used to repair full thickness sternal defects spanning 2–3 intercostal spaces in allogeneic kits (n=6). Grafts were submitted to multiple analyses 2 months thereafter. Results Chest roentgenograms showed defect closure in all animals, confirmed at necropsy. Graft density as assessed by micro-CT scans increased significantly in vivo, yet there were no differences in mineralization by extracellular calcium measurements pre- and post-implantation. There was a borderline increase in alkaline phosphatase activity in vivo, suggesting ongoing graft remodeling. Histologically, implants contained GFP-positive cells and few mononuclear infiltrates. There were no differences between the two construct groups in any comparison. Conclusions Engineered osseous grafts derived from amniotic mesenchymal stem cells may become a viable alternative for sternal repair. The amniotic fluid can be a practical cell source for engineered chest wall reconstruction

Individualized Image Display Improves Performance in Laparoscopic Surgery

Background: Laparoscopic surgery has made great advances over the years, but it is still dependent on a single viewpoint. This single-lens system impedes multitasking and may provide suboptimal views of the operative field. We have previously developed a prototype of interactive laparoscopic image display to enable individualized manipulation of the displayed image by each member of the operating team. The current study examines whether the concept of individualized image display improves performance during laparoscopic surgery. Materials and Methods: Individualized display of the endoscopic image was implemented in vitro using two cameras, independently manipulated by each operator, in a Fundamental of Laparoscopic Surgery (Society of American Gastrointestinal and Endoscopic Surgeons) endotrainer model. The standardized bead transfer and endoloop tasks were adapted to a two-operator exercise. Each team of two was paired by experience level (novice or expert) and was timed twice: once while using a single camera (control) and once using two cameras (individualized image). Results: In total, 20 medical students, residents, and attending surgeons were paired in various combinations. Bead transfer times for the individualized image experiment were significantly shorter in the expert group (61.8 +/- 14.8% of control, P = .002). Endoloop task performance time was significantly decreased in both novices (80.3 +/- 44.4%, P = .04) and experts (69.5 +/- 12.9%, P = .001) using the two-camera set-up. Conclusions: Many advances in laparoscopic image display have led to an incremental improvement in performance. They have been most beneficial to novices, as experts have learned to overcome the shortcomings of laparoscopy. Using a validated tool of laparoscopic training, we have shown that efficiency is improved with the use of an individualized image display and that this effect is more pronounced in experts. The concept of individual image manipulation and display will be further developed into a hands-free, intuitive system and must be validated in a clinical setting